Intersil ISL94212EVKIT1Z Multi-cell li-ion battery manager Datasheet

DATASHEET
Multi-Cell Li-Ion Battery Manager
ISL94212
Features
The ISL94212 Li-ion battery manager IC supervises up to 12
series connected cells. The part provides accurate monitoring,
cell balancing and extensive system diagnostics functions.
Three cell balancing modes are provided: Manual Balancing
mode, Timed Balancing mode and Auto Balance mode. The
Auto Balance mode terminates balancing functions when a
charge transfer value has been met.
• Up to 12-cell voltage monitors, support Li-Ion CoO2, Li-ion
Mn2O4, and Li-ion FePO4 chemistries
The ISL94212 communicates to a host microcontroller via an
SPI interface and to other ISL94212 devices using a robust,
proprietary, two-wire Daisy Chain system.
• Cell voltage scan rate of 19.5µs per cell (234µs to scan
12 cells)
The ISL94212 is offered in a 64 Ld TQFP package and is
specified for an operational temperature range of -40°C to
+85°C.
• Cell voltage measurement accuracy ±10mV
• 13-bit cell voltage measurement
• Pack voltage measurement accuracy ±180mV
• 14-bit pack voltage and temperature measurements
• Internal temperature monitoring
• Up to four external temperature inputs
• Robust daisy chain communications system
• Integrated system diagnostics for all key internal functions
Applications
• Hardwired and communications based fault notification
• Light electric vehicle (LEV); E-Moto; E-Bike
• Battery backup systems; Energy Storage Systems (ESS)
• Integrated watchdog shuts down device if communication is
lost
• Solar Farms
• 7µA shutdown current: Enable = VSS
• Portable and semi-portable equipment
• 2Mbps SPI
TO OTHER DEVICES (OPTIONAL)
ISL94212
ISL94212
VG2 VG2
VG1 VG1
DHi2
DLo2
DHi2
DHi1
DLo2
DLo1
SCLK
DOUT
DIN
CS
DATA READY
HOST
MICRO
FAULT
EN
VG1
VG1
MONITOR BOARD (Master or Standalone)
VG2
MONITOR BOARD (Daisy Chain - Optional)
FIGURE 1. TYPICAL APPLICATION
April 23, 2015
FN7938.1
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Copyright Intersil Americas LLC 2012, 2015. All Rights Reserved
Intersil is a trademark owned by Intersil Corporation or one of its subsidiaries.
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ISL94212
Table of Contents
Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Pin Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Thermal Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Recommended Operating Conditions . . . . . . . . . . . . . . . . . . 7
Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
CRC Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Daisy Chain Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Daisy Chain Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Identify . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
ACK (Acknowledge) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
NAK (Not Acknowledge). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Address All. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Timing Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Alarm Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Typical Performance Curves . . . . . . . . . . . . . . . . . . . . . . . . .15
Watchdog Function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Device Description and Operation . . . . . . . . . . . . . . . . . . . . 21
Communications Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Communication Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Measurement Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Scan Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Measurement Mode Commands . . . . . . . . . . . . . . . . . . . . . . 21
Daisy Chain Communications Conflicts . . . . . . . . . . . . . . . . 45
Scan Once . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Memory Checksum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Scan Voltages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Settling Time Following Diagnostic Activity . . . . . . . . . . . . 45
Scan Temperatures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Open Wire Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Scan Mixed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Cell Balancing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Scan Wires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Fault Signal Filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Scan All . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Fault Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Scan Continuous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Sleep Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Measure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Wakeup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Cell Voltage Measurement Accuracy . . . . . . . . . . . . . . . . . . 24
Fault Response in Sleep Mode . . . . . . . . . . . . . . . . . . . . . . . . 50
Temperature Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Communication and Measurement Diagrams . . . . . . . . . . 50
Cell Balancing Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Measurement Timing Diagrams . . . . . . . . . . . . . . . . . . . . . . . 51
Balance Setup Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Command Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Balance Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Response Timing Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Manual Balance Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Communication and Measurement Timing Tables . . . . . . 56
Timed Balance Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Measurement Timing Tables. . . . . . . . . . . . . . . . . . . . . . . . . . 56
Auto Balance Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Command Timing Tables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Balance FET Drivers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Response Timing Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Device Setup Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
System Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Cell Balance Enabled Register . . . . . . . . . . . . . . . . . . . . . . . . . 30
Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
System Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Cell Voltage Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
SPI Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Full Duplex Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Temperature Data, Secondary Voltage Reference
Data, Scan Count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Half Duplex Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Fault Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Non-daisy Chain Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
Setup Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Normal Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Cell Balance Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Alarm Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Communication Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Fault Response in Sleep Mode. . . . . . . . . . . . . . . . . . . . . . . . . 34
Example Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Daisy Chain Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Daisy Chain Ports. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Reference Coefficient Registers . . . . . . . . . . . . . . . . . . . . . . . 69
Cells In Balance Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Device Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Nonvolatile Memory (EEPROM) Checksum . . . . . . . . . . . . . . 71
Applications Circuits Information . . . . . . . . . . . . . . . . . . . . 72
Typical Applications Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Communications Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Typical Application Circuits. . . . . . . . . . . . . . . . . . . . . . . . . . 73
Communication Sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Notes on Board Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
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FN7938.1
April 23, 2015
ISL94212
Component Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Operating the ISL94212 with Reduced Cell Counts . . . . . . . 78
Typical Application Circuits . . . . . . . . . . . . . . . . . . . . . . . . . .79
Power Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Voltage Reference Bypass Capacitor . . . . . . . . . . . . . . . . . . . 82
Cell Balancing Circuits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Cell Voltage Measurements During Balancing. . . . . . . . . . . . 83
Balancing with Scan Continuous Mode Enabled . . . . . . . . . . 83
Daisy Chain Communications System . . . . . . . . . . . . . . . . . . 83
External Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Board Level Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Worked Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86
Voltage Reference Check Calculation . . . . . . . . . . . . . . . . . . . 86
Cell Balancing – Manual Mode . . . . . . . . . . . . . . . . . . . . . . . . 87
Cell Balancing – Timed Mode . . . . . . . . . . . . . . . . . . . . . . . . . 87
Cell Balancing – Auto Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Register Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90
Revision History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .95
Package Outline Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . .96
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3
FN7938.1
April 23, 2015
ISL94212
Ordering Information
PART NUMBER
(Notes 2, 3, 4)
PART
MARKING
ISL94212INZ (Note 1)
ISL94212INZ
ISL94212EVKIT1Z
Evaluation Kit
TRIM VOLTAGE, VNOM
(V)
TEMP. RANGE
(°C)
3.3
-40 to +85
PACKAGE
(RoHS Compliant)
64 Ld TQFP
PKG.
DWG. #
Q64.10x10D
NOTES:
1. Add “-T*” suffix for tape and reel. Please refer to TB347 for details on reel specifications.
2. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte tin
plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil Pb-free
products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
3. For Moisture Sensitivity Level Rating (MSL) for the package, please see the Intersil ISL94212. For more information on handling and processing
moisture sensitive devices, please see Techbrief TB363.
4. For other trim options, please contact Marketing.
Pin Configuration
VC10
CB11
VC11
CB12
VC12
VBAT
VBAT
NC
DHi2
DLo2
NC
SCLK/DHi1
CS/DLo1
NC
DIN/NC
DOUT/NC
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
ISL94212
(64 LD 10x10 TQFP)
TOP VIEW
VC4
12
37
DNC
CB4
13
36
V3P3
VC3
14
35
V2P5
CB3
15
34
VCC
VC2
16
33
REF
Submit Document Feedback
4
32
BASE
VDDEXT
38
31
11
NC
CB5
30
DNC
29
COMMS SELECT 2
39
ExT4
40
10
TEMPREG
9
VC5
28
CB6
27
COMMS SELECT 1
NC
COMMS RATE 1
41
ExT3
42
8
26
7
VC6
25
CB7
NC
COMMS RATE 0
ExT2
43
24
DGND
6
ExT1
44
VC7
23
CB8
22
FAULT
NC
45
5
VSS
4
21
VC8
20
DATA READY
VC0
EN
46
VSS
47
3
19
2
CB9
18
VC9
VC1
DNC
CB1
48
17
1
CB2
CB10
FN7938.1
April 23, 2015
ISL94212
Pin Descriptions
SYMBOL
VC0, VC1, VC2, VC3, VC4,
VC5, VC6, VC7, VC8, VC9,
VC10, VC11, VC12
PIN NUMBER
DESCRIPTION
20, 18, 16, Battery cell voltage inputs. VCn connects to the positive terminal of CELLn and the negative terminal of
14, 12, 10, 8, CELLn+1. (VC12 connects only to the positive terminal of CELL12 and VC0 only connects with the negative
6, 4, 2, 64, terminal of CELL1.)
62, 60
19, 17, 15, Cell Balancing FET control outputs. Each output controls an external FET which provides a current path
CB1, CB2, CB3, CB4, CB5,
CB6, CB7, CB8, CB9, CB10, 13, 11, 9, 7, around the cell for balancing.
5, 3, 1, 63, 61
CB11, CB12
VBAT
58, 59
Main IC Supply pins. Connect to the most positive terminal in the battery string.
VSS
21, 22
Ground. These pins connect to the most negative terminal in the battery string.
ExT1, ExT2, ExT3, ExT4
24, 26, 28,
30
External temperature monitor or general purpose inputs. The temperature inputs are intended for use with
external resistor networks using NTC type thermistor sense elements but may also be used as general
purpose analog inputs at the user’s discretion. 0V to 2.5V input range.
TEMPREG
29
Temperature monitor voltage regulator output. This is a switched 2.5V output, which supplies a reference
voltage to external NTC thermistor circuits to provide ratiometric ADC inputs for temperature
measurement.
VDDEXT
32
External V3P3 supply input/output. Connected to the V3P3 pin via a switch, this pin may be used to power
external circuits from the V3P3 supply. The switch is open when the ISL94212 is placed in Sleep mode.
REF
33
2.5V voltage reference decoupling pin. Connect a 2.0µF to 2.5µF X7R capacitor to VSS. Do not connect any
additional external load to this pin.
VCC
34
Analog supply voltage input. Connect to V3P3 via a 33Ω resistor. Connect a 1µF capacitor to ground.
V2P5
35
Internal 2.5V digital supply decoupling pin. Connect a 1µF capacitor to DGND.
V3P3
36
3.3V digital supply voltage input. Connect the emitter of the external NPN regulator transistor to this pin.
Connect a 1µF capacitor to DGND.
Base
38
Regulator control pin. Connect the external NPN transistor’s base. Do not let this pin float,
DNC
37, 39, 48
Comms Select 1
41
Communications port 1 mode select pin. Connect via a 1kΩ resistor to V3P3 for Daisy Chain
communications on port 1 or to DGND for SPI operation on port 1.
Comms Select 2
40
Communications port 2 mode select pin. Connect via a 1kΩ resistor to V3P3 to enable port 2 or to DGND
to disable this port.
Comms Rate 0,
Comms Rate 1
43, 42
Daisy Chain communications data rate setting. Connect via a 1kΩ resistor to DGND (‘0’) or to V3P3 (‘1’) to
select between various communication data rates.
Do not connect. Leave pins floating.
DGND
44
Digital Ground.
Fault
45
Logic fault output. Asserted low if a fault condition exists.
Data Ready
46
SPI data ready. Asserted low when the device is ready to transmit data to the host microcontroller.
EN
47
Enable input. Tie to V3P3 to enable the part. Tie to DGND to disable (all IC functions are turned off).
DOUT/NC
49
Serial Data Output (SPI) or
NC (Daisy Chain). 0V to 3.3V push-pull output.
DIN/NC
50
Serial Data Input (SPI) or
NC (Daisy Chain). 0V to 3.3V input.
CS/DLo1
52
Chip-Select, active low 3.3V input (SPI) or
Daisy Chain port 1 Lo connection.
SCLK/DHi1
53
Serial-Clock Input (SPI) or
Daisy Chain port 1 Hi connection.
DHi2
56
Daisy Chain port 2 Hi connection.
DLo2
55
Daisy Chain port 2 Lo connection.
NC
23, 25, 27,
31, 51, 54,
57
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5
No internal connection.
FN7938.1
April 23, 2015
ISL94212
Block Diagram
DHi 2
DLo 2
CONTROL LOGIC AND COMMUNICATIONS
VBAT
VC12
CB12
VC11
CB11
VC10
CB10
VC9
INPUT BUFFER/LEVEL SHIFT AND FAULT DETECTION
CB9
CB8
VC7
CB7
VC6
CB6
VC5
CB5
VC4
SPI
COMMS
CS/DLo 1
DIN
DOUT
DATA READY
COMMS RATE 1
COMMS RATE 0
COMMS SELECT 2
COMMS SELECT 1
DGND
FAULT
EN
BASE
VREG
V3P3
VDDEXT
V2P5
V2P5
VCC
VREF
MUX
CB4
DAISY
CHAIN
AND
REF
VC MUX
VC8
SCLK/DHi 1
VC3
ADC
CB3
TEMPREG
VC2
TEMP MUX
IC TEMP
VC1
CB1
VC0
ExT1
ExT2
ExT3
ExT4
VSS
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REFERENCE
CB2
6
FN7938.1
April 23, 2015
ISL94212
Absolute Maximum Ratings
Thermal Information
Unless otherwise specified. With respect to VSS.
Thermal Resistance (Typical)
θJA (C/W)
θJC (C/W)
64 Ld TQFP Package (Notes 5, 6) . . . . . . .
42
9
Max Continuous Package Power Dissipation . . . . . . . . . . . . . . . . . .400mW
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-55°C to +125°C
Max Operating Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . .+125°C
Pb-Free Reflow Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . see TB493
DIN, SCLK, CS, DOUT, Data Ready, Comms Select n,
ExTn, TEMPREG, REF, V3P3, VCC, Fault,
Comms Rate n, Base, EN, VDDEXT. . . . . . . . . . . . . . . . . . . . . . .-0.2V to 4.1V
V2P5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.2V to 2.9V
VBAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to 63V
Dhi1, DLo1, DHi2, DLo2 . . . . . . . . . . . . . . . . . . . . . . .-0.5V to (VBAT + 0.5V)
VC0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to + 9.0V
VC1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to + 18V
VC2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to + 18V
VC3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to + 27V
VC4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to + 27V
VC5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to + 36V
VC6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to + 36V
VC7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to + 45V
VC8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to + 45V
VC9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to + 54V
VC10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to + 63V
VC11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to + 63V
VC12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to + 63V
VCn (for n = 0 to 12). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5 to VBAT + 0.5V
CBn (for n = 1 to 12) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5 to VBAT + 0.5V
CBn (for n = 1 to 9) . . . . . . . . . . . . . . . . . . . . . . . V(VCn-1) - 0.5V to V(VCn-1) + 9V
CBn (for n = 10 to 12). . . . . . . . . . . . . . . . . . . . . . . . .V(VCn) - 9V to V(VCn) + 0.5V
Current into VCn, VBAT, VSS (Latch up Test) . . . . . . . . . . . . . . . . . . ±100mA
ESD Rating
Human Body Model (Tested per JESD22-A114F) . . . . . . . . . . . . . . . . 2kV
Machine Model (Tested per JESD22A115-A) . . . . . . . . . . . . . . . . . . 200V
Charge Device Model (Tested per JESD22-C101D) . . . . . . . . . . . . . 750V
Latch-up (Tested per JESD-78B; Class 2, Level A) . . . . . . . . . . . . . . 100mA
Recommended Operating Conditions
TA, Ambient Temperature Range . . . . . . . . . . . . . . . . . . . . . -40°C to +85°C
VBAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6V to 60V
VBAT (Daisy Chain Operation) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10V to 60V
VCn (for n = 1 to 12) . . . . . . . . . . . . . . . . . . . . . . . . . . . .V(VCn-1) to V(VCn-1) + 5V
VC0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-0.1V to 0.1V
CBn (for n = 1 to 9) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .V(VCn-1) to V(VCn-1) + 9V
CBn (for n = 10 to 12). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V(VCn) - 9V to V(VCn)
DIN, SCLK, CS, DOUT, Data Ready, Comms Select 1,
Comms Select 2, TEMPREG,
REF, V3P3, VCC, Fault, Comms Rate 0, Comms Rate 1,
EN, VDDEXT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0V to 3.6V
ExT1,ExT2,ExT3,Ext4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0V to 2.5V
NOTE: DOUT, Data Ready, and Fault are digital outputs and should not be
driven from external sources. V2P5, REF, TEMPREG and BASE are analog
outputs and should not be driven from external sources.
CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product
reliability and result in failures not covered by warranty.
NOTES:
5. JA is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief TB379 for details.
6. For JC, the “case temp” location is taken at the package top center.
Electrical Specifications
temperature range, -40°C to +85°C.
PARAMETER
VBAT = 6 to 60V, TA = -40°C to +85°C, unless otherwise specified. Boldface limits apply across the operating
SYMBOL
Power-up Condition Threshold
VPOR
Power-up Condition Hysteresis
VPORhys
TEST CONDITIONS
VBAT voltage (rising)
MIN
(Note 7)
TYP
MAX
(Note 7)
UNITS
4.8
5.1
5.6
V
400
mV
Initial Power-up Delay
tPOR
Time after VPOR condition
VREF from 0V to 0.95 x VREF(nom) (EN tied to V3P3)
Device can now communicate
27.125
ms
Enable Pin Power-up Delay
tPUD
Delay after EN = 1 to
VREF from 0V to 0.95 x VREF(nom)
(VBAT = 39.6V) - Device can now communicate
27.125
ms
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7
FN7938.1
April 23, 2015
ISL94212
Electrical Specifications
VBAT = 6 to 60V, TA = -40°C to +85°C, unless otherwise specified. Boldface limits apply across the operating
temperature range, -40°C to +85°C. (Continued)
PARAMETER
SYMBOL
VBAT Supply Current
IVBAT
MIN
(Note 7)
TYP
MAX
(Note 7)
UNITS
6V
10
35
75
µA
39.6V
10
64
220
µA
60V
10
90
230
µA
6V
400
530
660
µA
39.6V
500
680
900
µA
60V
550
750
1000
µA
TEST CONDITIONS
Non-daisy chain configuration. Device
enabled. No communications, ADC,
measurement, balancing or open wire
detection activity.
IVBATMASTER Daisy chain configuration – master device.
Enabled. No communications, ADC,
measurement, balancing or open wire
detection activity.
Peak current when daisy chain transmitting
IVBATMID
Daisy chain configuration – mid stack device.
Enabled. No communications, ADC,
measurement, balancing or open wire
detection activity.
18
6V
700
1020
1300
µA
39.6V
900
1250
1600
µA
60V
1000
1400
1700
µA
Peak current when daisy chain transmitting
IVBATTOP
Daisy chain configuration – top device.
Enabled. No communications, ADC,
measurement, balancing or open wire
detection activity.
18
mA
6V
400
530
660
µA
39.6V
500
680
900
µA
60V
550
750
1000
µA
Peak current when daisy chain transmitting
18
mA
IVBATSLEEP1 Sleep mode
(EN = 1, daisy chain configuration).
10
19
36
µA
IVBATSLEEP2 Sleep mode
(EN = 1, standalone, non-daisy chain)
5
9
18
µA
5
7
18
µA
10.5
µA
IVBATSHDN Shutdown. device “off” (EN = 0)
(daisy chain and non-daisy chain configurations)
VBAT Supply Current Tracking.
Sleep Mode.
mA
IVBATΔSLEEP EN = 1, daisy chain sleep mode configuration.
VBAT current difference between any two devices
operating at the same temperature and supply voltage.
VBAT Incremental Supply Current,
Balancing
IVBATBAL
V3P3 Regulator Voltage (Normal)
0
All balancing circuits on. Incremental current:
Add to non-balancing VBAT current.
VBAT = 39.6V
200
300
400
µA
V3P3N
EN = 1, load current range 0 to 5 mA.
VBAT = 39.6V
3.2
3.35
3.5
V
V3P3 Regulator Voltage (Sleep)
V3P3S
EN = 1, load current range. No load. (SLEEP).
VBAT = 39.6V
2.4
2.7
3.05
V
V3P3 Regulator Control Current
IBase
Current sourced from base output.
VBAT = 6V
1
1.5
V3P3 Supply Current
IV3P3
Device enabled
No measurement activity, normal mode
0.8
1
VREF Reference Voltage
VREF
EN = 1, no load, normal mode
Submit Document Feedback
8
2.5
mA
1.3
mA
V
FN7938.1
April 23, 2015
ISL94212
Electrical Specifications
VBAT = 6 to 60V, TA = -40°C to +85°C, unless otherwise specified. Boldface limits apply across the operating
temperature range, -40°C to +85°C. (Continued)
PARAMETER
SYMBOL
VDDEXT Switch Resistance
RVDDEXT
VCC Supply Current
IVCC
TEST CONDITIONS
Switch ON-resistance, VBAT = 39.6V
Device enabled (EN = 1). Standalone or daisy
configuration. No ADC or daisy chain communications
active.
MIN
(Note 7)
TYP
MAX
(Note 7)
UNITS
5
12
22
Ω
2.0
3.25
5.0
mA
IVCCACTIVE1 Device enabled (EN = 1). Standalone or daisy
configuration. Average current during 16ms scan
continuous operation. VBAT = 39.6V
IVCCSLEEP
Device enabled (EN = 1). Sleep mode. VBAT = 39.6V
IVCCSHDN
Device disabled (EN = 0). Shutdown mode.
0
VC(N) - VC(N-1). For design reference.
0
6.0
mA
2.4
µA
1.2
9.0
µA
5
V
MEASUREMENT SPECIFICATIONS
Cell Voltage Input Measurement
Range
VCELL
Cell Monitor Voltage Resolution
VCELLRES
[VC(N)-VC(N-1)] LSB step size (13-bit signed number), 5V
full scale value
ISL94212 Cell Monitor Voltage
Error (Absolute)
VCELLA
Absolute cell measurement error
(Cell measurement error compared with applied
voltage with 1k series resistor.)
Temperature = 0°C to +50°C, VCELL = 2.6V to 4.0V
-10
10
mV
Temperature = +50°C to +85°C, VCELL = 2.0V to 4.3V
-25
25
mV
Temperature = -40°C to 0°C, VCELL = 2.0V to 4.3V
-35
35
mV
Relative cell measurement error
(Max absolute cell measurement error
Min absolute cell measurement error)
Temperature = 0°C to +50°C
0
7.5
mV
Temperature = -40°C to 0°C
0
7.5
mV
Temperature = +50°C to +85°C
0
20
mV
VCELLB
ISL94212 Cell Monitor Voltage
Error (Relative)
IVCELL
Cell Input Current.
Note: Cell accuracy figures assume
a fixed 1kΩ resistor is placed in
series with each VCn pin (n = 0
to 12)
VBAT Monitor Voltage Resolution
VBATRES
VBAT
VBAT Monitor Voltage Error
Submit Document Feedback
9
0.61
mV
VC0 input
-2.0
-1
-0.5
µA
VC1, VC2, VC3 inputs
-3.0
-2
-0.9
µA
VC4 input
-0.8
0
0.9
µA
VC5, VC6, VC7, VC8, VC9, VC10, VC11 inputs
0.5
2
3.2
µA
VC12 input
0.4
1
2.0
µA
ADC resolution referred to input (VBAT) level. 14b
unsigned number. Full scale value = 79.67V.
4.863
mV
Temperature = 0°C to +50°C,
Measured at VBAT = 31.2V to 43.2V
-180
180
mV
Temperature = 0°C to +50°C,
Measured at VBAT = 24V to 48V
-230
230
mV
Temperature = 0°C to +50°C,
Measured at VBAT = 6V to 59.4V
-390
390
mV
Temperature = -40°C to +85°C,
Measured at VBAT = 31.2V to 39.6V
-320
320
mV
Temperature = -40°C to +85°C,
Measured at VBAT = 6V to 48V
-440
440
mV
Temperature = -40°C to +85°C,
Measured at VBAT = 6V to 59.4V
-650
650
mV
FN7938.1
April 23, 2015
ISL94212
Electrical Specifications
VBAT = 6 to 60V, TA = -40°C to +85°C, unless otherwise specified. Boldface limits apply across the operating
temperature range, -40°C to +85°C. (Continued)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
(Note 7)
TYP
MAX
(Note 7)
UNITS
2.475
2.5
2.525
V
0.1
0.2
Ω
2344
mV
External Temperature Monitoring
Regulator
VTEMP
Voltage on TEMPREG output. (0 to 2mA load)
External Temperature Output
Impedance
RTEMP
Output impedance at TEMPREG pin.
0
ExTn input voltage range. For design reference.
0
External Temperature Input Range
VEXT
External Temperature Input Pull-up REXTTEMP
Pull-up resistor to VTEMPREG applied to each input
during measurement
External Temperature Input Offset
VEXTOFF
VBAT = 39.6V
External Temperature Input INL
External Temperature Input Gain
Error
10
MΩ
-12
12
mV
VEXTINL
-0.65
0.65
mV
VEXTG
-8
18.5
mV
Internal Temperature Monitor Error
VINTMON
Internal Temperature Monitor
Resolution
TINTRES
Internal Temperature Monitor
Output
TINT25
±10
°C
Output resolution (LSB/°C). 14b number.
31.9
LSB/°C
Output count at +25°C
9180
Decimal
150
°C
OVER-TEMPERATURE PROTECTION SPECIFICATIONS
Internal Temperature Limit
Threshold
TINTSD
External Temperature Limit
Threshold
TXT
Balance stops and auto scan stops.
Temperature rising or falling.
Corresponding to 0V (min) and VTEMPREG (max)
External temperature input voltages higher than 15/16
VTEMPREG are registered as open input faults.
0
16383
Decimal
FAULT DETECTION SYSTEM SPECIFICATIONS
Undervoltage Threshold
VUV
Programmable.
Corresponding to 0V (min) and 5V (max)
0
8191
Decimal
Overvoltage Threshold
VOV
Programmable.
Corresponding to 0V (min) and 5V (max)
0
8191
Decimal
V3P3 Power-good Window
V3PH
3.3V Power-good window high threshold.
VBAT = 39.6V
3.7
3.90
4.05
V
V3PL
3.3V Power-good window low threshold.
VBAT = 39.6V
2.5
2.65
2.8
V
V2PH
2.5V Power-good window high threshold.
VBAT = 39.6V
2.55
2.7
2.9
V
V2PL
2.5V Power-good window low threshold.
VBAT = 39.6V
1.90
2.0
2.15
V
VVCCH
VCC Power-good window high threshold.
VBAT = 39.6V
3.6
3.75
4.0
V
VVCCL
VCC Power-good window low threshold.
VBAT = 39.6V
2.55
2.7
2.85
V
VRPH
VREF Power-good window high threshold.
VBAT = 39.6V
2.525
2.7
2.9
V
VRPL
VREF Power-good window low threshold.
VBAT = 39.6V
2.0
2.30
2.50
V
V2P5 Power-good Window
VCC Power-good Window
VREF Power-good Window
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10
FN7938.1
April 23, 2015
ISL94212
Electrical Specifications
VBAT = 6 to 60V, TA = -40°C to +85°C, unless otherwise specified. Boldface limits apply across the operating
temperature range, -40°C to +85°C. (Continued)
PARAMETER
SYMBOL
VREF Reference Accuracy Error
VRACC
TEST CONDITIONS
MIN
(Note 7)
TYP
MAX
(Note 7)
UNITS
VREF value calculated using stored coefficients.
VBAT = 39.6V, VREF typical = 2.5V
(See “Voltage Reference Check Calculation” on
page 86.)
Temperature = 0°C to +50°C
-15
15
mV
Temperature = -40°C to 0°C
-40
40
mV
Temperature = +50°C to +85°C
-22
22
mV
Voltage Reference Check Timeout
tVREF
Time to check voltage reference value from power-on,
enable or wake up
20
ms
Oscillator Check Timeout
tOSC
Time to check main oscillator frequency from power-on,
enable or wake up
20
ms
Oscillator Check Filter Time
tOSCF
Minimum duration of fault required for detection
100
ms
CELL OPEN WIRE DETECTION
(See sections “Scan Wires” on page 22, “ISCN, PIN37, PIN39” on page 30, and “Open Wire Test” on page 45.)
Open Wire Current
IOW
ISCN bit = 0; VBAT = 39.6V
0.125
0.15
0.175
mA
ISCN bit = 1; VBAT = 39.6V
0.85
1.0
1.15
mA
Open Wire Detection Time
tOW
Open wire current source “on” time
Open VC0 Detection Threshold
VVC0
CELL1 negative terminal (with respect to VSS)
VBAT = 39.6V
1.2
1.5
1.8
V
Open VC1 Detection Threshold
VVC1
CELL1 positive terminal (with respect to VSS)
VBAT = 39.6V
0.6
0.7
0.8
V
-2
-1.5
0
V
-100
-30
50
mV
Primary Detection Threshold, VC2
to VC12
VVC2_12P
V(VC(n - 1)) - V(VCn), n = 2 to 12
VBAT = 39.6V
Secondary Detection Threshold,
VC2 to VC12
VVC2_12S
Via ADC. VC2 to VC12 only
VBAT = 39.6V
4.6
ms
Open VBAT Fault Detection
Threshold
VVBO
VC12 - VBAT
200
mV
Open VSS Fault Detection
Threshold
VVSSO
VSS - VC0
250
mV
Cell Sample Time Start
Time to sample the first cell (CELL12) following CS going
High. Scan voltages command
65
71.5
µs
Cell Sample Time Duration
Time to scan all 12 cells
(sample of CELL12 to sample of CELL1) scan voltages
command.
233
257
µs
Scan Voltages Processing Time
Time from start of scan to registers loaded to
DATA READY going low
770
847
µs
Scan Temperatures Processing
Time
Time from start of scan to registers loaded to
DATA READY going low
2690
2959
µs
Scan Mixed Processing Time
Time from start of scan to registers loaded to
DATA READY going low
830
913
µs
Scan Wires Processing Time
Time from start of scan to registers loaded to
DATA READY going low
59.4
65.3
ms
Scan All Processing Time
Time from start of scan to registers loaded to
DATA READY going low
63.2
69.5
ms
MEASUREMENT FUNCTION TIMING (Note 8)
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FN7938.1
April 23, 2015
ISL94212
Electrical Specifications
VBAT = 6 to 60V, TA = -40°C to +85°C, unless otherwise specified. Boldface limits apply across the operating
temperature range, -40°C to +85°C. (Continued)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
(Note 7)
TYP
MAX
(Note 7)
UNITS
Measure Cell Voltage Processing
Time
Time from start of measurement to register(s) loaded to
DATA READY going low
180
198
µs
Measure VBAT Voltage Processing
Time
Time from start of measurement to register(s) loaded to
DATA READY going low
130
143
µs
Measure Internal Temperature
Processing Time
Time from start of measurement to register(s) loaded to
DATA READY going low
110
121
µs
Measure External Temperature
Input Processing Time
Time from start of measurement to register(s) loaded to
DATA READY going low
2520
2772
µs
Measure Secondary Voltage
Reference Time
Time from start of measurement to register(s) loaded to
DATA READY going low
2520
2772
µs
CELL BALANCE OUTPUT SPECIFICATIONS
Cell Balance Pin Output
Impedance
RCBL
CBn output off impedance
between CB(n) to VC(n-1): cells 1 to 9 and
between CB(n) to VC(n): cells 10 to 12.
3
4
5
MΩ
Cell Balance Output Current
ICBH1
CBn output on. (CB1-CB9); VBAT = 39.6V;
device sinking current.
-28
-25
-21
μA
ICBH2
CBn output on. (CB10-CB12); VBAT = 39.6V;
device sourcing current.
21
25
28
μA
Cell Balance Output Leakage in
Shutdown
ICBSD
EN = GND. VBAT = 39.6V.
-500
10
700
nA
External Cell Balance FET Gate
Voltage
VGS
CBn Output on;
External 320kΩ between VCn and CBn (n = 10 to 12)
and between CBn and VCn-1 (n = 1 to 9)
7.05
8.0
8.95
V
ICB = 100µA.
8.9
Internal Cell Balance Output
Clamp
VCBCL
V
LOGIC INPUTS: SCLK, CS, DIN
Low Level Input Voltage
VIL
High Level Input Voltage
VIH
1.75
V
VHYS
100
mV
Input Hysteresis
Input Current
IIN
Input Capacitance
CIN
0.8
0V < VIN < V3P3
-1
V
+1
µA
10
pF
0.3*V3P3
V
LOGIC INPUTS: EN, COMMS SELECT1, COMMS SELECT2, COMMS RATE 0, COMMS RATE 1
Low Level Input Voltage
VIL
High Level Input Voltage
VIH
0.7*V3P3
V
VHYS
0.05*V3P3
V
Input Hysteresis
Input Current
IIN
Input Capacitance
CIN
0V < VIN < V3P3
-1
+1
µA
10
pF
LOGIC OUTPUTS: DOUT, FAULT, DATA READY
Low Level Output Voltage
High Level Output Voltage
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12
VOL1
At 3mA sink current
0
0.4
V
VOL2
At 6mA sink current
0
0.6
V
VOH1
At 3mA source current
V3P3 – 0.4V
V3P3
V
VOH2
At 6mA source current
V3P3 – 0.6V
V3P3
V
FN7938.1
April 23, 2015
ISL94212
Electrical Specifications
VBAT = 6 to 60V, TA = -40°C to +85°C, unless otherwise specified. Boldface limits apply across the operating
temperature range, -40°C to +85°C. (Continued)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
(Note 7)
TYP
MAX
(Note 7)
UNITS
2
MHz
200
ns
SPI INTERFACE TIMING (See Figures 2 and 3)
SCLK Clock Frequency
fSCLK
Pulse Width of Input Spikes
Suppressed
tIN1
Enable Lead Time
tLEAD
Clock High Time
50
200
ns
tHIGH
200
ns
Clock Low Time
tLOW
200
ns
Enable Lag Time
tLAG
Last data read clock edge to chip select high.
250
ns
Minimum high time for CS between bytes.
200
ns
CHIP SELECT High Time
tCS:WAIT
Chip select low to ready to receive clock data
Slave Access Time
tA
Chip select low to DOUT active.
200
ns
Data Valid Time
tV
Clock low to DOUT valid.
350
ns
Data Output Hold Time
tHO
Data hold time after falling edge of SCLK.
DOUT Disable Time
tDIS
DOUT disabled following rising edge of CS.
Data Setup Time
tSU
Data input valid prior to rising edge of SCLK.
100
ns
Data Input Hold Time
tHI
Data input to remain valid following rising edge of SCLK.
80
ns
100
ns
Data Ready Start Delay Time
tDR:ST
Chip select high to Data Ready low.
Data Ready Stop Delay Time
tDR:SP
Chip select high to Data Ready high.
Data Ready High Time
tDR:WAIT
SPI Communications Timeout
tSPI:TO
Time between bytes.
0
ns
240
750
0.6
ns
ns
µs
Time the CS remains high before SPI communications
time out - requiring the start of a new command.
100
µs
DOUT Rise Time
tR
Up to 50pF load.
30
ns
DOUT Fall Time
tF
Up to 50pF load.
30
ns
DAISY CHAIN COMMUNICATIONS INTERFACE: DHi1, DLo1, DHi2, DLo2
Daisy Chain Clock Frequency
Comms Rate (0, 1) = 11
450
500
550
kHz
Comms Rate (0, 1) = 10
225
250
275
kHz
Comms Rate (0, 1) = 01
112.5
125
137.5
kHz
Comms Rate (0, 1) = 00
56.25
62.5
68.75
kHz
Common Mode Reference Voltage
VBAT/2
V
NOTES:
7. Compliance to datasheet limits is assured by one or more methods: production test, characterization and/or design.
8. Scan and Measurement start times are synchronized by the receiver to the falling edge of the 24th clock pulse (Daisy Chain systems) or to the falling edge
of the 16th clock pulse (non-daisy chain, single device systems) of the Scan or Measure command. Clock pulses are at the SCLK pin for master and
standalone devices, and at the DHi/DLo1 pins for middle and top daisy chain devices. Max values are based on characterization of the internal clock and
are not 100% tested.
9. Biasing setup as in Figure 57 on page 82 or equivalent.
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FN7938.1
April 23, 2015
ISL94212
Timing Diagrams
CS
(FROM µC)
tSPI:TO
tLEAD
tHIGH
tLOW
tCS:WAIT
tLAG
SCLK
(FROM µC)
tA
tF
tV
tDIS
tHO
DOUT
(TO µC)
tSU
tR
tHI
DIN
(FROM µC)
CLOCK DATA INTO
ISL94212
CLOCK DATA OUT OF
ISL94212
FIGURE 2. SPI FULL DUPLEX (4-WIRE) INTERFACE TIMING
CS
(FROM µC)
tCS:WAIT
tSPI:TO
tDR:ST
tDR:SP
tDR:WAIT
DATA READY
(TO µC)
SCLK
(FROM µC)
tA
DOUT
(TO µC)
CLOCK DATA OUT OF
ISL94212
SIGNALS ON DIN IGNORED
WHILE DATA READY IS LOW
DIN
(FROM µC)
CLOCK DATA INTO
ISL94212
FIGURE 3. SPI HALF DUPLEX (3-WIRE) INTERFACE TIMING
Submit Document Feedback
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FN7938.1
April 23, 2015
ISL94212
40
40
30
30
READING ERROR (mV)
READING ERROR (mV)
Typical Performance Curves
20
10
0
-10
-20
-30
-40
20
10
0
-10
-20
-30
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
-40
5.0
0
0.5
1.0
CELL VOLTAGE (V)
2.0
2.5
3.0
3.5
4.0
4.5
5.0
CELL VOLTAGE (V)
FIGURE 4. CELL VOLTAGE READING ERROR FROM 0°C TO +50°C
FIGURE 5. CELL VOLTAGE READING ERROR FROM -40°C TO +85°C
500
800
400
600
300
READING ERROR (mV)
READING ERROR (mV)
1.5
200
100
0
-100
-200
400
200
0
-200
-400
-300
-600
-400
-500
0
10
20
30
40
PACK VOLTAGE (V)
50
-800
60
FIGURE 6. PACK VOLTAGE READING ERROR FROM 0°C TO +50°C
BGVREF ACCURACY (mV)
NORMALIZED VARIATIONS (%)
1
+105°C
+85°C
-1
-2
+60°C
-3
+25°C
-4
-5
50
60
0.4
-40°C
0
20
30
40
PACK VOLTAGE (V)
0.5
-20°C
2
10
FIGURE 7. PACK VOLTAGE READING ERROR FROM -40°C TO +85°C
4
3
0
0.3
0.2
0.1
0.0
-0.1
-0.2
-0.3
-0.4
0
10
20
30
40
50
PACK VOLTAGE (V)
FIGURE 8. IC TEMPERATURE ERROR vs PACK VOLTAGE
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15
60
-0.5
6
15
24
33
VBAT (V)
42
51
60
FIGURE 9. VOLTAGE REFERENCE CHECK FUNCTION vs PACK
VOLTAGE (AT +25°C)
FN7938.1
April 23, 2015
ISL94212
(Continued)
50
0
40
-0.05
30
-0.10
20
-0.15
VREF SHIFT (mV)
BGVREF ACCURACY (mV)
Typical Performance Curves
10
0
-10
-20
-0.20
-0.25
-0.30
-0.35
-30
-0.40
-40
-0.45
-50
-40
-15
10
35
TEMPERATURE (°C)
60
-0.50
85
0
100
FIGURE 10. VOLTAGE REFERENCE CHECK FUNCTION vs
TEMPERATURE (VBAT = 39.6)
200
300 400 500 600 700
HOURS AT +125°C
800
900 1000
FIGURE 11. VREF SHIFT OVER HTOL
25.6
25.60
VCELL = 3.3V
BALANCE CURRENT (µA)
BALANCE CURRENT (µA)
25.4
25.55
25.50
25.45
25.2
25.0
24.8
24.6
24.4
25.40
0
10
20
30
40
PACK VOLTAGE (V)
50
24.2
-40
60
0
20
40
60
80
100
TEMPERATURE (°C)
FIGURE 12. BALANCE CURRENT vs PACK VOLTAGE
FIGURE 13. BALANCE CURRENT vs TEMPERATURE
157
156
-20
970
VCELL = 3.3V
VCELL = 3.3V
965
154
IOPWI (µA)
IOPWI (µA)
155
153
152
960
955
950
151
945
150
149
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
FIGURE 14. OPEN WIRE TEST CURRENT vs TEMPERATURE
(150µA SETTING)
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16
100
940
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
FIGURE 15. OPEN WIRE TEST CURRENT vs TEMPERATURE
(1mA SETTING)
FN7938.1
April 23, 2015
ISL94212
(Continued)
158.0
1000
157.5
950
IOPWI (µA)
IOPWI (µA)
Typical Performance Curves
157.0
156.5
156.0
900
850
0
10
20
30
40
50
800
60
0
10
20
30
40
PACK VOLTAGE (V)
PACK VOLTAGE (V)
FIGURE 16. OPEN WIRE TEST CURRENT vs PACK VOLTAGE
(150µA SETTING)
50
60
FIGURE 17. OPEN WIRE TEST CURRENT vs PACK VOLTAGE
(1mA SETTING)
0.4
1
0
0.2
0
ERROR (%)
ERROR (%)
-1
-0.2
-2
-3
-4
-5
-0.4
-6
-0.6
2.7
2.9
3.1
3.3
3.5
-7
-40
3.7
-20
0
VCC (V)
FIGURE 18. 4MHz OSCILLATOR ERROR vs VCC
40
60
80
100
120
FIGURE 19. 4MHz OSCILLATOR ERROR vs TEMPERATURE
0.4
1
0
0.2
-1
ERROR (%)
ERROR (%)
20
TEMPERATURE (°C)
-2
0
-0.2
-3
-0.4
-4
-5
-40
-20
0
20
40
60
TEMPERATURE (°C)
80
100
120
FIGURE 20. 32kHz OSCILLATOR ERROR vs TEMPERATURE
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17
-0.6
2.7
2.9
3.1
3.3
3.5
3.7
VCC (V)
FIGURE 21. 32kHz OSCILLATOR ERROR vs VCC
FN7938.1
April 23, 2015
ISL94212
Typical Performance Curves
(Continued)
19
35
33
VBAT = 60V
15
29
13
27
VBAT = 39.6V
11
VBAT = 6V
25
23
VBAT = 39.6V (MASTER)
21
9
19
7
5
-60
VBAT = 60V (MASTER)
31
IVBAT (µA)
IVBAT (µA)
17
17
-40
-20
0
20
40
60
80
100
VBAT = 6V (MASTER)
15
-60
120
-40
-20
FIGURE 22A. PACK VOLTAGE SLEEP CURRENT vs TEMPERATURE AT
6V, 39.6V, 60V (STANDALONE MODE)
40
60
80
100
120
35
33
33
VBAT = 60V (TOP)
31
31
29
VBAT = 39.6V (MID)
29
27
VBAT = 39.6V (TOP)
IVBAT (µA)
IVBAT (µA)
20
FIGURE 22B. PACK VOLTAGE SLEEP CURRENT vs TEMPERATURE AT
6V, 39.6V, 60V (DAISY CHAIN MODE)
35
25
23
21
27
25
VBAT = 60V (MID)
23
21
VBAT = 6V (TOP)
19
19
17
15
-60
0
TEMPERATURE ( °C )
TEMPERATURE ( °C )
17
-40
-20
0
20
40
60
80
100
15
-60
120
VBAT = 6V (MID)
-40
-20
TEMPERATURE ( °C )
0
20
40
60
80
100
120
TEMPERATURE ( °C )
FIGURE 22C. PACK VOLTAGE SLEEP CURRENT vs TEMPERATURE AT
6V, 39.6V, 60V (DAISY CHAIN MODE)
FIGURE 22D. PACK VOLTAGE SLEEP CURRENT vs TEMPERATURE AT
6V, 39.6V, 60V (DAISY CHAIN MODE)
120
850
VBAT = 60V (TOP)
800
VBAT = 60V
100
750
VBAT = 39.6V
700
IVBAT (µA)
IVBAT (µA)
80
60
40
650
VBAT = 39.6V (TOP)
600
550
500
VBAT = 6V
20
VBAT = 6V (TOP)
450
0
-60
-40
-20
0
20
40
60
80
100
120
TEMPERATURE ( °C )
FIGURE 23A. PACK VOLTAGE SUPPLY CURRENT vs TEMPERATURE AT
6V, 39.6V, 60V (STANDALONE MODE)
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18
400
-60
-40
-20
0
20
40
60
TEMPERATURE ( °C )
80
100
120
FIGURE 23B. PACK VOLTAGE SUPPLY CURRENT vs TEMPERATURE AT
6V, 39.6V, 60V (DAISY CHAIN TOP)
FN7938.1
April 23, 2015
ISL94212
Typical Performance Curves
1500
(Continued)
850
VBAT = 60V (MID)
VBAT = 60V (MASTER)
800
1400
750
700
1200
IVBAT (µA)
IVBAT (µA)
1300
VBAT = 39.6V (MID)
1100
650
VBAT = 39.6V (MASTER)
600
550
1000
500
VBAT = 6V (MID)
900
VBAT = 6V (MASTER)
450
800
-60
-40
-20
0
20
40
60
80
100
400
-60
120
-40
-20
0
FIGURE 23C. PACK VOLTAGE SUPPLY CURRENT vs TEMPERATURE AT
6V, 39.6V, 60V (DAISY CHAIN MIDDLE)
80
100
120
11
IVBAT (µA)
10
9
VBAT = 39.6V (STANDALONE)
10
9
8
VBAT = 60V (STANDALONE)
6
-40
-20
0
20
40
60
80
TEMPERATURE ( °C )
100
120
VBAT = 6V (MASTER)
6
5
-60
140
FIGURE 24A. PACK VOLTAGE SHUTDOWN CURRENT vs TEMPERATURE
(EN = 0) AT 6V, 39.6V, 60V
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
100
120
140
FIGURE 24B. VBAT SHUTDOWN CURRENT vs TEMPERATURE (EN = 0)
AT 6V, 39.6V, 60V
13
13
12
12
VBAT = 60V (MID)
11
10
10
IVBAT (µA)
11
9
VBAT = 39.6V (MID)
8
VBAT = 60V (TOP)
9
VBAT = 39.6V (TOP)
8
7
7
VBAT = 6V (MID)
6
5
-60
VBAT = 39.6V (MASTER)
7
7
5
-60
VBAT = 60V (MASTER)
12
VBAT = 6V (STANDALONE)
11
IVBAT (µA)
60
13
12
IVBAT (µA)
40
FIGURE 23D. PACK VOLTAGE SUPPLY CURRENT vs TEMPERATURE AT
6V, 39.6V, 60V (DAISY CHAIN MASTER)
13
8
20
TEMPERATURE ( °C )
TEMPERATURE ( °C )
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
100
120
140
FIGURE 24C. VBAT VOLTAGE SHUTDOWN CURRENT vs TEMPERATURE
(EN = 0) AT 6V, 39.6V, 60V
Submit Document Feedback
19
VBAT = 6V (TOP)
6
5
-60
-40
-20
0
20
40
60
80
100 120 140
TEMPERATURE (°C)
FIGURE 24D. VBAT VOLTAGE SHUTDOWN CURRENT vs TEMPERATURE
(EN = 0) AT 6V, 39.6V, 60V
FN7938.1
April 23, 2015
ISL94212
Typical Performance Curves
(Continued)
1.06
3.50
3.45
1.05
SUPPLY CURRENT (mA)
3.40
IVCC (mA)
3.35
3.30
3.25
3.20
3.15
3.10
1.04
39.6V
1.03
60V
1.02
6V
1.01
1.00
3.05
3.00
-60
-40
-20
0
20
40
60
80
100
0.99
-40
120
-20
FIGURE 25. VCC SUPPLY CURRENT vs TEMPERATURE AT 6V, 39.6V, 60V
1.5
VC11
VC10
1.0
VC8
VC7
VC9
VC6
VC12
0.5
0
VC4
-0.5
-1.0
VC0
-1.5
-2.0
-2.5
-40
VC3
-20
VC2
0
VC1
20
40
60
TEMPERATURE (°C)
80
100
FIGURE 27. CELL INPUT CURRENT vs TEMPERATURE
Submit Document Feedback
20
40
60
80
100
2.5
VC5
CELL INPUT CURRENT (µA)
CELL INPUT CURRENT (µA)
VCELL = 3.3V
20
FIGURE 26. V3P3 SUPPLY CURRENT vs TEMPERATURE
2.5
2.0
0
TEMPERATURE (°C)
TEMPERATURE ( °C )
120
2.0 VC11
VC10
VC9
1.5 VC8
VC7
1.0 VC6
VC5
0.5
VC12
VC4
0.0
-0.5
VC0
-1.0
-1.5
VC3
-2.0 VC2
VC1
-2.5
0
10
20
30
40
PACK VOLTAGE (V)
50
60
FIGURE 28. CELL INPUT CURRENT vs PACK VOLTAGE (+25°C)
FN7938.1
April 23, 2015
ISL94212
Device Description and
Operation
The ISL94212 is a Li-ion battery manager IC that supervises up
to 12 series connected cells. Up to 14 ISL94212 devices can be
connected in series to support systems with up to 168 cells. The
ISL94212 provides accurate monitoring, cell balance control,
and diagnostic functions. The ISL94212 includes a voltage
reference, 14 bit A/D converter and registers for control and
data. An external microcontroller communicates to the ISL94212
through an SPI interface. Series connected ISL94212 devices
communicate to each other via a proprietary daisy chain
communications interface.
The ISL94212 devices handle daisy chain communications
differently depending on their position within the daisy chain. The
ISL94212 at one end of the daisy chain acts as a master device
for communication purposes. The master device, also called the
bottom device, occupies the first position in the daisy chain and
communicates to a host microcontroller using an SPI interface. A
single daisy chain port then connects the master device to the
next device in the daisy chain.
The device at the other end of the daisy chain from the master is
the top device. The top device has a single daisy chain port
connection to the device below. Devices other than the master
and top devices are middle devices. Middle devices have two
daisy chain port connections. The up port connects to the device
above while the down port connects to the device below. The
master ISL94212 device is device number 1. The top device is
device number n, where n equals the total number of ISL94212
devices in the daisy chain. The middle devices are numbered 2 to
(n-1) with device number 2 being connected to the master device.
If n = 2, then there is a master device and a top device, with no
middle device.
When multiple ISL94212 devices are connected to a series of
cells, their power supply domains are normally non-overlapping.
The lower (VSS) supply of each ISL94212 nominally connects to
the same potential as the upper (VBAT) supply of the ISL94212
device below.
The ISL94212 provides two multiple parameter measurement
“scanning” modes in addition to single parameter direct
measurement capability. These scanning modes provide pseudo
simultaneous measurement of all cell voltages in the stack. In
daisy chain applications all measurement data is sent with the
corresponding device stack address (the position within the daisy
chain), parameter identifier, and data address. In stand alone
applications (non-daisy chain) data is sent without additional
address information. This maximizes the throughput for full
duplex SPI operation. Daisy chain communication throughput is
maximized by allowing streamed data (accessed by a “read all
data” address).
The addressed device, the top device and the bottom device act
as masters for the purposes of communications timing. All other
devices are repeaters, passing data up or down the chain.
The only filtering applied to the ADC measurements is that
resulting from external protection circuits and the limited
bandwidth of the measurement path. No additional filtering is
performed within the part. This arrangement is typically needed
Submit Document Feedback
21
to maintain timing integrity between the cell voltage and pack
current measurements. The ISL94212 does not measure current.
The system performs this separately using other measurement
systems. However, the ISL94212 does apply filtering to the fault
detection systems.
Power Modes
The ISL94212 has three main power modes: Normal mode,
Sleep mode and Shutdown mode (“off”).
Sleep mode is entered in response to a Sleep command or after
a watchdog timeout. Only the communications input circuits, low
speed oscillator and internal registers are active in Sleep mode,
allowing the part to perform timed scan and balancing activity
and to wake up in response to communications.
Drive the enable pin low to place the part in Shutdown mode.
When entering Shutdown mode, the internal bias for most of the
IC is powered down except digital core, sleep mode regulators,
and digital input buffers. When exiting, the device powers up and
does not reload the factory programmed configuration data from
EEPROM.
The Normal mode consists of an Active state and a Standby
state. In the Standby state, all systems are powered and the
device is ready and waiting to perform an operation in response
to commands from the host microcontroller. In the Active state,
the device performs an operation, such as ADC conversion, open
wire detection, etc.
Measurement Modes
The ISL94212 provides three types of measurement modes.
• Scan Once
• Scan Continuous
• Measure
In Scan Once mode the part performs the requested scan a
single time. In Scan Continuous mode the ISL94212 performs
repeated scans at intervals controlled by registers settings.
Measure mode allows a single parameter to be measured.
The ISL94212 ignores a Scan or Measure command, when the
device is already in a scan mode or measure mode. But, the
command passes through to other devices in the daisy chain. All
other communications functions respond normally while the
device is scanning or measuring.
Measurement Mode Commands
Measurement modes are activated by commands from an
external microcontroller. The ISL94212 uses a memory mapped
command structure. Commands are sent to the device using a
memory read operation from a specific address. The addresses
for the measurement mode commands1 are shown in Table 1.
There are other commands that perform other actions, but these
are discussed in other sections.
1. In this document, the terminology for a hex value (e.g., h0000) is modified by a
leading value (e.g., 16’) which defines the number of bits. For the measurement
mode command address, a value of 6’h02 refers to a binary value of ‘00 0010’.
FN7938.1
April 23, 2015
ISL94212
TABLE 1. MEASUREMENT MODE COMMAND ADDRESSES
REGISTER
ADDRESS
COMMAND SUFFIX
COMMAND
SCAN ONCE
6’h01
6’h00
Scan Voltages
6’h02
6’h00
Scan Temperatures
6’h03
6’h00
Scan Mixed
6’h04
6’h00
Scan Wires
6’h05
6’h00
Scan All
6’h00
Scan Continuous
6 bit addr of element to measure
Measure
SCAN CONTINUOUS
6’h06
MEASURE
6’h08
Scan Once
Five different scan functions are available in single scan (Scan
Once mode.) Each Scan function is activated by a command from
the host microcontroller. The scan functions are:
1. Scan Voltages
2. Scan Temperatures
3. Scan Mixed
4. Scan Wires
5. Scan All
The Scan Once functions are synchronous: all addressed stack
devices begin scanning immediately following command receipt.
There is a scan start latency between subsequent stack devices of
one daisy chain clock cycle (e.g., for a stack of 10 devices with a
daisy chain operating at 500kHz, the scan start latency between
the bottom and top stack devices is approximately 20µs).
Scan Voltages
The Scan Voltages command causes the addressed part (or all
parts if the common address is used) to scan through the cell
voltage inputs followed by the Pack Voltage. IC temperature is
also recorded for use with the internal calibration routines. Cell
voltages connected to each device are scanned in order from
cell-12 (top) to cell-1 (bottom). Cell overvoltage and undervoltage
compares are performed on each cell voltage sample. The VBAT
and VSS connections are also checked at the end of the scan.
on each temperature measurement depending on the condition
of the appropriate bit in the Fault Setup register.
Temperature data, along with any fault conditions, are stored in
local memory ready for reading by the system host
microcontroller. If there is a fault condition, the device sets the
FAULT pin and returns a fault signal (sent down the stack) on
completion of a scan. Devices revert to the standby state on
completion of the scan activity.
Scan Mixed
The Scan Mixed command causes the addressed part (or all
parts if the common address is used) to scan through the cell
voltage inputs (followed by the pack voltage) with a single
external input (ExT1) interposed. IC temperature is also recorded
for use with the internal calibration routines. Cell voltages
connected to each device are scanned in order from cell-12 (top)
to cell-1 (bottom). The external input ExT1 is scanned in the
middle of the cell voltages such that half the cells are sampled
before ExT1 and half after ExT1. This mode allows ExT1 to be
used for an external voltage measurement, such as a current
sensing and performs it along with the cell voltage
measurements, reducing the latency between measurements.
Cell overvoltage and cell undervoltage compares are performed
on each cell voltage sample. The VBAT and VSS conditions are
also checked at the end of the scan.
The Scan Mixed command is intended for use in standalone
systems, or by the Master device in stacked applications, and
would typically measure a single system parameter, such as
battery current. Other stack devices also measure their ExT1
input but these would normally be ignored by the host.
Cell voltage, pack voltage and ExT1 data, along with any fault
conditions are stored in local memory ready for reading by the
system host microcontroller. Access the data from the ExT1
measurement by a direct Read ET1 Voltage command or by the
All Temperatures read command. If there is a fault condition, the
device sets the FAULT pin and returns a fault signal (sent down
the stack) on completion of a scan. Devices revert to the standby
state on completion of the scan activity.
Scan Wires
The Scan Wires command causes the addressed part (or all parts
if the common address is used) to measure all the VCn pin
voltages while applying load currents to each input pin in turn.
This is part of the fault detection system.
Cell voltage and pack voltage data, along with any fault
conditions are stored in local memory ready for reading by the
system host microcontroller. If there is a fault condition, the
device sets the FAULT pin and returns a fault signal (sent down
the stack) on completion of a scan. Devices revert to the standby
state on completion of the scan activity.
If there is a fault condition, the device sets the FAULT pin and
returns a fault signal (sent down the stack) on completion of a
scan. No cell voltage data is sent as a result of the Scan Wires
command. Devices revert to the standby state on completion of
this activity.
Scan Temperatures
Scan All
The Scan Temperatures command causes the addressed part (or
all parts if the common address is used) to scan through the
internal and 4 external temperature signals followed by
multiplexer loopback and reference measurements. The
loopback and reference measurements are part of the internal
diagnostics function. Over-temperature compares are performed
The Scan All command incorporates the Scan Voltages, Scan
Wires and Scan Temperatures commands and causes the
addressed part (or all parts if the common address is used) to
execute each of these three scan functions once, in sequence
(see Figure 29 on page 25 for example on timing).
Submit Document Feedback
22
FN7938.1
April 23, 2015
ISL94212
Scan Continuous
Scan Continuous mode is used primarily for fault monitoring and
incorporates the scan voltages, scan temperatures and scan
wires commands.
The Scan Continuous command causes the addressed part to set
the SCAN bit in the Device Setup register and performs a
succession of scans at a predetermined scan rate. Each device
operates asynchronously on its own clock. This is similar to the
Scan All command except that the scans are repeated at
intervals determined by the SCN0-3 bits in the Fault Setup
register. The Scan Inhibit command is used to stop scanning (i.e.,
receipt of this command by the target device resets the SCAN bit
and stops the scan continuous function).
The ISL94212 provides an option that pauses cell balancing
activity while measuring cell voltages in Scan Continuous mode.
This is controlled by the BDDS bit in the Device Setup register. If
BDDS is set, then cell balancing is inhibited during cell voltage
measurement and for 10ms before the cell voltages are
scanned. Balancing is reenabled at the end of the scan to allow
balancing to continue. This function only applies during the scan
continuous and the auto balance functions and allows the
implementation of a circuit arrangement that can be used to
diagnose the condition of external balancing components. It is up
to the host microcontroller to manually stop balancing functions
(if required) when operating a scan once or measure command.
The Scan Continuous scan interval is set using the SCN3:0 bits
(lower nibble of the Fault Setup register.) The temperature and
wire scans occur at slower rates and depend on the value of the
scan interval selected. The scan system is synchronized such that
the wire and temperature scans always follow a voltage scan.
The three scan sequences, depending on the scans required at a
particular instance, are as follows:
• Scan Voltages
• Scan Voltages, Scan Wires
The response to a detected fault condition is to send the fault
signal, either immediately in the case of standalone devices or
daisy chain devices in Normal mode, or following transmission of
the wakeup signal if the device is being used in a daisy chain
configuration and is in Sleep mode.
To operate the “Scan Continuous” function in Sleep mode the
host microcontroller simply configures the ISL94212, starts the
Scan Continuous mode and then sends the Sleep command. The
ISL94212 then wakes itself up each time a scan is required. Note
that for the fastest scan settings (scan interval codes 0000,
0001 and 0010) the main measurement functions do not power
down between scans, since the ISL94212 remains in Normal
mode.
TABLE 2. SCAN CONTINUOUS TIMING MODES
WIRE
WIRE
SCAN
SCAN
WSCN = 0 WSCN = 1
(ms)
(ms)
SCAN
INTERVAL
SCN3:0
SCAN
INTERVAL
(ms)
TEMP
SCAN
(ms)
0000
16
512
512
512
0001
32
512
512
512
0010
64
512
512
512
0011
128
512
512
512
0100
256
1024
512
1024
0101
512
2048
512
2048
0110
1024
4096
1024
4096
0111
2048
8192
2048
8192
1000
4096
16384
4096
16384
1001
8192
32768
8192
32768
1010
16384
65536
16384
65536
1011
32768
131072
32768
131072
1100
65536
262144
65536
262144
• Scan Voltages, Scan Wires, Scan Temperatures.
The temperature and wire scans occur at 1/5 the voltage scan
rate for voltage scan intervals above 128ms. Below this value the
temperature scan interval is fixed at 512ms. The behavior of the
wire scan interval is determined by the WSCN bit in the Fault
Setup register. A bit value of ‘1’ causes the wire scan to be
performed at the same rate as the temperature scan. A bit value
of ‘0’ causes the wire scan rate to track the voltage scan rate for
voltage scan intervals above 512ms while at and below this
value the wire scan is performed at a fixed 512ms rate. Table 2
shows the various scan rate combinations available.
Data is not automatically returned while devices are in Scan
Continuous mode except in the case where a fault condition is
detected. The results of voltage and temperature scans are
stored in local volatile memory and may be accessed at any time
by the system host microcontroller. Devices may be operated in
Scan Continuous mode while in Normal mode or in Sleep mode.
Devices revert to the Sleep mode or remain in Normal mode, as
applicable on completion of each scan.
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Measure
This command allows a single cell voltage, internal temperature,
any of the four external temperature inputs or the secondary
voltage reference measurements to be made. The command
incorporates a 6-bit suffix that contains the address of the
required measurement element. See Table 3 on page 24. The
device matching the target address responds by conducting the
single measurement and loading the result to local memory. The
host microcontroller then reads from the target device to obtain
the measurement result. All devices revert to the standby state
on completion of this activity.
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TABLE 3. MEASURE COMMAND TARGET ELEMENT ADDRESSES
MEASURE MEASURE ELEMENT
COMMAND ADDRESS (SUFFIX)
6’h08
DESCRIPTION
6’h00
VBAT Voltage
6’h01
Cell 1 Voltage
6’h02
Cell 2 Voltage
6’h03
Cell 3 Voltage
6’h04
Cell 4 Voltage
6’h05
Cell 5 Voltage
6’h06
Cell 6 Voltage
6’h07
Cell 7 Voltage
6’h08
Cell 8 Voltage
6’h09
Cell 9 Voltage
6’h0A
Cell 10 Voltage
6’h0B
Cell 11 Voltage
6’h0C
Cell 12 Voltage
6’h10
Internal temperature reading
6’h11
External temperature input 1 reading
6’h12
External temperature input 2 reading
6’h13
External temperature input 3 reading
6’h14
External temperature input 4 reading
6’h15
Reference voltage (raw ADC) value. Use
to calculate corrected reference value
using reference coefficient data. See
page 2 data, address 6’h38 – 6’h3A.
Cell Voltage Measurement
Accuracy
The cell voltage monitoring system comprises two basic
elements; a level shift to eliminate the cell common mode
voltage and an analog-to-digital conversion of the cell voltage.
Each ISL94212 is calibrated at a specific cell input voltage value,
VNOM. Cell voltage measurement error data is given in
“MEASUREMENT SPECIFICATIONS” on page 9 for various voltage
and temperature ranges with voltage ranges defined with
respect to VNOM. Plots showing the typical error distribution over
the full input range are included in the “Typical Performance
Curves” section beginning on page 15.
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Temperature Monitoring
One internal and four external temperature inputs are provided
together with a switched bias voltage output (TEMPREG, pin 29).
The voltage at the TEMPREG output is nominally equal to the
ADC reference voltage such that the external voltage
measurements are ratiometric to the ADC reference (see
Figure 61 on page 85).
The temperature inputs are intended for use with external
resistor networks using NTC type thermistor sense elements but
may also be used as general purpose analog inputs. Each
temperature input is applied to the ADC via a multiplexer. The
ISL94212 converts the voltage at each input and loads the 14-bit
result to the appropriate register.
The TEMPREG output is turned “on” in response to a Scan
temperatures or Measure temperature command. A dwell time
of 2.5ms is provided to allow external circuits to settle, after
which the ADC measures each external input in turn. The
TEMPREG output turns “off” after measurements are completed.
Figure 29 on page 25 shows an example temperature scan with
the ISL94212 operating in scan continuous mode with a scan
interval of 512ms. The preceding voltage and wire scans are
shown for comparison.
The external temperature inputs are designed such that an open
connection results in the input being pulled up to the full scale
input level. This function is provided by a switched 10MΩ pull-up
from each input to VCC. This feature is part of the fault detection
system and is used to detect open pins.
The internal IC temperature, along with the auxiliary reference
voltage and multiplexer loopback signals, are sampled in
sequence with the external signals using the scan temperatures
command.
The converted value from each temperature input is also
compared to the external over-temperature limit and open
connection threshold values on condition of the [TST4:1] bits in
the Fault Setup register (see “Fault Setup:” on page 64.) If a TSTn
bit is set to “1”, then the temperature value is compared to the
external temperature threshold and a fault occurs if the
measured value is lower than the threshold value. If a TSTn bit is
set to “0”, then the temperature measurement is not compared
to the threshold value and no fault occurs. The [TST4:1] bits are
“0” by default.
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ISL94212
512ms
VOLTAGE SCAN
765µs
WIRE SCAN
59.4ms
TEMPERATURE SCAN
2.69ms
2.5V
TEMPREG PIN
Hi-Z
Hi-Z
Hi-Z
2.5ms
ADC SAMPLING
FIGURE 29. SCAN TIMING EXAMPLE DURING SCAN CONTINUOUS MODE AND SCAN ALL MODE
Cell Balancing Functions
Cell balancing is an important function in a battery pack
consisting of a stack of multiple Li-ion cells. As the cells charge
and discharge, differences in each cell’s ability to take on and
give up charge, typically leads to cells with different states of
charge. The problem with a stack of cells having different states
of charge is that Li-ion cells have a maximum voltage, above
which it should not be charged and a minimum voltage, below
which it should not be discharged. The extreme case, where one
cell in the stack is at the maximum voltage and one cell is at the
minimum voltage, results in a nonfunctional battery stack, since
the battery stack cannot be charged or discharged.
Cell balancing is performed using external MOSFETs and external
current setting resistors (see Figure 30 on page 30). Each
MOSFET is controlled independently by the CB1 to CB12 pins of
the ISL94212. The CB1 to CB12 outputs are controlled either
directly, or indirectly by an external microcontroller through bits
in various control registers.
The balancing functions within the ISL94212 are controlled by
multiple registers:
• Balance Setup register (All balance modes, see Table 4)
• Balance Status register (All balance modes, see Table 7 on
page 26)
Balance Setup Register
TABLE 4. BALANCE SETUP REGISTER (ADDRESS 6’h13)
7
6
5
4
3
2
1
9
0
8
BSP2
BSP1
BSP0
BWT2
BWT1
BWT0
BMD1
BMD0
BEN
BSP3
The Balance Setup register (see Table 7) contents break down
into 4 sub groups.
• Balance wait time: BWT[2:0] bits (also referred to as balance
dwell time)
• Balance status pointer: BSP[3:0] bits
• Balance enable: BEN bit
• Balance mode: BMD[1:0] bits
BALANCE WAIT TIME
The balance wait time control bits, BWT[2:0], set the interval
between balancing operations in Auto Balance mode, as shown
in Table 5.
TABLE 5. BALANCE WAIT TIME CONTROL BITS
BWT[2:0]
SECONDS
• Device Setup register (auto balance mode only, see
Table 13 on page 30)
000
0
001
1
• Watchdog/Balance Time register (timed and auto balance
modes, see Table 9 on page 27)
010
2
011
4
100
8
• Balance Values registers (auto balance only, see example
in Table 11 on page 28)
Additional registers are provided for the balance timeout (Timed
mode and Auto Balance mode) and balance value (Auto Balance
mode only).
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101
16
110
32
111
64
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ISL94212
BALANCE STATUS POINTER
See “Balance Status Register”.
BALANCE ENABLE
When all of the other balance control bits are properly set,
setting the balance Enable bit to “1” starts the balance
operation. The BEN bit can be set by writing directly to the
Balance Setup register or by sending a Balance Enable
command.
BALANCE MODE
Three methods of cell balance control are provided (see Table 6).
TABLE 6. BALANCE MODE CONTROL BITS
BMD[1:0]
BALANCE MODE
00
Off
01
Manual
10
Timed
11
Auto
In Manual mode, the host microcontroller directly controls the
state of each MOSFET output. In Timed mode, the host
microcontroller programs a balance duration value and selects
which cells are to be balanced, then starts the balance operation.
The ISL94212 turns all the FETs off when the balance duration
has been reached. In Auto Balance mode, the host
microcontroller programs the ISL94212 to control the balance
MOSFETs to remove a programmed “charge delta” value from
each cell. The ISL94212 does this by controlling the amount of
charge removed from each cell over a number of cycles, rather
than trying to balance all cells to a specific voltage.
Balance Status Register
TABLE 7. BALANCE STATUS REGISTER AND BALANCE STATUS POINTER
BALANCE STATUS REGISTER (ADDRESS 6’h14)
BSP BAL BAL BAL BAL BAL BAL BAL BAL BAL BAL BAL BAL
8
7
6
5
4
3
2
1
[3:0] 12 11 10 9
0000
Reserved for Manual and Timed Balance modes
0001
Auto balance status register 1
0010
Auto balance status register 2
0011
Auto balance status register 3
0100
Auto balance status register 4
0101
Auto balance status register 5
0110
Auto balance status register 6
0111
Auto balance status register 7
1000
Auto balance status register 8
1001
Auto balance status register 9
1010
Auto balance status register 10
1011
Auto balance status register 11
1100
Auto balance status register 12
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The Balance Status register contents control which external
balance FET is turned on during a balance event. Each bit in the
Balance Status register controls one external balancing FET, such
that Bit 0 [BAL1] controls the cell 1 FET and Bit 11 [BAL12]
controls the FET for cell 12 (see Table 7.) Bits are set to enable
the balancing for that cell and cleared to disable balancing.
The Balance Status register is a “multiple instance” register.
There are 13 locations within this register. The Balance Status
Pointer BSP[3:0] points to one of these 13 locations in the
register (see Table 7). Only one location in the Balance Status
register may be accessed at a time.
The Balance Status register instance at pointer location 0
(BSP[3:0] = 0000) is used for Manual Balance mode and Timed
Balance mode. The Balance Status register instances at pointer
locations 1 to 12 (BSP[3:0] = 4’h1 to 4’hC) are used for Auto
Balance mode. The arrangement is illustrated in Table 7.
In Auto Balance mode, the ISL94212 increments the Balance
Status pointer on each auto balance cycle to step through
Balance Status register locations 1 to 12. This allows the
programming of up to twelve different balance profiles for each
Auto Balance operation. On each Auto Balance cycle, the
Balance Status pointer increments by one. When the operation
encounters a zero value at a pointer location, the Auto Balance
operation returns to the pattern at location 1 and resumes
balancing with that pattern.
More information about the Auto Balance mode is provided in
“Auto Balance Mode” on page 27. Example balancing setup
information is provided in “Auto Balance Mode Cell Balancing
Example” on page 88.
Manual Balance Mode
Select Manual Balance mode by setting the balance mode bits
BMD[1:0] to 2’b01.
To manually control the cells to be balanced, set the balance
status pointer to zero: BSP[3:0] = 4’b0000. Then, program the
cells to be balanced by setting bits in the Balance Status register
(e.g., to balance cell 5, set the BAL5 bit to 1).
Enable balancing, either by setting the BEN bit in the balance
setup register or by sending a balance enable command.
Disable balancing either by resetting the BEN bit or by sending a
balance inhibit command.
The balance enable and balance inhibit commands may be used
with the “Address All” device address to control all devices in a
stack simultaneously.
Balancing is not possible in Manual Balance mode while the
ISL94212 is in Sleep mode. If the watchdog timer is off and the
Sleep command is received while the device is balancing, then
balancing stops immediately and the device goes into the Sleep
mode.
If the watchdog timer is active during balancing and the device
receives the Sleep command, then balancing also stops
immediately and the device goes into the Sleep mode, but the
WDTM bit is set when the watchdog timer expires. (see Table 8).
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TABLE 8. MANUAL AND TIMED BALANCE MODE WATCHDOG TIMER,
BALANCE, SLEEP OPERATION
WATCHDOG
TIMER
ACTIONS
Off
Receiving a Sleep command immediately stops
balancing and the device enters the Sleep mode.
On
If the device has not received a Sleep command
before the watchdog timer expires, then when the
watchdog timer does expire, balance stops, the
WDTM bit is set and the device enters the Sleep
mode.
Receiving a Sleep command immediately stops
balancing and the device enters the Sleep mode.
Then, when the watchdog timer expires, the WDTM
bit is set.
The watchdog timer function protects the battery from excess
discharge due to balancing, in the event that communications is
lost while the part is in Manual Balance mode. All balancing
ceases and the device goes into the Sleep mode if the watchdog
timeout value is exceeded.
Timed Balance Mode
Select Timed Balance mode by setting the balance mode bits
BMD[1:0] to 2’b10.
To set up a timed balance operation, set the balance status
pointer to zero: BSP[3:0] = 4’b0000. Then program the cells to be
balanced by setting bits in the Balance Status register (e.g., to
balance cells 7 and 10, set BAL7 and BAL10 bits to 1).
Set the balance on time. The balance on time is programmable
in 20 second intervals from 20 seconds to 42.5 minutes using
BTM[6:0] bits. These bits are in locations [13:7] of the
Watchdog/Balance Time register. See Tables 9 and 10 for
details.
TABLE 9. WATCHDOG/BALANCE TIME REGISTER (ADDRESS 6’h15)
7
6
5
13
4
12
3
11
2
10
1
9
0
8
BTM0
WDG6
WDG5
WDG4
WDG3
WDG2
WDG1
WDG0
BTM6
BTM5
BTM4
BTM3
BTM2
BTM1
Enable balancing, either by setting the BEN bit in the balance
setup register or by sending a balance enable command. The
selected balance FETs (corresponding to the bits set in balance
status register location 4’b0000) turn on when BEN is asserted
and turn off when the balance timeout period is met.
Resetting BEN, either directly or by using the balance inhibit
command stops the balancing functions and resets the timer
values. When BEN is reasserted, or when a new balance enable
command is received, balancing resumes, using the full time
specified by the BTM[6:0] bits.
When the balance timeout period is met, the End Of Balance
(EOB) bit in the Device Setup register is set and BEN is reset.
Balancing is not possible in the Timed Balance mode while the
ISL94212 is in Sleep mode. If the watchdog timer is off and the
Sleep command is received while the device is balancing, then
balancing stops immediately and the device goes into Sleep
mode.
If the watchdog timer is active during balance and the device
receives the Sleep command, then balancing also stops
immediately and the device enters Sleep mode, but the WDTM
bit is set when the watchdog timer expires (see Table 8).
The watchdog can be disabled at any time by writing the
watchdog password (6’h3A) to the watchdog password bits
[WP5:0] in the Device Setup register (see Table 13 on page 30),
and then writing 6’h00 to the watchdog timeout bits [WDG5:0] in
the Watchdog/Balance time register (see Table 9).
Auto Balance Mode
Auto Balance mode provides the capability to perform balancing
autonomously and in an intelligent manner. Thermal issues are
accommodated by the provision of the multiple instance Balance
Status register and a balance wait time. Cells are balanced with
periodic measurements being performed at the balance cycle on
time interval (see Table 10). These measurements are used to
calculate the reduction in State of Charge (SOC) with each
balancing cycle and to terminate balancing of a particular cell
when the total SOC change target has been reached.
Select Auto Balance mode by setting the balance mode bits
BMD[1:0] to 2’b11.
BTM[6:0]
MINUTES
In Auto Balance mode, the ISL94212 cycles through each
balance status register instance and turns on the balancing
outputs corresponding to the bits set in each balance status
register instance.
0000000
Disabled
AUTO BALANCE SEQUENCE
0000001
0.33
0000010
0.67
0000011
1.00
-
-
1111101
41.67
1111110
42.00
1111111
42.33
TABLE 10. BALANCE CYCLE ON TIME SETTINGS
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The Auto Balance sequence is programmed using the “multiple
instance” Balance Status register and the balance status pointer
bits.
The first cycle of the auto balance operation begins with the
balance status pointer at location 1, specifying the first Balance
Status register instance. For the next auto balance cycle, the
balance status pointer increments to location 2. For each
subsequent cycle, the pointer increments to the next Balance
Status register instance, until a zero value instance is
encountered. At this point the sequence repeats from the
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balance status register instance at the balance status pointer
location 1 until all the cells have met their SOC adjustment value.
For example, to balance odd numbered cells during the first cycle
and even numbered cells on the second cycle:
(see example in “Cell Balancing – Auto Mode” on page 88.)
• First set the balance status pointer to 1:
BSP[3:0] = 0001.
• Specify the even bits by setting
Balance Status register bits 0, 2, 4, 6, 8 and 10 to “1”.
Balance Status register = 14’h0555
• Set the balance status pointer to 2:
BSP[3:0] = 0010.
• Specify the odd bits by setting
Balance Status register bits 1, 3, 5, 7, 9 and 11 to “1”.
Balance Status register = 14’h0AAA
• Set the balance status pointer to 3:
BSP[3:0] = 0011.
• Specify sequence termination by resetting all the bits in the
Balance Status register to zero. The next cycle will go back to
balance status pointer = 1.
Balance Status register = 14’h0000.
• Leave the balance status pointer to 3:
BSP[3:0] = 0011.
AUTO BALANCE TIMING
Set the desired interval between balancing cycles using the
balance wait time bits BWT[2:0] (locations [4:2] of the Balance
Setup register), see Table 4 on page 25 and Table 5 on page 25.
Set the balance cycle on time using the BTM[6:0] bits (locations
[13:7] of the Watchdog/Balance Time register), see Tables 9 and
10 on page 27.
Set or clear the BDDS bit, Bit 7 in the Device Setup register, as
required. If BDDS is set, then cell balancing is turned off 10ms
before the cell voltage scan at the end of each balance cycle. If
BDDS is cleared, then balance functions remain “on” during Auto
Balance mode cell scan measurements. BDDS must be set in
Auto Balance mode when using the standard battery connection
configuration shown in Figure 50 on page 73.
AUTO BALANCE (DELTA SOC) VALUE
The next step in setting up an Auto Balance operation is to
program the balance value for each cell. The balance value (delta
SOC) is the difference between the present charge in a cell and
the desired charge for that cell.
The method for calculating the state of charge for a cell is left to
the system designer. Typically, determining the state of charge is
dependent on the chosen cell type and manufacturer, is
dependent on cell voltage, charge and discharge rates,
temperature, age of the cell, number of cycles, and other factors.
Tables for determining SOC are often available from the battery
cell manufacturer.
The balance value itself is a function of the current SOC, required
SOC, balancing leg impedance, and sample interval. This value is
calculated by the host microcontroller for each cell. The
balancing leg impedance is made up of the external balance FET
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and balancing resistor. The sample interval is equal to the
balance cycle on time period (e.g., each cell voltage is sampled
at the end of the balance on time).
The balancing value B for each cell is calculated using the
formula shown in Equation 1. (See also “Balance Value
Calculation Example” on page 88):
8191
Z
B = -------------   CurrentSOC – T arg etSOC   ----5
dt
(EQ. 1)
Where:
B = the balance register value
CurrentSOC = the present SOC of the cell (Coulombs)
TargetSOC = the required SOC value (Coulombs)
Z = the balancing leg impedance (ohms)
dt = the sampling time interval
(Balance cycle on time in seconds)
8191/5 = a voltage to Hex conversion value
The balancing leg impedance is normally the sum of the balance
FET rDS(ON) and the balance resistor.
The balancing value (B) can also be defined as in the set of
equations following. Auto balance is guided by Equations 2
and 3:
V
SOC = I  t = ----  t
Z
(EQ. 2)
Z
V
Z
V
B = SOC  ----- = ----  t  ----- = -----  t
dt
Z
dt
dt
(EQ. 3)
Where:
dt = Balance cycle on time
t = Total balance time
Looking at Equations 2 and 3, the impedance drops out of the
equation, leaving only voltage and time elements. Thus, “B”
becomes a collection of voltages that integrate during the
balance cycle on time, and accumulate over the total balance
time period, to equal the programmed delta capacity.
Twelve 28-bit registers are provided for the balance value for
each cell. The balance values are programmed for all cells as
needed using Balance Value registers 6’h20 to 6’h37 (see
Table 11 for the contents of the CELL1 Balance Values Register).
TABLE 11. BALANCE VALUES REGISTER CELL1 (ADDRESS 6’h20, 6’h21)
ADDR
6’20
7
15
6
14
5
13
4
12
3
11
2
10
1
9
0
8
B0107 B0106 B0105 B0104 B0103 B0102 B0101 B0100
B0113 B0112 B0111 B0110 B0109 B0108
6’21
B0121 B0120 B0119 B0118 B0117 B0116 B0115 B0114
B0127 B0126 B0125 B0124 B0123 B0122
At the end of each balance cycle on time interval the ISL94212
measures the voltage on each of the cells that were balanced
during that interval. The measured values are then subtracted
from the balance values for those cells. This process continues
until the balance value for each cell is zero, at which time the
auto balancing process is complete.
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ISL94212
AUTO BALANCE OPERATION
Once all of the cell balance FET controls, the balance values and
the timers are set up, balance is enabled either by setting the
BEN bit in the Balance Setup register or by sending a balance
enable command.
Once enabled, the ISL94212 cycles through each instance of the
Balance Status register for the duration given by the balance
timeout. Between each balance status register instance, the
device does a scan all operation and inserts a delay equal to the
balance wait time. The process continues with the balance status
pointer wrapping back to 1 until all the balance value registers
equal zero. If one cell balance value register reaches zero before
the others, balancing for that cell stops, but the others continue.
Resetting BEN, either directly or by using the Balance Inhibit
command, stops the balancing functions but maintains the
current Balance Value register contents. Auto balancing
continues from the balance status register location 1 when BEN
is reasserted.
When auto balancing is complete, the End of balance (EOB) bit in
the Device Setup register is set and BEN bit is reset.
Balancing is not possible using the Auto Balance Mode while the
ISL94212 is in Sleep mode. If the sleep command is received
while the device is balancing (and the watchdog timer is off) then
balancing continues until it is finished and device enters Sleep
mode. If the watchdog timer is active during the Auto Balance
mode and the device receives the sleep command, then
balancing immediately stops and device enters Sleep mode. The
WDTM bit is set when the watchdog timer expires (see Table 12).
The watchdog can be disabled at any time by writing the
watchdog password (6’h3A) to the watchdog password bits
[WP5:0] in the Device Setup register (see Table 13 on page 30)
and then writing 6’h00 to the watchdog timeout bits [WDG5:0] in
the Watchdog/Balance Time register (see Table 9 on page 27).
Balance FET Drivers
External balancing FETs are controlled by current sources or
current sinks attached to the cell balancing (CB) pins. The gate
voltage on each FET is then controlled by a locally placed
gate-to-source resistor. Voltage clamps are included at each CB
output to limit the maximum gate drive voltage. Series gate
resistors are used to protect both the external FET and internal IC
circuits from external voltage transient effects. An internal
gate-to-source connected resistor is used to provide a redundant
gate discharge path.
A mix of N-channel and P-channel devices are used for the external
FETs in order to remove the need for a charge pump. Cell 12, Cell 11
and Cell 10 balance positions use P-channel devices. The remaining
positions use N-channel devices. The basic balance FET drive
arrangement is shown in Figure 30.
Additional circuit guidelines are provided in the “Typical
Applications Circuits” on page 72.
Reduced cell counts for fewer than 12 cells are accommodated
by removing connections to the cells in the middle of the stack
first. The top and bottom cell locations are always occupied. See
“Operating the ISL94212 with Reduced Cell Counts” on page 78
for suggested cell configurations when using fewer than 12 cells.
TABLE 12. AUTO BALANCE MODE WATCHDOG TIMER, BALANCE,
SLEEP OPERATION
WATCHDOG
TIMER
ACTIONS
Off
Receiving a Sleep command puts the device into
Sleep mode when the auto balance operation is
finished.
On
If the device has not received a Sleep command, then
when the watchdog timer expires, balance stops, the
WDTM bit is set and the device enters Sleep mode.
When the device receives a Sleep command, balance
stops immediately. When the watchdog timer
expires, the WDTM bit is set and the device enters
Sleep mode.
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April 23, 2015
ISL94212
Device Setup Register
TABLE 13. DEVICE SETUP REGISTER (ADDRESS 6’h19)
7
6
BDDS
5
13
4
12
3
11
ISCN
SCAN
EOB
WP5
WP4
WP3
2
10
WP2
1
9
0
8
PIN37
PIN39
WP1
WP0
BDDS
A function is provided to allow any cell balancing activity to be
paused while measuring cell voltages in scan continuous mode
and auto balance mode. This is controlled by the BDDS bit in the
Device Setup register (address 6’h19) (see Table 13). If BDDS is
set, then cell balancing is inhibited during cell voltage
measurement and for 10ms before the cell voltage scan.
Balancing is reenabled at the end of the scan. This function only
applies during the scan continuous mode and the auto balance
mode. It is up to the host microcontroller to manually stop
balancing functions (if required) before sending a scan or
measure command.
WATCHDOG PASSWORD
Before writing a zero to the watchdog timer, which turns off the
timer, it is necessary to write a password to the [WP5:0] bits. The
password value is 6’h3A.
EOB
This End of balance bit indicates that a Timed Balance mode or
an Auto Balance mode has completed.
SCAN
This bit is set in response to a Scan Continuous command and
cleared by the Scan Inhibit command.
ISCN, PIN37, PIN39
The ISCN bit is used in the Open Wire scan. PIN37 and PIN39 bits
show the state of the respective device pins.
Cell Balance Enabled Register
TABLE 14. CELLS BEING BALANCED REGISTER (ADDRESS 6’h3B)
ISL94212
ISL78600
FIGURE 30. EXTERNAL FET DRIVING CIRCUITS
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30
7
6
5
13
4
12
3
11
2
10
1
9
0
8
CBEN
8
CBEN
7
CBEN
6
CBEN
5
CBEN
4
CBEN
3
CBEN
2
CBEN
1
CBEN
12
CBEN
11
CBEN
10
CBEN
9
To facilitate the system monitoring of the cell balance operation,
the ISL94212 has a register that shows the present state of the
balance drivers. Table 14 shows the Cells Being Balanced
register, located on Page 2 at address 6’h3B. If the bit is “1” it
indicates that the CBn output is enabled. A “0” indicates that the
CBn output is disabled.
FN7938.1
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ISL94212
System Configuration
V3P3
ISL94212
The ISL94212 provides two communications systems. An SPI
synchronous port is provided for communication between a
microcontroller and the ISL94212. For standalone (non-daisy
chain) systems, the SPI port is the only port needed. In systems
where there is more than one ISL94212, daisy chain
(asynchronous) ports provide communication between the SPI
port on the Master and other ISL94212 devices.
COMMS SELECT2
COMMS SELECT1
VSS
V3P3
ISL94212
The communications setup is controlled by the COMMS SELECT 1
and COMMS SELECT 2 pins on each device. These pins specify
whether the ISL94212 is a standalone device, the daisy chain
master, the daisy chain top, or a middle position in the daisy
chain. See Figures 31 and 32 and Table 15. This configuration
also specifies the use of SPI or daisy chain on the
communication ports.
TABLE 15. COMMUNICATIONS MODE CONTROL
COMMS COMMS
SELECT 1 SELECT 2
PORT 1
COMM
PORT 2
COMM
0
SPI
(Full Duplex)
Disabled Standalone
0
1
SPI
(Half Duplex)
Enabled
1
0
Daisy Chain
Disabled Daisy Chain,
Top device setting
1
1
Daisy Chain
Enabled
Daisy Chain,
Master device setting
Daisy Chain
Middle device setting
SPI
VSS
FIGURE 31. NON-DAISY CHAIN COMMUNICATIONS CONNECTIONS
AND SELECT
All communications are conducted through the SPI port in single
8-bit byte increments. The MSB is transmitted first and the LSB is
transmitted last.
.
Commands in non-daisy chain systems are composed of a
read/write bit, page address (3 bits), data address (6 bits) and
data (6 bits). Commands in daisy chain systems are composed of
a device address (4 bits), a read/write bit, page address (3 bits),
data address (6 bits), data (6 bits), and CRC (4 bits).
Commands and data are memory mapped to 14-bit data
locations. The memory map is arranged in pages. Pages 1 and 2
are used for volatile data. Page 3 contains the action and
communications administration commands. Page 4 accesses
non-volatile memory. Page 5 is used for factory test.
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31
COMMS SELECT2
COMMS SELECT1
Daisy Down
VSS
V3P3
ISL94212
Daisy Up
COMMS SELECT2
COMMS SELECT1
SPI
VSS
FIGURE 32. DAISY CHAIN COMMUNICATIONS CONNECTIONS AND
SELECTION
SPI Interface
The ISL94212 operates as a SPI slave capable of bus speeds up
to 2Mbps. Four lines make up the SPI interface: SCLK, DIN, DOUT
and CS. The SPI interface operates in either full duplex or half
duplex mode depending on the daisy chain status of the part.
ISL94212
COMMS SELECT2
COMMS SELECT1
Daisy Up
COMMUNICATIONS
CONFIGURATION
0
Daisy Down
The DOUT line is normally tri-stated (high impedance) to allow
use in a multidrop bus. DOUT is only active when CS is low.
Full Duplex Operation
In non-daisy chain applications, the SPI bus operates as a
standard, full duplex, SPI port. Read and write commands are
sent to the ISL94212 in 8-bit blocks. CS is taken high between
each block. Data flow is controlled by interpreting the first bit of
each transaction and counting the requisite number of bytes. It is
the host microcontroller’s responsibility to ensure that
commands are correctly formulated as an incorrect formulation,
(e.g., read bit instead of write bit), would cause the port to lose
synchronization. There is a timeout period associated with the CS
inactive (high) condition, which resets all the communications
counters. This effectively resets the SPI port to a known starting
condition. If CS stays high for more than 100µs then the SPI state
machine resets.
The ISL94212 responds to read commands by loading the
requested data to its output buffer. The output buffer contents
are then loaded to the shift register when CS goes low and are
shifted out on the DOUT line on the falling edges of SCLK. This
sequence continues until all the requested data has been sent.
All single register read commands and responses are 2-bytes
long. All bytes are handled in pairs during device reads. Device
writes are 3-bytes long.
FN7938.1
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ISL94212
A pending device response from a previous command is sent by
the ISL94212 during the first 2 bytes of the 3-byte Write
transaction. The third byte from the ISL94212 is then discarded
by the host microcontroller. This maintains sequencing during
3-byte (Write) transactions.
3. The host microcontroller asserts CS low and clocks 8 bits of
data out of DOUT using SCLK.
4. The host microcontroller then raises CS. The ISL94212
responds by raising DATA READY and tri-stating DOUT.
5. The ISL94212 reasserts DATA READY for the next byte and so
on.
Half Duplex Operation
The host microcontroller must service the ISL94212 if
DATA READY is low before sending further commands. Any data
sent to DIN while DATA READY is low is ignored by the ISL94212.
The SPI operates in half duplex mode in Daisy Chain applications
(see Table 15 on page 31). Data flow is controlled by a
handshake system using the DATA READY and CS signals.
DATA READY is controlled by the ISL94212. CS is controlled by
the host microcontroller. This handshake accommodates the
delay between command receipt and device response due to the
latency of the daisy chain communications system.
A 4 byte data buffer is provided for SPI communications. This
accommodates all single transaction responses. Multiple
responses, such as those that may be produced by a device
detecting an error would overflow this buffer. It is important
therefore that the host microcontroller reads the first byte of data
before a 5th byte arrives on the Master device’s daisy chain port
so as not to risk losing data.
Responses from stack devices are received by the stack Master
(stack bottom device). The stack Master then asserts its
DATA READY output once the first full data byte is available. The
host microcontroller responds by asserting CS and clocking the
data out of the DOUT port. The DATA READY line is then cleared
and DOUT is tri-stated in response to CS being taken high. In this
mode the DIN and DOUT lines may be connected externally.
The DATA READY output from the ISL94212 is not asserted if CS
is already asserted. It is possible for the microcontroller to
interrupt a sequential data transfer by asserting CS before the
ISL94212 asserts DATA READY. This causes a conflict with the
communications and is not recommended. A conflict created in
this manner would be recognized by the microcontroller either
not receiving the expected response or receiving a
communications failure notification.
Half duplex communications are conducted using the
DATA READY/CS handshake as follows:
1. The host microcontroller sends a command to the ISL94212
using the CS line to select the ISL94212 and clocking data
into the ISL94212 DIN pin.
Interface timing for full and half duplex SPI transfers are shown
in Figures 2 and 3 on page 14.
2. The ISL94212 asserts DATA READY low when it is ready to
send data to the host microcontroller. When DATA READY is
low, the ISL94212 is in transmit mode and will ignore any
data on DIN.
Examples of full duplex SPI read and write sequences are shown
in Figures 33 and 34.
CS
SCLK
Note 10
Note
1
Note 110
Note
DOUT
Note 11
Note
2
MSB
DIN
1
0
LSB
1
DA TA
TYPE
0
0
1
0
0
0
1
0
DATA
ADD RESS
0
1
1
1
0
0
1
1
0
0
1
1
0
CELL U ND ERVOLTAGE TH RESH OLD D ATA
HIGH IM PEDANCE
NOTES:
10. Last data byte pair from previous
command.
NOT DETERM INED
11. Not defined.
AC TIVE
FIGURE 33. SPI WRITE EXAMPLE: WRITE UNDERVOLTAGE THRESHOLD DATA
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ISL94212
CS
SC LK
Note 12
Note
1
Note
N
ote 12
1
D OUT
0
0
0
1
0
1
1
1
0
0
0
0
1
0
1
0
C ELL 7 DA TA
D IN
0
0
0
1
0
0
DATA
TYPE
0
1
1
1
0
0
0
0
0
Note
Note133
0
Note 13
Note
3
DA TA
A DD RESS
HIGH IM PEDAN CE
NOTES:
NOT D ETER MIN ED
12. Last data byte pair from previous
command.
ACTIVE
13. Next command (or 8’h00 if no
command).
FIGURE 34. SPI READ EXAMPLE: READ CELL 7 DATA
Non-daisy Chain Systems
In non-daisy chain (standalone) systems, all communications
sent from the master are 2 or 3 bytes in length. Data read and
action commands are 2 bytes. Data writes are 3 bytes. Device
responses are 2 bytes in length and contain data only.
timeout period. The communications interface is reset after the
timeout period.
The following commands have no meaning in non-daisy chain
systems such as:
• Identify
Commands are composed of a read/write bit, page (3 bits), data
address (6 bits) and data (6 bits).
• ACK
Action commands, such as scan and communications
administration commands are treated as reads.
The Sleep and Wakeup commands are sent as normal
commands.
Non-daisy chain communications are conducted without CRC
(Cyclical Redundancy Check) error detection.
The device resets on receipt of the Reset command.
The rules for non-daisy chain installations are shown in Table 16.
Alarm Signals
TABLE 16. ISL94212 DATA INTERPRETATION RULES FOR NON-DAISY
CHAIN INSTALLATIONS
FIRST BIT IN
SEQUENCE
PAGE
DATA
ADDRESS
0
011
001000
Measure command. Last six bits of
transmission contain element
address.
0
Any
All other
Device read or action command.
Last six bits of transmission are zero.
1
Any
Any
INTERPRETATION
Device write command.
Normal Communications
Non-daisy chain devices do not generate a response to write or
system level commands. Data integrity may be verified by
reading register contents after writing. The ISL94212 does
nothing in response to a write or administration command that is
not recognized. An unrecognized read command returns
16’h0000. An incomplete command, such as may occur if
communications are interrupted, is registered as an
unrecognized command either when CS is taken high or after a
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33
• NAK
The FAULT logic output is asserted low in response to a fault
condition. The output then remains low until the bits of the Fault
Status register are reset. The host microcontroller writes
14’h0000 to this register to clear the bits. Bits in the fault data
registers must first be cleared before the associated bits in the
Fault Status register can be cleared. Additionally, the fault status
of each part may be obtained at any time by reading the Fault
Status register.
The FAULT logic output is asserted in Sleep mode, if a fault has
been detected and has not been cleared.
Communication Faults
There is no specific response to a communications fault. A fault
is indicated by an absence of normal communications function.
Non-daisy chain device responses are 2-byte sequences
containing 14-bit data with leading zeros. Non-daisy chain
responses are conducted without CRC (Cyclical Redundancy
Check) error detection.
FN7938.1
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ISL94212
When a standalone device is in Sleep mode, the device may still
detect faults if operating in the Scan Continuous mode. If an
error occurs, the FAULT output pin is asserted low.
Example Communications
0
0
1
0
1
1
1
0
0
R/W
0
0
1
0
1
0
0
1
BYTE 1
1
0
0
1
0
ELEMENT
ADDRESS
(5, 0)
0
0
0
BYTE 1
0
0
1
0
BYTE 0
1
LSB
BYTE 0
PAGE
DATA
ADDRESS
(19, 14)
DATA
(13, 0)
1 0 1 0 0 1 0 0 1 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1
MSB
MSB
0
DATA
ADDRESS
(11, 6)
FIGURE 36E. DEVICE LEVEL COMMAND: MEASURE CELL 5 VOLTAGE
DATA
(13, 0)
0
PAGE
(14, 12)
MSB
An example read response is shown in Figure 35.
LDG.
ZERO
(15, 14)
R/W
Fault Response in Sleep Mode
BYTE 2
BYTE 1
BYTE 0
LSB
LSB
FIGURE 35. NON-DAISY CHAIN DEVICE RESPONSE EXAMPLE: CELL 7
VOLTAGE = 16’h170A (3.6V)
FIGURE 36F. DEVICE WRITE: WRITE EXTERNAL TEMPERATURE
LIMIT = 14’h0FFF
FIGURE 36. NON-DAISY CHAIN DEVICE READ AND WRITE EXAMPLES
R/W
Examples of the various write command structures for non-daisy
chain installations are shown in Figures 36A through 36F.
0
DATA
ADDRESS
(11, 6)
PAGE
(14, 12)
0
1
MSB
1
0
0
1
0
The daisy chain communication is intended for use with large
stacks of battery cells where a number of ISL94212 devices are
used.
TRAILING
ZEROS
(5, 0)
1
0
0
BYTE 1
0
0
0
0
BYTE 0
0
LSB
R/W
FIGURE 36A. DEVICE LEVEL COMMAND: SLEEP
0
0
1
MSB
1
TRAILING
ZEROS
(5, 0)
DATA
ADDRESS
(11, 6)
PAGE
(14, 12)
0
0
1
1
1
1
0
BYTE 1
0
0
0
0
BYTE 0
0
LSB
R/W
FIGURE 36B. DEVICE LEVEL COMMAND: WAKE UP
0
0
0
MSB
1
TRAILING
ZEROS
(5, 0)
DATA
ADDRESS
(11, 6)
PAGE
(14, 12)
0
0
0
1
1
1
0
BYTE 1
0
0
0
0
BYTE 0
0
LSB
R/W
FIGURE 36C. DEVICE READ: GET CELL 7 DATA
0
MSB
0
1
1
TRAILING
ZEROS
(5, 0)
DATA
ADDRESS
(11, 6)
PAGE
(14, 12)
0
0
0
0
BYTE 1
0
1
0
0
0
BYTE 0
0
0
Daisy Chain Systems
Daisy Chain Ports
A daisy chain consists of a bottom device, a top device and up to
12 middle devices. The ISL94212 device located at the bottom of
the stack is called the Master and communicates to the host
microcontroller using SPI communications and to other
ISL94212 devices using the daisy chain port. Each middle device
provides two daisy chain ports: one is connected to the ISL94212
above in the stack and the other to the ISL94212 below.
Communications between the SPI and daisy chain interfaces are
buffered by the master device to accommodate timing
differences between the two systems.
The daisy chain ports are fully differential, DC balanced,
bidirectional and AC-coupled to provide maximum immunity to
EMI and other system transients while only requiring two wires
for each port. Four operating data rates are available and are
configurable by pin selection using the COMMS RATE 0 and
COMMS RATE 1 pins (see Table 17).
TABLE 17. DAISY CHAIN COMMUNICATIONS DATA RATE SELECTION
COMMS RATE 0
COMMS RATE 1
DATA RATE
(kHz)
0
0
62
0
1
125
1
0
250
1
1
500
0
LSB
FIGURE 36D. DEVICE LEVEL COMMAND: SCAN VOLTAGES
Maximum operating data rates is 2Mbps for the SPI interface.
When using the daisy chain communications system it is
recommended that the synchronous communications data rate
be at least twice that of the daisy chain system.
The communications pins are monitored when the device is in
Sleep mode, allowing the part to wake up in response to
communications.
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ISL94212
Communications Protocol
All daisy chain communications are passed from device to device
such that all devices in the stack receive the same information.
Each device then decodes the message and responds as needed.
The originating device (Master in the case of commands,
addressed device or top stack device in the case of responses)
generates the system clock and data stream. Each device delays
the data stream by one clock cycle. Each device knows its stack
location (see command “Identify” on page 40). Each device
knows the total number of devices in the stack. Each originating
device adds a number of clock pulses to the daisy chain data
stream to allow transmission through the stack.
All communications from the host microcontroller are passed from
device to device to the last device in the chain (top device). The top
device responds to read and write messages with an “ACK” (or with
the requested data if this is the addressed device and the message
was a read command). The addressed device then waits to receive
the “ACK” before responding. With data, in the case of a read, or
with an “ACK” in the case of a write. Action commands such as the
Scan commands do not require a response.
A read or write communications transmission is only considered to
be complete following receipt of a response from the target device
or the identification of a communications fault condition. The host
microcontroller should not transmit further data until either a
response has been received from the target stack device or a
communications fault condition has been identified. A normal
daisy chain communications sequence for a stack of 10 devices:
read device 4, cell 7 data, is illustrated in Figure 37 on page 35.
The maximum response time: time from the rising edge of CS at
the end of the first byte of a read/write command, sent by the host
microcontroller, to the assertion of DATA READY by the master
device, is given in Table 18 for various daisy chain data rates.
TABLE 18. MAXIMUM RESPONSE TIMES FOR DAISY CHAIN READ AND
WRITE COMMANDS. STACK OF 10 DEVICES
MAXIMUM TIME TO ASSERTION OF
DATA READY
UNIT
Daisy Chain Data Rate
500
250
125
62.5
kHz
Response Time
240
480
960
1920
µs
SCLK
DIN
SPI
A
A
A
DOUT
B
B
B
B
CS
DATA READY
PACKET A
MASTER TX
10 EXTRA
CLOCKS
MASTER RX
PACKET B
4 EXTRA
CLOCKS
4 DAISY CLOCK PULSES
DAISY
CHAIN
DEVICE 4 TX
6 EXTRA
CLOCKS
PACKET B
ACK
PACKET A
DEVICE 4 RX
ACK
DEVICE 10 TX
DEVICE 10 RX
PACKET A
NO EXTRA
CLOCKS
10 Extra
Clocks
5 EXTRA
CLOCKS
NO EXTRA CLOCKS
10 DAISY CLOCK PULSES
• Host microcontroller sends “Read device 4, cell 7” = Packet A
• Device 4 receives and decodes ACK.
• Master begins relaying Packet A following receipt of the 1st
• Device 4 transmits the cell 7 data = Packet B. Device 4
subtracts one clock cycle to synchronize timing for lower stack
devices to relay the message.
byte of A. Master adds 10 extra clock cycles to allow all stack
devices to relay the message.
• Device 4 receives and decodes “Read device 4, cell 7” and
waits for a response from top stack device.
• Master asserts DATA READY after receiving the 1st byte of
Packet B.
• Top stack device (device 10) receives and decodes Packet A.
• Host responds by asserting CS and clocking out 8 bits of data
from DOUT. CS is taken high following the 8th bit. The master
responds by taking DATA READY high and tri-stating DOUT. Master
asserts DATA READY after receiving the next byte and so on.
• Device 10 responds “ACK”. Device 10 adds 10 clock cycles to
allow all stack devices to relay the message.
FIGURE 37. DAISY CHAIN READ EXAMPLE “READ DEVICE 4, CELL 7”, STACK OF 10 DEVICES
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ISL94212
TABLE 19. ISL94212 DATA INTERPRETATION RULES FOR DAISY CHAIN INSTALLATIONS
5TH BIT
(R/W)
PAGE
DATA ADDRESS
Stack address [3:0] (nonzero)
0
011
001000
Measure command. Data address is followed by 6-bit element address.
0000
0
011
001001
Identify command. Data address is followed by device count data.
Stack address [3:0] (nonzero)
0
Any
All other
Device Read command. Data address is followed by 6 zeros.
Stack address [3:0] (nonzero)
1
Any
Any
FIRST 4 BITS IN SEQUENCE
INTERPRETATION
Device Write command.
Communication Sequences
All Daisy chain device responses are 4-byte sequences, except for
the responses to the Read All command. All responses start with
the device stack address. All responses use a 4-bit CRC. The
response to the “Read All Commands” is to send a normal 4-byte
data response for the first data segment and continue sending
the remaining data segments in 3-byte sections composed of
data address, data and CRC. This creates an anomaly with the
normal CRC usage in that the first 4 bytes have a 4-bit CRC at the
end (operating on 3.5 bytes of data) while the remaining bytes
have a CRC which only operates on 2.5 bytes. The host
microcontroller, having requested the data, must be prepared for
this.
Daisy chain devices require device stack address information to
be added to the basic command set. Daisy chain writes are
4-byte sequences. Daisy chain reads are 3 bytes. Action
commands, such as scan and communications administration
commands are treated as reads. Daisy chain communications
employ a 4-bit CRC (Cyclic Redundancy Check) using a
polynomial of the form 1 + x + x4. The first four bits of each Daisy
chain transmission contain the stack address, which can be any
number from 0001 to 1110. All devices respond to the Address
All (1111) and Identify (0000) stack addresses. The fifth bit is set
to ‘1’ for write and ‘0’ for read. The rules for daisy chain
installations are shown in Table 19.
CRC Calculation
Daisy chain communications employ a 4-bit CRC using a
polynomial of the form 1 + x + x4. The polynomial is
implemented as a 4 stage internal XOR standard linear feedback
shift register as shown in Figure 38. The CRC value is calculated
using the base command data only. The CRC value is not
included in the calculation.
The host microcontroller calculates the CRC when sending
commands or writing data. The calculation is repeated in the
ISL94212 and checked for compliance. The ISL94212 calculates
the CRC when responding with data (device reads). The host
microcontroller then repeats the calculation and checks for
compliance.
DIN
+
+
FF0
FF1
FF2
FF3
FIGURE 38. 4-BIT CRC CALCULATION
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ISL94212
Attribute VB_Name = "isl94212evb_crc4_lib"
' File - isl94212evb_crc4_lib.bas
' Copyright (c) 2010 Intersil
' ----------------------------------------------------------------------------Option Explicit
'***********************************************************
' CRC4 Routines
'***********************************************************
Public Function CheckCRC4(myArray() As Byte) As Boolean
'returns True if CRC4 checksum (low nibble of last byte in myarray)
'is good. Array can be any length
Dim crc4 As Byte
Dim lastnibble As Byte
lastnibble = myArray(UBound(myArray)) And &HF
crc4 = CalculateCRC4(myArray)
If lastnibble = crc4 Then
CheckCRC4 = True
Else
CheckCRC4 = False
End If
arraycopy(i) = myArray(i)
Next
'initialize bits
bit0 = False
bit1 = False
bit2 = False
bit3 = False
'simple implementation of CRC4 (using polynomial 1 + X + X^4)
For i = LBound(arraycopy) To UBound(arraycopy)
'last nibble is ignored for CRC4 calculations
If i = UBound(arraycopy) Then
k=4
Else
k=8
End If
For j = 1 To k
'shift left one bit
carry = (arraycopy(i) And &H80) > 0
arraycopy(i) = (arraycopy(i) And &H7F) * 2
End Function
Public Sub AddCRC4(myArray() As Byte)
'adds CRC4 checksum (low nibble in last byte in array)
'array can be any length
Dim crc4 As Byte
crc4 = CalculateCRC4(myArray)
myArray(UBound(myArray)) = (myArray(UBound(myArray)) And
&HF0) Or crc4
End Sub
Public Function CalculateCRC4(ByRef myArray() As Byte) As Byte
'calculates/returns the CRC4 checksum of array contents excluding
'last low nibble. Array can be any length
Dim size As Integer
Dim i As Integer
Dim j As Integer
Dim k As Integer
Dim bit0 As Boolean, bit1 As Boolean, bit2 As Boolean, bit3 As
Boolean
Dim ff0 As Boolean, ff1 As Boolean, ff2 As Boolean, ff3 As Boolean
Dim carry As Boolean
Dim arraycopy() As Byte
Dim result As Byte
'copy data so we do not clobber source array
ReDim arraycopy(LBound(myArray) To UBound(myArray)) As Byte
For i = LBound(myArray) To UBound(myArray)
'see ISL94212 datasheet, Fig 11: 4-bit CRC calculation
ff0 = carry Xor bit3
ff1 = bit0 Xor bit3
ff2 = bit1
ff3 = bit2
bit0 = ff0
bit1 = ff1
bit2 = ff2
bit3 = ff3
Next j
Next i
'combine bits to obtain CRC4 result
result = 0
If bit0 Then
result = result + 1
End If
If bit1 Then
result = result + 2
End If
If bit2 Then
result = result + 4
End If
If bit3 Then
result = result + 8
End If
CalculateCRC4 = result
End Function
FIGURE 39. CRC CALCULATION ROUTINE (VISUAL BASIC) EXAMPLE
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ISL94212
Daisy Chain Addressing
When used in a daisy chain system each individual device
dynamically assigns itself a unique address (see “Identify” on
page 40). In addition, all daisy chain devices respond to a
common address allowing them to be controlled simultaneously
(e.g., when using the balance enable and balance inhibit
commands). See “Communication and Measurement Diagrams”
on page 50 and “Communication and Measurement Timing
Tables” on page 56.
TABLE 20. COMMS SETUP REGISTER (ADDRESS 6’h18)
1
1
MSB
1
R/W
1
PAGE
(18, 16)
0
0
1
1
6
5
13
4
12
SIZE3
SIZE2
SIZE1
SIZE0
0
1
BYTE 2
2
10
1
9
0
8
ADDR3 ADDR2 ADDR1 ADDR0
CRAT0
CSEL2
CSEL1
Examples of the various read and write command structures for
daisy chain installations are shown in Figures 40C through 40G.
The MSB is transmitted first and the LSB is transmitted last.
DATA
ADDRESS
(15, 10)
0
3
11
CRAT1
The state of the COMMS SELECT 1, COMMS SELECT 2, COMMS
RATE 0, and COMMS RATE 1 pins can be checked by reading the
CSEL[2:1] and CRAT[1:0] bits in the Comms Setup register, (see
Table 20). The SIZE[3:0] bits show the number of devices in the
daisy chain and the ADDR[3:0] bits indicate the location of a
device within the Daisy Chain.
DEVICE
ADDRESS
(23, 20)
7
0
CRC
(3, 0)
ZERO
(9, 4)
1
0
0
0
0
0
0
0
1
1
1
LSB
BYTE 0
BYTE 1
0
DEVICE
ADDRESS
(23, 20)
1
1
1
MSB
1
R/W
FIGURE 40A. DEVICE LEVEL COMMAND: SLEEP
PAGE
(18, 16)
0
0
1
1
DATA
ADDRESS
(15, 10)
0
0
1
BYTE 2
1
1
ZERO
(9, 4)
1
0
0
0
0
CRC
(3, 0)
0
BYTE 1
0
0
1
1
1
LSB
BYTE 0
DEVICE
ADDRESS
(23, 20)
1
0
0
MSB
1
R/W
FIGURE 40B. DEVICE LEVEL COMMAND: WAKE UP
PAGE
(18, 16)
0
0
1
1
DATA
ADDRESS
(15, 10)
0
0
0
BYTE 2
0
0
ZERO
(9, 4)
1
0
0
0
0
CRC
(3, 0)
0
BYTE 1
0
1
1
1
1
LSB
BYTE 0
DEVICE
ADDRESS
(23, 20)
1
0
0
MSB
1
R/W
FIGURE 40C. DEVICE LEVEL COMMAND: DEVICE 9, SCAN VOLTAGES
PAGE
(18, 16)
0
0
0
1
DATA
ADDRESS
(15, 10)
0
0
0
BYTE 2
1
1
CRC
(3, 0)
ZERO
(9, 4)
1
0
0
0
0
0
BYTE 1
0
1
1
0
0
LSB
BYTE 0
DEVICE
ADDRESS
(23, 20)
0
MSB
1
0
0
R/W
FIGURE 40D. DEVICE READ: DEVICE 9, GET CELL 7 DATA
PAGE
(18, 16)
0
0
BYTE 2
1
1
DATA
ADDRESS
(15, 10)
0
0
1
0
0
BYTE 1
ELEMENT
ADDRESS
(9, 4)
0
0
0
0
1
0
CRC
(3, 0)
1
0
BYTE 0
1
0
1
LSB
FIGURE 40E. ELEMENT LEVEL COMMAND: DEVICE 4, MEASURE CELL 5 VOLTAGE
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DEVICE
ADDRESS
(23, 20)
0
0
0
MSB
0
R/W
ISL94212
PAGE
(18, 16)
0
0
1
1
DATA
ADDRESS
(15, 10)
0
0
1
BYTE 2
0
DEVICE
COUNT
(9, 4)
0
1
0
0
0
0
CRC
(3, 0)
0
BYTE 1
0
0
1
0
0
LSB
BYTE 0
DEVICE
ADDRESS
(31, 28)
0
1
1
MSB
1
R/W
FIGURE 40F. IDENTIFY COMMAND
PAGE
(26, 24)
1
0
1
0
DATA
ADDRESS
(23, 18)
0
1
0
BYTE 3
0
DATA
(17, 4)
1
0
0
0
1
1
1
BYTE 2
1
1
1
CRC
(3, 0)
1
1
1
1
1
1
1
0
0
LSB
BYTE 0
BYTE 1
0
FIGURE 40G. DEVICE WRITE: DEVICE 7, WRITE EXTERNAL TEMPERATURE LIMIT = 14’h0FFF
FIGURE 40. DAISY CHAIN DEVICE READ AND WRITE EXAMPLES
DEVICE
ADDRESS
(31, 28)
1
0
0
MSB
1
R/W
Response examples are shown in Figures 41A through 41D.
PAGE
(26, 24)
0
0
0
1
DATA
ADDRESS
(23, 18)
0
0
0
BYTE 3
1
CRC
(3, 0)
DATA
(17, 4)
1
1
0
1
0
1
1
1
0
0
0
0
1
0
1
BYTE 1
BYTE 2
0
0
1
0
0
LSB
BYTE 0
DEVICE
ADDRESS
(31, 28)
1
0
1
MSB
0
R/W
FIGURE 41A. DEVICE DATA RESPONSE: DEVICE 9, CELL 7 VOLTAGE = 14’h170A (3.6V)
PAGE
(26, 24)
0
0
1
1
DATA
ADDRESS
(23, 18)
0
0
1
BYTE 3
1
ZEROS
(17, 4)
0
0
0
0
0
0
0
BYTE 2
0
0
0
CRC
(3, 0)
0
0
0
0
0
0
0
1
0
LSB
BYTE 0
BYTE 1
0
DEVICE
ADDRESS
(31, 28)
0
0
0
MSB
0
R/W
FIGURE 41B. DEVICE COMMUNICATIONS ADMINISTRATION RESPONSE: DEVICE 10, ACK
0
BYTE 3
DATA
ADDRESS
(23, 18)
PAGE
(26, 24)
0
1
1
0
0
1
0
DEVICE TYPE/
ADDRESS
(17, 4)
0
BYTE 2
1
0
0
0
0
0
0
0
BYTE 1
0
1
CRC
(3, 0)
1
0
1
0
0
0
BYTE 0
1
1
0
LSB
FIGURE 41C. DEVICE COMMUNICATIONS ADMINISTRATION RESPONSE: IDENTIFY, DEVICE 4, MID STACK DEVICE
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DEVICE
ADDRESS
(319,316)
R/W
ISL94212
PAGE
(314,
312)
CELL 12
DATA
(305, 292)
DATA
ADDRESS 0CH
(311, 306)
CRC
(291,288)
1 0 0 1 0 0 0 1 0 0 1 1 0 0 1 0 1 1 1 0 0 0 0 1 0 1 0 0 1 1 0 0
MSB BYTE 39
BYTE 38
DATA
ADDRESS 0AH
(263, 258)
BYTE 37
CELL 10
DATA
(257, 244)
BYTE 36
CRC
(243, 240)
0 0 0 1 1 1 0 1 1 1 1 0 0 0 0 1 0 1 0 0 0 0 0 1
BYTE 32
BYTE 31
BYTE 30
DATA
ADDRESS 0BH
(287, 282)
CELL 11
DATA
(281, 268)
CRC
(287, 264)
0 0 1 0 1 1 0 1 0 1 1 1 0 0 0 0 1 0 1 0 0 0 0 1
BYTE 35
DATA
ADDRESS 00H
(23, 18)
BYTE 34
PACK VOLTAGE
DATA
(17, 4)
BYTE 33
CRC
(3, 0)
0 0 0 0 0 0 0 1 0 0 1 0 1 0 0 0 1 1 1 1 0 0 0 1
BYTE 2
BYTE 1
BYTE 0
LSB
FIGURE 41D. DEVICE DATA RESPONSE: DEVICE 9, READ ALL CELL VOLTAGE DATA
FIGURE 41. DAISY CHAIN DEVICE RESPONSE EXAMPLES
Daisy Chain Commands
Normal communications include the normal usage of the read,
write and system level commands. System level commands
come in two types: action commands such as the scan and
measure commands which require the devices to perform
measurements and administration commands such as Reset.
Daisy chain devices also use commands such as ACK to indicate
communications status. All Daisy chain communications, except
the scan, measure and reset commands, require a response
from the addressed device.
Identify
Identify mode is a special case mode that must be executed
before any other communications to Daisy chained devices,
except for the Sleep and Wakeup commands. The Identify
command initiates address assignments to the devices in the
Daisy chain stack.
While in Identify mode devices determine their stack position.
Identify mode is entered on receipt of the “base” Identify
command (this is the Identify command with the device address
set to 6’h00). The Top stack device responds ACK on receiving
the base identify command and then enters the Identify mode.
Other stack devices wait to allow the ACK response to be relayed
to the host microcontroller then they enter Identify mode. Once in
Identify mode all stack devices except the Master load address
4’h0 to their stack address register. The Master (identified by the
state of the Comms Select pins = 2’b01) loads 4’h1 to its stack
address.
The host microcontroller then sends the Identify command with
stack address 6’h3. Device 3 responds by setting its stack
address and stack size information to 4’h3 and returning the
identify response with address 6’h33. Devices 1 and 2 set their
stack size information to 4’h3.
The process continues with the host microcontroller
incrementing the stack address until all devices in the stack have
received their stack address. Identified devices update their
stack size information with each new transmission. The stack
Top device (identified by the state of the Comms Select
pins = 10) loads the stack address and stack size information
and returns the Identify response with address 6’h2x, where x
corresponds to the stack position of the Top device. The host
microcontroller recognizes the top stack response and loads the
total number of stack devices to local memory. The host
microcontroller then sends the Identify command with data set
to 6’h3F. Devices exit Identify mode on receipt of this command.
The stack Top device responds ACK. An example Identify transmit
and receive sequence for a stack of 3 devices is shown in
Figure 42.
When in Normal mode, only the base Identify command is
recognized by devices. Any other Identify command variant or an
Identify command sent with a nonzero stack address causes a
NAK response from the addressed device(s).
On receiving the ACK response the host microcontroller then
sends the Identify command with stack address 6’h2 (i.e.,
24’h0000 0011 0010 0100 0010 0110). The stack address is
bolded. The last four bits are the corresponding CRC value. The
Master passes the command onto the stack. The device at stack
position 2 responds by setting the stack address bits (ADDR[3:0])
and stack size bits (SIZE[3:0]) in the Comms Setup register to
4’h2 and returns the identify response with CRC and an address
of 6’h32 (i.e., 32’b0000 0011 0010 0111 0010 0000 0000
1111). The address bits are bolded. The address bits contains the
normal stack address (2’h0010) and the state of the Comms
Select pins (2’b11). Note that the in an identify response the data
LSBs are always zero.
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ISL94212
Send Identify Command
Send Identify Device 2
Send Identify Device 3
Send Identify Complete
Tx
0 0 0 0 0 0 1 1 0 0 1 0 0 1 0 0 0 0 0 0 0 1 0 0
03 24 04
Rx
0 0 0 0 0 0 1 1 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0
03 30 00 0C
Tx
0 0 0 0 0 0 1 1 0 0 1 0 0 1 0 0 0 0 1 0 0 1 1 0
03 24 26
Rx
0 0 0 0 0 0 1 1 0 0 1 0 0 1 1 1 0 0 1 0 0 0 0 0 0 0 0 0 1 1 1 1
03 27 20 0F
Tx
0 0 0 0 0 0 1 1 0 0 1 0 0 1 0 0 0 0 1 1 0 1 1 1
03 24 37
Rx
0 0 0 0 0 0 1 1 0 0 1 0 0 1 1 0 0 0 1 1 0 0 0 0 0 0 0 0 0 1 0 1
03 26 30 05
Tx
0 0 0 0 0 0 1 1 0 0 1 0 0 1 1 1 1 1 1 1 1 1 1 0
03 27 FE
Rx
0 0 1 1 0 0 1 1 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1
33 30 00 01
FIGURE 42. IDENTIFY EXAMPLE. STACK OF 3 DEVICES
.
TABLE 21. IDENTIFY TIMING WITH DAISY CHAIN OPERATING AT 500kHz
NUMBER OF SPI COMMAND
SEND TIME
DEVICES
(μs)
(2 MINIMUM)
DAISY
TRANSMIT
TIME
(μs)
RESPONSE
DELAY
(µs)
DAISY RECEIVE SPI COMMAND TIME FOR EACH
DEVICE
IDENTIFY TOTAL
RECEIVE TIME
TIME
(µs)
TIME (µs)
(µs)
(µs)
IDENTIFY +
IDENTIFY
COMPLETE
TIME (µs)
1 (Master)
24
0
0
0
32
56
56
56
2
8
50
18
66
8
150
206
356
3
8
52
18
68
8
154
360
514
4
8
54
18
70
8
158
518
676
5
8
56
18
72
8
162
680
842
6
8
58
18
74
8
166
846
1012
7
8
60
18
76
8
170
1016
1186
8
8
62
18
78
8
174
1190
1364
9
8
64
18
80
8
178
1368
1546
10
8
66
18
82
8
182
1550
1732
11
8
68
18
84
8
186
1736
1922
12
8
70
18
86
8
190
1926
2116
13
8
72
18
88
8
194
2120
2314
14
8
74
18
90
8
198
2318
2516
IDENTIFY TIMING
To determine the time required to complete an identify
operation, refer to Table 21. In the table are two SPI command
columns showing the time required to send the Identify
command and receive the response (with an SPI clock of 1MHz.)
In the case of the Master, there are no daisy chain clocks, so all
three bytes of the send and four bytes of the receive are
accumulated. For the daisy chain devices, the daisy
communication overlaps with two of the SPI send bytes and with
three of the SPI receive bytes, so there is no extra time needed
for these bits.
receiving the daisy response, the Master sends the response to
the Host through the SPI port.
There is a column showing the time for each Identify command
and, in the second column from the right, is a column showing
the total accumulated time required to send all Identify
commands for each of the cell configurations. The final column
on the right adds the Identify complete timing to the total. The
Identify complete command takes the same number of clock
cycles as the last Identify command.
Once the device receives the Identify command, it adds a delay
time before sending the response back to the master. Then, on
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ISL94212
TABLE 22. IDENTIFY TIMING WITH DAISY CHAIN OPERATING AT 250kHz
NUMBER OF SPI COMMAND
SEND TIME
DEVICES
(µs)
(2 MINIMUM)
DAISY
TRANSMIT
TIME
(μs)
RESPONSE
DELAY
(μs)
DAISY RECEIVE SPI COMMAND TIME FOR EACH
DEVICE
RECEIVE TIME
TIME
(µs)
(µs)
(µs)
IDENTIFY
TOTAL TIME
(µs)
IDENTIFY +
IDENTIFY
COMPLETE
TIME (µs)
1 (Master)
24
0
0
0
32
56
56
56
2
8
100
34
132
8
282
338
620
3
8
104
34
136
8
290
628
918
4
8
108
34
140
8
298
926
1224
5
8
112
34
144
8
306
1232
1538
6
8
116
34
148
8
314
1546
1860
7
8
120
34
152
8
322
1868
2190
8
8
124
34
156
8
330
2198
2528
9
8
128
34
160
8
338
2536
2874
10
8
132
34
164
8
346
2882
3228
11
8
136
34
168
8
354
3236
3590
12
8
140
34
172
8
362
3598
3960
13
8
144
34
176
8
370
3968
4338
14
8
148
34
180
8
378
4346
4724
ACK (Acknowledge)
ACK is used by daisy chain devices to acknowledge receipt of a
valid command. ACK is also useful as a communications test
command: the stack top device returns ACK in response to
successful receipt of the ACK command. No other action is
performed in response to an ACK.
Note: A Reset command should be issued following a “hard
reset” in which the EN pin is toggled.
Address All
The “Address All” stack address 1111 is used with device
commands to cause all stack devices to perform functions
simultaneously.
NAK (Not Acknowledge)
Receipt of an unrecognized command by either the target device
or the top stack device results in a NAK being returned by that
device. If a command addressed to all devices using the Address
All stack address 1111 or the Identify stack address 0000 is not
recognized by any device, then all devices not recognizing the
command respond NAK. In this case, the host microcontroller
receives the NAK response from the lowest stack device that
failed to recognize the command. An incomplete command (e.g.,
one that is less than the length required) also causes a NAK to be
returned.
Reset
All digital registers can be reset to their power-up condition using
the Reset Command.
Daisy chain devices must be reset in sequence from top stack
device to stack bottom (Master) device. Sending the Reset
command to all devices using the address all stack address has
no effect. There is no response from the stack when sending a
Reset command.
All stack address and stack size information is set to zero in
response to a Reset command. Once all devices have been reset
it is necessary to reprogram the stack address and stack size
information using the Identify command.
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TABLE 23. “ADDRESS ALL” COMPATIBILITY
FUNCTION
“ADDRESS ALL”
COMPATIBLE
Scan Voltages
Yes
Scan Temperatures
Yes
Scan Mixed
Yes
Scan Wires
Yes
Scan All
Yes
Scan Continuous
No
Scan Inhibit
No
Measure
No
Identify (special command – only responds to
0000 stack address)
No
Sleep
Yes
NAK
No
ACK
No
Comms Failure
No
Wakeup
Yes
Balance Enable
Yes
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April 23, 2015
ISL94212
TABLE 23. “ADDRESS ALL” COMPATIBILITY (Continued)
“ADDRESS ALL”
COMPATIBLE
FUNCTION
Balance Inhibit
Yes
Reset
No
Calculate Register Checksum
No
Check Register Checksum
No
Alarm Signals
Further, read communications to the device, return the fault
response followed by the requested data. Write communications
return only the fault response. Action commands return nothing.
The host microcontroller resets the register bits corresponding to
the fault by writing 14’h0000 to the Fault Status register, having
first cleared the bits in the fault data register(s) if these are set.
The device then responds ACK as with a normal write response
since the fault status bits are now cleared. This also prevents
further fault responses unless the fault reappears, in which case
the fault response is repeated.
Watchdog Function
Bits are set in the following fault data registers:
TABLE 25. WATCHDOG/BALANCE TIME REGISTER (ADDRESS 6’h15)
• Overvoltage register (address 6’h00),
• Undervoltage register (address 6’h01),
• Open Wires register (address 6’h02),
7
6
5
13
4
12
3
11
2
10
1
9
0
8
BTM0
WDG6
WDG5
WDG4
WDG3
WDG2
WDG1
WDG0
BTM6
BTM5
BTM4
BTM3
BTM2
BTM1
• Over-temperature register (address 6’h06)
Bits are also set in the Fault Status register (address 6’h04) in
response to a fault being detected. Additionally, the bits from
each of the fault data registers are OR’d and reflected to bits in
the Fault Status register (one bit per data register).
A fault is registered when any of the bits in the Fault Status
register is asserted. Two fault response methods are provided to
indicate the existence of a fault: a fault response is sent via the
daisy chain communications interface and the FAULT logic
output is asserted low immediately on detection of the fault. The
FAULT output remains low until the bits of all fault data registers
and the Fault Status register are reset (host microcontroller
writes 14’h0000 to these registers to clear the bits).
The Daisy chain fault response is immediate, as long as there is
no communication activity on the device ports and comprises the
normal fault status register read response. The fault response is
only sent for the first fault occurrence. Subsequent faults do not
activate the fault response until after the fault status register has
been cleared.
If a fault occurs while the device ports are active, then the device
waits until communication activity ceases before sending the
fault response. The host microcontroller has the option to wait for
this response before sending the next message. Alternately, the
host microcontroller may send the next message immediately
(after allowing the daisy chain ports to clear – see “Sequential
Daisy Chain communications” on page 55). Any conflicts
resulting from additional transmissions from the stack are
recognized by the lack of response from the stack.
Table 24 provides the maximum time from DATA READY going
low for the last byte of the normal response to DATA READY going
low for the first byte of the fault response in the case where a
fault response is held up by active communications.
TABLE 24. MAXIMUM TIME BETWEEN DATA READY SIGNALS –
DELAYED FAULT RESPONSE
SIGNALS
MAXIMUM TIME BETWEEN
DATA READY ASSERTIONS
UNIT
Daisy Chain Data Rate
500
250
125
62.5
kHz
Fault Response
68
136
272
544
µs
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A watchdog function is provided as part of the daisy chain
communications fault detection system. The watchdog has no
effect in non-daisy chain systems. The watchdog timeout is
settable in two ranges using the lower 7 bits of the
Watchdog/Balance time register (see Table 25). The low range
(7’b0000001 to 7’b0111111) provides timeout settings in 1s
increments from 1s to 63s. The high range (7’b1000000 to
7’b1111111) provide timeout settings in 2 minute intervals from
2 minutes to 128 minutes (see Table 26 for details).
.
TABLE 26. WATCHDOG TIMEOUT SETTINGS
WDG[6:0]
TIMEOUT
0000000
Disabled
0000001
1s
0000010
2s
-
-
0111110
62s
0111111
63s
1000000
2 min
1000001
4 min
-
-
1111110
126 min
1111111
128 min
A zero setting (7’b0000000) disables the watchdog function. A
watchdog password function is provided to guard against
accidental disabling of the watchdog function. The upper 6 bits of
the Device Setup register must be set to 6’h3A (111010) to allow
the watchdog to be set to zero. The watchdog is disabled by first
writing the password to the Device Setup register (see Table 13
on page 30) and then writing zero to the lower bits of the
Watchdog/Balance time register. The password function does
not prevent changing the watchdog timeout setting to a different
nonzero value.
FN7938.1
April 23, 2015
ISL94212
Each device must receive a valid communications sequence
before its watchdog timeout period is exceeded. Failure to receive
valid communications within the required time causes the WDGF
bit to be set in the Fault Status register and the device to be placed
in Sleep mode, with all measurement and balancing functions
disabled. Daisy chain devices assert the FAULT output in response
to a watchdog fault and maintain this asserted state while in Sleep
mode. Notice that no watchdog fault response is automatically
sent on the daisy chain interface.
The watchdog continues to function when the ISL94212 is in
Sleep mode. Parts in Sleep mode assert the FAULT output when
the watchdog timer expires.
A valid communications sequence is one that requires an action
or response from the device. Address All commands, such as the
Scan and Balance commands provide a simple way to reset the
watchdog timers on all devices with a single communication.
Single device communications (e.g., ACK) must be sent
individually to each device to reset the watchdog timer in that
device. A read of the Fault Status register of each device is also a
good way to reset the watchdog timer on each device. This
functionality guards against situations where a runaway host
microcontroller might continually send data.
Communications Faults
All commands except the Scan, Measure and Reset commands
require a response from either the stack top device or the target
device (see Table 27), each device in the stack waits for a
response from the stack device above. Correct receipt of a
command is indicated by the correct response. Failure to receive
a response within a timeout period indicates a communications
fault. The timeout value is stack position dependent. The device
that detects the fault then transmits the Communications Failure
response, which includes its stack address.
TABLE 27. SUMMARY OF NORMAL COMMUNICATIONS RESPONSES AND
THE COMMUNICATIONS TIMEOUT FUNCTION
TOP STACK
DEVICE
RESPONSE
TARGET
DEVICE
RESPONSE
DEVICE WAITS FOR A
RESPONSE FOR THIS
COMMAND?
Read
ACK
Data
Yes
Write
ACK
ACK
Yes
Scan Voltages
-
-
No
Scan
Temperatures
-
-
No
Scan Mixed
-
-
No
Scan Wires
-
-
No
Scan All
-
-
No
Scan
Continuous
ACK
ACK
No
Scan Inhibit
ACK
ACK
No
Measure
-
-
No
Identify
ACK
NAK
No
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TOP STACK
DEVICE
RESPONSE
TARGET
DEVICE
RESPONSE
DEVICE WAITS FOR A
RESPONSE FOR THIS
COMMAND?
Sleep
ACK
NAK
No
NAK
ACK
ACK
Yes
ACK
ACK
ACK
Yes
Comms
Failure (Note)
NAK
NAK
Yes
Wakeup
ACK
NAK
No
Balance
Enable
ACK
ACK
Yes
Balance
Inhibit
ACK
ACK
Yes
-
-
No
Calc Checksum
ACK
ACK
Yes
Check
Checksum
ACK
ACK
Yes
COMMAND
Reset
NOTE: Comms Failure is a device response only and has no meaning as a
command.
Communication Failure
COMMAND
TABLE 27. SUMMARY OF NORMAL COMMUNICATIONS RESPONSES AND
THE COMMUNICATIONS TIMEOUT FUNCTION (Continued)
If the target device receives a communications failure response
from the device above then the target device relays the
communications failure followed by the requested data (in the
case of a read) or simply relays the communications failure only
(in the case of a Write, Balance command, etc). The maximum
time required to return the Communications Failure response to
the host microcontroller (the time from the falling edge of the
24th clock pulse of an SPI command to receiving a DATA READY
low signal) is given for various data rates in Table 28.
TABLE 28. MAXIMUM TIME TO COMMUNICATIONS FAILURE RESPONSE
MAXIMUM TIME TO
ASSERTION OF DATA READY
UNIT
Daisy Chain Data Rate
500
250
125
62.5
kHz
Communications Failure
Response
5.8
11.6
23.2
46.4
ms
A communications fault can be caused by one of three
circumstances: the communications system has been
compromised, the device causing the fault is in Sleep mode or
that a daisy chain input port is in the wrong idle state. This latter
condition is unlikely but could arise in response to external
influence, such as a large transient event. The daisy chain ports
are forced to the correct idle condition at the end of each
communication. An external event would have the potential to
“flip” the input such that the port settles in the inverse state.
A flipped input condition recovers during the normal course of
communications. If a flipped input is suspected, having received
notification of a communications fault condition for example, the
user may send a sequence of all 1’s (e.g., FF FF FF FF) to clear the
fault. Wait for the resulting NAK response and then send an ACK
to the device that reported the fault. The “all 1” sequence allows
a device to correct a flipped condition via normal end of the
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communication process. The command FB FF FF FF also works
and contains the correct CRC value (should this be a
consideration in the way the control software is set up).
If the process mentioned previously results in a Communications
Failure response, the next step is for the host microcontroller to
send a Sleep command, wait for all stack devices to go to sleep,
then send a Wakeup command. If successful then the host
microcontroller receives an ACK once all devices are awake. In
the case where a single stack device was asleep, the devices
above the sleeping device would not have received the Sleep
command and would respond to the Wakeup sequence with a
NAK due to incomplete communications. The host
microcontroller would then send a command (e.g., ACK) to check
that all devices are awake. This process can be repeated as often
as needed to wakeup sleeping devices.
In the event that the Wakeup command does not generate a
response, this is a likely indication that the communications
have been compromised. The host microcontroller may send a
Sleep command to all units. If the communications watchdog is
enabled then all parts go automatically into Sleep mode when
the watchdog period expires so long as there are no valid
communications activity. Table 27 provides a summary of the
normal responses and an indication if the device waits for a
response from the various communications commands.
Scan Counter
A scan counter is provided to allow confirmation of receipt of the
Scan and Measure commands. This is a 4-bit counter located in
the Scan Count register (page 1, address 6’h16). The counter
increments each time a Scan or Measure command is received.
This allows the host microcontroller to compare the counter
value before and after the Scan or Measure command was sent
to verify receipt. The counter wraps to zero when overflowed.
The scan counter increments whenever the ISL94212 receives a
Scan or Measure command. The ISL94212 does not perform a
requested scan or measure function if there is already a scan or
measure function in progress, but it still increments the scan
counter.
Daisy Chain Communications Conflicts
Conflicts in the daisy chain system can occur if both a stack
device and the host microcontroller are transmitting at the same
time, or if more than one stack device transmits at the same
time. Conflicts caused by a stack device transmitting at the same
time as the host microcontroller are recognized by the absence
of the required response (e.g., an ACK response to a write
command), or by the scan counter not being incremented in the
case of Scan and Measure commands.
Conflicts which arise from more than one device transmitting
simultaneously can occur if two devices detect faults at the same
time. This can occur when the stack is operating normally (e.g., if
two devices register an undervoltage fault in response to a scan
voltages command sent to all devices). It is recommended that
the host microcontroller checks the Fault Status register
contents of all devices whenever a Fault response is received
from one device.
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Memory Checksum
There are two checksum operations, one for the EEPROM and
one for the Page 2 registers.
Two registers are provided to verify the contents of EEPROM
memory. One (Page 4, address 6’h3F) contains the correct
checksum value, which is calculated during factory testing at
Intersil. The other (Page 5, address 6’h00) contains the
checksum value calculated each time the nonvolatile memory is
loaded to shadow registers, either after a power cycle or after a
device reset. An inequality between these two numbers indicates
corruption of the shadow register contents (and possible
corruption of EEPROM data). The external microcontroller needs
to compare the two registers, since it is not automatic. Resetting
the device (using the Reset command) reloads the shadow
registers. A persistent difference between these two register
values indicates EEPROM corruption.
All Page 2 registers (device configuration registers) are subject to
a checksum calculation. A Calculate Register Checksum
command calculates the Page 2 checksum and saves the value
internally (it is not accessible). The Calculate Register Checksum
command may be run any time, but should be sent whenever a
Page 2 register is changed.
A Check Register Checksum command recalculates the Page 2
checksum and compares it to the internal value. The occurrence
of a Page 2 checksum error sets the PAR bit in the Fault Status
register and causes a Fault response accordingly. The normal
response to a PAR error is for the host microcontroller to rewrite
the Page 2 register contents. A PAR fault also causes the device
to cease any scanning or cell balancing activity.
See items 42 through 49 in Table 30 on page 47.
Settling Time Following
Diagnostic Activity
The majority of diagnostic functions within the ISL94212 do not
affect other system activity and there is no requirement to wait
before conducting further measurements. The exceptions to this
are the open wire test and cell balancing functions.
Open Wire Test
The open wire test loads each VCn pin in turn with 150µA or 1mA
current. This disturbs the cell voltage measurement while the
test is being applied e.g., a 1mA test current applied with an
input path resistance of 1kΩ reduces the pin voltage by 1V. The
time required for the cell voltage to settle following the open wire
test is dependent on the time constant of components used in
the cell input circuit. The standard input circuit (Figure 50 on
page 73) with the components given in Table 48 on page 77
provide settling to within 0.1mV in approximately 2.8ms. This
time should be added at the end of each open wire scan to allow
the cell voltages to settle.
Cell Balancing
The standard applications circuit (Figure 50 on page 73)
configures the balancing circuits so that the cell input
measurement reads close to zero volts when balancing is
activated. There are time constants associated with the turn-on
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and turn-off characteristics of the cell balancing system that
must be allowed for when conducting cell voltage
measurements.
length (number of sequential positive samples) is set by the
[TOT2:0] bits in the Fault Setup register. See Table 29.
The turn-on time of the balancing circuit is primarily a function of
the 25µA drive current of the cell balancing output and the gate
charge characteristic of the MOSFET and needs to be determined
for a particular setup. Turn-on settling times to within 2mV of
final “on” value are typically less than 5ms.
The turn-off time is a function of the MOSFET gate charge and
the VGS connected resistor and capacitor values (for example
R27 and C27 in Figure 50 on page 73) and is generally longer
than the turn-on time. As with the turn-on case, the turn-off time
needs to be determined for the particular components used.
Turn-off settling times in the range 10ms to 15ms are typical for
settling to within 0.1mV of final value.
Fault Signal Filtering
Filtering is provided for the cell overvoltage, cell undervoltage,
VBAT open and VSS open tests. These fault signals use a
totalizing method in which an unbroken sequence of positive
results is required to validate a fault condition. The sequence
Separate filter functions are provided for each cell input and for
the VBAT and VSS open faults. The filter is reset whenever a test
results in a negative result (no fault). All filters are reset when the
Fault Status register [TOT2:0] bits are changed. When a fault is
detected, the [TOT2:0] bits should be rewritten.
The cell overvoltage, cell undervoltage, VBAT open and VSS open
faults are sampled at the same time at the end of a Scan
Voltages command. The cell undervoltage and cell overvoltage
signals are also checked following a Measure cell voltage
command.
Fault Diagnostics
The ISL94212 incorporates extensive fault diagnostics functions,
which include cell overvoltage and undervoltage as well as open
cell input detection. The current status of all faults is accessible
using the ISL94212 registers. Table 30 shows a summary of
commands and responses for the various fault diagnostics
functions.
TABLE 29. FAULT TOTALIZING TIME (ms) AS A FUNCTION OF SCAN INTERVAL AND NUMBER OF TOTALIZED SAMPLES
TOTALIZE – FAULT SETUP REGISTER
SCAN
INTERVAL
CODE
SCAN
INTERVAL
(ms)
1
000
2
001
4
010
8
011
16
100
32
101
64
110
128
111
0000
16
16
32
64
128
256
512
1024
2048
0001
32
32
64
128
256
512
1024
2048
4096
0010
64
64
128
256
512
1024
2048
4096
8192
0011
128
128
256
512
1024
2048
4096
8192
16384
0100
256
256
512
1024
2048
4096
8192
16384
32768
0101
512
512
1024
2048
4096
8192
16384
32768
65536
0110
1024
1024
2048
4096
8192
16384
32768
65536
131072
0111
2048
2048
4096
8192
16384
32768
65536
131072
262144
1000
4096
4096
8192
16384
32768
65536
131072
262144
524288
1001
8192
8192
16384
32768
65536
131072
262144
524288
1048576
1010
16384
16384
32768
65536
131072
262144
524288
1048576
2097152
1011
32768
32768
65536
131072
262144
524288
1048576
2097152
4194304
1100
65536
65536
131072
262144
524288
1048576
2097152
4194304
8388608
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ISL94212
TABLE 30. SUMMARY OF FAULT DIAGNOSTICS COMMANDS AND RESPONSES
ITEM
1
DIAGNOSTIC
FUNCTION
Static fault
detection
functions.
ACTION REQUIRED
REGISTER READ/WRITE
COMMENTS
Check Fault Status (or look Read Fault Status register The main internal functions of the ISL94212 are monitored
for normal fault response)
continuously. Bits are set in the Fault Status register is response to
faults being detected in these functions.
2
Oscillator check Check for device in Sleep
function
mode if stack returns a
Communications Failure
response.
3
Cell overvoltage Set cell overvoltage limit
Oscillator faults are detected as part of the Static Fault detection
functions. The response to an oscillator fault detection is to set the OSC
bit in the Fault Status register and then to enter Sleep mode. A sleeping
device does not respond to normal communications, producing a
communications failure notification from the next device down the
stack. The normal recovery procedure is send repeated Sleep and
Wakeup commands ensure all devices are awake.
Write Overvoltage Limit
register
Full scale value 14'h1FFF = 5V
Write TOT bits in Fault
Setup register
Default is 3'b011 (8 samples) - (see “Fault Setup:” on page 64)
4
Set fault filter sample
value
5
Identify which inputs have Write Cell Setup register
cells connected
A '0' bit value indicates cell is connected. A '1' bit value indicates no cell
connected to this input. The overvoltage test is not applied to
unconnected cells.
6
Scan cell voltages
Send Scan Voltages
command
A cell overvoltage condition is flagged after a number of sequential
overvoltage conditions are recorded for a single cell. The number is
programmed above in item 4.
7
Check fault status
Read Fault Status register The device sends the Fault Status register contents automatically if a
fault is detected, if the register value is zero before the fault is detected.
8
Check overvoltage fault
register
Read Overvoltage Fault
register
9
Reset fault bits
Reset bits in Overvoltage Fault register followed and bits in Fault Status
register.
10
Reset fault filter
Change the value of the [TOT2:0] bits in the Fault Setup register and
then change back to the required value. This resets the filter. The filter
is also reset if a false overvoltage test is encountered.
11
Cell
Undervoltage
Only required if the Fault Status register returns a fault condition.
Set cell Undervoltage Limit Write Undervoltage Limit Full scale value 14'h1FFF = 5V
register
12
Set fault filter sample
value
13
Identify which inputs have Write Cell Setup register
cells connected
A '0' bit value indicates cell is connected. A '1' bit value indicates no cell
connected to this input. The undervoltage test is not applied to
unconnected cells.
14
Scan cell voltages
Send Scan Voltages
command
A cell undervoltage condition is flagged after a number of sequential
undervoltage conditions are recorded for a single cell. The number is
programmed above in item 12.
15
Check Fault Status
Read Fault Status register The device sends the Fault Status register contents automatically if a
fault is detected, if the register value is zero before the fault is detected.
16
Check undervoltage fault
register
Read undervoltage Fault Only required if the Fault Status register returns a fault condition.
register
17
Reset fault bits
Reset bits in undervoltage fault register followed by bits in Fault Status
register.
18
Reset fault filter
Change the value of the [TOT2:0] bits in the Fault Setup register and
then change back to the required value. This resets the filter. The filter
is also reset if a false undervoltage test is encountered.
19
VBAT or VSS Set fault filter sample
Connection Test value
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47
Write TOT Bits in Fault
Setup register
Write TOT bits in Fault
Setup register
Default is 3'b011 (8 samples)
Default is 3'b011 (8 samples)
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TABLE 30. SUMMARY OF FAULT DIAGNOSTICS COMMANDS AND RESPONSES (Continued)
ITEM
DIAGNOSTIC
FUNCTION
ACTION REQUIRED
REGISTER READ/WRITE
COMMENTS
20
Scan cell voltages
Send Scan Voltages
command
21
Check Fault Status
Read Fault Status register The device sends the Fault Status register contents automatically if a
fault is detected, if the register value is zero before the fault is detected.
22
Reset fault bits
Reset bits in the Fault Status register.
23
Reset fault filter
Change the value of the [TOT2:0] bits in the Fault Setup register and
then change back to the required value. This resets the filter. The filter
is also reset if a false open test is encountered.
24
Open Wire Test Set Scan current value
Write Device Setup
register: ISCN = 1 or 0
A open condition on VBAT or VSS is flagged after a number of sequential
open conditions are recorded for a single cell. The number is
programmed in item 19.
Sets scan current to 1mA (recommended) by setting ISCN = 1. Or, set
the scan current to 150µA by setting ISCN = 0.
25
Identify which inputs have Write Cell Setup register
cells connected
A '0' bit value indicates cell is connected. A '1' bit value indicates no cell
connected to this input. Cell inputs VC2 to VC12: the open wire
detection system is disabled for cell inputs with a '1' setting in the Cell
Setup register. Cell inputs VC0 and VC1 are not affected by the Cell
Setup register.
26
Activate Scan Wires
function
Send Scan Wires
command
Wait for Scan Wires to complete.
27
Check Fault Status
Read Fault Status register The device sends the Fault Status register contents automatically if a
fault is detected, if the register value is zero before the fault is detected.
28
Check Open Wire Fault
register
Read Open Wire Fault
register
29
Reset fault bits
30
Overtemperature
Indication
Only required if the Fault Status register returns a fault condition.
Reset bits in Open Wire Fault register followed by bits in Fault Status
register.
Set External Temperature Write External Temp Limit Full scale value 14'h3FFF = 2.5V
limit
register
31
Identify which inputs are
required to be tested
Write Fault Setup register A '1' bit value indicates input is tested. A '0' bit value indicates input is
bits TST1 to TST4
not tested.
32
Scan temperature inputs
Send Scan Temperatures An over-temperature condition is flagged immediately if the input
command
voltage is below the limit value.
33
Check Fault Status
Read Fault Status register The device sends the Fault Status register contents automatically if a
fault is detected, if the register value is zero before the fault is detected.
34
Check Over-temperature
fault register
Read Over-temperature
Fault register
35
Reset fault bits
Reset bits in Over-temperature Fault register followed by bits in Fault
Status register.
36
Reference
Read reference coefficient Read Reference
Check Function A
Coefficient A register
37
Read reference coefficient Read Reference
B
Coefficient B register
38
Read reference coefficient Read Reference
C
Coefficient C register
39
Scan temperature inputs
Send Scan Temperatures
command
40
Read reference voltage
value
Read Reference Voltage
register
41
Calculate voltage
reference value
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Only required if the Fault Status register returns a fault condition.
See Voltage Reference Check Calculation in the “Worked Examples” on
page 86 of this data sheet.
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TABLE 30. SUMMARY OF FAULT DIAGNOSTICS COMMANDS AND RESPONSES (Continued)
ITEM
42
DIAGNOSTIC
FUNCTION
REGISTER READ/WRITE
COMMENTS
Calculate register
checksum value
Send Calc Register
Checksum command
This causes the ISL94212 to calculate a checksum based on the
current contents of the page 2 registers. This action must be performed
each time a change is made to the register contents. The checksum
value is stored for later comparison.
43
Check register checksum
value
Send Check Register
Checksum command
The checksum value is recalculated and compared to the value stored
by the previous Calc Register Checksum command. The PAR bit in the
Fault Status register is set if these two numbers are not the same.
44
Check Fault Status
Read Fault Status register The device sends the Fault Status register contents automatically if a
fault is detected, if the register value is zero before the fault is detected.
45
Re-write registers
Load all page 2 registers This is only required if a PAR fault is registered. It is recommended that
with their correct values. the host reads back the register contents to verify values prior to
sending a Calc Register Checksum command.
46
Reset fault bits
47
Register
Checksum
ACTION REQUIRED
EEPROM MISR Read checksum value
Checksum
stored in EEPROM
48
Read checksum value
calculated by ISL94212
49
Compare checksum
values
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49
Reset bits in the Fault Status register.
Read the EEPROM MISR
Register
Read the MISR
Checksum register
The checksum value is calculated each time the EEPROM contents are
loaded to registers, either following the application of power, cycling
the EN pin followed by a host initiated Reset command, or simply the
host issuing a Reset command.
Correct function is indicated by the two values being equal. Memory
corruption is indicated by an unequal comparison. In this event the host
should send a Reset command and repeat the check process.
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Sleep Mode
Devices enter Sleep mode in response to a Sleep command, a
watchdog time out or in response to an oscillator fault. Devices
wakeup in response to a Wakeup command or to a Scan
Continuous cycle if the device was set to Sleep mode with Scan
Continuous mode active.
Using a Sleep command or Wakeup command does not require
that the devices in a stack are identified first. They do not need to
know their position in the stack.
In a daisy chain system, the Sleep command must be written
using the Address All stack address: 1111. The command is not
recognized if sent with an individual device address and causes
the addressed device to respond NAK. The top stack device
responds ACK on receiving a valid Sleep command.
Having received a valid Sleep command, devices wait before
entering the Sleep mode. This is to allow time for the top stack
device to respond ACK, or for all devices that don’t recognize the
command to respond NAK, and for the host microcontroller to
respond with another command. Receipt of any valid
communications on port 1 of the ISL94212 before the wait
period expires cancels the Sleep command. Receipt of another
Sleep command restarts the wait timers. Table 31 provides the
maximum wait time for various daisy chain data rates. The
communications fault checking timeout is not applied to the
Sleep command. A problem with the communications is
indicated by a lack of response to the host microcontroller. The
host microcontroller may choose to do nothing if no response is
received in which case devices that received the Sleep command
go to sleep when the wait time expires. Devices that do not
receive the message go to sleep when their watchdog timer
expires (as long as this is enabled).
TABLE 31. MAXIMUM WAIT TIME FOR DEVICES ENTERING SLEEP MODE
MAXIMUM WAIT TIME FROM
TRANSMISSION OF SLEEP
COMMAND
UNIT
Daisy Chain Data Rate
500
250
125
62.5
kHz
Time to Enter Sleep mode
500
1000
2000
4000
µs
NOTE: Devices exit Sleep mode on receipt of a valid Wakeup command.
Wakeup
The host microcontroller wakes up a stack of sleeping devices by
sending the Wakeup command to the Master stack device. The
Wakeup command must be written using the Address All stack
address: 1111. The command is not recognized if sent with an
individual device address and causes the Master device to
respond NAK.
The Master exits Sleep mode on receipt of a valid Wakeup
command and proceeds to transmit the Wakeup signal to the
next device in the stack. The Wakeup signal is a few cycles of a
4kHz clock. Each device in the chain wakes up on receipt of the
Wakeup signal and proceeds to send the signal onto the next
device. Any communications received on port 1 by a device which
is transmitting the Wakeup signal on port 2 are ignored. The Top
stack device, after waking up, waits for some time before
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50
sending an ACK response to the Master. This wait time is
necessary to allow for the Wakeup signal being originated by a
stack device other than the Master. See “Fault Response in Sleep
Mode” in the following section for more information. The Master
device passes the ACK on to the host microcontroller to complete
the Wakeup sequence. The total time required to wakeup a
complete stack of devices is dependent on the number of
devices in the stack. Table 32 gives the maximum time from
Wakeup command transmission to receipt of ACK response
(DATA READY asserted low) for stacks of 8 devices and 14
devices at various daisy chain data rates (interpolate linearly for
different number of devices).
TABLE 32. MAXIMUM WAKEUP TIMES FOR STACKS OF 8 DEVICES AND
14 DEVICES (WAKEUP COMMAND TO ACK RESPONSE)
MAXIMUM WAKEUP TIMES
UNIT
Daisy Chain Data Rate
500
250
125
62.5
kHz
Stack of 8 Devices
63
63
63
63
ms
Stack of 14 Devices
100
100
100
100
ms
There is no additional checking for communications faults while
devices are waking up. A communications fault is indicated by
the host microcontroller not receiving an ACK response within
the expected time.
Fault Response in Sleep Mode
Devices may detect faults if operating in Scan Continuous mode
while also in Sleep mode.
Daisy chain devices registering a fault in Sleep mode proceed to
wakeup the other devices in the stack (e.g., Middle devices send
the Wakeup signal on both ports). Any communications received
by a device on one port while it is transmitting the Wakeup signal
on its other port are ignored. After receiving the Wakeup signal,
the top stack device waits before sending an ACK response on
port 1. This is to allow other stack devices to wakeup. The total
wait time is dependent on the number of devices in the stack.
The time from a device detecting a fault to receipt of the ACK
response is also dependent on the stack position of the device.
See Table 32 for maximum response times for stacks of 8 and
14 devices.
The normal host microcontroller response to receiving an ACK
while the stack is in Sleep mode is to read the Fault Status
register contents of each device in the stack to determine which
device (or devices) has a fault.
Communication and
Measurement Diagrams
Collecting voltage and temperature data from daisy chained
ISL94212 devices consists of three separate types of operations:
A Command to initiate measurement, the Measurement itself,
and a Command and Response to retrieve data.
Commands are the same for all types of operations, but the
timing is dependent on the number of devices in the stack, the
daisy chain clock rate, and the SPI clock rate.
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Actual measurement operations occur within the device and
start with the last bit of the command byte and end with data
being placed in a register. Measurement times are dependent on
the ISL94212 internal clock. This clock has the same variations
(and is related to) the daisy chain clock.
Responses have different timing calculations, based on the
position of the addressed device in the daisy chain stack and the
daisy chain and SPI clock rates.
Measurement Timing Diagrams
All measurement timing is derived from the ISL94212’s internal
oscillators. Figures given as typical are those obtained with the
oscillators operating at their nominal frequencies and with any
synchronization timing also at nominal value. Maximum figures
are those obtained with the oscillators operating at their
minimum frequencies and with the maximum time for any
synchronization timing.
Measurement timing begins with a Start Scan signal. This signal
is generated internally by the ISL94212 at the last clock falling
edge of the Scan or Measure command. (This is the last falling
edge of the SPI clock in the case of a standalone or Master
device, or the last falling edge of the daisy chain clock, in the
case of a daisy chain device). Daisy chain middle or top devices
impose an additional synchronization delays. Communications
sent on the SPI port are passed on to the Master device’s daisy
chain port at the end of the first byte of data. Then, for each
device, there is an additional delay of one daisy chain clock cycle.
devices perform additional operations, such as checking for
overvoltage conditions. The measurement command ends when
registers are updated. At this time the registers may be read
using a separate command. Refer to the “SPI INTERFACE TIMING
(See Figures 2 and 3)” on page 13 of the Electrical Specifications
table for the time required to complete each measurement type.
A more detailed timing breakdown is provided for each
measurement type shown in the following.
See Figure 43 for the measurement timing for a standalone
device. See Figure 44 for the measurement timing for daisy
chain devices.
Tables 34 through 39 give the typical and maximum timing for
the critical elements of measurement process. Each table shows
the timing from the last edge of the Scan command clock.
SCAN COMMAND
DIN
SCK
INTERNAL SCAN
INTERNAL OPERATION
MEASURE
UPDATE REGISTERS
See Tables 34 through 39
FIGURE 43. MEASUREMENT TIMING (STANDALONE)
On receiving the Start Scan signal, the device initializes
measurement circuits and proceeds to perform the requested
measurement(s). Once the measurements are made, some
SPI SCAN COMMAND
DIN
SCK
SCAN/MEASURE
INTERNAL
OPERATION (MASTER)
UPDATE REGISTERS
See Tables 34 through 39
See Figure 46 on page 53, Tables 40 and 41 on page 58
DAISY CHAIN SCAN COMMAND
UNIT 2
UNIT 6
4 DAISY CHAIN CLOCKS
SCAN/MEASURE
INTERNAL OPERATION
(DAISY CHAIN UNIT 6)
UPDATE REGISTERS
See Tables 34 through 39
FIGURE 44. MEASUREMENT TIMING (6 DEVICE DAISY CHAIN).
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Command Timing Diagram
SPI COMMAND
DOUT
tCS:WAIT
CS
MASTER
SCK
tLEAD
tLAG
tSPI
tD
T1A
DAISY CLOCK
(P2 TRANSMIT)
8* tD
8* tD
8* tD
8* tD
8* tD
8* tD
12 * tD
(Note 14) (Note 15)
DEVICE 2
2 * tD
(P1 RECEIVE)
8* tD
8* tD
2µs
2 * tD
4 * tD
DEVICE 6
12 * tD
SCAN
8* tD
(P1 RECEIVE)
(FROM DEVICE 5)
8* tD
8* tD
8* tD
8 * tD
SCAN
2µs
2 * tD
DEVICE 14
8 * tD
(P1 RECEIVE)
(FROM DEVICE 13)
8* tD
8* tD
8* tD
8* tD
SCAN
2µs
2 * tD
T1B
T1C
To Start of Scan (Master)
T1A = T SPI  8 + T LEAD + T LAG  3 + 2  T CSWAIT
To Start of Scan (Top/Middle)
T1B = T SPI  8 + T LEAD + T LAG + T D   28 + n – 2  + 2s
COMMANDS:
• Scan Voltages
• Scan Temperatures
• Scan Mixed
• Scan Wires
To End of Command
• Scan All
T1C = T SPI  8 + T LEAD + T LAG + T D   34 + N – 2 
• Measure
• Read
Where:
TSPI = SPI clock period
TD = Daisy chain clock period
TCS:WAIT = CS High time
TLEAD = CS Low to first SPI Clock
TLAG = Last SPI Clock CS High
n = stack position of target device
N = stack position of TOP device
• Write
• Scan Continuous
• Scan Inhibit
• Sleep
• NAK
NOTES:
14. Master adds extra byte of zeros as part of Daisy protocol
15. Master adds N-2 clocks to allow communication to the end of the chain.
FIGURE 45. COMMAND TIMING
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Response Timing Diagrams
Responses are different for Master, Middle, and Top devices. The response timings are shown in
Figures 46, 47, and 48.
DIN
CS
MASTER
SCK
tCS
2µs
DEVICE 2
(P2 RECEIVE)
DEVICE 6
tLAG
tLEAD
DATA READY
(P1 TRANSMIT)
tDR:WAIT
8* tD
2µs
8* tD
8* tD
8* tD
8* tD
8* tD
8* tD
8* tD
8* tD
4 * tD
8* tD
(P1 TRANSMIT)
2*tD
DEVICE 14
tDR:SP
8 * tD
8* tD
8* tD
8* tD
8* tD
4*tD
8 * tD
8* tD
(P1 TRANSMIT)
8* tD
8* tD
12 * tD
DAISY CHAIN ACK RESPONSE
2µs
T2
T2 =  8  T SPI + T DRSP + T DRWAIT + T CS + T LEAD + T LAG   D – T DRSP + T D   42 + N – 2 + 8  + 4s
Where:
TSPI = SPI clock period
TD = Daisy Chain clock period
TCS = Host delay from DATA READY Low to the CS Low
TDRSP = CS High to DATA READYHigh
TDRWAIT = DATA READY High time
TLEAD = CS Low to first SPI Clock
TLAG = Last SPI Clock CS High
N = Stack position of TOP device
D = Number of data bytes
D = 4 for one register read (or ACK/NAK response)
D = 40 for read all voltages
D = 22 for read all temperatures
D = 22 for read all faults
D = 43 for read all setup
FIGURE 46. RESPONSE TIMING (MASTER DEVICE)
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Response Timing Diagrams
Responses are different for Master, Middle, and Top devices. The response timings are shown in
Figures 46, 47, and 48. (Continued)
tCS
DIN
CS
MASTER
tLEAD
tLAG
SCK
tDR:SP
DATA READY
2µs
DEVICE 2
(P2 RECEIVE)
(P1 TRANSMIT)
2µs
8* tD
8* tD
8* tD
8* tD
8* tD
8* tD
8* tD
8* tD
4* tD
DEVICE 6
(P1 TRANSMIT)
8* tD
n
8* tD
(P2 RECEIVE)
(FROM DEVICE 7)
8* tD
DEVICE 14
2*tD
N
(P1 TRANSMIT)
8* tD
8* tD
8* tD
4*tD
Note 16
DAISY CHAIN READ DATA RESPONSE
8* tD
7*tD (= N - n - 1)
8* tD
8 * tD
8* tD
2µs
8* tD
8* tD
8* tD
8* tD
7* tD
DAISY CHAIN ACK RESPONSE Note 17
2µs
COMMAND
RESPONSE
T3
T4
T3 = T D   50 + N – n – 1  + 4s
T4 = T SPI  8 + T CS + T LEAD + T LAG + T DRSP + T D   D  8 + n – 2  + 2s
Where:
TD = Daisy Chain clock period
TSPI = SPI Clock Period
N = Stack position of TOP device
n = Stack position of MIDDLE stack device
TCS = Delay imposed by host from DATA READY to the first SPI clock cycle
D = Number of bytes in the Middle stack device response e.g. read all cell data = 40 bytes, Register or ACK response = 4 bytes.
NOTES:
16. Top Device adds (N - n - 1) Daisy clocks to allow communications to the targeted Middle Stack device.
17. Middle Stack Device adds (n - 2) Daisy clocks to allow communications to the Master device.
FIGURE 47. RESPONSE TIMING (MIDDLE STACK DEVICE)
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Response Timing Diagrams
Responses are different for Master, Middle, and Top devices. The response timings are shown in
Figures 46, 47, and 48. (Continued)
tCS
DIN
CS
MASTER
tLEAD
tDR:SP
DATA READY
2µs
DEVICE 6
DEVICE 2
(P2 RECEIVE)
(P1 TRANSMIT)
2µs
8* tD
8* tD
8* tD
8* tD
8* tD
8* tD
8* tD
8* tD
4 * tD
8* tD
(P1 TRANSMIT)
2*tD
DEVICE 14
tLAG
SCK
8 * tD
8* tD
8* tD
8* tD
4*tD
8* tD
8 * tD
8* tD
(P1 TRANSMIT)
8* tD
8* tD
12 * tD
DAISY CHAIN DATA RESPONSE
2µs
T5
T5 = T SPI  8 + T LEAD + T LAG + T DRSP + T CS + T D   D  8 + 10 + N – 2  + 4s
Where:
TSPI = SPI clock period
TD = Daisy Chain clock period
TCS = Host delay from DATA READY to the first SPI clock
TDRSP = CS High to DATA READY High
TLEAD = CS Low to first SPI Clock
TLAG = Last SPI Clock CS High
N = stack position of TOP device
D = Number of bytes in response
FIGURE 48. RESPONSE TIMING (TOP DEVICE)
SEQUENTIAL DAISY CHAIN COMMUNICATIONS
When sending a sequence of commands to the Master device,
the host must allow time, after each response and before
sending the next command, for the daisy chain ports of all stack
devices (other than the Master) to switch to receive mode. This
wait time is equal to 8 daisy chain clock cycles and is imposed
from the time of the last edge on the Master’s input daisy chain
port to the last edge of the first byte of the subsequent command
on the SPI, (see Figure 33). The minimum recommended wait
time, between the host receiving the last edge of a response and
sending the first edge of the next command, is given for the
various daisy chain data rates in Table 33.
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TABLE 33. MINIMUM RECOMMENDED COMMUNICATIONS WAIT TIME
MAXIMUM TIME FOR DAISY CHAIN PORTS TO
CLEAR
UNIT
Daisy Chain Data
Rate
500
250
125
62.5
kHz
Communications
Wait Time
18
36
72
144
µs
FN7938.1
April 23, 2015
ISL94212
SPI
COMMAND
NEXT SPI
COMMAND
SPI RESPONSE
DIN
SCK
DATA READY
Minimum Wait time
between commands.
See Table 33
UNIT 2
UNIT n
FIGURE 49. MINIMUM WAIT BETWEEN COMMANDS (DAISY CHAIN RESPONSE - TOP DEVICE)
Communication and
Measurement Timing Tables
SCAN TEMPERATURES
Measurement Timing Tables
SCAN VOLTAGES
The Scan Voltages command initiates a sequence of
measurements starting with a scan of each cell input from
cell 12 to cell 1, followed by a measurement of pack voltage.
Additional measurements are then performed for the internal
temperature and to check the connection integrity test of the VSS
and VBAT inputs. The process completes with the application of
calibration parameters and the loading of registers. Table 34
shows the times after the start of scan that the cell voltage
inputs are sampled. The voltages are held until the ADC
completes its conversion.
TABLE 34. SCAN VOLTAGES FUNCTION TIMING - DAISY CHAIN MASTER
OR STANDALONE DEVICE
EVENT
TYP (µs)
MAX (µs)
Sample cell 12
17
19
Sample cell 11
38
42
Sample cell 10
59
65
Sample cell 9
81
89
Sample cell 8
102
112
Sample cell 7
123
135
Sample cell 6
144
159
Sample cell 5
166
182
Sample cell 4
187
206
Sample cell 3
208
229
Sample cell 2
229
252
Sample cell 1
251
276
Complete cell voltage capture (ADC
complete).
Sample VBAT
304
334
Complete VBAT voltage capture
318
349
Measure internal temperature
423
465
Complete VSS test
550
605
Complete VBAT test
726
799
Load registers
766
842
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The Scan Temperatures command turns on the TEMPREG output
and, after a 2.5ms settling interval, samples the ExT1 to ExT4
inputs. TEMPREG turns off on completion of the ExT4
measurement. The Reference Voltage, IC Temperature and
Multiplexer loopback function are also measured. The sequence
is completed with respective registers being loaded.
TABLE 35. SCAN TEMPERATURES FUNCTION TIMING– DAISY CHAIN
MASTER OR STANDALONE DEVICE
ELAPSED TIME (µs)
EVENT
TYP
MAX
2
2
2518
2770
Sample ExT4
2564
2820
Sample Reference
2584
2842
Measure Internal Temperature
2689
2958
Load registers
2689
2958
Turn on TEMPREG
Sample ExT1
~
FN7938.1
April 23, 2015
ISL94212
SCAN MIXED
SCAN ALL
The Scan Mixed command performs all the functions of the Scan
Voltages command but interposes a measurement of the ExT1
input between the cell 7 and cell 6 measurements.
The Scan All command combines the Scan Voltages, Scan Wires
and Scan Temperatures commands into a single scan function.
TABLE 36. SCAN MIXED FUNCTION TIMING – DAISY CHAIN MASTER
OR STANDALONE DEVICE
EVENT
TYP (µs)
MAX (µs)
Sample cell 12
17
19
Sample cell 11
38
42
Sample cell 10
59
65
Sample cell 9
80
88
Sample cell 8
101
111
Sample cell 7
122
134
Complete cell voltage capture 12-7
Sample Ext1
176
194
Complete Ext1 capture
192
211
Sample cell 6
207
228
Sample cell 5
228
251
Sample cell 4
249
274
Sample cell 3
270
297
Sample cell 2
291
321
Sample cell 1
312
344
Complete cell voltage capture 6-1
Sample VBAT
367
404
Complete VBAT voltage capture
381
419
Load registers
829
911
TABLE 38. SCAN ALL FUNCTION TIMING – DAISY CHAIN MASTER OR
STANDALONE DEVICE
ELAPSED TIME (ms)
EVENT
TYP
MAX
0
0
Start Scan Wires
0.8
0.9
Start Scan Temperatures
60.1
66.2
Complete Sequence
62.8
69.1
Start Scan Voltages
MEASURE COMMAND
Single parameter measurements of the cell voltages, Pack
Voltage, ExT1 to ExT4 inputs, IC temperature and Reference
voltage are performed using the Measure command.
TABLE 39. VARIOUS MEASURE FUNCTION TIMINGS – DAISY CHAIN
MASTER OR STANDALONE DEVICE
ELAPSED TIME (µs)
EVENT
TYP
MAX
Measure Cell Voltage
178
196
Measure Pack Voltage
122
134
Measure ExT Input
2517
2768
Measure IC Temperature
106
116
Measure Reference Voltage
106
116
SCAN WIRES
Command Timing Tables
The Scan Wires command initiates a sequence in which each
input is loaded in turn with a test current for a duration of 4.5ms
(default). At the end of this time the input voltage is checked and
the test current is turned off. The result of each test is recorded
and the Open Wire Fault and Fault Status registers are updated
(data latched) at the conclusion of the tests.
The command timing tables (see Tables 40 and 41) include the
time from the start of the command to the start of an internal
operation and the time required for the communication to
complete (since the internal operation begins before the end of
the daisy chain command.)
TABLE 37. SCAN WIRES FUNCTION TIMING – DAISY CHAIN MASTER
OR STANDALONE DEVICE
ELAPSED TIME (ms)
EVENT
TYP
MAX
Turn on VC0 current
0.03
0.05
Test VC0
4.5
5.0
Turn on VC1 current
4.6
5.1
Test VC1
9.1
10.0
Turn on VC12 current
54.9
60.3
Test VC12
59.4
65.3
Load registers
59.4
65.3
~
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In the case of a command that starts a scan or measurement,
the host needs to wait until the command completes, by
reaching the last device, plus a communications wait time (see
Table 33) before sending another command. For a Read
command, the response begins in the top device immediately
following the end of the command.
In calculating overall timing, use the time for each target device
command. This time is repeated for each device in the daisy
chain, except when an “Address All” option is used. In an address
all operation, use the command timing for the top device in the
stack to determine when the command ends, but use the time to
start of scan for each device to determine when that device
begins its internal voltage sampling. For example, in a stack of
six devices, it takes 86.9µs for the command to complete, but
internal operations start at 7.8µs for the Master, 66.7µs for
device 2, 68.9µs for device 3, etc.
FN7938.1
April 23, 2015
ISL94212
In Tables 40 and 41, the calculation assumes a daisy chain (and
internal) clock that is 10% slower than the nominal and an SPI
clock that is running at the nominal speed (since the SPI clock is
normally crystal controlled.) For the 500kHz Daisy setting, timing
assumes a 450kHz clock.
TABLE 40. MAXIMUM COMMAND TIMING
(DAISY CLOCK = 500kHz, SPI CLOCK = 2MHz)
Response Timing Tables
Response timing depends on the number of devices in the stack,
the position of the device in the stack, and how many bytes are
read back. There are four “sizes” of read responses that are as
follows:
• Single register read or ACK/NAK responses, where four bytes
are returned by the Read Command
TARGET
DEVICE
TIME TO START OF SCAN
FOR TARGET DEVICE
(µs)
1
13.8
2
68.7
80.1
• Read all setup registers response, which returns 43 bytes
3
70.9
82.3
4
73.2
84.5
5
75.4
86.7
In the following tables, the Master, Middle and Top device
response times for any number of daisy chain devices are
included with the command timing for that configuration. The
right hand column shows the total time to complete the read
operation. This is calculated by Equation 4:
COMMAND TIME TO START OF
RESPONSE (DAISY)
(µs)
6
77.6
88.9
7
79.8
91.2
8
82.1
93.4
9
84.3
95.6
10
86.5
97.8
11
88.7
100.1
12
90.9
102.3
13
93.2
104.5
14
95.4
106.7
TABLE 41. MAXIMUM COMMAND TIMING
(DAISY CLOCK = 250kHz, SPI CLOCK = 2MHz)
COMMAND TIME TO START OF
RESPONSE (DAISY)
(µs)
TARGET
DEVICE
TIME TO START OF SCAN
FOR TARGET DEVICE
(µs)
1
13.8
2
130.9
155.6
3
135.4
160.1
4
139.8
164.5
5
144.3
168.9
6
148.7
173.4
7
153.2
177.8
8
157.6
182.3
9
162.1
186.7
10
166.5
191.2
11
170.9
195.6
12
175.4
200.1
13
179.8
204.5
14
184.3
208.9
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• Read all voltage response, which returns 40 bytes
• Read all temps or read all faults responses, which returns 22
bytes
 N  T COMMAND  +   N – 2   T MID  + T TOP + T MASTER
(EQ. 4)
Where N = Number of devices in the stack.
In the following tables, internal and daisy clocks are assumed to
be slow by 10% and the SPI clock is assumed to be at the stated
speed.
For an example, consider a stack of 6 devices. To get the full scan
time with a daisy clock of 500kHz and SPI clock of 2MHz, it takes
77.6µs from the start of the Scan All command to the start of the
internal scan (see Table 40), 842µs to complete a scan of all
voltages (see Table 34 on page 56), 5.334ms to read all cell
voltages from all devices (see Table 44 on page 60) and 18µs
delay before issuing another command. In this case, all cell
voltages in the host controller can be updated every 6.28ms.
FN7938.1
April 23, 2015
ISL94212
4-BYTE RESPONSE
Tables 42 and 43 show the calculated timing for read operations
for 4 byte responses. This is the timing for an ACK or NAK, as well
as Read Register command.
TABLE 42. READ TIMING (MAX): 4-BYTE RESPONSE, DAISY CLOCK = 500kHz, SPI CLOCK = 2MHz
TOP
STACK
DEVICE
COMMAND
TIME TO START OF
RESPONSE
(EACH DAISY DEVICE)
(µs)
2
80
139
3
82
142
4
85
5
MIDDLE RESPONSE
MASTER RESPONSE TIME TO COMPLETE
TIME TO COMPLETE RESPONSE (EACH MID
DAISY DEVICE)
RESPONSE (DAISY)
(µs)
(µs)
TOP RESPONSE
TIME TO COMPLETE
RESPONSE (DAISY)
(µs)
RESPONSE ALL
DEVICES
(µs)
COMMAND +
RESPONSE ALL
DEVICES
(µs)
110
250
410
201
113
455
702
144
203
115
666
1004
87
146
206
117
880
1314
6
89
148
208
119
1099
1633
7
91
151
210
121
1323
1961
8
93
153
212
124
1550
2298
9
96
155
215
126
1783
2643
10
98
157
217
128
2020
2998
11
100
159
219
130
2261
3361
12
102
162
221
133
2506
3734
13
105
164
223
135
2757
4115
14
107
166
226
137
3011
4505
TABLE 43. READ TIMING (MAX): 4-BYTE RESPONSE, DAISY CLOCK = 250kHz, SPI CLOCK = 2MHz
TOP
STACK
DEVICE
COMMAND
TIME TO START OF
RESPONSE
(EACH DAISY DEVICE)
(µs)
2
156
228
3
160
233
4
165
5
MIDDLE RESPONSE
MASTER RESPONSE TIME TO COMPLETE
TIME TO COMPLETE RESPONSE (EACH MID
DAISY DEVICE)
RESPONSE (DAISY)
(µs)
(µs)
TOP RESPONSE
TIME TO COMPLETE
RESPONSE (DAISY)
(µs)
RESPONSE ALL
DEVICES
(µs)
COMMAND +
RESPONSE ALL
DEVICES
(µs)
204
432
743
383
208
824
1304
237
388
213
1226
1884
169
242
392
217
1636
2480
6
173
246
397
221
2055
3095
7
178
251
401
226
2483
3727
8
182
255
406
230
2919
4378
9
187
259
410
235
3365
5045
10
191
264
415
239
3820
5731
11
196
268
419
244
4283
6435
12
200
273
423
248
4755
7156
13
205
277
428
253
5237
7895
14
209
282
432
257
5727
8652
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ISL94212
40-BYTE RESPONSE
Tables 44 and 45 show the calculated timing for read operations
for 40-byte responses. Specifically, this is the timing for a Read
All Voltages command.
TABLE 44. READ TIMING (MAX): 40-BYTE RESPONSE, DAISY CLOCK = 500kHz, SPI CLOCK = 2MHz
TOP
STACK
DEVICE
COMMAND
TIME TO START OF
RESPONSE
(EACH DAISY DEVICE)
(µs)
2
80
643
3
82
646
4
85
5
MIDDLE RESPONSE
MASTER RESPONSE TIME TO COMPLETE
TIME TO COMPLETE RESPONSE (EACH MID
DAISY DEVICE)
RESPONSE (DAISY)
(µs)
(µs)
TOP RESPONSE
TIME TO COMPLETE
RESPONSE (DAISY)
(µs)
RESPONSE ALL
DEVICES
(µs)
COMMAND +
RESPONSE ALL
DEVICES
(µs)
750
1394
1554
841
753
2239
2486
648
843
755
3090
3428
87
650
846
757
3944
4378
6
89
652
848
759
4803
5337
7
91
655
850
761
5667
6305
8
93
657
852
764
6534
7282
9
96
659
855
766
7407
8267
10
98
661
857
768
8284
9262
11
100
663
859
770
9165
10265
12
102
666
861
773
10050
11278
13
105
668
863
775
10941
12299
14
107
670
866
777
11835
13329
TABLE 45. READ TIMING (MAX): 40-BYTE RESPONSE, DAISY CLOCK = 250kHz, SPI CLOCK = 2MHz
TOP
STACK
DEVICE
COMMAND
TIME TO START OF
RESPONSE
(EACH DAISY DEVICE)
(µs)
2
156
732
3
160
737
4
165
5
MIDDLE RESPONSE
MASTER RESPONSE TIME TO COMPLETE
TIME TO COMPLETE RESPONSE (EACH MID
DAISY DEVICE)
RESPONSE (DAISY)
(µs)
(µs)
TOP RESPONSE
TIME TO COMPLETE
RESPONSE (DAISY)
(µs)
RESPONSE ALL
DEVICES
(µs)
COMMAND +
RESPONSE ALL
DEVICES
(µs)
1484
2216
2527
1663
1488
3888
4368
741
1668
1493
5570
6228
169
746
1672
1497
7260
8104
6
173
750
1677
1501
8959
9999
7
178
755
1681
1506
10667
11911
8
182
759
1686
1510
12383
13842
9
187
763
1690
1515
14109
15789
10
191
768
1695
1519
15844
17755
11
196
772
1699
1524
17587
19739
12
200
777
1703
1528
19339
21740
13
205
781
1708
1533
21101
23759
14
209
786
1712
1537
22871
25796
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22-BYTE RESPONSE
Tables 46 and 47 show the calculated timing of read operations
for 22-byte responses. This is the timing for Read All
Temperature or Read All Faults command.
TABLE 46. READ TIMING (MAX): 22-BYTE RESPONSE, DAISY CLOCK = 500kHz, SPI CLOCK = 2MHz
TOP
STACK
DEVICE
COMMAND
TIME TO START OF
RESPONSE
(EACH DAISY DEVICE)
(µs)
2
80
391
3
82
394
4
85
5
MIDDLE RESPONSE
MASTER RESPONSE TIME TO COMPLETE
TIME TO COMPLETE RESPONSE (EACH MID
DAISY DEVICE)
RESPONSE (DAISY)
(µs)
(µs)
TOP RESPONSE
TIME TO COMPLETE
RESPONSE (DAISY)
(µs)
RESPONSE ALL
DEVICES
(µs)
COMMAND +
RESPONSE ALL
DEVICES
(µs)
430
822
982
521
433
1347
1594
396
523
435
1878
2216
87
398
526
437
2412
2846
6
89
400
528
439
2951
3485
7
91
403
530
441
3495
4133
8
93
405
532
444
4042
4790
9
96
407
535
446
4595
5455
10
98
409
537
448
5152
6130
11
100
411
539
450
5713
6813
12
102
414
541
453
6278
7506
13
105
416
543
455
6849
8207
14
107
418
546
457
7423
8917
TABLE 47. READ TIMING (MAX): 22-BYTE RESPONSE, DAISY CLOCK = 250kHz, SPI CLOCK = 2MHz
TOP
STACK
DEVICE
COMMAND
TIME TO START OF
RESPONSE
(EACH DAISY DEVICE)
(µs)
2
156
480
3
160
485
4
165
5
MIDDLE RESPONSE
MASTER RESPONSE TIME TO COMPLETE
TIME TO COMPLETE RESPONSE (EACH MID
DAISY DEVICE)
RESPONSE (DAISY)
(µs)
(µs)
TOP RESPONSE
TIME TO COMPLETE
RESPONSE (DAISY)
(µs)
RESPONSE ALL
DEVICES
(µs)
COMMAND +
RESPONSE ALL
DEVICES
(µs)
844
1324
1635
1023
848
2356
2836
489
1028
853
3398
4056
169
494
1032
857
4448
5292
6
173
498
1037
861
5507
6547
7
178
503
1041
866
6575
7819
8
182
507
1046
870
7651
9110
9
187
511
1050
875
8737
10417
10
191
516
1055
879
9832
11743
11
196
520
1059
884
10935
13087
12
200
525
1063
888
12047
14448
13
205
529
1068
893
13169
15827
14
209
534
1072
897
14299
17224
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System Registers
System registers contain 14-bits each. All register locations are
memory mapped using a 9-bit address. The MSBs of the address
form a 3-bit page address. Page 1 (3’b001) registers are the
measurement result registers for cell voltages and temperatures.
Page 3 (3’b011) is used for commands. Pages 1 and 3 are not
subject to the checksum calculations. Page addresses 4 and 5
(3’b100 and 3b’101), with the exception of the EEPROM
checksum registers, are reserved for internal functions.
All page 2 registers (device configuration registers), together with
the EEPROM checksum registers, are subject to a checksum
calculation. The checksum is calculated in response to the
Calculate Register Checksum command using a Multiple Input
Shift Register (MISR) error detection technique. The checksum is
tested in response to a Check Register Checksum command. The
occurrence of a checksum error sets the PAR bit in the Fault
Status register and causes a Fault response accordingly. The
normal response to a PAR error is for the host microcontroller to
re-write the page 2 register contents. A PAR fault also causes the
device to cease any scanning or cell balancing activity.
A description of each register is included in “Register
Descriptions” as follows and includes a depiction of the register
with bit names and initialization values at power-up, when the EN
pin is toggled and the device receives a Reset Command, or
when the device is reset. Bits which reflect the state of external
pins are notated “Pin” in the initialization space. Bits which
reflect the state of nonvolatile memory bits (EEPROM) are
notated “NV” in the initialization space. Initialization values are
shown below each bit name.
Reserved bits (indicated by grey areas) should be ignored when
reading and should be set to “0” when writing to them.
Register Descriptions
Cell Voltage Data
BASE ADDR
(PAGE)
3’b001
ADDRESS
RANGE
ACCESS
DESCRIPTION
Read Only 6’h00 - 6’h0C Measured cell voltage and pack voltage values. Address 001111 accesses all cell and Pack Voltage data
and 6’h0F
with one read operation. See Figure 41D on page 40.
Cell and Pack Voltage values are output as 13-bit signed integers with the 14th bit (MSB) denoting the sign,
(e.g., positive full scale is 14’h1FFF, 8191 decimal, negative full scale is 14’h2000, 8192 decimal).
ACCESS
PAGE
ADDR
REGISTER
ADDRESS
Read Only
3’b001
6’h00
VBAT Voltage
6’h01
Cell 1 Voltage
6’h02
Cell 2 Voltage
6’h03
Cell 3 Voltage
6’h04
Cell 4 Voltage
6’h05
Cell 5 Voltage
6’h06
Cell 6 Voltage
6’h07
Cell 7 Voltage
6’h08
Cell 8 Voltage
6’h09
Cell 9 Voltage
DESCRIPTION
6’h0A
Cell 10 Voltage
6’h0B
Cell 11 Voltage
6’h0C
Cell 12 Voltage
6’h0F
Read all cell voltages
 HEXvalue 10 – 16384   15.9350784  2.5
ifHEXvalue 10  8191  VBAT = -------------------------------------------------------------------------------------------------------------------------------------8192
 HEXvalue 10 – 16384   2  2.5
VCx = ---------------------------------------------------------------------------------------------------8192
HEXvalue10  15.9350784  2.5
else  VBAT = ------------------------------------------------------------------------------8192
HEXvalue 10  2  2.5
VCx = ----------------------------------------------------8192
Temperature Data, Secondary Voltage Reference Data, Scan Count
BASE ADDR
(PAGE)
3’b001
ACCESS
ADDRESS
RANGE
DESCRIPTION
6’h10 - 6’h16 Measured temperature, Secondary reference, Scan Count. Address 011111 accesses all these data in a
See
and 6’h1F
continuous read (see Figure 41D on page 40.) Temperature and reference values are output as 14-bit
individual
register
unsigned integers, (e.g., full scale is 14’h3FFF (16383 decimal)).
HEXvalue 10  2.5
Vtemp = -------------------------------------------16384
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ACCESS
PAGE
ADDR
REGISTER
ADDRESS
Read Only
3’b001
6’h10
Read/
Write
3’h001
DESCRIPTION
Internal temperature reading.
6’h11
External temperature input 1 reading.
6’h12
External temperature input 2 reading.
6’h13
External temperature input 3 reading.
6’h14
External temperature input 4 reading.
6’h15
Reference voltage (raw ADC) value. Use to calculate corrected reference value using reference coefficient data.
See page 2 data, address 6’h38 – 6’h3A.
6’h16
Scan Count: Current scan instruction count. Count is incremented each time a scan command is received and
wraps to zero when overflowed. Register may be compared to previous value to confirm scan command receipt.
Bit Designations:
13
12
11
10
0
0
0
0
9
8
7
6
5
4
0
0
0
0
RESERVED
Read Only
3’h001
6’h1F
0
0
3
2
1
0
SCN3
SCN2
SCN1
SCN0
0
0
0
0
Read all: Temperature Data, Secondary Voltage Reference Data, Scan Count (locations 6’h10 - 6’h16)
Fault Registers
BASE ADDR
(PAGE)
3’h010
ACCESS
Read/
Write
ACCESS
Read/
Write
ADDRESS
RANGE
DESCRIPTION
6’h00 - 6’h05 Fault registers. Fault setup and status information. Address 6’h0F accesses all fault data in a continuous
and 6’h0F
read (Daisy Chain configuration only). See Figure 41D on page 40.
PAGE
ADDR
REGISTER
ADDRESS
3’h010
6’h00
DESCRIPTION
Overvoltage Fault:
Overvoltage fault on cells 12 to 1 correspond with bits OF12 to OF1, respectively.
Default values are all zero.
Bits are set to 1 when faults are detected.
The contents of this register may be reset via register write (14’h0000).
13
12
RESERVED
0
Read/
Write
3’h010
6’h01
0
12
RESERVED
0
3’h010
6’h02
9
8
7
6
5
4
3
2
1
0
OF10
OF9
OF8
OF7
OF6
OF5
OF4
OF3
OF2
OF1
0
0
0
0
0
0
0
0
0
0
0
0
0
11
10
9
8
7
6
5
4
3
2
1
0
UF12
UF11
UF10
UF9
UF8
UF7
UF6
UF5
UF4
UF3
UF2
UF1
0
0
0
0
0
0
0
0
0
0
0
0
Open Wire Fault:
Open Wire fault on Pins VC12 to VC0 correspond with bits OC12 to OC0, respectively.
Default values are all zero.
Bits are set to 1 when faults are detected.
The contents of this register may be reset via register write (14’h0000).
13
12
RESER OC12
VED
0
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10
OF11
Undervoltage Fault:
Undervoltage fault on cells 12 to 1 correspond with bits UF12 to UF1, respectively.
Default values are all zero.
Bits are set to 1 when faults are detected.
The contents of this register may be reset via register write (14’h0000).
13
Read/
Write
11
OF12
63
0
11
10
9
8
7
6
5
4
3
2
1
0
OC11
OC10
OC9
OC8
OC7
OC6
OC5
OC4
OC3
OC2
OC1
OC0
0
0
0
0
0
0
0
0
0
0
0
0
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ACCESS
Read/
Write
PAGE
ADDR
REGISTER
ADDRESS
3’h010
6’h03
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DESCRIPTION
Fault Setup:
These bits control various Fault configurations.
Default values are shown below, as are descriptions of each bit.
13
12
11
10
9
8
7
6
5
4
3
2
1
0
RESER
VED
TST4
TST3
TST2
TST1
TST0
TOT2
TOT1
TOT0
WSCN
SCN3
SCN2
SCN1
SCN0
0
0
0
0
1
0
0
1
1
1
0
0
0
0
SCN0, 1, 2, 3
Scan interval code. Decoded to provide the scan interval setup for the auto scan function.
Initialized to 0000 (16ms scan interval). See Table 2 on page 23.
WSCN
Scan wires timing control. Set to 1 for tracking of the temperature scan interval. Set to 0 for
tracking of the cell voltage scan interval above 512ms. Interval is fixed at 512ms for faster
cell scan rates. See Table 2 on page 23.
TOT0, 1, 2
Fault totalize code bits. Decoded to provide the required fault totalization. An unbroken
sequence of positive fault results equal to the totalize amount is needed to verify a fault
condition. Initialized to 011 (8 sample totalizing.) See Table 29 on page 46.
This register must be re-written following an error detection resulting from totalizer
overflow.
TST0
Controls temperature testing of internal IC temperature. Set bit to 1 to enable internal
temperature test. Set to 0 to disable (not recommended). Initialized to 1 (on).
TST1 to TST4
Controls temperature testing on the external temperature inputs 1 to 4, respectively. Set bit
to 1 to enable the corresponding temperature test. Set to 0 to disable. Allows external
inputs to be used for general voltage monitoring without imposing a limit value.
TST1 to TST4 are initialized to 0 (off).
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ISL94212
ACCESS
Read/
Write
Read/
Write
PAGE
ADDR
REGISTER
ADDRESS
3’h010
6’h04
3’h010
6’h05
DESCRIPTION
Fault Status:
The FAULT logic output is an OR function of the bits in this register: the output will be asserted low if any bits in the
Fault Status register are set.
13
12
11
10
9
8
7
6
5
4
3
2
MUX
REG
REF
PAR
OVSS
OVBAT
OW
UV
OV
OT
WDGF
OSC
0
0
0
0
0
0
0
0
0
0
0
0
1
0
RESERVED
0
0
OSC
Oscillator fault bit. Bit is set in response to a fault on either the 4MHz or 32kHz oscillators.
Note that communications functions may be disrupted by a fault in the 4MHz oscillator.
WDGF
Watchdog timeout fault. Bit is set in response to a watchdog timeout.
OT
Over-temperature fault. ‘OR’ of over-temperature fault bits: TFLT0 to TFLT4. This bit is
latched. The bits in the Over-temperature Fault register must first be reset before this bit can
be reset. Reset by writing 14’h0000 to this register.
OV
Overvoltage fault. ‘OR’ of Overvoltage fault bits: OF1 to OF12. This bit is latched. The bits in
the Overvoltage Fault register must first be reset before this bit can be reset. Reset by
writing 14’h0000 to this register.
UV
Undervoltage fault. ‘OR’ of Undervoltage fault bits: UF1 to UF12. This bit is latched. The bits
in the Undervoltage Fault register must first be reset before this bit can be reset. Reset by
writing 14’h0000 to this register.
OW
Open Wire fault. ‘OR’ of open wire fault bits: OC0 to OC12. This bit is latched. The bits in the
Open Wire Fault register must first be reset before this bit can be reset. Reset by writing
14’h0000 to this register.
OVBAT
Open wire fault on VBAT connection. Bit set to 1 when a fault is detected. May be reset via
register write (14’h0000).
OVSS
Open wire fault on VSS connection. Bit set to 1 when a fault is detected. May be reset via
register write (14’h0000).
PAR
Register checksum (Parity) error. This bit is set in response to a register checksum error. The
checksum is calculated and stored in response to a Calc Register Checksum command and
acts on the contents of all page 2 registers. The Check Register Checksum command is
used to repeat the calculation and compare the results to the stored value. The PAR bit is
then set if the two results are not equal. This bit is not set in response to a nonvolatile
EEPROM memory checksum error. See table on page 71.
REF
Voltage reference fault. This bit is set if the voltage reference value is outside its
“power-good” range.
REG
Voltage regulator fault. This bit is set if a voltage regulator value (V3P3, VCC or V2P5) is
outside its “power-good” range.
MUX
Temperature multiplexer error. This bit is set if the VCC loopback check returns a fault. The
VCC loopback check is performed at the end of each temperature scan.
Cell Setup:
Default values are shown below, as are descriptions of each bit.
13
12
11
10
9
8
7
6
5
4
3
2
1
0
FFSN
FFSP
C12
C11
C10
C9
C8
C7
C6
C5
C4
C3
C2
C1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
C1 to C12
Enable/disable cell overvoltage, undervoltage and open wire detection on cell 1 to 12,
respectively. Set to 1 to disable OV/UV and open wire tests.
FFSP
Force ADC input to Full Scale Positive. All cell scan readings forced to 14'h1FFF. All
temperature scan readings forced to 14'h3FFF.
FFSN
Force ADC input to Full Scale Negative. All cell scan readings forced to 14'h2000. All
temperature scan readings forced to 14'h0000.
NOTE: The ADC input functions normally if both FFSN and FFSP are set to '1' but this setting is not supported.
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ACCESS
Read/
Write
PAGE
ADDR
REGISTER
ADDRESS
3’h010
6’h06
DESCRIPTION
Over-temperature Fault:
Over-temperature fault on cells 12 to 1 correspond with bits OF12 to OF1, respectively.
Default values are all zero.
Bits are set to 1 when fault are detected.
The contents of this register may be reset via register write (14’h0000).
13
12
11
10
0
0
0
0
9
8
7
6
5
0
0
0
0
RESERVED
Read Only
3’h010
6’h0F
0
4
3
2
1
0
TFLT4
TFLT3
TFLT2
TFLT1
TFLT0
0
0
0
0
0
TFLT0
Internal over-temperature fault. Bit set to 1 when a fault is detected. May be reset via
register write (14’h0000).
TFLT1 - TFLT4
External over-temperature inputs 1 to 4 (respectively.) Bit set to 1 when a fault is detected.
May be reset via register write (14’h0000).
Read all Fault and Cell Setup data from locations: 6’h00 - 6’h06. See Figure 41D on page 40.
Setup Registers
BASE ADDR
(PAGE)
ADDRESS
RANGE
Access
3’b010
ACCESS
Read/
Write
6’h10 - 6’h1D
and 6’h1F
PAGE
ADDR
REGISTER
ADDRESS
3’b010
6’h10
DESCRIPTION
Device Setup registers. All device setup data.
DESCRIPTION
Overvoltage Limit:
Overvoltage Limit Value
Overvoltage limit is compared to the measured values for cells 1 to 12 to test for an Overvoltage condition at any of
the cells.
Bit 0 is the LSB, Bit 12 is the MSB. Bit 13 is not used and must be set to 0.
13
12
RESER OV12
VED
0
Read/
Write
3’b010
6’h11
1
13
0
3’b010
6’h12
10
9
8
7
6
5
4
3
2
1
0
OV11
OV10
OV9
OV8
OV7
OV6
OV5
OV4
OV3
OV2
OV1
OV0
1
1
1
1
1
1
1
1
1
1
1
1
Undervoltage Limit:
Undervoltage Limit Value
Undervoltage limit is compared to the measured values for cells 1 to 12 to test for an undervoltage condition at any
of the cells.
Bit 0 is the LSB, Bit 12 is the MSB. Bit 13 is not used and must be set to 0.
12
RESER UV12
VED
Read/
Write
11
0
11
10
9
8
7
6
5
4
3
2
1
0
UV11
UV10
UV9
UV8
UV7
UV6
UV5
UV4
UV3
UV2
UV1
UV0
0
0
0
0
0
0
0
0
0
0
0
0
External Temperature Limit:
Over-temperature limit value
Over-temperature limit is compared to the measured values for external temperatures 1 to 4 to test for an
over-temperature condition at any input. The temperature limit assumes NTC temperature measurement devices
(i.e., an over-temperature condition is indicated by a temperature reading below the limit value).
Bit 0 is the LSB, Bit 13 is the MSB.
13
12
11
10
ETL13 ETL12 ETL11 ETL10
0
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66
0
0
0
9
8
7
6
5
4
3
2
1
0
ETL9
ETL8
ETL7
ETL6
ETL5
ETL4
ETL3
ETL2
ETL1
ETL0
0
0
0
0
0
0
0
0
0
0
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ISL94212
ACCESS
Read/
Write
PAGE
ADDR
REGISTER
ADDRESS
3’b010
6’h13
DESCRIPTION
Balance Setup:
Default values are shown below, as are descriptions of each bit.
13
12
11
10
RESERVED
0
0
0
BMD0, 1
0
9
8
7
6
5
BEN
BSP3
BSP2
BSP1
BSP0
0
0
0
0
0
3’b010
6’h14
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0
0
0
0
0
0
Mode
0
0
OFF
0
1
Manual
1
0
Timed
1
1
Auto
BSP0, 1, 2, 3
Balance Status register pointer. Points to one of the 13 incidents of the Balance Status
register. Balance Status register 0 is used for Manual Balance mode and Timed Balance
mode. Balance status registers 1 to 12 are used for Auto Balance mode. Reads and writes
to the Balance Status register are accomplished by first configuring the Balance Status
register pointer (e.g., to read (write) Balance Status register 5, load 0101 to the Balance
Status register pointer, then read (write) to the Balance Status register). See Table 7 on
page 26.
BEN
Balance enable. Set to ‘1’ to enable balancing. ‘0’ inhibits balancing. Setting or clearing this
bit does not affect any other register contents. Balance Enable and Balance Inhibit
commands are provided to allow control of this function without requiring a register write.
These commands have the same effect as setting this bit directly. This bit is cleared
automatically when balancing is complete and the EOB bit (see “6’h19” on page 68) is set.
Balance Status
The Balance Status register is a Multiple Incidence register controlled by the BSP0-4 bits in the Balance Setup
register. See Table 7 on page 26.
Bit 0 is the LSB, Bit 11 is the MSB.
12
11
10
9
8
7
6
5
4
3
2
1
0
RESERVED
BAL
12
BAL
11
BAL
10
BAL
8
BAL
8
BAL
7
BAL
6
BAL
5
BAL
4
BAL
3
BAL
2
BAL
1
0
0
0
0
0
0
0
0
0
0
0
0
0
BAL1 to BAL12
6’h15
1
Balance wait time. Register contents are decoded to provide the required wait time
between device balancing. This is to assist with thermal management and is used with the
Auto Balance mode. See Table 4 on page 25.
0
3’b010
2
BWT0, 1, 2
13
Read/
Write
3
Balance mode. These bits set balance mode.
BMD1 BMD0
Read/
Write
4
BWT2 BWT1 BWT0 BMD1 BMD0
Cell 1 to Cell 12 balance control, respectively. A bit set to 1 enables balance control (turns
FET on) of the corresponding cell. Writing this bit enables balance output for the current
incidence of the Balance Status register for the cells corresponding to the particular bits,
depending on the condition of BEN in the Balance Setup register. Read this bit to determine
the current status of each cell’s balance control.
Watchdog/Balance Time
Defaults are shown below:
13
12
11
10
9
8
BTM6
BTM5
BTM4
BTM3
BTM2
BTM1
0
0
0
0
0
0
67
7
6
5
4
3
2
1
0
BTM0 WDG6 WDG5 WDG4 WDG3 WDG2 WDG1 WDG0
0
1
1
1
1
1
1
1
WDG0 to WDG6
Watchdog timeout setting. Decoded to provide the time out value for the watchdog function.
See “Watchdog Function” on page 43 for details. The watchdog may only be disabled (set
to 7’h00) if the watchdog password is set. The watchdog setting can be changed to a
nonzero value without writing to the watchdog password. See “Device Setup Register” on
page 30. Initialized to 7’h7F (128 minutes).
BTM0 to BTM6
Balance timeout setting. Decoded to provide the time out value for Timed Balance mode
and Auto Balance mode. Initialized to 7’00 (Disabled). See Table 9 on page 27.
FN7938.1
April 23, 2015
ISL94212
PAGE
ADDR
REGISTER
ADDRESS
Read/
Write
3’b010
6’h16
6’h17
User Register
28 bits of register space arranged as 2 x 14 bits available for user data. These registers have no effect on the
operation of the ISL94212. These registers are included in the register checksum function.
Read Only
3’b010
6’h18
Comms Setup
ACCESS
DESCRIPTION
13
Read/
Write
3’b010
6’h19
12
11
0
6’h1B
6’h1C
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6
5
4
SIZE
2
SIZE
1
SIZE
0
0
0
0
0
3
2
1
0
ADDR ADDR ADDR ADDR
3
2
1
0
0
0
0
0
ADDR0-3
Device stack address. The stack address (device position in the stack) is determined
automatically by the device in response to an “Identify” command. The resulting address is
stored in ADDR0-3 and is used internally for communications paring and sequencing. The
stack address may be read by the user but not written to.
SIZE0-3
Device stack size (top stack device address). Corresponds to the number of devices in the
stack. The stack size is determined automatically by the stack devices in response to an
“Identify” command. The resulting number is stored in SIZE0-3 and is used internally for
communications paring and sequencing. The stack size may be read by the user but not
written to.
CSEL1, 2
Communications setup bits. These bits reflect the state of the COMMS SELECT 1,2 pins and
determine the operating mode of the communications ports. See Table 15 on page 31.
CRAT0, 1
Communications rate bits. These bits reflect the state of the COMMS RATE 0,1 pins and
determine the bit rate of the Daisy Chain communications system. Table 17 on page 34.
Device Setup
13
12
11
10
9
8
WP5
WP4
WP3
WP2
WP1
WP0
0
0
0
0
0
0
7
6
BDDS RESER
VED
0
0
5
4
3
ISCN
SCAN
EOB
0
0
0
2
1
0
RESER PIN37 PIN39
VED
0
Pin
Pin
These bits indicate the signal level on pin 37 and pin 39 of the device.
End Of Balance. This bit is set by the device when balancing is complete. This function is
used in the Timed Balance mode and Auto Balance mode. The BEN bit is cleared as a result
of this bit being set. Initialized to 1.
SCAN
Scan Continuous mode. This bit is set in response to a Scan Continuous command and
cleared by a Scan Inhibit command.
ISCN
Set wire scan current source/sink values. Set to 0 for 150µA. Set to 1 for 1mA.
BDDS
Balance condition during measurement. Controls the balance condition in Scan Continuous
mode and Auto Balance mode. Set to 1 to have balancing functions turned off 10ms prior
to and during cell voltage measurement. Set to 0 for normal operation (balancing functions
not affected by measurement).
WP5:0
Watchdog disable password. These bits must be set to 6’h3A (111010) before the
watchdog can be disabled. Disable watchdog by writing 7’h00 to the watchdog bits.
Internal Temperature Limit
Bit 0 is the LSB, Bit 13 is the MSB.
13
12
11
10
9
8
7
6
5
4
3
2
1
0
ITL
13
ITL
12
ITL
11
ITL
10
ITL
8
ITL
8
ITL
7
ITL
6
ITL
5
ITL
4
ITL
3
ITL
2
ITL
1
ITL
0
NV
NV
NV
NV
NV
NV
NV
NV
NV
NV
NV
NV
NV
ITL1 to ITL12
3’b010
7
SIZE
3
COMS COMS COMS COMS
RATE1 RATE0 SEL2 SEL1
pin
pin
pin
pin
NV
Read Only
8
CSEL
1
0
EOB
6’h1A
9
CSEL
2
CRAT1 CRAT0
PIN37, PIN39
Read Only 3’b010
Value set in
EEPROM
10
RESERVED
IC over-temperature limit value. Over-temperature limit is compared to the measured
values for internal IC temperature to test for an over-temperature condition. The internal
temperature limit value is stored in nonvolatile memory during test and loaded to these
register bits at power-up. The register contents may be read by the user but not written to.
Serial Number
The 28b serial number programmed in nonvolatile memory during factory test is mirrored to these 2 x 14 bit
registers. The serial number may be read at any time but may not be written.
68
FN7938.1
April 23, 2015
ISL94212
ACCESS
PAGE
ADDR
REGISTER
ADDRESS
Read Only 3’b010
Value set in
EEPROM
6’h1D
DESCRIPTION
Trim Voltages
13
12
11
10
9
8
TV5
TV4
TV3
TV2
TV1
TV0
RESERVED
NV
NV
NV
NV
NV
NV
Ignore the Contents of these bits
TV5:0
Read Only
3’h010
6’h1F
7
6
5
4
3
2
1
0
Trim voltage (VNOM). The nominal cell voltage is programmed to nonvolatile memory during
test and loaded to the Trim Voltage register at power up. The VNOM value is a 7-bit
representation of the 0V to 5V cell voltage input range with 50 (7’h32) representing 5V (e.g.,
LSB = 0.1V). The parts are additionally marked with the trim voltage by the addition of a two
digit code to the part number e.g., 3.3V is denoted by the code 33. (1 bit per 0.1V of trim
voltage, so 0 to 50 decimal covers the full range.)
Read all setup data from locations: 6’h10 - 6’h1D. See Figure 41D on page 40.
Cell Balance Registers
BASE ADDR
(PAGE)
3’b010
ACCESS
Read/
Write
ADDRESS
RANGE
ACCESS
Read/
Write
6’h20 - 6’h37
DESCRIPTION
Cell balance registers. These registers are loaded with data related to change in SOC desired for each cell.
This data is then used during Auto Balance mode. The data value is decremented with each successive ADC
sample until a zero value is reached. The register space is arranged as 2 x 14-bit per cell for 24 x 14-bit
total. The registers are cleared at device power up or by a Reset command. See “Auto Balance Mode” on
page 27.
PAGE
ADDR
REGISTER
ADDRESS
3’b010
6’h20
Cell 1 balance value bits 0 to 13.
6’h21
Cell 1 balance value bits 14 to 27.
DESCRIPTION
~
6’h36
Cell 12 balance value bits 0 to 13.
6’h37
Cell 12 balance value bits 14 to 27.
Reference Coefficient Registers
BASE ADDR
(PAGE)
3’b010
ACCESS
Read Only
Value set in
EEPROM
ADDRESS
RANGE
ACCESS
Read
Only
6’h38 - 6’h3A
PAGE
ADDR
REGISTER
ADDRESS
3’b010
6’h38
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DESCRIPTION
Reference Coefficients.
Bit 13 is the MSB, Bit 0 is the LSB
DESCRIPTION
Reference Coefficient C
Reference calibration coefficient C LSB. Use with coefficients A and B and the measured reference value to obtain
the compensated reference measurement. This result may be compared to limits given in the “Electrical
Specifications” table beginning on page 7 to check that the reference is within limits. The register contents may be
read by the user but not written to.
69
13
12
11
10
9
8
7
6
5
4
3
2
1
0
RCC
13
RCC
12
RCC
11
RCC
10
RCC
9
RCC
8
RCC
7
RCC
6
RCC
5
RCC
4
RCC
3
RCC
2
RCC
1
RCC
0
NV
NV
NV
NV
NV
NV
NV
NV
NV
NV
NV
NV
NV
NV
FN7938.1
April 23, 2015
ISL94212
ACCESS
PAGE
ADDR
REGISTER
ADDRESS
Read Only
3’b010
6’h39
Read Only
3’b010
DESCRIPTION
Reference Coefficient B
Reference calibration coefficient B LSB. Use with coefficients A and C and the measured reference value to obtain
the compensated reference measurement. This result may be compared to limits given in the “Electrical
Specifications” table beginning on page 7 to check that the reference is within limits. The register contents may be
read by the user but not written to.
6’h3A
13
12
11
10
9
8
7
6
5
4
3
2
1
0
RCB
13
RCB
12
RCB
11
RCB
10
RCB
9
RCB
8
RCB
7
RCB
6
RCB
5
RCB
4
RCB
3
RCB
2
RCB
1
RCB
0
NV
NV
NV
NV
NV
NV
NV
NV
NV
NV
NV
NV
NV
NV
Reference Coefficient A
Reference calibration coefficient A LSB. Use with coefficients B and C and the measured reference value to obtain
the compensated reference measurement. This result may be compared to limits given in the “Electrical
Specifications” table beginning on page 7 to check that the reference is within limits. The register contents may be
read by the user but not written to.
13
12
11
10
9
8
7
6
5
RCA
8
RCA
7
RCA
6
RCA
5
RCA
4
RCA
3
RCA
2
RCA
1
RCA
0
4
3
RESERVED
2
1
0
NV
NV
NV
NV
NV
NV
NV
NV
NV
Ignore the content of these bits
Cells In Balance Register
BASE ADDR
(PAGE)
3’b010
ADDRESS
RANGE
ACCESS
Read
Only
6’h3B
ACCESS
PAGE
ADDR
REGISTER
ADDRESS
Read Only
3’b010
6’h3B
DESCRIPTION
Cells In balance (valid for non-daisy chain configuration only).
DESCRIPTION
Cells Balance Enabled
This register reports the current condition of the cell balance outputs.
Bit 0 is the LSB, Bit 11 is the MSB.
13
12
RESERVED
0
0
11
10
9
8
7
6
5
4
3
2
1
0
CBEN
12
CBEN
11
CBEN
10
CBEN
8
CBEN
8
CBEN
7
CBEN
6
CBEN
5
CBEN
4
CBEN
3
CBEN
2
CBEN
1
0
0
0
0
0
0
0
0
0
0
0
0
BALI1 to BALI12
Indicates the current balancing status of cell 1 to cell 12 (respectively). “1” indicates
balancing is enabled for this cell. “0” indicates that balancing is turned off.
Device Commands
BASE ADDR
(PAGE)
3’b011
ACCESS
Read
Only
Submit Document Feedback
ADDRESS
RANGE
6’h01 - 6’h14
70
DESCRIPTION
Device commands. Actions and communications administration. Not physical registers but memory
mapped device commands. Commands from host and device responses are all configured as reads (BASE
ADDR MSB = 0).
Write operations breaks the communication rules and produce NAK from the target device.
FN7938.1
April 23, 2015
ISL94212
PAGE
ADDR
REGISTER
ADDRESS
3’b011
6’h01
Scan Voltages. Device responds by scanning VBAT and all 12 cell voltages and storing the results in local memory.
6’h02
Scan Temperatures. Device responds by scanning external temperature inputs, internal temperature, and the secondary
voltage reference, and storing the results in local memory.
6’h03
Scan Mixed. Device responds by scanning VBAT, cell and ExT1 voltages and storing the results in local memory. The ExT1
measurement is performed in the middle of the cell voltage scans to minimize measurement latency between the cell
voltages and the voltage on ExT1.
6’h04
Scan Wires. Device responds by scanning for pin connection faults and stores the results in local memory.
6’h05
Scan All. Device responds by performing the functions of the Scan Voltages, Scan Temperatures, and Scan Wires commands
in sequence. Results are stored in local memory
BASE ADDR
(PAGE)
DESCRIPTION
6’h06
Scan Continuous. Places the device in Scan Continuous mode by setting the Device Setup register SCAN bit.
6’h07
Scan Inhibit. Stops Scan Continuous mode by clearing the Device Setup register SCAN bit.
6’h08
Measure. Device responds by measuring a targeted single parameter (cell voltage/VBAT/external or internal temperatures
or secondary voltage reference).
6’h09
Identify. Special mode function used to determine device stack position and address. Devices record their own stack address
and the total number of devices in the stack. See “Identify” on page 40 for details.
6’h0A
Sleep. Places the part in Sleep mode (wakeup via daisy comms). See “Sleep Mode” on page 50.
6’h0B
NAK. Device response if communications is not recognized. The device responds NAK down the Daisy Chain to the host
microcontroller. The host microcontroller typically retransmits on receiving a NAK.
6’h0C
ACK. Used by host microcontroller to verify communications without changing anything. Devices respond with ACK.
6’h0E
Comms Failure. Used in daisy chain implementations to communicate comms failure. If a communication is not
acknowledged by a stack device, the last stack device that did receive the communication responds with Comms Failure.
This is part of the communications integrity checking. Devices downstream of a communications fault are alerted to the fault
condition by the watchdog function.
6’h0F
Wakeup. Used in daisy chain implementations to wakeup a sleeping stack of devices. The Wakeup command is sent to the
Bottom stack device (Master device) via SPI. The Master device then wakes up the rest of the stack by transmitting a low
frequency clock. The Top stack device responds ACK once it is awake. See “Wakeup” on page 50.
6’h10
Balance Enable. Enables cell balancing by setting BEN. May be used to enable cell balancing on all devices simultaneously
using the address All Stack Address 1111.
6’h11
Balance Inhibit. Disables cell balancing by clearing BEN. May be used to disable cell balancing on all devices simultaneously
using the address All Stack Address 1111.
6’h12
Reset. Resets all digital registers to its power-up state (i.e., reloads the factory programmed configuration data from
non-volatile memory. Stops all scan and balancing activity. Daisy chain devices must be reset in sequence starting with the
Top stack device and proceeding down the stack to the Bottom (Master) device. The Reset command must be followed by an
Identify command (Daisy chain configuration) before volatile registers can be re-written.
6’h13
Calculate register checksum. Calculates the checksum value for the current Page 2 register contents (registers with base
address 0010). See “System Registers” on page 62.
6’h14
Check register checksum. Verifies the register contents are correct for the current checksum. An incorrect result sets the PAR
bit in the Fault status register, which starts a standard fault response. See “System Registers” on page 62.
ACCESS
ADDRESS
RANGE
DESCRIPTION
100
Read
Only
6’h3F
Nonvolatile memory Multiple Input Shift Register (MISR) register. This checksum value for the nonvolatile
memory contents. It is programmed during factory testing at Intersil.
101
Read
Only
6’h00
MISR shadow register checksum value. This value is calculated when shadow registers are loaded from
nonvolatile memory either after a power cycle or a reset.
Nonvolatile Memory (EEPROM) Checksum
A checksum is provided to verify the contents of EEPROM
memory. Two registers are provided. One contains the correct
checksum value, which is calculated during factory testing at
Intersil. The other contains the checksum value that is calculated
each time the non volatile memory is loaded to shadow registers,
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71
either after a power cycle or after a device reset. Also refer to
“Memory Checksum” on page 45.
FN7938.1
April 23, 2015
ISL94212
Applications Circuits Information
Typical Applications Circuits
Typical applications circuits are shown in Figures 50 to 53.
Table 48 on page 77 contains recommended component values.
All external (off-board) inputs to the ISL94212 are protected
against battery voltage transients by RC filters, they also provide
a current limit function during hot plug events. The ISL94212 is
calibrated for use with 1kΩ series protection resistors at the cell
inputs. VBAT uses a lower value resistor to accommodate the
VBAT supply current of the ISL94212. A value of 27Ω is used for
this component. As much as possible, the time constant
produced by the filtering applied to VBAT should be matched to
that applied to the cell 12 monitoring input. Component values
given in Table 48 produce the required matching characteristics.
Figure 50 on page 73 shows the standard arrangement for
connecting the ISL94212 to a stack of 12 cells. The cell input
filter is designed to maximize EMI suppression. These
components should be placed close to the connector with a well
controlled ground to minimize noise for the measurement inputs.
The balance circuits shown in Figure 50 provide normal cell
monitoring when the balance circuit is turned off, and a near zero
cell voltage reading when the balance circuit is turned on. This is
part of the diagnostic function of the ISL94212.
Figure 51 on page 74 shows connections for the daisy chain
system, setup pins, power supply and external voltage inputs for
daisy chain devices other than the Master (stack bottom) device.
The remaining circuits are discussed in more detail later in this
datasheet.
Figure 52 on page 75 shows the daisy chain system, setup pins,
microcontroller interface, power supply and external voltage
inputs for the daisy chain master device. Figure 52 is also
applicable to standalone (non-daisy chain) devices although in
this case the daisy chain components connected to DHi2 and
DLo2 would be omitted.
Figure 53 on page 76 shows an alternate arrangement for the
battery connections in which the cell input circuits are connected
directly to the battery terminal and not via the balance resistor. In
this condition the balance diagnostic function capability is
removed.
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FN7938.1
April 23, 2015
ISL94212
Typical Application Circuits
P la c e th e s e
c o m p o n e n ts
c lo s e to
c o n n e c to r
Pack
V o lta g e
B 12b
R1
C1
D1
58
59
B 12
R2
Q1
B 11
B 10
R 28
C27
R 31
R 33
R36
R 37
C 31
R 40
B7
Q6
C 32
R 43
Q7
C 33
R 46
B5
Q8
C 34
R 49
B4
Q9
C 35
R 52
B3
C 36
R 55
C7
6
7
C8
8
9
C9
R50
10
11
C 10
R53
R11
R54
4
5
R47
R 10
R51
C6
R44
R9
R48
2
3
R 41
R8
B6
R45
C5
R 38
R7
R42
1
R 5a
R6
Q5
64
R 5b
C 30
B8
R39
C4
R 34
C 29
62
63
R4
B9
Q4
C3
R 30
R 32
Q3
R35
61
R3
C 28
60
R 27
R 29
Q2
C2
12
13
C 11
R56
14
15
Q 10
B2
R12
R57
Q 11
C 37
R 58
R59
R13
B1
C 12
16
17
C 13
18
R60
Q 12
C 38
B0
R 61
R62
R71
19
C 39
20
21
B 0b
22
V B AT
V B AT
IS L 9 4 2 1 2
VC12
CB12
VC11
CB11
VC10
CB10
VC9
CB9
VC8
CB8
ISL94212
VC7
CB7
VC6
CB6
VC5
CB5
VC4
CB4
VC3
CB3
VC2
CB2
VC1
CB1
VC0
VSS
VSS
FIGURE 50. BATTERY CONNECTION CIRCUITS
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FN7938.1
April 23, 2015
ISL94212
Typical Application Circuits (Continued)
Place these
components
close to
device
ISL94212
ISL94212
DHI2
56
Place these
components
close to
connector
R63
R65
C44
DAISY UP HI
R66
C45
DAISY UP LO
R69
C51
DAISY DN HI
R70
C52
DAISY DN LO
C42
DLO2
DHI1
55
R64
53
R67
C43
C49
DLO1
COMMS RATE 0
COMMS RATE 1
COMMS SELECT 1
COMMS SELECT 2
EN
52
R68
C50
43
42
Connect Pins 40 – 43 to V3P3 or VSS
Depending on Comms Selection
and Daisy Chain clock speed
41
40
Connect Pin 47 to V3P3 to Enable
Connect Pin 47 to VSS to Disable
47
Pack
Voltage
DGND
V2P5
44
R81
35
C53
C55
V3P3
BASE
V3P3
VCC
REF
38
Q13
36
R82
34
C54
33
C56
C57
TEMPREG
EXT4
EXT3
EXT2
EXT1
R83
29
R84
R85 R86
30
R87
EXT IN 4
28
R90
EXT IN 3
26
R93
EXT IN 2
24
R96
EXT IN 1
C58
C59
C60 C61
R100
EXT return (x4)
FIGURE 51. NON BATTERY CONNECTIONS, MIDDLE AND TOP DAISY CHAIN DEVICES
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FN7938.1
April 23, 2015
ISL94212
Typical Application Circuits (Continued)
Place these
components
close to
device
ISL94212
ISL94212
DHI2
56
Place these
components
close to
connector
R63
R65
C44
DAISY UP HI
R66
C45
DAISY UP LO
C42
DLO2
COMMS RATE 0
COMMS RATE 1
COMMS SELECT 1
COMMS SELECT 2
SCLK
CS
DIN
DOUT
EN
DATA READY
FAULT
55
R64
C43
43
42
Connect Pins 40 – 43 to V3P3 or VSS
Depending on Comms Selection
and Daisy Chain clock speed
41
40
Connect Pin 47 to V3P3 to Enable
Connect Pin 47 to VSS to Disable
53
52
50
Microcontroller
Interface
49
47
46
45
Pack
Voltage
DGND
V2P5
44
R81
35
C53
C55
V3P3
BASE
V3P3
VCC
REF
38
Q13
36
R82
34
C54
33
C56
C57
TEMPREG
EXT4
EXT3
EXT2
EXT1
R83 R84 R85 R86
29
30
R87
EXT IN 4
28
R90
EXT IN 3
26
R93
EXT IN 2
24
R96
EXT IN 1
C58 C59 C60 C61
R100
EXT return (x4)
FIGURE 52. NON BATTERY CONNECTIONS, MASTER DAISY CHAIN DEVICE
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FN7938.1
April 23, 2015
ISL94212
Typical Application Circuits (Continued)
Place these
components
close to
connector
Pack
Voltage
B12b
R1
C1
D1
58
59
B12
C27
R27
R29
C28
R30
R32
C29
R33
C3
R4
R35
R5
62
63
C4
R34
Q3
B9
R3
60
61
R31
Q2
B10
C2
R28
Q1
B11
R2
64
1
C5
2
VBAT
VBAT
ISL94212
ISL94212
VC12
CB12
VC11
CB11
VC10
CB10
VC9
R36
Q4
C30
R37
B8
R38
R6
3
C6
4
CB9
VC8
ISL94212
R39
Q5
C31
R40
B7
R41
R7
5
C7
6
CB8
VC7
R42
Q6
C32
R43
R44
R8
B6
7
C8
8
CB7
VC6
R45
Q7
C33
R46
B5
R47
R9
9
C9
10
CB6
VC5
R48
Q8
C34
R49
B4
R50
R10
11
C10
12
CB5
VC4
R51
Q9
C35
R52
B3
R53
R11
13
C11
14
CB4
VC3
R54
Q10
C36
R55
B2
R56
R12
15
C12
16
CB3
VC2
R57
Q11
C37
R58
R59
R13
B1
17
C13
18
CB2
VC1
R60
Q12
B0
C38
R61
R62
R71
19
C39
20
21
B0b
22
CB1
VC0
VSS
VSS
FIGURE 53. BATTERY CONNECTION CIRCUITS ALTERNATIVE CONFIGURATION
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April 23, 2015
ISL94212
Notes on Board Layout
TABLE 48. RECOMMENDED COMPONENT VALUES FOR FIGURES (Figures 50 to 53)
RESISTORS
VALUE
COMPONENTS
0
R101
27
R1
33
R82
1k
R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R71
100
R29, R32, R35, R36, R39, R42, R45, R48, R51, R54, R57, R60, R63, R64, R67, R68, R81
2k
R5a, R5b
470
R65, R66, R69, R70
10k
R28, R31, R34, R38, R41, R44, R47, R50, R53, R56, R59, R62, R83, R84, R85, R86, R87, R90, R93,
R96, R100a, R100b, R100c, R100d
330k
R27, R30, R33, R37, R40, R43, R46, R49, R52, R55, R58, R61
CAPACITORS
VALUE
VOLTAGE
COMPONENTS
200p
100
C42, C43, C49, C50
220p
500
C44, C45, C51, C52
10n
50
C27, C28, C29, C30, C31, C32, C33, C34, C35, C36, C37, C38, C58, C59, C60, C61
22n
100
C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C39
220n
100
C1
1µ
10
C53, C54, C56
1µ
100
C55
2.2µ
10
C57
ZENER DIODES
VALUE
EXAMPLE
60V
1N5371BRLG
COMPONENTS
D1
Referring to Figure 50 on page 73 (battery connection circuits),
the basic input filter structure comprises resistors R2 to R13, R71
and capacitors C2 to C13, C39. These components provide
protection against transients and EMI for the cell inputs. They
carry the loop currents produced by EMI and should be placed as
close to the connector as possible. The ground terminals of the
capacitors must be connected directly to a solid ground plane. Do
not use vias to connect these capacitors to the input signal path
or to ground. Any vias should be placed in line to the signal inputs
so that the inductance of these forms a low pass filter with the
grounded capacitors.
Referring to Figure 51 on page 74, the daisy chain components
are shown to the top right of the drawing. These are split into two
sections. Components to the right of this section should be
placed close to the board connector with the ground terminals of
capacitors connected directly to a solid ground plane. This is the
same ground plane that serves the cell inputs. Components to
the left of this section should be placed as closely to the device
as possible.
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The battery connector and daisy chain connectors should be
placed closely to each other on the same edge of the board to
minimize any loop current area.
Two grounds are identified on the circuit diagram. These are
nominally referred to as noisy and quiet grounds. The noisy
ground, denoted by an “earth” symbol carries the EMI loop
currents and digital ground currents while the quiet ground is
used to define the decoupling voltage for voltage reference and
the analog power supply rail. The quiet and noisy grounds should
be joined at the VSS pin. Keep the quiet ground area as small as
possible.
The circuits shown to the bottom right of Figure 51 on page 74
provide signal conditioning and EMI protection for the external
temperature inputs. These inputs are designed to operate with
external NTC thermistors. See “External Inputs” on page 85 for
more information about component selection.
FN7938.1
April 23, 2015
ISL94212
Component Selection
Certain failures associated with external components can lead to
unsafe conditions in electronic modules. A good example of this
is a component that is connected between high energy signal
sources failing short. Such a condition can easily lead to the
component overheating and damaging the board and other
components in its proximity.
One area to consider with the external circuits on the ISL94212 is
the capacitors connected to the cell monitoring inputs. These
capacitors are normally protected by the series protection
resistors but could present a safety hazard in the event of a dual
point fault where both the capacitor and associated series
resistor fail short. Also, a short in one of these capacitors would
dissipate the charge in the battery cell if left uncorrected for an
extended period of time. It is recommended that capacitors C1 to
C13 be selected to be “fail safe” or “open mode” types. An
alternative strategy would be to replace each of these capacitors
with two devices in series, each with double the value of the
single capacitor.
A dual point failure in the balancing resistor (R29, R32, R35, etc.)
of Figure 50 on page 73 and associated balancing MOSFET (Q1
to Q12) could also give rise to a shorted cell condition. It is
recommended that the balancing resistor be replaced by two
resistors in series.
Operating the ISL94212 with Reduced Cell
Counts
When using the ISL94212 with fewer than 12 cells it is important
to ensure that each used cell has a normal input circuit
connection to the top and bottom monitoring inputs for that cell.
The simplest way to use the ISL94212 with any number of cells is
to always use the full input circuit arrangement for all inputs, and
short together the unused inputs at the battery terminal. In this
way each cell input sees a normal source impedance
independent of whether or not it is monitoring a cell.
The cell balancing components associated with unconnected cell
inputs are not required and can be removed. Unused cell balance
outputs should be tied to the adjacent cell voltage monitoring
pin.
The input circuit component count can be reduced in cases
where fewer than 10 cells are being monitored. It is important
that cell inputs that are being used are not connected to other
(unused) cell inputs as this would affect measurement accuracy.
Figure 54 on page 79, Figure 55 on page 80, and Figure 56 on
page 81 show examples of systems with 10 cells, 8 cells, and 6
cells, respectively.
The component notations and values used in Figures 55 and 56
are the same as those used in Figures 50 to 53.
In Figure 56 the resistor associated with the input filter on VC9 is
noted as R5, rather than R5a. This value change is needed to
maintain the correct input network impedance in the absence of
the cell 9 balance circuits.
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FN7938.1
April 23, 2015
ISL94212
Typical Application Circuits
Place these
components
close to
connector
Pack
Voltage
B10b
R1
C1
D1
58
59
B10
R2
Q1
B9
C2
R28
C27
61
R27
R29
R3
C3
R31
Q2
B8
R32
Q3
B7
C28
62
63
R30
R4
C4
R34
C29
60
64
C30
C5
R38
R37
B6
ISL94212
VC12
CB12
VC11
CB11
VC10
CB10
R5
2
R36
Q4
VBAT
1
R33
R35
VBAT
R6
3
C6
4
VC9
CB9
VC8
R39
C31
Q5
R40
R41
R7
5
C7
6
7
R8
C8
8
9
B5
R9
R48
Q8
C9
R50
C34
10
VC7
ISL94212
CB7
VC6
CB6
VC5
11
R49
B4
CB8
CB5
R10
C10
12
VC4
R51
Q9
C35
R52
B3
R53
R11
R54
Q10
C11
14
CB4
VC3
R56
C36
15
R55
B2
R12
R57
Q11
13
C12
16
CB3
VC2
R59
C37
R58
17
R13
B1
C13
18
CB2
VC1
R60
Q12
B0
C38
R61
R62
R71
B0b
19
C39
20
21
22
CB1
VC0
VSS
VSS
FIGURE 54. BATTERY CONNECTION CIRCUITS, SYSTEM WITH 10 CELLS
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FN7938.1
April 23, 2015
ISL94212
Typical Application Circuits (Continued)
Place these
components
close to
connector
Pack
Voltage
B8b
R1
C1
D1
58
59
B8
R2
Q1
B7
C2
R28
C27
61
R27
R29
R3
C3
R31
B6
Q2
R32
Q3
B5
C28
62
63
R30
R4
C4
R34
C29
60
64
C30
ISL94212
VC12
CB12
VC11
CB11
VC10
CB10
R5
C5
2
R36
Q4
VBAT
1
R33
R35
VBAT
R38
R37
R6
3
C6
4
5
6
7
R9
C9
8
9
10
VC9
CB9
VC8
CB8
VC7
ISL94212
CB7
VC6
CB6
VC5
11
CB5
B4
R10
C10
12
VC4
R51
Q9
C35
R52
B3
R53
R11
C36
14
15
R55
B2
R12
R57
Q11
C11
CB4
VC3
R56
R54
Q10
13
C12
16
CB3
VC2
R59
C37
17
R58
R13
B1
C13
18
CB2
VC1
R60
Q12
B0
C38
R61
R71
B0b
19
R62
C39
20
21
22
CB1
VC0
VSS
VSS
FIGURE 55. BATTERY CONNECTION CIRCUITS, SYSTEM WITH 8 CELLS
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FN7938.1
April 23, 2015
ISL94212
Typical Application Circuits (Continued)
Place these
components
close to
connector
Pack
Voltage
B6b
R1
C1
D1
58
59
B6
R2
Q1
B5
C2
R28
C27
61
R27
R29
R3
C3
R31
Q2
B4
R32
Q3
C28
62
63
R30
R4
C4
R34
C29
60
64
VBAT
ISL94212
VC12
CB12
VC11
CB11
VC10
1
CB10
R33
R35
VBAT
R5
C5
R38
2
3
4
5
6
7
R10
C10
8
9
10
VC9
CB9
VC8
CB8
VC7
ISL94212
CB7
VC6
CB6
VC5
11
CB5
12
13
B3
R11
C36
15
R55
B2
R12
R57
Q11
14
CB4
VC3
R56
R54
Q10
C11
VC4
C12
16
CB3
VC2
R59
C37
17
R58
R13
B1
C13
18
CB2
VC1
R60
Q12
B0
C38
R61
R62
R71
B0b
19
C39
20
21
22
CB1
VC0
VSS
VSS
FIGURE 56. BATTERY CONNECTION CIRCUITS, SYSTEM WITH 6 CELLS
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FN7938.1
April 23, 2015
ISL94212
PACK
VOLTAGE
ISL94212
ISL78600
ISL78610
R1
Q1
BASE
C1
V3P3
R2
VCC
C2
C3
D1
VDDEXT
C4
TO EXTERNAL
CIRCUITS
COMPONENT
VALUE
R1
Note 18
R2
33Ω
C1
Note 19
C2
1μF
C3
1μF
C4
1μF
Q1
Note 20
NOTES:
18. R1 should be sized to pass the maximum supply current at the minimum specified battery pack voltage.
19. C1 should be selected to produce a time constant with R1 of a few milliseconds. C1 and R1 provide transient protection for the collector of Q1.
Component values and voltage ratings should be obtained through simulation of measurement of the worst case transient expected on VBAT.
20. Q1 should be selected for power dissipation at the maximum specified battery voltage and load current. The load current includes the V3P3 and
VCC currents for the ISL94212 and the maximum current drawn by external circuits supplied via VDDEXT. The voltage rating should be
determined as described in Note 19.
FIGURE 57. ISL94212 REGULATOR AND EXTERNAL CIRCUIT SUPPLY ARRANGEMENT
Power Supplies
The two VBAT pins, along with V3P3, VCC and VDDEXT are used
to supply power to the ISL94212. Power for the high voltage
circuits and Sleep mode internal regulators is provided via the
VBAT pins. V3P3 is used to supply the logic circuits and VCC is
similarly used to supply the low voltage analog circuits. The V3P3
and VCC pins must not be connected to external circuits other
than those associated with the ISL94212 main voltage regulator.
The VDDEXT pin is provided for use with external circuits.
The ISL94212 main low voltage regulator uses an external NPN
pass transistor to supply 3.3V power for the V3P3 and VCC pins.
This regulator is enabled whenever the ISL94212 is in Normal
mode and may also be used to power external circuits via the
VDDEXT pin. An internal switch connects the VDDEXT pin to the
V3P3 pin. Both the main regulator and the switch are off when
the part is placed in Sleep mode or Shutdown mode (EN pin
LOW.) The pass transistor’s base is connected to the ISL94212
BASE pin. A suitable configuration for the external components
associated with the V3P3, VCC and VDDEXT pins is shown in
Figure 57. The external pass transistor is required. Do not allow
this pin to float.
Voltage Reference Bypass Capacitor
A bypass capacitor is required between REF (pin 33) and the
analog ground VSS. The total value of this capacitor should be in
the range 2.0µF to 2.5µF. Use X7R type dielectric capacitors for
this function. The ISL94212 continuously performs a power-good
check on the REF pin voltage starting 20ms after a power-up,
enable or wakeup condition. If the REF capacitor is too large,
then the reference voltage may not reach its target voltage range
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82
before the Power-good check starts and result in a REF Fault. If
the capacitor is too small, then it may lead to inaccurate voltage
readings.
Cell Balancing Circuits
The ISL94212 uses external MOSFETs for the cell balancing
function. The gate drive for these is derived from on-chip current
sources on the ISL94212, which are 25µA nominally. The current
sources are turned on and off as needed to control the external
MOSFET devices. The current sources are turned off when the
device is in Shutdown mode or in Sleep mode. The ISL94212
uses a mix of N-channel and P-channel MOSFETs for the external
balancing function. The top three cell locations, cell 10, 11, 12
are configured to use P-channel MOSFETs while the remaining
cell locations, cell 1 through 9, use N-channel MOSFETs.
Figure 58 shows the circuit detail for one cell balancing system
with typical component values. An N-channel MOSFET (cell
locations 1 through 9) is shown. The gate of the external FET is
normally protected against excessive voltages during cell voltage
transients by the action of the parasitic Cgs and Cgd
capacitances. These momentarily turn on the FET in the event of
a large transient, thus limiting the Vgs values to reasonable
levels. A 10nF capacitor is included between the MOSFET gate
and source terminals to protect against EMI effects. This
capacitor provides a low impedance path to ground at high
frequencies and prevents the MOSFET turning on in response to
high frequency interference.
The external component values should be chosen to prevent the
9V clamp at the output from the ISL94212 from activating.
FN7938.1
April 23, 2015
ISL94212
Cell Voltage Measurements During Balancing
The standard cell balancing circuit (Figure 50 on page 73 and
Figure 58 on page 84) is configured so that the cell
measurement is taken from the drain connection of the
balancing MOSFET. When balancing is enabled for a cell, the
resulting cell measurement is then the voltage across the
balancing MOSFET (VGS voltage). This system provides the
diagnostic for the cell balancing function. The input voltage of the
cell adjacent to the MOSFET drain connection is also affected by
this mechanism: the input voltage for this cell increases by the
same amount that the voltage of the balance cell decreases.
For example, if cell 2 and cell 3 are both at 3.6V and balancing is
enabled for cell 2, then the voltage across the balancing MOSFET
may be only 50mV. In this case, cell 2 would read 50mV and cell
3 would read 7.15V. The cell 3 value in this case is outside the
measurement range of the cell input. Cell 3 would then read full
scale voltage, which is 4.9994V. This full scale voltage reading
will occur if the sum of the voltages on the two adjacent cells is
greater than the total of 5V plus the “balancing on” voltage of the
balanced cell. Table 49 shows the cell affected when each cell is
balanced.
TABLE 49. CELL READINGS DURING BALANCING
CELL BALANCED
CELL WITH LOW
READING
CELL WITH HIGH READING
1
1
2
2
2
3
3
3
4
4
4
5
5
5
6
6
6
7
7
7
8
8
8
9
9
9*
10*
10
10*
9*
11
11
10
12
12
11
NOTE: *cells 9 and 10 produce a different result from the other cells.
Cell 9 uses an N-channel MOSFET while cell 10 uses a P-channel MOSFET.
The circuit arrangement used with these devices produces approximately
half the normal cell voltage when balancing is enabled. The adjacent cell
then sees an increase of half the voltage of the balanced cell.
The voltage measurement behavior outlined above is modified by
impedances in the cell connector and any associated wiring. The
balance current passes through the connections at the top and
bottom of the balanced cell. This effect further reduces the
measured voltage on the balanced cell and also increase the
voltage measured on cells above and below the balanced cell.
For example, if cell 4 is balanced with 100mA and the total
impedance of the connector and wiring for each cell connection
is 0.1Ω, then cell 4 would read low by an additional 20mV (10mV
due to each connection) while cells 3 and 5 would both read high
by 10mV.
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Balancing with Scan Continuous Mode
Enabled
Cell balancing may be active while the ISL94212 is operating in
Scan Continuous mode. In Scan Continuous mode the ISL94212
scans cell voltages, temperatures and open wire conditions at a
rate determined by the Scan Interval bits in the Fault Setup
register. (See Table 2 on page 23). The behavior of the balancing
functions while operating in Scan Continuous mode is controlled
by the BDDS bit in the Device Setup register. If BDDS is set, then
cell balancing is inhibited during cell voltage measurements and
for 10ms before the cell voltage scan to allow the balance
devices to turn off. Balancing is reenabled at the end of the scan
and then balancing continues.
Daisy Chain Communications System
The ISL94212 daisy chain communications system uses
differential, AC-coupled signaling. The external circuit
arrangement is symmetrical to provide a bidirectional
communications function. The performance of the system under
transient voltage and EMI conditions is enhanced by the use of a
capacitive load. A schematic of the daisy chain circuit is shown in
Figure 59.
The basic circuit elements are the series resistor and capacitor
elements R1 and C1, which provide the transient current limit
and AC coupling functions, and the line termination components
C2, which provide the capacitive load. Capacitors C1 and C2
should be located as closely as possible to the board connector.
The AC coupling capacitors C1 need to be rated for the maximum
voltage, including transients, that will be applied to the interface.
Specific component values are needed for correct operation with
each daisy chain data rate and are given in Table 50.
The daisy chain operates with standard unshielded twisted pair
wiring. The component values given in Table 50 will
accommodate cable capacitance values from 0pF to 50pF when
operating at the 500kHz data rate. Higher cable capacitance
values may be accommodated by either reducing the value of C2
or operating at lower data rates.
The values of components in Figure 59 are given in Table 50 for
various daisy chain operating data rates.
The circuit and component values in Figure 59 and Table 50 will
accommodate cables with differential capacitance values in the
ranges given. This allows a range of cable lengths to be
accommodated through careful selection of cable properties.
The circuit in Figure 59 provides full isolation when used with off
board wiring. The daisy chain external circuit can be simplified in
cases where the daisy chain system is contained within a single
board. Figure 60 on page 85 and Table 51 on page 85 show the
circuit arrangement and component values for single board use.
In this case the AC coupling capacitors C1 need only be rated for
the maximum transient voltage expected from device to device.
FN7938.1
April 23, 2015
ISL94212
ISL94212
FIGURE 58. BALANCE CIRCUIT ARRANGEMENT
FIGURE 59. ISL94212 DAISY CHAIN CIRCUIT IMPLEMENTATION
TABLE 50. COMPONENT VALUES IN FIGURE 59 FOR VARIOUS DAISY CHAIN DATA RATES
DAISY CHAIN CLOCK RATES
COMPONENT
500kHz
250kHz
125kHz
62.5kHz
C1 (4 pcs)
220pF
470pF
1nF
2.2nF
C2 (4 pcs)
200pF
(Note)
440pF
940pF
2nF
R1 (4 pcs)
470Ω
470Ω
470Ω
470Ω
R2 (4 pcs)
100Ω
100Ω
100Ω
100Ω
Cable Capacitance Range
0 to 50pF
0 to 100pF
0 to 200pF
0 to 400pF
Comments
NPO dielectric type capacitors are recommended.
Please consult Intersil if Y type or "open mode"
devices are required for your application.
Use same dielectric type as C1
NOTE: Can be accommodated using two 100pF capacitors in parallel.
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FN7938.1
April 23, 2015
ISL94212
.
FIGURE 60. ISL94212 DAISY CHAIN – BOARD LEVEL IMPLEMENTATION CIRCUIT
ISL94212
FIGURE 61. CONNECTION OF NTC THERMISTOR TO INPUT EXT4
TABLE 51. DAISY CHAIN COMPONENT VALUES FOR BOARD LEVEL IMPLEMENTATION
DAISY CHAIN DATA RATE
COMPONENT
TOLERANCE
500kHz
250kHz
125kHz
62.5kHz
C1 (2 pcs)
5%
100pF
220pF
470pF
1nF
C2 (4 pcs)
5%
220pF
470pF
1nF
2.2nF
1kΩ
1kΩ
1kΩ
1kΩ
R1 (4 pcs)
External Inputs
The ISL94212 provides 4 external inputs for use either as
general purpose analog inputs or for NTC type thermistors. Each
of the external inputs has an internal pull-up resistor, which is
connected by a switch to the VCC pin whenever the TEMPREG
output is active. This arrangement results in an open input being
pulled up to the VCC voltage.
Inputs above 15/16 of full scale are registered as open inputs
and cause the relevant bit in the Over-temperature Fault register,
along with the OT bit in the Fault Status register to be set, on
condition of the respective temperature test enable bit in the
Fault Setup register. The user must then read the register value
associated with the faulty input to determine if the fault was due
to an open input (value above 15/16 full scale) or an
over-temperature condition (value below the external temp limit
setting).
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The arrangement of the external inputs is shown in Figure 61
using the ExT4 input as an example. It is important that the
components are connected in the sequence shown in Figure 61,
e.g., C1 must be connected such the trace from this capacitor’s
positive terminal connects to R2 before connecting to R1. This
guarantees the correct operation of the various fault detection
functions.
The function of each of the components in Figure 61 is listed in
Table 52 together with the diagnostic result of an open or short
fault in each component
FN7938.1
April 23, 2015
ISL94212
TABLE 52. COMPONENT FUNCTIONS AND DIAGNOSTIC RESULTS FOR CIRCUIT OF FIGURE 61
COMPONENT
FUNCTION
DIAGNOSTIC RESULT
R1
Protection from wiring shorts to external HV
connections.
Open: Open wire detection
Short: No diagnostic result
R2
Measurement high-side resistor
Open: Low input level (over-temperature indication)
Short: High input level (open wire indication).
Thermistor
C1
Open: High input level (open wire indication).
Short: Low input level (over-temperature indication)
Noise Filter. Connects to measurement ground
VSS.
Board Level Calibration
For best accuracy, the ISL94212 may be recalibrated after
soldering to a board using a simple resistor trim. The adjustment
method involves obtaining the average cell reading error for the
cell inputs at a single temperature and cell voltage value and
applying a select-on-test resistor to zero the average cell reading
error.
Open: no diagnostic result.
Short: Low input level (over-temperature indication)
TABLE 53. COMPONENT VALUES FOR ACCURACY CALIBRATION
ADJUSTMENT OF FIGURE 62
MEASURED ERROR AT
VC = 3.3V (mV)
V78600 - VCELL (mV)
R1
(kΩ)
R2
(kΩ)
4
205
DNP
3
274
DNP
2
412
DNP
1
825
DNP
0
DNP
DNP
-1
DNP
2550
-2
DNP
1270
-3
DNP
866
-4
DNP
649
The adjustment system uses a resistor placed either between
VDDEXT and VREF or VREF and VSS as shown in Figure 62. The
value of resistor R1 or R2 is then selected based on the average
error measured on all cells at 3.3V per cell and room
temperature e.g., with 3.3V on each cell input scan the voltage
values using the ISL94212 and record the average reading error
(ISL94212 reading – cell voltage value). Table 53 shows the
value of R1 and R2 required for various measured errors.
To use Table 53, find the measured error value closest to the
result obtained with measurements using the ISL94212 and
select the corresponding resistor value. Alternatively, if finer
adjustment resolution is required then this may be obtained by
interpolation using Table 53.
DNP = Do Not populate
Worked Examples
The following worked examples are provided to assist with the
setup and calculations associated with various functions.
Voltage Reference Check Calculation
TABLE 54. EXAMPLE REGISTER DATA
R/W PAGE
FIGURE 62. CELL READING ACCURACY ADJUSTMENT SYSTEM
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86
ADDRESS
PARAMETER
VALUE
(HEX)
DECIMAL
0
001
010000
IC Temperature
14’h2425
9253
0
001
010101
Reference Voltage
14’h20A7
8359
0
010
111000
Coefficient C
14’h00A4
164
0
010
111001
Coefficient B
14’h3FCD
-51
0
010
111010
Coefficient A
9’h006
6
FN7938.1
April 23, 2015
ISL94212
Coefficients A, B and C are two’s compliment numbers. B and C
have a range +8191 to -8192. A has a range +255 to -256.
Coefficient B above is a negative number (Hex value > 1FFF).
The value for B is 14’h3FCD - 14h3FFF- 1 or
(1633310 -1638310 - 1) = -51.
Coefficient A occupies the upper 9 bits of register 6’b111010
(6'h3A). One way to extract the coefficient data from this register
is to divide the complete register value by 32 and rounding the
result down to the nearest integer. With 9'h006 in the upper 9
bits, and assuming the lower 5 bits are 0, the complete register
value will be 14'h0C0 = 192 decimal. Divide this by 32 to
obtain 6.
Coefficients A, B and C are used with the IC temperature reading
to calibrate the Reference Voltage reading. The calibration is
applied by subtracting an adjustment of the form (see
Equation 5) from the Reference Voltage reading.
2
B
A
Adjustment = -----------------------------  dT + -------------  dT + C
8192
256  8192
(EQ. 5)
(EQ. 6)
Where 9180 is the Internal Temperature Monitor reading at +25°C
(see the “Electrical Specifications” table, TINT25 on page 10).
2
51
6
Adjustment = -----------------------------   36.5  – -------------  36.5 + 164 = 163.8
8192
256  8192
(EQ. 7)
(EQ. 8)
Corrected V REF = 8359 – 163.8 = 8195.2
8195.2
V REF value = ------------------  5 = 2.5010
16384
BAL12:1 = 0100 0101 0001
BALANCE STATUS REGISTER
R/W
PAGE
ADDRESS
DATA
1
010
010100
XX 0100 0101 0001
Step 3. Enable balancing using Balance Enable command
BALANCE ENABLE COMMAND
R/W
PAGE
ADDRESS
DATA
0
011
010000
00 0000
Or enable balancing by setting BEN directly in the Balance Setup
register:
BEN = 1
BALANCE SETUP REGISTER
An example calculation using the data from Table 54 is given in
Equation 6.
9253 – 9180
dT = -------------------------------- = 36.5
2
Step 2. Write Balance Status register: Set bits 0, 4, 6 and 10
(EQ. 9)
R/W
PAGE
ADDRESS
DATA
1
010
010011
XX XX1X XXXX XXXX
The balance FETs attached to cells 1, 5, 7 and 11 turn on.
Turn balancing off by resetting BEN or by sending the Balance
Inhibit command (Page 3, address 6’h11).
Cell Balancing – Timed Mode
Refer to “Timed Balance Mode” on page 27.
EXAMPLE: ACTIVATE BALANCING ON CELLS 2 AND 8
FOR 1 MINUTE.
Step 1. Write Balance Setup register: Set Timed Balance mode,
Balance Status pointer, and turn off balance.
Cell Balancing – Manual Mode
Refer to “Manual Balance Mode” on page 26.
EXAMPLE: ACTIVATE BALANCING ON CELLS 1, 5, 7
AND 11
Step 1. Write Balance Setup register: Set Manual Balance mode,
Balance Status pointer, and turn off balance.
BMD = 01 (Manual Balance mode)
BWT = XXX
BSP = 0000 (Balance status pointer location 0)
BEN = 0 (Balancing disabled)
BMD = 10 (Timed Balance mode)
BWT = XXX
BSP = 0000 (Balance status pointer location 0)
BEN = 0 (BALANCING disabled)
BALANCE SETUP REGISTER
R/W
PAGE
ADDRESS
DATA
1
010
010011
XX XX00 000X XX10
X = don’t care
Note: Green text indicates a register change.
Step 2. Write Balance Status register: Set bits 1 and 7
BALANCE SETUP REGISTER
BAL12:1 = 0000 1000 0010
R/W
PAGE
ADDRESS
DATA
1
010
010011
XX XX00 000X XX01
X = don’t care
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87
BALANCE STATUS REGISTER
R/W
PAGE
ADDRESS
DATA
1
010
010100
XX 0000 1000 0010
FN7938.1
April 23, 2015
ISL94212
Step 3. Write balance timeout setting to the Watchdog/Balance
Time register (page 2, address 6’h15, bits [13:7])
BTM6:1 = 0000011 (1 minute)
WATCHDOG/BALANCE TIME REGISTER
R/W
PAGE
ADDRESS
DATA
1
010
010101
00 0001 1XXX XXXX
• Balance time = 20s
Step 4. Enable balancing using Balance Enable command
BALANCE ENABLE COMMAND
PAGE
ADDRESS
DATA
0
011
010000
00 0000
BALANCE SETUP REGISTER
ADDRESS
DATA
1
010
010011
XX XX1X XXXX XXXX
• Balancing disabled during cell measurements.
• Balance Values: See Table 55
TABLE 55. CELL BALANCE VALUES (HEX) FOR EACH CELL
28’h 28’h 28’h 28’h 28’h 28’h 28’h 28’h 28’h 28’h 28’h 28’h
406A 3E4D 0 292F 3E00 0 2903 3D06 0 151E 502 6D6
BEN = 1
PAGE
• Balance wait time (dead time between balancing cycles) = 8s
CELL CELL CELL CELL CELL CELL CELL CELL CELL CELL CELL CELL
1
2
3
4
5
6
7
8
9
10
11 12
Or enable balancing by setting BEN directly in the Balance Setup
register:
R/W
The following describes a simple setup to demonstrate the Auto
Balance mode cell balancing function of the ISL94212. Note that
this balancing setup is not related to the balance value
calculation in Equation 10.
Auto balance cells using the following criteria:
X = don’t care – the lower bits are the watchdog timeout value and
should be set to a time longer than the balance time. A value of 111
1111 is suggested.
R/W
AUTO BALANCE MODE CELL BALANCING EXAMPLE
• Balance Status Register: Set up balance:
Cells 1, 4, 7 and 10 on 1st cycle.
Cells 3, 6, 9 and 12 on 2nd cycle.
Cells 2, 5, 8 and 11 on 3rd cycle
(See Table 56)
TABLE 56. BALANCE STATUS SETUP
The balance FETs attached to cells 2 and 8 turn on. The FETs turn
off after 1 minute. Balancing may be stopped by resetting BEN or
by sending the Balance Inhibit command.
Cell Balancing – Auto Mode
Refer to “Auto Balance Mode” on page 27.
CELL
BPS
[3:0]
1
0000
Reserved for Manual Balance mode and Timed Balance mode
0001
1
0
0
1
0
0
1
0
0
1
0
0
0010
0
0
1
0
0
1
0
0
1
0
0
1
0011
0
1
0
0
1
0
0
1
0
0
1
0
2
3
4
5
6
7
8
9
10
11
12
BALANCE VALUE CALCULATION EXAMPLE
This example is based on a cell State of Charge (SOC) of 9360
coulombs, a target SOC of 8890 coulombs, a balancing leg
impedance of 31Ω (30Ω resistor plus 1Ω FET on resistance) and a
sampling time interval of 5 minutes (300 seconds).
The Balance Value is calculated using Equation 10.
8191
31
B = -------------   9360 – 8890   ---------- = 79562 = 28h00136CA
5
300
(EQ. 10)
The value 8191/5 is the scaling factor of the cell voltage
measurement.
The value of 28’h00136CA is loaded to the required Cell Balance
Register and the value 7’b0001111 (5 minutes) is loaded to the
Balance Time bits in the Watchdog/Balance time register.
In this example, the total coulomb difference to be balanced is:
470 coulomb (9360 - 8890). At 3.3V/31Ω*300s = 31.9 coulomb
per cycle, it takes about 15 cycles for the balancing to terminate.
Submit Document Feedback
88
FN7938.1
April 23, 2015
ISL94212
Step 1. Write Balance Value registers
Step 3. Write balance timeout setting to the Watchdog/Balance
Time register: Balance timeout code = 0000001 (20 seconds)
BALANCE VALUE REGISTERS
R/W
PAGE
ADDRESS
DATA (HEX)
CELL
1
010
100000
14’h006A
1
1
010
100001
14’h0001
1
010
100010
14’h3E4D
1
010
100011
14’h0000
1
010
100100
14’h0000
1
010
100101
14’h0000
1
010
100110
14’h292F
1
010
100111
14’h0000
1
010
101000
14’h3E00
1
010
101001
14’h0000
1
010
101010
14’h0000
1
010
101011
14’h0000
1
010
101100
14’h2903
1
010
101101
14’h0000
1
010
101110
14’h3D06
1
010
101111
14’h0000
1
010
110000
14’h0000
1
010
110001
14’h0000
1
010
110010
14’h151E
1
010
110011
14’h0000
1
010
110100
14’h0502
1
010
110101
14’h0000
1
010
110110
14’h06D6
1
010
110111
14’h0000
2
3
1
1
0
1
0
6’21
0
0
0
0
0
0
0
0
0
0
0
DATA
1
010
010101
00 0000 1XXX XXXX
X = don’t care – the lower bits are the watchdog timeout value and
should be set to a time longer than the balance time. A value 111 1111
is suggested.
6
BMD = 11 (Auto Balance mode)
BWT = 100 (8 seconds)
BEN = 0 (Balancing disabled)
7
BALANCE SETUP REGISTER
8
9
R/W
PAGE
ADDRESS
DATA
1
010
010011
XX XX0X XXX1 0011
X = don’t care
10
Step 4B. Write Balance Setup register: Set Balance Status
Pointer = 1
11
BSP = 0001 (Balance status pointer = 1)
BALANCE SETUP REGISTER
12
R/W
PAGE
ADDRESS
DATA
1
010
010011
XX XXX0 001X XXXX
X = don’t care
1
0
0
0
0
1
B0127 B0126 B0125 B0124 B0123 B0122
0
ADDRESS
Step 4A. Write Balance Setup register: Set Auto Balance mode,
set 8 second Balance wait time, and set balance off:
B0121 B0120 B0119 B0118 B0117 B0116 B0115 B0114
0
PAGE
5
B0113 B0112 B1011 B0110 B0109 B0108
0
R/W
Step 4. Set up Balance Status register (from Table 56 on
page 88)
B0107 B0106 B0105 B0104 B0103 B0102 B0101 B0100
0
BALANCE TIMEOUT REGISTER
4
BALANCE VALUE REGISTERS (CELL1) - VALUE 28’h406A
6’20
BTM6:0 = 000 0001
0
0
Step 2. Write BDDS bit in Device Setup register (turn balancing
functions off during measurement)
BDDS = 1
Step 4C. Write Balance Status register: Set bits 1, 4, 7 and 10
BAL12:1 = 0010 0100 1001
BALANCE STATUS REGISTER
R/W
PAGE
ADDRESS
DATA
1
010
010100
XX 0010 0100 1001
Step 4D. Write Balance Setup register: Set Balance Status
Pointer = 2
BSP = 0010 (Balance status pointer = 2)
BALANCE SETUP REGISTER
R/W
PAGE
ADDRESS
DATA
1
010
010011
XX XXX0 010X XXXX
X = don’t care
DEVICE SETUP REGISTER
R/W
PAGE
ADDRESS
DATA
1
010
011001
XX XXXX 1XXX XXXX
X = don’t care
Submit Document Feedback
89
FN7938.1
April 23, 2015
ISL94212
Step 4E. Write Balance Status register: Set bits 3, 6, 9 and 12
Step 4I. Write Balance Status register: Set bits to all zero to set
the end point for the instances.
BAL12:1 = 1001 0010 0100
BAL12:1 = 0000 0000 0000
BALANCE STATUS REGISTER
R/W
PAGE
ADDRESS
DATA
1
010
010100
XX 1001 0010 0100
BALANCE STATUS REGISTER
R/W
PAGE
ADDRESS
DATA
1
010
010100
XX 0000 0000 0000
Step 4F. Write Balance Setup register: Set Balance Status
Pointer = 3
Step 5. Enable balancing using the Balance Enable command
BSP = 0011 (Balance status pointer = 3)
BALANCE ENABLE COMMAND
BALANCE SETUP REGISTER
R/W
PAGE
ADDRESS
DATA
1
010
010011
XX XXX0 011X XXXX
R/W
PAGE
ADDRESS
DATA
0
011
010000
00 0000
Or enable balancing by setting BEN directly in the Balance Setup
register:
X = don’t care
BEN = 1
Step 4G. Write Balance Status register: Set bits 2, 5, 8 and 11
BALANCE SETUP REGISTER
BAL12:1 = 0100 1001 0010
BALANCE STATUS REGISTER
R/W
PAGE
ADDRESS
DATA
1
010
010100
XX 0100 1001 0010
R/W
PAGE
ADDRESS
DATA
1
010
010011
XX XX1X XXXX XXXX
The balance FETs cycle through each instance of the Balance
Status register in a loop, interposing the balance wait time
between each instance. The measured voltage of each cell being
balanced is subtracted from the balance value for that cell at the
end of each balance status instance. The process continues until
the Balance Value register for each cell contains zero.
Step 4H. Write Balance Setup register: Set Balance Status
Pointer = 4
BSP = 0100 (Balance status pointer = 4)
BALANCE SETUP REGISTER
R/W
PAGE
ADDRESS
DATA
1
010
010011
XX XXX0 100X XXXX
X = don’t care
Register Map
R/W + PAGE
READ
0001
0001
0001
0001
0001
0001
WRITE
BIT 7
ADDRESS
000000
000001
000010
000011
000100
000101
Submit Document Feedback
BIT 6
REGISTER NAME
VBAT Voltage
Cell 1 Voltage
Cell 2 Voltage
Cell 3 Voltage
Cell 4 Voltage
Cell 5 Voltage
90
VB7
C1V7
C2V7
C3V7
C4V7
C5V7
VB6
C1V6
C2V6
C3V6
C4V6
C5V6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
BIT 13
BIT 12
BIT 11
BIT 10
BIT 9
BIT 8
VB5
VB4
VB3
VB2
VB1
VB0
VB13
VB12
VB11
VB10
VB9
VB8
C1V5
C1V4
C1V3
C1V2
C1V1
C1V0
C1V13
C1V12
C1V11
C1V10
C1V9
C1V8
C2V5
C2V4
C2V3
C2V2
C2V1
C2V0
C2V13
C2V12
C2V11
C2V10
C2V9
C2V8
C3V5
C3V4
C3V3
C3V2
C3V1
C3V0
C3V13
C3V12
C3V11
C3V10
C3V9
C3V8
C4V5
C4V4
C4V3
C4V2
C4V1
C4V0
C4V13
C4V12
C4V11
C4V10
C4V9
C4V8
C5V5
C5V4
C5V3
C5V2
C5V1
C5V0
C5V13
C5V12
C5V11
C5V10
C5V9
C5V8
FN7938.1
April 23, 2015
ISL94212
Register Map (Continued)
R/W + PAGE
READ
WRITE
0001
BIT 7
ADDRESS
000110
000111
0001
0001
001000
0001
001001
001010
0001
0001
001011
0001
001100
REGISTER NAME
Cell 6 Voltage
Cell 7 Voltage
Cell 8 Voltage
Cell 9 Voltage
Cell 10 Voltage
Cell 11 Voltage
Cell 12 Voltage
0001
001111
All Cell Voltage Data
0001
010000
IC Temperature
0001
010001
0001
010010
0001
010011
010100
0001
010101
0001
C11V7
C12V7
ICT7
External Temperature Input 4
Voltage (ExT4 pin)
ET4V7
Secondary Reference Voltage
RV7
000000
Overvoltage Fault
Undervoltage Fault
91
C6V6
C7V6
C8V6
C9V6
C10V6
C11V6
C12V6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
BIT 13
BIT 12
BIT 11
BIT 10
BIT 9
BIT 8
C6V5
C6V4
C6V3
C6V2
C6V1
C6V0
C6V13
C6V12
C6V11
C6V10
C6V9
C6V8
C7V5
C7V4
C7V3
C7V2
C7V1
C7V0
C7V13
C7V12
C7V11
C7V10
C7V9
C7V8
C8V5
C8V4
C8V3
C8V2
C8V1
C8V0
C8V13
C8V12
C8V11
C8V10
C8V9
C8V8
C9V5
C9V4
C9V3
C9V2
C9V1
C9V0
C9V13
C9V12
C9V11
C9V10
C9V9
C9V8
C10V5
C10V4
C10V3
C10V2
C10V1
C10V0
C10V13
C10V12
C10V11
C10V10
C10V9
C10V8
C11V5
C11V4
C11V3
C11V2
C11V1
C11V0
C11V13
C11V12
C11V11
C11V10
C11V9
C11V8
C12V5
C12V4
C12V3
C12V2
C12V1
C12V0
C12V13
C12V12
C12V11
C12V10
C12V9
C12V8
Daisy chain configuration only. This command returns all Page 1 data from address
6’h00 through 6’h0C in a single data stream. See “Communication Sequences” on
page 36 and “Address All” on page 42. See example in Figure 41D on page 40.
ET3V7
All Temperature Data
Submit Document Feedback
C10V7
External Temperature Input 3
Voltage (ExT3 pin)
011111
000001
C9V7
ET2V7
0001
1010
C8V7
External Temperature Input 2
Voltage (ExT2 pin)
Scan Count
0010
C7V7
ET1V7
010110
1010
C6V7
External Temperature Input 1
Voltage (ExT1 pin)
0001
0010
BIT 6
ICT6
ET1V6
ET2V6
ET3V6
ET4V6
RV6
ICT5
ICT4
ICT3
ICT2
ICT1
ICT0
ICT13
ICT12
ICT11
ICT10
ICT9
ICT8
ET1V5
ET1V4
ET1V3
ET1V2
ET1V1
ET1V0
ET1V13
ET1V12
ET1V11
ET1V10
ET1V9
ET1V8
ET2V5
ET2V4
ET2V3
ET2V2
ET2V1
ET2V0
ET2V13
ET2V12
ET2V11
ET2V10
ET2V9
ET2V8
ET3V5
ET3V4
ET3V3
ET3V2
ET3V1
ET3V0
ET3V13
ET3V12
ET3V11
ET3V10
ET3V9
ET3V8
ET4V5
ET4V4
ET4V3
ET4V2
ET4V1
ET4V0
ET4V13
ET4V12
ET4V11
ET4V10
ET4V9
ET4V8
RV5
RV4
RV3
RV2
RV1
RV0
RV13
RV12
RV11
RV10
RV9
RV8
SCN3
SCN2
SCN1
SCN0
Daisy chain configuration only. This command returns all Page 1 data from address
6’h10 through 6’h16 in a single data stream. See “Communication Sequences” on
page 36 and “Address All” on page 42.
OF8
UF8
OF7
UF7
OF6
UF6
OF5
UF5
OF4
OF3
OF2
OF1
OF12
OF11
OF10
OF9
UF4
UF3
UF2
UF1
UF12
UF11
UF10
UF9
FN7938.1
April 23, 2015
ISL94212
Register Map (Continued)
R/W + PAGE
BIT 7
READ
WRITE
ADDRESS
0010
1010
000010
0010
0010
0010
0010
1010
1010
1010
1010
0010
0010
0010
0010
0010
0010
0010
0010
0010
1010
1010
1010
1010
1010
1010
1010
1010
0010
0010
0010
000100
000101
1010
REGISTER NAME
Open Wire Fault
Fault Setup
Fault Status
Cell Setup
000110
Over-temperature Fault
001111
All Fault Data
010000
Overvoltage Limit
010001
010010
010011
010100
010101
010110
010111
011000
0010
0010
000011
011001
011010
011011
011100
Submit Document Feedback
BIT 6
Undervoltage Limit
External Temp Limit
Balance Setup
OC7
TOT2
OW
C8
OV7
UV7
ETL7
BSP2
BAL8
Watchdog/Balance Time
BTM0
User Register
Comms Setup
Device Setup
Internal Temp Limit
Serial Number 0
Serial Number 1
92
TOT1
UV
C7
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
BIT 13
BIT 12
BIT 11
BIT 10
BIT 9
BIT 8
OC5
OC4
OC3
OC2
OC1
OC0
OC12
OC11
OC10
OC9
OC8
WSCN
SCN3
SCN2
SCN1
SCN0
TTST4
TTST3
TTST2
TTST1
TTST0
OV
OT
WDGF
OSC
0
0
MUX
REG
REF
PAR
OVSS
OVBAT
C6
C5
C4
C3
C2
C1
FFSN
FFSP
C12
C11
C10
C9
TFLT4
TFLT3
TFLT2
TFLT1
TFLT0
TOT0
Daisy Chain configuration only. This command returns all Page 2 data from address
6’h00 through 6’h06 in a single data stream. See “Communication Sequences” on
page 36 and “Address All” on page 42.
Balance Status (Cells to
Balance)
User Register
OC6
BIT 5
UR7
UR21
SIZE3
BDDS
ITL7
SN7
SN21
OV6
UV6
ETL6
BSP1
BAL7
WDG6
UR6
UR20
SIZE2
0
ITL6
SN6
SN20
OV5
OV4
OV3
OV2
OV1
OV0
OV13
OV12
OV11
OV10
OV9
OV8
UV5
UV4
UV3
UV2
UV1
UV0
UV13
UV12
UV11
UV10
UV9
UV8
ETL5
ETL4
ETL3
ETL2
ETL1
ETL0
ETL13
ETL12
ETL11
ETL10
ETL9
ETL8
BSP0
BWT2
BWT1
BWT0
BMD1
BMD0
BEN
BSP3
BAL6
BAL5
BAL4
BAL3
BAL2
BAL1
BAL12
BAL11
BAL10
BAL9
WDG5
WDG4
WDG3
WDG2
WDG1
WDG0
BTM6
BTM5
BTM4
BTM3
BTM2
BTM1
UR5
UR4
UR3
UR2
UR1
UR0
UR13
UR12
UR11
UR10
UR9
UR8
UR19
UR18
UR17
UR16
UR15
UR14
UR27
UR26
UR25
UR24
UR23
UR22
SIZE1
SIZE0
ADDR3
ADDR2
ADDR1
ADDR0
CRAT1
CRAT0
CSEL2
CSEL1
ISCN
SCAN
EOB
0
Pin 37
Pin 39
WP5
WP4
WP3
WP2
WP1
WP0
ITL5
ITL4
ITL3
ITL2
ITL1
ITL0
ITL13
ITL12
ITL11
ITL10
ITL9
ITL8
SN5
SN4
SN3
SN2
SN1
SN0
SN13
SN12
SN11
SN10
SN9
SN8
SN19
SN18
SN17
SN16
SN15
SN14
SN27
SN26
SN25
SN24
SN23
SN22
FN7938.1
April 23, 2015
ISL94212
Register Map (Continued)
R/W + PAGE
READ
WRITE
0010
BIT 7
ADDRESS
011101
BIT 6
REGISTER NAME
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
BIT 13
BIT 12
BIT 11
BIT 10
BIT 9
BIT 8
TV2
TV1
TV0
Trim Voltage
RESERVED
TV5
0010
0010
0010
0010
0010
1010
1010
1010
1010
0010
0010
0010
0010
1010
TV3
011111
All Setup Data
Daisy Chain configuration only. This command returns all Page 2 data from address
6’h10 through 6’h1D in a single data stream. See “Communication Sequences” on
page 36 and “Address All” on page 42.
100000
Cell 1 Balance Value 0
B0107
100001
100010
100011
Cell 1 Balance Value 1
Cell 2 Balance Value 0
Cell 2 Balance Value 1
~
0010
TV4
110111
111000
111001
111010
111011
B0207
B0221
B0120
B0206
B0220
B0105
B0104
B0103
B0102
B0101
B0100
B0113
B0112
B1011
B0110
B0109
B0108
B0119
B0118
B0117
B0116
B0115
B0114
B0127
B0126
B0125
B0124
B0123
B0122
B0205
B0204
B0203
B0202
B0201
B0200
B0213
B0212
B1011
B0210
B0209
B0208
B0219
B0218
B0217
B0216
B0215
B0214
B0227
B0226
B0225
B0224
B0223
B0222
~
Cell 12 Balance Value 1
Reference Coefficient C
Reference Coefficient B
Reference Coefficient A
Cell Balance Enabled
0011
000001
Scan Voltages
0011
000010
Scan Temperatures
0011
000011
Scan Mixed
0011
000100
Scan Wires
0011
000101
Scan All
0011
000110
Scan Continuous
0011
000111
Scan Inhibit
0011
001000
Measure
0011
001001
Identify
0011
001010
Sleep
0011
001011
NAK
0011
001100
ACK
0011
001110
Comms Failure
0011
001111
Wakeup
0011
010000
Balance Enable
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B0121
B0106
93
~
B1221
RCC7
RCB7
RCA2
CBEN8
B1220
RCC6
RCB6
RCA1
CBEN7
B1219
B1218
B1217
B1216
B1215
B1214
B1227
B1226
B1225
B1224
B1223
B1222
RCC5
RCC4
RCC3
RCC2
RCC1
RCC0
RCC13
RCC12
RCC11
RCC10
RCC9
RCC8
RCB5
RCB4
RCB3
RCB2
RCB1
RCB0
RCB13
RCB12
RCB11
RCB10
RCB9
RCB8
RCA0
RESERVED
RCA8
RCA7
RCA6
RCA5
RCA4
RCA3
CBEN6
CBEN5
CBEN4
CBEN3
BAL2
CBEN1
CBEN12
CBEN11
CBEN10
CBEN9
FN7938.1
April 23, 2015
ISL94212
Register Map (Continued)
R/W + PAGE
READ
WRITE
BIT 7
ADDRESS
REGISTER NAME
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
BIT 13
BIT 12
BIT 11
BIT 10
BIT 9
BIT 8
0011
010001
Balance Inhibit
0011
010010
Reset
0011
010011
Calc Register Checksum
0011
010100
Check Register Checksum
0100
111111
EEPROM MISR Data Register
14-bit MISR EEPROM checksum value. Programmed during test.
0101
000000
MISR Calculated Checksum
14-bit shadow register MISR checksum value. Calculated when shadow registers
are loaded from nonvolatile memory
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FN7938.1
April 23, 2015
ISL94212
Revision History
The revision history provided is for informational purposes only and is believed to be accurate, but not warranted. Please go to web to make sure you
have the latest Rev.
DATE
April 23, 2015
REVISION
CHANGE
FN7938.1 Changed ground references in Figure 1 on page 1.
Abs Max “Absolute Maximum Ratings” on page 7 changed the text in the ESD Ratings from Capacitive Discharge to
Charge Device Model
“Recommended Operating Conditions” on page 7 moved ExT1, ExT2, ExT3, ExT4, which had voltage range 0V to 3.6V
to separate line with voltage range 0V to 2.5V.
Added to “BASE” in “Pin Descriptions” on page 5, “Do not let this pin float.”
Table 3 on page 24, Changed “Cell 0 Voltage” to “VBAT Voltage”.
Section , “CRC Calculation,” on page 36: Added example software CRC calculation code (Figure 39 on page 37.)
Section , “Reset,” on page 42 - Added note: “A Reset command should be issued following a “hard reset” in which the
EN pin is toggled.”
Changed “Fault Signal Filtering” on page 46 to add the comment in 2nd paragraph, “When a fault is detected, the
[TOT2:0] bits should be rewritten.”
Table 30 on page 47, changed in comments for “Read checksum value calculated by ISL94212” from: ...“cycling the
EN pin or the host issuing a Reset command.” to: ...“cycling the EN pin followed by a host initiated Reset command,
or simply the host issuing a Reset command.”
Changed Section, “System Registers,” on page 62. Changed in 4th paragraph 1st sentence “when the EN pin is low”
to “when the EN pin is toggled and the device receives a Reset Command”.
Section, “Register Descriptions,” on page 62: Changed “Cell 0 Voltage” to “VBAT Voltage” and added voltage
calculation equations.
System Register description “TOT0, 1, 2” on page 64 added the comment, “This register must be re-written following
an error detection resulting from totalizer overflow.”
Added to last sentence 2nd paragraph in Section, “Power Supplies,” on page 82, “The external pass transistor is
required. Do not allow this pin to float.”
Changed all pin name references to all caps.
Updated Definitions for Shutdown Mode in “Power Modes” on page 21 and “Reset” on page 42.
Table 50 on page 84, Updated recommendation for C1
Replaced “Measurement and Communication Timing” Section (pages 51 to 58 of previous document) with new
sections “Communication and Measurement Diagrams” on page 50 and “Communication and Measurement Timing
Tables” on page 56 with new figures and tables to offer more clarity and flexibility in communication and
measurement timing calculations.
December 14, 2012 FN7938.0 Initial Release.
About Intersil
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address some of the largest markets within the industrial and infrastructure, mobile computing and high-end consumer markets.
For the most updated datasheet, application notes, related documentation and related parts, please see the respective product
information page found at www.intersil.com.
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Reliability reports are also available from our website at www.intersil.com/support
For additional products, see www.intersil.com/en/products.html
Intersil products are manufactured, assembled and tested utilizing ISO9001 quality systems as noted
in the quality certifications found at www.intersil.com/en/support/qualandreliability.html
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time
without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be
accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third
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95
FN7938.1
April 23, 2015
ISL94212
Package Outline Drawing
Q64.10x10D
64 LEAD THIN PLASTIC QUAD FLATPACK PACKAGE
Rev 2, 9/12
12.00
4 5
10.00
D 3
12.00
A
10.00
4 5
B
0.50
3
4X
0.20 C A-B D
TOP VIEW
4X
11/13°
0.20 H A-B D
BOTTOM VIEW
1.20 MAX
0.05
/ / 0.10 C
C
SIDE VIEW
7
0.08
SEE DETAIL "A"
0° MIN.
H
3
0.08 M C A-B D
WITH LEAD FINISH
0.22 ±0.05
0.09/0.20
2
1.00 ±0.05
0.05/0.15
0.09/0.16
0.08
R. MIN.
0.20 MIN.
0.20 ±0.03
BASE METAL
DETAIL "A"
SCALE: NONE
0.25
0-7° GAUGE
PLANE
0.60 ±0.15
(1.00)
NOTES:
1. All dimensioning and tolerancing conform to ANSI Y14.5-1982.
2. Datum plane H located at mold parting line and coincident
with lead, where lead exits plastic body at bottom of parting line.
3. Datums A-B and D to be determined at centerline between
leads where leads exit plastic body at datum plane H.
4. Dimensions do not include mold protrusion. Allowable mold
protrusion is 0.254mm.
5. These dimensions to be determined at datum plane H.
6. Package top dimensions are smaller than bottom dimensions
and top of package will not overhang bottom of package.
7. Does not include dambar protrusion. Allowable dambar
protrusion shall be 0.08mm total at maximum material
condition. Dambar cannot be located on the lower radius
or the foot.
8. Controlling dimension: millimeter.
9. This outline conforms to JEDEC publication 95 registration
MS-026, variation ACD.
10. Dimensions in ( ) are for reference only.
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96
FN7938.1
April 23, 2015