TI ADC128D818CIMT-NOPB

ADC128D818
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SNAS483E – FEBRUARY 2010 – REVISED MARCH 2013
ADC128D818 12-Bit, 8-Channel, ADC System Monitor with Temperature Sensor,
Internal/External Reference, and I2C Interface
Check for Samples: ADC128D818
FEATURES
KEY SPECIFICATIONS
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12-bit Resolution Delta-Sigma ADC
Local Temperature Sensing
Configurable Single-Ended and/or Pseudo-Diff.
Inputs
+2.56V Internal VREF or Variable External
VREF
WATCHDOG Window Comparators with Status
and Mask Registers of All Measured Values
Independent Registers for Storing Measured
Values
INT Output Notifies Microprocessor of Error
Event
I2C Serial Bus Interface Compatibility
9 Selectable Addresses
TIMEOUT Reset Function to Prevent I2C Bus
Lock-Up
Individual Channel Shutdown to Limit Power
Consumption
Deep Shutdown Mode to Minimize Power
Consumption
TSSOP 16-Lead Package
APPLICATIONS
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Communications Infrastructure
Thermal / Hardware Server Monitors
System Monitors
Industrial and Medical Systems
Electronic Test Equipment and
Instrumentation
Power Supply Monitoring / Supervision
ADC Resolution 12-bit
Supply Voltage Range +3 to +5.5 V
Total Unadjusted Error –0.45%/+0.2%
Integral Non-Linearity ±1 LSb
Differential Non-Linearity ±1 LSb
Operating Current 0.56 mA
Deep Shutdown Current 10 µA
Temperature Resolution °C/LSb
Temp. Accuracy (–40°C to 125°C) ±3°C
Temp. Accuracy (–25°C to 100°C) ±2°C
DESCRIPTION
The ADC128D818 I2C system monitor is designed for
maximum flexibility. The system monitor can be
configured for single-ended and/or pseudo-differential
inputs. An on-board temperature sensor, combined
with WATCHDOG window comparators, and an
interrupt output pin, INT, allow easy monitoring and
out-of-range alarms for every channel. A high
performance internal reference is also available to
provide for a complete solution in the most difficult
operating conditions.
The ADC128D818’s 12-bit delta-sigma ADC supports
Standard Mode (Sm, 100 kbits/s) and Fast Mode
(Fm, 400kbits/s) I2C interfaces. The ADC128D818
includes a sequencer to control channel conversions
and stores all converted results in independent
registers for easy microprocessor retrieval. Unused
channels can be shut down independently to
conserve power.
The ADC can use either an internal 2.56V reference
or a variable external reference. An analog filter is
included on the I2C digital control lines to provide
improved noise immunity. The device also includes a
TIMEOUT reset function on SDA and SCL to prevent
I2C bus lock-up.
The ADC128D818 operates from +3.0 to +5.5V
power supply voltage range, –40°C to 125°C
temperature range, and the device is available in a
16-pin TSSOP package.
1
2
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2010–2013, Texas Instruments Incorporated
ADC128D818
SNAS483E – FEBRUARY 2010 – REVISED MARCH 2013
www.ti.com
Typical Application
V+
Single-Ended
Positive Voltage
Internal
VREF = +2.56V
IN0
IN1
IN2
IN3
IN4 (+)
IN5 (-)
IN7 (+)
IN6 (-)
Pseudo-Differential
Positive Voltage
10VIN
VOUT
DC-DC
Shutdown
VREF
ADC128D818
LM94022
Margining
Voltage
12-bit
Delta-Sigma
ADC
Temperature
Sensor
Interrupt
Status
Registers
Interrupt
Masking
and
Interrupt
Control
2
I C Interface and Control
INT
SDA
SCL
A0
A1
GND
RTRACE
Connection Diagram
VREF
1
16
IN0
SDA
2
15
IN1
SCL
3
14
IN2
GND
4
13
IN3
V+
5
12
IN4
INT
6
11
IN5
A0
7
10
IN6
A1
8
9
IN7
ADC128D818
16-pin TSSOP
PIN DESCRIPTIONS
Pin
Number
2
Pin
Name(s)
ESD
Structure
Type
Description
ADC external reference.
ADC128D818 allows two choices for sourcing VREF:
internal or external. If the +2.56V internal VREF is used,
leave this pin unconnected. If the external VREF is used,
source this pin with a voltage between +1.25V and V+. At
Power-On-Reset (POR), the default setting is the internal
VREF.
Bypass with the parallel combination of 1 μF (electrolytic or
tantalum) and 0.1 μF (ceramic) capacitors.
1
VREF
Analog Input
2
SDA
Digital I/O
3
SCL
Digital Input
4
GND
GROUND
5
V+
ESD
Clamp
POWER
Serial Bus Bidirectional Data. NMOS open-drain output.
Requires external pull-up resistor to function properly.
Serial Bus Clock. Requires external pull-up resistor to
function properly.
Internally connected to all of the circuitry.
+3.0V to +5.5V power. Bypass with the parallel combination
of 1 μF (electrolytic or tantalum) and 0.1 μF (ceramic)
bypass capacitors.
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PIN DESCRIPTIONS (continued)
Pin
Number
Pin
Name(s)
ESD
Structure
6
INT
Digital Output
Interrupt Request. Active Low, NMOS, open-drain.
Requires external pull-up resistor to function properly.
7-8
A0 - A1
Tri-Level Inputs
Tri-Level Serial Address pins that allow 9 devices on a
single I2C bus.
9 - 16
IN7 - IN0
Analog Inputs
Type
Description
The full scale range will be controlled by the internal or
external VREF. These inputs can be assigned as singleended and/or pseudo-differential inputs.
Block Diagram
Watchdog
Upper Limit
IN0
IN0
IN1
IN2
IN3
IN4
IN5
IN6
IN7
16
15
14
13
12
11
10
9
Lower Limit
Upper Limit
IN1
Lower Limit
IN2
Lower Limit
Upper Limit
IN3
12-bit
DeltaSigma
ADC and
MUX
Lower Limit
Upper Limit
IN4
Lower Limit
Upper Limit
IN5
Lower Limit
VREF
Interrupt
Masking
and
Interrupt
Control
Lower Limit
Upper Limit
IN7
Lower Limit
Thot
Temperature
1
Interrupt
Status
Registers
Upper Limit
IN6
Temperature
INT
6
Upper Limit
Thot_hyst
Internal
VREF =
2.56V
Interface and Control
5
4
3
2
SCL SDA
7
A0
8
V+
GND
A1
Serial Bus Interface
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Product Highlights
The maximum number of channels that can be enabled for each input mode are shown in the table below.
Unusued channels may be disabled through software.
Table 1. Input Modes
Modes of
Operation
Single-Ended Inputs
Pseudo-Differential
Inputs
Internal Temperature
Measurement
Cycle Time with Maximum
Number of Channels Enabled
(ms - typ).
0
7
-
1
88
1
8
-
-
96
2
-
4
1
52
3
4
2
1
76
Table 2. Conversion Modes
Conversion Modes
Description
Continuous
Enabled channels are measured continuously.
Low Power
Enabled channels are measured, then the device is automatically placed into shutdown mode. This
cycle is repeated every 728 ms.
One-Shot
When One-Shot Register (address 09h) is programmed while the device is in shutdown or deep
shutdown mode, the device will initiate a single conversion and comparison cycle, after which the
device returns to the respective mode it was in.
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
4
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Absolute Maximum Ratings (1) (2) (3)
Supply Voltage (V+)
6.0V
Voltage on SCL, SDA, A0, A1, INT
–0.3V to 6.0V
Voltage on IN0-IN7, VREF
–0.3V to (V+ + 0.3)V and ≤ 6.0V
Input Current at Any Pin (4)
±5 mA
Package Input Current
(4)
±30 mA
Maximum Junction Temperature (TJMAX) (5)
150°C
Human Body Model
ESD Susceptibility (6)
3,000V
Machine Model
300V
Charged Device Model
Storage Temperature
1,000V
–65°C to +150°C
For soldering specifications,
http://www.ti.com/lit/SNOA549
(1)
(2)
(3)
(4)
(5)
(6)
All voltages are measured with respect to GND, unless otherwise specified.
Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for
which the device is functional, but do not ensured specific performance limits. For ensured specifications and test conditions, see the
Electrical Characteristics. The specified specifications apply only for the test conditions listed. Some performance characteristics may
degrade when the device is not operated under the listed test conditions.
If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/Distributors for availability and
specifications.
If the input voltage at any pin exceeds the power supply ( that is, VIN < GND or VIN > V +) but is less than the absolute maximum
ratings, then the current at that pin should be limited to 5mA. The 30 mA maximum package input current rating limits the number of
pins that can safely exceed the power supply with an input current of 5mA to six pins. Parasitic components and/or ESD protection
circuitry are shown in the Pin Descriptions table.
The maximum power dissipation must be derated at elevated temperatures and is dictated by TJMAX, θJA and the ambient temperature,
TA. The maximum allowable power dissipation at any temperature is PD = (TJMAX − T A) / θJA.
Human body model (HBM) is a charged 100pF capacitor discharged into a 1.5kΩ resistor. Machine model (MM) is a charged 200pF
capacitor discharged directly into each pin. Charged Device Model (CDM) simulates a pin slowly acquiring charge (such as from a
device sliding down the feeder in an automated assembler) then rapidly being discharged.
Operating Ratings (1) (2)
Supply Voltage (V+)
3.0V to 5.5V
Voltage on SCL, SDA, A0, A1, INT
–0.05V to 5.5V
–0.05V to (V+ + 0.05)V and ≤ 5.5V
Voltage on IN0-IN7, VREF
TMIN = –40°C
Temperature Range for Electrical Characteristics
TMAX = 125°C
–40°C ≤ TA ≤ +125°C
Operating Temperature Range
Junction to Ambient Thermal Resistance (θJA)
(1)
(2)
(3)
(3)
130°C/W
Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for
which the device is functional, but do not ensured specific performance limits. For ensured specifications and test conditions, see the
Electrical Characteristics. The specified specifications apply only for the test conditions listed. Some performance characteristics may
degrade when the device is not operated under the listed test conditions.
All voltages are measured with respect to GND, unless otherwise specified.
For the given θJA, the device is on a 2-layer printed circuit board with 1 oz. copper foil and no airflow.
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DC Electrical Characteristics
The following specifications apply for +3.0 VDC ≤ V+ ≤ +5.5 VDC , External VREF = +2.56V, unless otherwise specified.
Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = 25°C (1).
Min (2)
Typical (3)
Max (2)
Units
Supply Voltage
3.0
3.3 or 5.0
5.5
V
External Reference Voltage
1.25
2.56
V+
V
Symbol
Parameter
Conditions
POWER SUPPLY CHARACTERISTICS
V+
VREF
I+
Internal Reference Voltage
Supply Current (see the POWER
MANAGEMENT section for more
information).
2.56
V
23
ppm/°C
Interface Inactive, V+ = 5.5V, Mode 2
0.74
mA
Interface Inactive, V+ = 3.6V, Mode 2
0.56
mA
Shutdown Mode, V+ = 5.5V
0.65
mA
Shutdown Mode, V+ = 3.6V
0.48
mA
10
µA
–40°C ≤ TA ≤ +125°C
±3
°C
–25°C ≤ TA ≤ +100°C
±2
°C
Deep Shutdown Mode (4).
TEMPERATURE-to-DIGITAL CONVERTER CHARACTERISTICS
Temperature Error
Resolution
0.5
°C
0.625
mV
ANALOG-to-DIGITAL CONVERTER CHARACTERISTICS
n
Resolution
12-bit with full-scale at VREF = 2.56V.
External VREF = 1.25V, PseudoDifferential, V+ = 3.0V to 3.3V. (4)
INL
Integral Non-Linearity
External VREF = 2.56V, PseudoDifferential
External VREF = 5.0V, PseudoDifferential, V+ = 5.0V to 5.5V.
DNL
Differential Non-Linearity
See (5)
Internal VREF, Single-Ended, V+ = 3.0V
to 3.6V.
Internal VREF, Single-Ended, V+ = 4.5V
to 5.5V (7).
Internal VREF, Pseudo-Differential, V+ =
3.0V to 3.6V or V+ = 4.5V to 5.5V (7).
TUE
Total Unadjusted Error (6)
External VREF = 1.25V, Single-Ended,
V+ = 3.0V to 3.6V.
External VREF = 2.56V, Single-Ended,
V+ = 3.0V to 5.5V.
External VREF = 1.25V, PseudoDifferential, V+ = 3.0V to 3.6V.
External VREF = 2.56V, PseudoDifferential, V+ = 3.0V to 5.5V.
(1)
(2)
(3)
(4)
(5)
(6)
(7)
6
–1
0.36
1
LSb
–2
1.58
4
LSb
-1
±0.25
1
LSb
–0.5
0.5
% of FS
–0.3
0.5
% of FS
–0.6
0.1
% of FS
–0.45
0.2
% of FS
Each input and output is protected by an ESD structure to GND, as shown in the Pin Descriptions table. Input voltage magnitude up to
0.3V above V+ or 0.3V below GND will not damage the ADC128D818. There are diodes that exist between some inputs and the power
supply rails. Errors in the ADC conversion can occur if these diodes are forward biased by more than 50mV. As an example, if V+ is
4.50 VDC, INx (where 0 ≤ x ≤ 7) must be ≤ 4.55 VDC to ensure accurate conversions.
Limits are ensured to AOQL (Average Outgoing Quality Level).
Typicals are at TJ = TA = 25°C and represent most likely parametric normal.
Limit is specified by characterization.
Limit is specified by design.
TUE (Total Unadjusted Error) includes Offset, Gain and Linearity errors of the ADC.
The range is up to 7/8 of full scale.
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DC Electrical Characteristics (continued)
The following specifications apply for +3.0 VDC ≤ V+ ≤ +5.5 VDC , External VREF = +2.56V, unless otherwise specified.
Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = 25°C(1).
Symbol
Parameter
Conditions
Internal VREF, V+ = 3.0V to 3.6V.
Internal VREF, V+ = 4.5V to 5.5V (7)
GE
Gain Error
External VREF = 1.25V or 2.56V, V+ =
3.0V to 3.6V.
External VREF = 2.56V or 5.0V, V+ =
4.5V to 5.5V.
Internal VREF, Pseudo-Differential,V+ =
4.5V to 5.5V (7).
External VREF = 1.25V or 2.56V,
Single-Ended, V+ = 3.0V to 3.6V.
OE
Offset Error
External VREF = 2.56V or 5.0V, SingleEnded, V+ = 4.5V to 5.5V
External VREF = 1.25V or 2.56V,
Pseudo-Differential, V+ = 3.0V to 3.6V.
External VREF = 2.56V or 5.0V,
Pseudo-Differential, V+ = 4.5V to 5.5V
Continuous Conversion Mode
tC
Low Power Conversion Mode
Min (2)
Typical (3)
Max (2)
Units
–0.25
0.45
% of FS
–0.45
0.2
% of FS
–0.15
0.2
% of FS
–0.5
0.1
% of FS
–0.2
0.15
% of FS
Each Enabled Voltage Channel
12
ms
Internal Temperature Sensor
3.6
ms
Enabled Voltage Channel(s) and
Internal Temperature Sensor
728
ms
MULTIPLEXER / ADC INPUT CHARACTERISTICS
RON
On Resistance
ION
Input Current (On Channel Leakage
Current)
2
10
kΩ
±0.005
μA
IOFF
Off Channel Leakage Current
±0.005
μA
DIGITAL OUTPUTS: INT
VOUT(0)
Logical “0” Output Voltage
IOUT = +5.0 mA at V+ = +4.5V, IOUT =
+3.0 mA at V+ = +3.0V
0.4
V
IOUT = +3.0 mA at V+ = +4.5V,
0.4
V
1
μA
V
OPEN DRAIN SERIAL BUS OUTPUT: SDA
VOUT(0)
IOH
Logical “0” Output Voltage
High Level Output Current
+
VOUT = V
0.005
DIGITAL INPUTS: A0 and A1
VIN(1)
Logical “1” Input Voltage
0.90 x V+
5.5
Logical Middle Input Voltage
0.43 x V+
0.57 x V+
GND 0.05
0.10 x V+
V
Logical “1” Input Voltage
0.7 × V+
5.5
v
VIN(0)
Logical “0” Input Voltage
GND 0.05
VHYST
Hysteresis Voltage
VIM
VIN(0)
Logical “0” Input Voltage
SERIAL BUS INPUTS: SCL and SDA
VIN(1)
+
0.3 × V
V
V+ = +3.3V
0.67
V
V+ = +5.5V
1.45
V
ALL DIGITAL INPUTS: SCL, SDA, A0, A1
IIN(1)
Logical “1” Input Current
VIN = V+
IIN(0)
Logical “0” Input Current
VIN = 0 VDC
CIN
Digital Input Capacitance
−1
– 0.005
0.005
µA
1
20
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AC Electrical Characteristics
The following specifications apply for +3.0 VDC ≤ V+ ≤ +5.5 VDC , unless otherwise specified. Boldface limits apply for TA =
TJ = TMIN to TMAX; all other limits TA = TJ = 25°C.
Symbol
Parameter
Conditions
Min (1)
Typical (2)
Max (1)
Units
100
µs
SERIAL BUS TIMING CHARACTERISTICS
t1
SCL (Clock) Period
2.5
t2
Data In Setup Time to SCL High
100
ns
t3
Data Out Stable After SCL Low
0
ns
t4
SDA Low Setup Time to SCL Low (start)
100
ns
t5
SDA High Hold Time After SCL High (stop)
100
SCL or SDA time low for I2C bus reset
25
tTIMEOUT
(1)
(2)
ns
35
ms
Limits are ensured to AOQL (Average Outgoing Quality Level).
Typicals are at TJ = TA = 25°C and represent most likely parametric normal.
Figure 1. Serial Bus Timing Diagram
8
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Typical Performance Characteristics
The following typical performance plots apply for the internal VREF = 2.56V, V+ = 3.3V, Pseudo-Differential connection,
unless otherwise specified. Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = 25°C. (1)
TUE vs. Code (External VREF = 1.25V)
-0.010
0.014
-0.074
0.004
-0.138
TUE (%)
TUE (%)
TUE vs. Code
0.023
-0.005
-0.015
-0.202
-0.266
-0.024
500.0
1.2k
1.9k
2.7k
CODE
3.4k
-0.330
500.0
4.1k
1.2k
Figure 2.
4.1k
TUE vs. Code (External VREF = 5V, V+ = 5V)
-0.020
-0.060
-0.064
-0.100
-0.108
TUE (%)
TUE (%)
TUE vs. Code (External VREF = 2.56V)
-0.140
-0.180
(1)
3.4k
Figure 3.
-0.020
-0.220
500.0
1.9k
2.7k
CODE
-0.152
-0.196
1.2k
1.9k
2.7k
CODE
3.4k
4.1k
-0.240
500.0
1.2k
1.9k
2.7k
CODE
3.4k
4.1k
Figure 4.
Figure 5.
INL vs. Code (External VREF = 1.25V for 1 Unit)
INL vs. Code (External VREF = 1.25V for 28 Units)
Figure 6.
Figure 7.
Timing specifications are tested at the Serial Bus Input logic levels: VIN(0) = 0.3 × V+ for a falling edge and VIN(1) = 0.7 × V+ for a rising
edge if the SCL and SDA edge rates are similar.
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Typical Performance Characteristics (continued)
The following typical performance plots apply for the internal VREF = 2.56V, V+ = 3.3V, Pseudo-Differential connection,
unless otherwise specified. Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = 25°C.(1)
10
INL vs. Code (External VREF = 2.56V for 1 Unit)
INL vs. Code (External VREF = 2.56V for 28 Units)
Figure 8.
Figure 9.
INL vs. Code (External VREF = 5V, V+ = 5V for 1 Unit)
INL vs. Code (External VREF = 5V, V+ = 5V for 28 Units)
Figure 10.
Figure 11.
DNL vs. Code (External VREF = 2.56V for 1 Unit)
DNL vs. Code (External VREF = 2.56V for 28 Units)
Figure 12.
Figure 13.
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Typical Performance Characteristics (continued)
The following typical performance plots apply for the internal VREF = 2.56V, V+ = 3.3V, Pseudo-Differential connection,
unless otherwise specified. Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = 25°C.(1)
Offset Error vs. V+
Offset Error vs. Temperature
0.040
0.025
0.024
OFFSET ERROR (%)
OFFSET ERROR (%)
0.023
0.030
0.020
0.010
0.022
0.021
0.020
0.019
0.018
0.017
0.016
0.000
3.2
3.7
4.1
4.6
V+ (V)
5.0
0.015
-50.0
5.5
-14.0
Figure 14.
22.0
58.0
94.0
TEMPERATURE (°C)
130.0
Figure 15.
Gain Error vs. V+
Gain Error vs. Temperature
0.100
0.230
0.075
0.188
GAIN ERROR (%)
GAIN ERROR (%)
0.050
0.025
-6.939E-18
-0.025
0.146
0.104
-0.050
0.062
-0.075
3.5
4.0
4.5
V+ (V)
5.0
0.020
-50.0
5.5
I+ vs. Temperature
I+ vs. V+ Typical
0.490
0.440
0.470
0.420
0.450
0.400
0.410
0.360
0.390
22.0
58.0
94.0
130.0
130.0
0.430
0.380
-14.0
22.0
58.0
94.0
TEMPERATURE (°C)
Figure 17.
0.460
-50.0
-14.0
Figure 16.
I+ (mA)
I+ (mA)
-0.100
3.0
2.7
TEMPERATURE (°C)
3.3
3.8
4.4
4.9
V+ (V)
Figure 18.
Figure 19.
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Typical Performance Characteristics (continued)
The following typical performance plots apply for the internal VREF = 2.56V, V+ = 3.3V, Pseudo-Differential connection,
unless otherwise specified. Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = 25°C.(1)
I+ vs. V+ for Voltage Conversion
I+ vs. V+ for Temperature Conversion
1.340
1.70
1.298
1.256
I+ (mA)
I+ (mA)
1.60
1.214
1.50
1.40
1.172
1.30
1.130
2.5
3.0
3.5
4.0
4.5
5.0
5.5
2.5
6.0
3.0
3.5
4.0
4.5
5.0
5.5
6.0
V+ (V)
V+ (V)
Figure 20.
Figure 21.
I+ vs. V+ in Shutdown Mode
I+ vs. V+ in Deep Shutdown Mode
0.440
0.004
0.420
0.003
I+ (mA)
I+ (mA)
0.400
0.380
0.360
0.002
0.002
0.340
0.320
2.5
0.003
0.001
3.0
3.5
4.0 4.5
V+ (V)
5.0
5.5
6.0
2.5
3.5
4.0
4.5
5.0
5.5
6.0
V+ (V)
Figure 22.
12
3.0
Figure 23.
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FUNCTIONAL DESCRIPTION
GENERAL DESCRIPTION
The ADC128D818 provides 8 analog inputs, a temperature sensor, a delta-sigma ADC, an external or internal
VREF option, and WATCHDOG registers on a single chip. An I2C Serial Bus interface is also provided. The
ADC128D818 can perform voltage and temperature monitoring for a variety of systems.
The ADC128D818 continuously converts the voltage input to 12-bit resolution with an internal VREF of 0.625mV
LSb (Least Significant bit) weighting, yielding input range of 0V to 2.56V. There is also an external VREF option
that ranges from 1.25V to V+. The analog inputs are intended to be connected to several power supplies present
in a variety of systems. Eight inputs can be configured for single-ended and/or pseudo-differential channels.
Temperature can be converted to a 9-bit two's complement word with resolutions of 0.5°C per LSb.
The ADC128D818 provides a number of internal registers. These registers are summarized in the Table 6
section.
The ADC128D818 supports Standard Mode (Sm, 100kbits/s) and Fast Mode (Fm, 400kbits/s) I2C interface
modes of operation. ADC128D818 includes an analog filter on the I2C digital control lines that allows improved
noise immunity. The device also supports TIMEOUT reset function on SDA and SCL to prevent I2C bus lock-up.
Two tri-level address pins allow up to 9 devices on a single I2C bus.
At start-up, ADC128D818 cycles through each measurement in sequence and continuously loops through the
sequence based on the Conversion Rate Register (address 07h) setting. Each measured value is compared to
values stored in the Limit Registers (addresses 2Ah - 39h). When the measured value violates the programmed
limit, the ADC128D818 will set a corresponding interrupt bit in the Interrupt Status Registers (address 01h). An
interrupt output pin, INT, is also available and fully programmable.
SUPPLY VOLTAGE (V+)
The ADC128D818 operates with a supply voltage, V+, that has a range between +3.0V to +5.5V. Care must be
taken to bypass this pin with a parallel combination of 1 µF (electrolytic or tantalum) capacitor and 0.1 µF
(ceramic) bypass capacitor.
VOLTAGE REFERENCES (VREF)
The reference voltage (VREF) sets the analog input range. The ADC128D818 has two options for setting VREF.
The first option is to use the internal VREF, which is equal to 2.56V. The second option is to source VREF
externally via pin 1 of ADC128D818. In this case, the external VREF will operate in the range of 1.25V to V+.
The default VREF selection is the internal VREF. If the external VREF is preferred, use the Advanced
Configuration Register — Address 0Bh to change this setting.
VREF source must have a low output impedance and needs to be bypassed with a minimum capacitor value of
0.1 µF. A larger capacitor value of 1 µF placed in parallel with the 0.1 µF is preferred. VREF of the
ADC128D818, like all ADC converters, does not reject noise or voltage variations. Keep this in mind if VREF is
derived from the power supply. Any noise and/or ripple from the supply that is not rejected by the external
reference circuitry will appear in the digital results. The use of a reference source is recommended. The LM4040
and LM4050 shunt reference families as well as the LM4120 and LM4140 series reference families are excellent
choices for a reference source.
ANALOG INPUTS (IN0 - IN7)
The ADC128D818 allows up to 8 single-ended inputs or 4 pseudo-differential inputs as selected by the modes of
operation. The input types are described in the next subsections.
Single-Ended Input
ADC128D818 allows a maximum of 8 single-ended inputs, where the source's voltage is connected to INx (0 ≤ x
≤ 7). The source’s ground should be connected to ADC128D818’s GND pin. In theory, INx can be of any value
between 0V and (VREF-3LSb/2), where LSb = VREF/212.
To use the device single-endedly, refer to the Modes of Operation section and to bits [2:1] of the Advanced
Configuration Register — Address 0Bh. Figure 24 shows the appropriate configuration for a single-ended
connection.
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IN0
IN1
IN2
IN3
ADC128D818
+
IN4
IN5
IN6
IN7
SRC
-
GND
Figure 24. Single-Ended Configuration
Pseudo-Differential Input
Pseudo-differential mode is defined as the positive input voltage applied differentially to the ADC128D818, as
shown in Figure 25. The input that is digitized is (ΔVIN = IN+ - IN-), where (IN+ - IN-) is (IN0-IN1), (IN3-IN2),
(IN4-IN5), or (IN7-IN6). Be aware of this input configuration because the order is swapped. In theory, ΔVIN can
be of any value between 0V and (VREF-3LSb/2),where LSb = VREF/212.
By using this pseudo-differential input, small signals common to both inputs are rejected. Thus, operation with a
pseudo-differential input signal will provide better performance than with a single-ended input. Refer to the
Table 3 section for more information.
IN0 (+)
IN1 (-)
+
SRC
-
IN3 (+)
IN2 (-)
ADC128D818
IN4 (+)
IN5 (-)
IN7 (+)
IN6 (-)
Figure 25. Pseudo-Differential Configuration
Modes of Operation
ADC128D818 allows 4 modes of operation, as summarized in the following table. Set the desired mode of
operation using the Advanced Configuration Register — Address 0Bh, bits [2:1]).
Table 3. Modes of Operation
(1)
Ch.
Mode 0
Mode 1
Mode 2
Mode 3
1
IN0
IN0
IN0 (+) & IN1 (-)
IN0
2
IN1
IN1
IN3 (+) & IN2 (-)
IN1
3
IN2
IN2
IN4 (+) & IN5 (-)
IN2
4
IN3
IN3
IN7 (+) & IN6 (-)
IN3
5
IN4
IN4
IN4 (+) & IN5 (-)
6
IN5
IN5
IN7 (+) & IN6 (-)
7
IN6
IN6
8
nc (1)
IN7
Local Temp
Yes
No
Yes
Yes
nc = No Connect
DIGITAL OUTPUT (DOUT)
The digital output code for a 12-bit ADC can be calculated as:
DOUT = [ΔVIN / VREF] x 212
14
(1)
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For the above equation, ΔVIN = INx - GND, where 0 ≤ x ≤ 7, for the single-ended configuration, and ΔVIN = (IN+
- IN-) for the pseudo-differential configuration. In theory, ΔVIN can be of any value between 0V and (VREF3LSb/2). Any ΔVIN value outside of this range will produce a digital output code of 0 or 4095. Figure 26 shows a
theoretical plot of DOUT vs. ΔVIN and some sample DOUT calculation using the equation above.
DOUT
4095d
|
|
3200d
|
|
|
|
2V
1V
'VIN
|
|
|
1600d
(VREF - 3VREF)
12
2(2 )
Figure 26. DOUT vs ΔVIN for a 12-bit ADC assuming VREF = 2.56V.
POWER MANAGEMENT
To understand the average supply current (I+), the conversion rates must be introduced. ADC128D818 has three
types of conversion rates: Continuous Conversion Mode, Low Power Conversion Mode, and One Shot Mode. In
the Low Power Conversion Mode, the device converts all of the enabled channels then enters shutdown mode;
this process takes approximately 728 ms to complete. (More information on the conversion rate will be discussed
in the Conversion Rate Register — Address 07h and One-Shot Register — Address 09h sections).
Each type of conversion produces a different average supply current. The supply current for a voltage conversion
will be referred to as I+_VOLTAGE, a temperature conversion as I+_TEMP, and the shutdown mode as
I+_SHUTDOWN. These values can be obtained from Typical Performance Characteristics plots.
In general, I+ is the average supply current while ADC128D818 is operating in the Low Power Conversion Mode
with all of the available channels enabled. Its plot can be seen in the Typical Performance Characteristics section
and its equation is shown below.
I+ = [(0.0168)(b)(I+_VOLTAGE)] + [(4.932)(10-3)(a)(I+_TEMP)]
+ [1 ± (4.932)(10-3)(a) ± 0.0168(b)](I+_SHUTDOWN)
where
•
•
"a" is the number of local temperature available.
"b" is the number of ENABLED voltage channel.
(2)
Each mode of operation has a different "a" and "b" values. The following table shows the value for "a" and the
maximum value for "b" for each mode.
Table 4. "a" and "b" Values
a
b (Max)
Mode 0
1
7
Mode 1
0
8
Mode 2
1
4
Mode 3
1
6
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INTERFACE
The Serial Bus control lines include the SDA (serial data), SCL (serial clock), and A0-A1 (Serial Bus Address)
pins. The ADC128D818 can only operate as a slave. The SCL line only controls the serial interface, and all of
other clock functions within ADC128D818 are done with a separate asynchronous internal clock.
When the Serial Bus Interface is used, a write will always consists of the ADC128D818 Serial Bus Address byte,
followed by the Register Address byte, then the Data byte. Figure 27 and Figure 28 are two examples showing
how to write to the ADC128D818.
There are two cases for a read:
1. If the Register Address is known to be at the desired address, simply read the ADC128D818 with the Serial
Bus Address byte, followed by the Data byte read from the ADC128D818. Examples of this type of read can
be seen in Figure 29 and Figure 30.
2. If the Register Address value is unknown, write to the ADC128D818 with the Serial Bus Address byte,
followed by the desired Register Address byte. Then restart the Serial Communication with a Read
consisting of the Serial Bus Address byte, followed by the Data byte read from the ADC128D818. See
Figure 31 and Figure 32 for examples of this type of read.
The Serial Bus Address can be found in the next section, and the Register Address can be found in the
REGISTER MAP section. For more information on the I2C Interface, refer to NXP's "I2C-Bus Specification and
User Manual", rev. 03.
Serial Bus Address
There are nine different configurations for the ADC128D818 Serial Bus Address, thus nine devices are allowed
on a single I2C bus. Examples to set each address bit low, high, or to midscale can be found in the EXAMPLE
APPLICATIONS section. The Serial Bus Address can be set as follows:
Table 5. Serial Bus Address Table
A1
A0
Serial Bus Address
[A6][A5][A4]...[A0]
Serial Bus Address (hex)
LOW
LOW
001_1101b
1Dh
LOW
MID
001_1110b
1Eh
LOW
HIGH
001_1111b
1Fh
MID
LOW
010_1101b
2Dh
MID
MID
010_1110b
2Eh
MID
HIGH
010_1111b
2Fh
HIGH
LOW
011_0101b
35h
HIGH
MID
011_0110b
36h
HIGH
HIGH
011_0111b
37h
Timeout
The ADC128D818 I2C state machine resets to its idle state if either SCL or SDA is held low for longer than
35ms. This feature also ensures that ADC128D818 will automatically release SDA after driving it low
continuously for 25-35ms, hence preventing I2C bus lock-up. The TIMEOUT feature should not be used when the
device is operating in deep shutdown mode.
Example Writes and Reads
1
9
1
9
SCL
SDA
A6
A5
A4
A3
A2
A1
A0 R/W
D7
D6
D5
D4
D3
D2
D1
Ack by
ADC128D818
Start by
Master
Frame 1
Serial Bus Address
Byte from Master
D0
Ack by
Stop by
ADC128D818 Master
Frame 2
Register Address
Byte from Master
Figure 27. Serial Bus Interface Write Example 1 - Internal Address Register Set Only.
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1
9
1
9
SCL
SDA
A6
A5
A4
A3
A2
A1
A0 R/W
D7
D6
D5
D4
D3
D2
D1
D0
Ack by
ADC128D818
Start by
Master
Frame 1
Serial Bus Address
Byte from Master
1
SCL
(continued)
SDA
(continued)
Ack by
ADC128D818
Frame 2
Register Address
Byte from Master
9
D7
D6
D5
D4
D3
D2
D0
D1
Stop by
Ack by
ADC128D818 Master
Frame 3
Data Byte
Figure 28. Serial Bus Interface Write Example 2 - Internal Address Register Set with Data Byte Write.
1
9
1
9
SCL
SDA
A6
A5
A4
A3
A2
A1
A0 R/W
Start by
Master
D7
D6
D5
D4
D3
D2
D1
D0
No Ack
by
Master
Ack by
ADC128D818
Frame 1
Serial Bus Address
Byte from Master
Frame 2
Data Byte
from ADC128D818
Stop
by
Master
Figure 29. Serial Bus Interface Read Example 1 - Single Byte Read with Preset Internal Address Register.
1
9
1
9
1
9
SCL
SDA
A6
A5
A4
A3
A2
A1
A0 R/W
Start by
Master
Frame 1
Serial Bus Address
Byte from Master
D15 D14 D13 D12 D11 D10 D9
Ack by
ADC128D818
D8
D7
D6
Ack
by
Master
Frame 2
Data Byte
from ADC128D818
D5
D4
D3
D2
D1
Frame 3
Data Byte
from ADC128D818
D0
No Ack Stop
by
by
Master Master
Figure 30. Serial Bus Interface Read Example 2 - Double Byte Read with Preset Internal Address
Register.
1
9
1
9
SCL
SDA
A6
A5
A4
A3
A2
A1
A0
D7
R/W
D6
D5
D4
SDA
(continued)
D2
D1
Frame 2
Register Address
Byte from Master
1
A6
Repeat
Start by
Master
9
A5
A4
A3
A2
A1
Frame 3
Serial Bus Address
Byte from Master
D0
Ack by
ADC128D818
Frame 1
Serial Bus Address
Byte from Master
SCL
(continued)
D3
Ack by
ADC128D818
Start by
Master
A0 R/W
1
D7
9
D6
D5
D4
D3
D2
D1
Ack by
ADC128D818
Frame 4
Data Byte
from ADC128D818
D0
No Ack Stop
by
by
Master Master
Figure 31. Serial Bus Interface Read Example 3 - Single Byte Read with Internal Address Set using a
Repeat Start.
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1
9
1
9
SCL
SDA
A6
A5
A4
A3
A2
A1
A0 R/W
Start by
Master
D7
D6
D5
SDA
(continued)
D3
D2
D1
Frame 2
Register Address
Byte from Master
1
A6
Repeat
Start by
Master
9
A5
A4
A3
A2
A1
D0
Ack by
ADC128D818
Frame 1
Serial Bus Address
Byte from Master
SCL
(continued)
D4
Ack by
ADC128D818
A0 R/W
1
9
D15 D14 D13 D12 D11 D10 D9
D8
Ack by
ADC128D818
Frame 3
Serial Bus Address
Byte from Master
1
D7
9
D6
D5
Ack by
Master
Frame 4
Data Byte
from ADC128D818
D4
D3
D2
D1
D0
Frame 5
Data Byte from
ADC128D818
No Ack by
Master
Stop
by
Master
Figure 32. Serial Bus Interface Read Example 4 - Double Byte Read with Internal Address Set using a
Repeat Start.
USING THE ADC128D818
Table 6. ADC128D818 Internal Registers
Register Name
Configuration Register
Read/
Write
Register
Address
(hex)
Default Value
[7:0]
R/W
00h
0000_1000
Provides control and configuration
8-bit
8-bit
Register Description
Register
Format
Interrupt Status Register
R
01h
0000_0000
Provides status of each WATCHDOG limit or interrupt
event
Interrupt Mask Register
R/W
03h
0000_0000
Masks the interrupt status from propagating to INT
8-bit
Conversion Rate Register
R/W
07h
0000_0000
Controls the conversion rate
8-bit
08h
0000_0000
Disables conversion for each voltage or temperature
channel
8-bit
Channel Disable Register
One-Shot Register
R/W
W
09h
0000_0000
Initiates a single conversion of all enabled channels
8-bit
Deep Shutdown Register
R/W
0Ah
0000_0000
Enables deep shutdown mode
8-bit
Advanced Configuration
Register
R/W
0Bh
0000_0000
Selects internal or external VREF and modes of
operation
8-bit
Busy Status Register
R
0Ch
0000_0010
Reflects the ADC128D818 'Busy' and 'Not Ready'
statuses
8-bit
Channel Readings
Registers
R
20h - 27h
---
Report channels (voltage or temperature) readings
16-bit
R/W
2Ah - 39h
---
Set the limits for the voltage and temperature
channels
8-bit
Manufacturer ID Register
R
3Eh
0000_0001
Reports the manufacturer's ID
8-bit
Revision ID Register
R
3Fh
0000_1001
Reports the revision's ID
8-bit
Limit Registers
Quick Start
1. Power on the device, then wait for at least 33ms.
2. Read the Busy Status Register (address 0Ch). If the 'Not Ready' bit = 1, then increase the wait time until 'Not
Ready' bit = 0 before proceeding to the next step.
3. Program the Advanced Configuration Register — Address 0Bh:
– a. Choose to use the internal or external VREF (bit 0).
– b. Choose the mode of operation (bits [2:1]).
4. Program the Conversion Rate Register (address 07h).
5. Choose to enable or disable the channels using the Channel Disable Register (address 08h).
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6. Using the Interrupt Mask Register (address 03h), choose to mask or not to mask the interrupt status from
propagating to the interrupt output pin, INT.
7. Program the Limit Registers (addresses 2Ah – 39h).
8. Set the ‘START’ bit of the Configuration Register (address 00h, bit 0) to 1.
9. Set the 'INT_Clear' bit (address 00h, bit 3) to 0. If needed, program the 'INT_Enable' bit (address 00h, bit 1)
to 1 to enable the INT output.
The ADC128D818 then performs a round-robin monitoring of enabled voltage and temperature channels. The
sequence of items being monitored corresponds to locations in the Channel Readings Registers (except for the
temperature reading). Detailed descriptions of the register map can be found at the end of this datasheet.
Power On Reset (POR)
When power is first applied, the ADC128D818 performs a power on reset (POR) on several of its registers, which
sets the registers to their default values. These default values are shown in the table above or in the REGISTER
MAP section.
Registers whose default values are not shown have power on conditions that are indeterminate.
Configuration Register (address 00h)
The Configuration Register (address 00h) provides all control to the ADC128D818. After POR, the 'START' bit
(bit 0) is set low and the 'INT_Clear' bit (bit 3) is set high.
The Configuration Register has the ability to start and stop the ADC128D818, enable and disable the INT output,
and set the registers to their default values.
• Bit 0, ‘START’, controls the monitoring loop of the ADC128D818. After POR, set this bit high to start
conversion. Setting this bit low stops the ADC128D818 monitoring loop and puts the ADC128D818 in
shutdown mode; thus, reducing power consumption. Even though this bit is set low, serial bus communication
is possible with any register in the ADC128D818.
– After an interrupt occurs, the INT pin will not be cleared if the user sets this bit low.
• Bit 1, 'INT_Enable', enables the interrupt output pin, INT, when this bit is set high.
• Bit 3, 'INT_Clear', clears the interrupt output pin, INT, when this bit is set high. When this bit is set high, the
ADC128D818 monitoring function will stop. The content of the Interrupt Status Register (address 01h) will not
be affected.
• Bit 7, ‘INITIALIZATION’, accomplishes the same function as POR, that is, it initializes some of the registers to
their default values. This bit automatically clears after being set high. Setting this bit high, however, does not
reset the Channel Readings Registers (addresses 20h - 27h) and the Limit Registers (addresses 2Ah - 39h).
These registers will be indeterminate immediately after power on. If the Channel Readings Registers contain
valid conversion results and/or the Limit Registers have been previously set, they will not be affected by this
bit.
Interrupt Status Register (address 01h)
Each bit in this read-only register indicates whether the voltage reading > the voltage high limit or ≤ the voltage
low limit, or the temperature reading > the temperature high limit. For example, if "IN0 High Limit" register
(address 2Ah) were set to 2V and if IN0 reading (address 20h) were 2.56V, then bit 'IN0 Error' would be 1,
indicating that the voltage high limit has been exceeded.
Interrupt Mask Register (address 03h)
This register masks the interrupt status from propagating to the interrupt output pin, INT. For example, if bit 'IN0
Mask' = 1, then the interrupt output pin, INT, would not be pulled low even if an error event occurs at IN0.
Conversion Rate Register (address 07h)
There are three options for controlling the conversion rate. The first option is called the Low Power Conversion
Mode, where the device converts all of the enabled channels then enters shutdown mode. This process takes
approximately 728 ms to complete.
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The second option is the Continuous Conversion Mode, where the device continuously converts the enabled
channels, thus never entering shutdown mode. A voltage conversion takes 12.2 ms, and a temperature
conversion takes 3.6 ms. For example, if operating in mode 2 and three voltage channels were enabled, then
each round-robin monitor would take 40.2 ms (3 x 12.2ms + 3.6ms) to complete. Use the "Channel Disable
Register" (address 08h) to disable the desired channel(s).
The third option is called the On-Shot mode, which will be discussed in the next subsection.
One-Shot Register (address 09h)
The One-Shot register is used to initiate a single conversion and comparison cycle when the device is in
shutdown mode or deep shutdown mode, after which the device returns to the respective mode it was in. The
obvious advantage of using this mode is lower power consumption because the device is operating in shutdown
or deep shutdown mode.
This register is not a data register, and it is the write operation that causes the one-shot conversion. The data
written to this address is irrelevant and is not stored. A zero will always be read from this register.
Deep Shutdown Register (address 0Ah)
The ADC128D818 can be placed in deep shutdown mode, thus reducing more power consumption. The
procedures for deep shutdown entrance are:
1. Enter shutdown by setting the ‘START’ bit of the “Configuration Register’ (address 00h, bit 0) to 0.
2. Enter deep shutdown by setting the ‘DEEP SHUTDOWN’ bit (address 0Ah, bit 0) to 1.
3. A one-shot conversion can be triggered by writing any values to register address 09h.
Deep Shutdown Exit Procedure:
1. Set the ‘DEEP SHUTDOWN’ bit to 0.
Channel Readings Registers (addresses 20h - 27h)
The channel conversion readings are available in registers 20h to 27h. Each register is 16-bit wide to
accommodate the 12-bit voltage reading or 9-bit temperature reading. Conversions can be read at any time and
will provide the result of the last conversion. If a conversion is in progress while a communication is started, that
conversion will be completed, and the Channel Reading Registers will not be updated until the communication is
complete.
TEMPERATURE MEASUREMENT SYSTEM
The ADC128D818 delta-VBE type temperature sensor and delta-sigma ADC perform 9-bit two's-complement
conversions of the temperature. This temperature reading can be obtained at the Temperature Reading Register
(address 27h). This register is 16-bit wide, and thus, all 9 bits of the temperature reading can be read using a
double byte read (Figure 30 or Figure 32). The following Figure 33 and the table below it show the theoretical
output code (DOUT) vs. temperature and some typical temperature-to-code conversions.
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(Non-Linear Scale for Clarity)
Figure 33. 9-bit Temperature-to-Digital Transfer Function
Temp
Digital Output (DOUT)
Binary [MSb...LSb]
Decimal
Hex
+125°C
0 _1111_1010
250
0_FA
+25°C
0_0011_0010
50
0_32
+0.5°C
0_0000_0001
1
0_01
+0°C
0_0000_0000
0
0_00
−0.5°C
1_1111_1111
511
1_FF
−25°C
1_1100_1110
462
1_CE
−40°C
1_1011_0000
432
1_B0
In general, the easiest way to calculate the temperature (°C) is to use the following formulas:
If DOUT[MSb] = 0: +Temp(°C) = DOUT(dec) / 2
If DOUT[MSb] = 1: –Temp(°C) = [29 - DOUT(dec)] / 2
(3)
(4)
Temperature Limits
One of the ADC128D818 features is monitoring the temperature reading. This monitoring is accomplished by
setting a temperature limit to the Temperature High Limit Register (Thot , address 38h) and Temperature
Hysteresis Limit Register (Thot_hyst, address 39h). When the temperature reading > Thot, an interrupt occurs. How
this interrupt occurs will be explained in the Temperature Interrupt section.
Each temperature limit is represented by an 8-bit, two's complement word with an LSb (Least Significant bit)
equal to 1°C. The table below shows some sample temperatures that can be programmed to the Temperature
Limit Registers.
In general, use the following equations to calculate the digital code that represents the desired temperature limit:
If Temp Limit (°C) >= 0: Digital Code (dec) = Temp Limit(°C)
If Temp Limit (°C) < 0: Digital Code (dec) = 28 - |Temp Limit(°C)|
Temp Limit
(5)
(6)
Digital Code
Binary [MSb...LSb]
Decimal
Hex
+125°C
0111_1101
125
7D
+25°C
0001_1001
25
19
+1.0°C
0000_0001
1
01
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Digital Code
Temp Limit
Binary [MSb...LSb]
Decimal
Hex
+0°C
0000_0000
0
00
−1.0°C
1111_1111
255
FF
−25°C
1110_1111
231
E7
−40°C
1101_1000
216
D8
INTERRUPT STRUCTURE
IN0 Watchdog
IN1 Watchdog
IN2 Watchdog
IN3 Watchdog
IN4 Watchdog
IN5 Watchdog
IN6 Watchdog
Interrupt
Status
Registers
Interrupt
Mask
Registers
INT
Enable INT_Clear
(00h[1]) (00h[3])
INT
IN7 Watchdog
TEMP Watchdog
Figure 34. Interrupt Structure
Figure 34 shows the ADC128D818's Interrupt Structure. Note that the number next to each bit name represents
its register address and bit number. For example, 'INT_Clear' (00h[3]) refers to bit 3 of register address 00h.
Interrupt Output (INT)
ADC128D818 generates an interrupt as a result of each of its internal WATCHDOG registers on the voltage and
temperature channels. In general, INT becomes active when all three scenarios, as depicted in Figure 34, occur:
1. 'INT_Clear' (00h[3]) = 0.
2. 'INT_Enable' (00h[1]) = 1 to enable interrupt output.
3. The voltage reading > the voltage high limit or ≤ the voltage low limit, or the temperature reading > Thot.
Interrupt Clearing
Reading the Interrupt Status Register (addresses 01h) will output the contents of the register and clear the
register. When the Interrupt Status Register clears, the interrupt output pin, INT, also clears until this register is
updated by the round-robin monitoring loop.
Another method to clear the interrupt output pin, INT, is setting 'INT_Clear' bit (address 00h, bit 3) = 1. When this
bit is high, the ADC128D818 round-robin monitoring loop will stop.
Temperature Interrupt
One of the ADC128D818 features is monitoring the temperature reading. This monitoring is accomplished by
setting a temperature limit to the Temperature High Limit Register (Thot , address 38h) and Temperature
Hysteresis Limit Register (Thot_hyst, address 39h). These limit registers have an interrupt mode, shown in
Figure 35, that operates the the following way: if the temperature reading > Thot, an interrupt will occur and will
remain active indefinitely until reset by reading the Interrupt Status Register (address 01h) or cleared by the
'INT_Clear' bit.
Once an interrupt event has occurred by crossing Thot, then reset, an interrupt will occur again once the next
temperature conversion has completed. The interrupts will continue to occur in this manner until the temperature
reading is ≤ Thot_hyst and a read of the Interrupt Status Register has occurred.
22
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Figure 35. Temperature Response Structure
(Assuming the interrupt output pin, INT, is reset before the next temperature reading)
EXAMPLE APPLICATIONS
General Voltage Monitoring
V+
+
1 PF
LM4140
1 PF
0.1 PF
VREF
+
R1
SCL
IN1
VIN2
IN2
R2
IN3
IN4+
VS2
Positive
PseudoDifferential
Input Voltage
R
SDA
IN0
IN5-
R3
ADC128D818
VS1
R
0.1 PF
(optional)
Positive
Single-Ended
Input Voltage
R
INT
GPO1
RA_top
A0
Microcontroller
RA_bottom
GPO2
GPO3
IN7+
RA_top
R4
A1
IN6-
RTRACE
RA_bottom
GND
GPO4
Figure 36. Typical Analog Input Application
A typical application for ADC128D818 is voltage monitoring. In this application, the inputs would most often be
connected to linear power supplies of 2.5V, 3.3V, ±5V and ±12V inputs. These inputs should be attenuated with
external resistors to any desired value within the input range. The attenuation is done with resistors R1 and R2
for the positive single-ended voltage, and R3 and R4 for the positive pseudo-differential voltage.
A typical single-ended application might select the input voltage divider to provide 1.9V at the analog input of the
ADC128D818. This is sufficiently high for good resolution of the voltage, yet leaves headroom for upward
excursions from the supply of about 25%. To simplify the process of resistor selection, set the value of R2 first.
Select a value for R2 between 10 kOhm and 100 kOhm. This is low enough to avoid errors due to input leakage
currents yet high enough to protect both the inputs under and overdrive conditions as well as minimize loading of
the source. Finally, calculate R1 to provide a 1.9V input using simple voltage divider derived formula:
R1 = [(VS1 - VIN2) / VIN2 ] x R2
(7)
Care should be taken to bypass V+ with decoupling 0.1 µF ceramic capacitor and 1 µF tantalum capacitor. If
using the external reference option, VREF should be connected to a voltage reference, such as the LM4140, and
should also be decoupled to the ground plane by a 0.1 µF ceramic capacitor and a 1 µF tantalum capacitor. For
both supplies, the 0.1 µF capacitor should be located as close as possible to the ADC128D818.
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Since SDA, SCL, and INT are open-drain pins, they should have external pull-up resistors to ensure that the bus
is pulled high until a master device or slave device sinks enough current to pull the bus low. A typical pull-up
resistor, R, ranges from 1.1 kOhm to 10 kOhm. Refer to NXP's "I2C-Bus Specification and User Manual" for
more information on sizing R.
Because there are two tri-level address pins (A0 and A1), up to 9 devices can share the same I2C bus. A trick to
set these serial addresses utilizes four GPO (general purpose output) pins from the master device as shown in
the example diagram. A table showing how to program these GPO pins can be seen below.
Table 7. Setting Serial Bus Address using GPO
A1
A0
GPO1
GPO2
GPO3
GPO4
LOW
LOW
Z
LOW
Z
LOW
LOW
MID
Z
LOW
HIGH
LOW
LOW
HIGH
Z
LOW
HIGH
Z
MID
LOW
HIGH
LOW
Z
LOW
MID
MID
HIGH
LOW
HIGH
LOW
MID
HIGH
HIGH
LOW
HIGH
Z
HIGH
LOW
HIGH
Z
Z
LOW
HIGH
MID
HIGH
Z
HIGH
LOW
HIGH
HIGH
HIGH
Z
HIGH
Z
Voltage Monitoring for Power Supplies
V+
+
1 PF
LM4140
1 PF
(optional)
10VIN
+
0.1 PF
R
VREF
R
R
SDA
0.1 PF
IN0
SCL
SHUTDOWN
DC-DC
IN2
argining Voltage
IN3
IN4+
ADC128D818
IN1
INT
V+
RB_top
Microcontroller
A0
RB_bottom
IN5-
V+
IN6
RB_top
RTRACE
A1
IN7
RB_bottom
GND
Figure 37. Power Supply Application
Figure 37 shows a more complete systems application using a DC/DC converter. Such configuration can be used
in a power supply application. The point to make with this example diagram is the Serial Bus Address
connections. The previous example shows A0 and A1 connected to four GPOs, but this example shows a
simpler A0 and A1 connection using two resistor dividers. This connection accomplishes the same goal as the
GPO connection, that is, it can set A0 and A1 high, low, or to midscale.
For example, to set A0 high, don't populate RB_bottom; to set A0 low, don't populate RB_top; and to set A0 to
midscale, leave RB_top and RB_bottom as is and set them equal to each other. A typical RB value ranges from
1 kOhm to 10 kOhm.
24
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Temperature Sensors
V+
1 PF
LM4140
1 PF
+
+
0.1 PF
R
VREF
R
SDA
0.1 PF
IN0
(optional)
R
SCL
VDD
GS1
GS0
LM94022
IN2
IN3
OUT
GND
IN4
ADC128D818
IN1
INT
GPO1
RA_top
Microcontroller
A0
RA_bottom
GPO2
IN5
GPO3
RA_top
IN6
A1
RA_bottom
IN7
GND
GPO4
Figure 38. Temperature Sensor Applications
An external temperature sensor can be connected to any of ADC128D818's eight single-ended input for
additional temperature sensing. One such temperature sensor can be TI's LM94022, a precision analog
temperature sensor with selectable gains. The application diagram shows LM94022's gains (GS1 and GS0) both
grounded indicating the lowest gain setting. Four possible gains can be set using these GS1 and GS0 pins.
According to the LM94022 datasheet, the voltage-to-temperature output plot can be determined using the
method of linear approximation as follows:
V - V1 = (V2 - V1) / (T2 - T1) x (T - T1)
(8)
Where V is in mV, T is in °C, V1 and T1 are the coordinates of the lowest temperature, and T2 and V2 are the
coordinates of the highest temperature.
For example, to determine the equation of a line over a temperature range of 20°C to 50°C, first find V1 and V2
relative to those temperatures, then use the above equation to find the transfer function.
V - 925 mV = (760 mV - 925 mV) / (50C - 20°C) x (T - 20°C)
V = (-5.50 mV /°C) x T + 1035 mV
(9)
(10)
For more information and explanation of this example, refer to the LM94022 datasheet.
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Bridge Sensors
V+
1 PF
LM4140
1 PF
+
0.1 PF
R
VREF
+
R2
SDA
SCL
IN2
1
+
2
1
1-
IN3
IN4
Instrumentation
Op-Amp
R2
ADC128D818
IN1
Bridge Sensor
R2
R
0.1 PF
IN0
R2
R
INT
V+
Microcontroller
RB_top
A0
RB_bottom
V+
IN5
IN6
RB_top
A1
IN7
RB_bottom
GND
Figure 39. Bridge Sensor Application
ADC128D818 is perfect for transducer applications such as pressure sensors. These sensors measure pressure
of gases or liquids and produce a pressure-equivalent voltage at their outputs. Figure 39 shows a typical
connection of a pressure sensor, represented by the bridge sensor.
Most pressure sensor has a low sensitivity characteristic, which means its output is typically in the millivolts
range. Because of that reason, an op-amp, such as an instrumentation amplifier, can be used for the gain stage.
The positive aspect of this configuration is its ratiometric connection. A ratiometric connection is when the ADC’s
VREF and GND are connected to the bridge sensor’s voltage references. With a ratiometric configuration,
external VREF accuracy can be ignored.
Layout and Grounding
Analog inputs will provide best accuracy when referred to the GND pin or a supply with low noise. A separate,
low-impedance ground plane for analog ground, which provides a ground point for the voltage dividers and
analog components, will provide best performance but is not mandatory. Analog components such as voltage
dividers should be located physically as close as possible to the ADC128D818.
REGISTER MAP
ADC128D818 Internal Registers
Table 8. ADC128D818 Internal Registers
Register Name
Configuration Register
Read/
Write
Register
Address
(hex)
Default Value
[7:0]
R/W
00h
0000_1000
Provides control and configuration
8-bit
8-bit
Register Description
Register
Format
Interrupt Status Register
R
01h
0000_0000
Provides status of each WATCHDOG limit or
interrupt event
Interrupt Mask Register
R/W
03h
0000_0000
Masks the interrupt status from propagating
to INT
8-bit
Conversion Rate Register
R/W
07h
0000_0000
Controls the conversion rate
8-bit
Channel Disable Register
R/W
08h
0000_0000
Disables conversion for each voltage or
temperature channel
8-bit
W
09h
0000_0000
Initiates a single conversion of all enabled
channels
8-bit
R/W
0Ah
0000_0000
Enables deep shutdown mode
8-bit
One-Shot Register
Deep Shutdown Register
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Table 8. ADC128D818 Internal Registers (continued)
Register Name
Read/
Write
Register
Address
(hex)
Default Value
[7:0]
Register Description
Register
Format
Advanced Configuration Register
R/W
0Bh
0000_0000
Selects internal or external VREF and modes
of operation
8-bit
Busy Status Register
R
0Ch
0000_0010
Reflects ADC128D818 'Busy' and 'Not Ready'
statuses
8-bit
Channel Readings Registers
R
20h - 27h
---
Report the channels (voltage or temperature)
readings
16-bit
R/W
2Ah - 39h
---
Set the limits for the voltage and temperature
channels
8-bit
Manufacturer ID Register
R
3Eh
0000_0001
Reports the manufacturer's ID
8-bit
Revision ID Register
R
3Fh
0000_1001
Reports the revision's ID
8-bit
Limit Registers
Configuration Register — Address 00h
Default Value [7:0] = 0000_1000 binary
Bit
Bit Name
Read/Write
Bit(s) Description
ALL MODES
0
Start
Read/Write
0: ADC128D818 in shutdown mode
1: Enable startup of monitoring operations
1
INT_Enable
Read/Write
1: Enable the interrupt output pin, INT
2
Reserved
Read Only
3
INT_Clear
Read/Write
4
Reserved
Read Only
5
Reserved
Read Only
6
Reserved
Read Only
7
Initialization
Read/Write
1: Clear the interrupt output pin, INT, without affecting the contents of Interrupt Status
Registers. When this bit is set high, the device stops the round-robin monitoring loop.
1: Restore default values to the following registers: Configuration, Interrupt Status, Interrupt
Mask, Conversion Rate, Channel Disable, One-Shot, Deep Shutdown, Advanced
Configuration, Busy Status, Channel Readings, Limit, Manufacturer ID, Revision ID. This bit
clears itself
Interrupt Status Register — Address 01h
Default Value [7:0] = 0000_0000 binary
Bit
Bit Name
Read/Write
Bit(s) Description
0
IN0 Error
Read Only
1: A High or Low limit has been exceeded
1
IN1 Error
Read Only
1: A High or Low limit has been exceeded
2
IN2 Error
Read Only
1: A High or Low limit has been exceeded
3
IN3 Error
Read Only
1: A High or Low limit has been exceeded
4
IN4 Error
Read Only
1: A High or Low limit has been exceeded
5
IN5 Error
Read Only
1: A High or Low limit has been exceeded
6
IN6 Error
Read Only
1: A High or Low limit has been exceeded
7
Hot Temperature Error
Read Only
1: A High limit has been exceeded
0
IN0 Error
Read Only
1: A High or Low limit has been exceeded
1
IN1 Error
Read Only
1: A High or Low limit has been exceeded
2
IN2 Error
Read Only
1: A High or Low limit has been exceeded
3
IN3 Error
Read Only
1: A High or Low limit has been exceeded
4
IN4 Error
Read Only
1: A High or Low limit has been exceeded
MODE 0
MODE 1
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Bit
Bit Name
Read/Write
5
IN5 Error
Read Only
1: A High or Low limit has been exceeded
Bit(s) Description
6
IN6 Error
Read Only
1: A High or Low limit has been exceeded
7
IN7 Error
Read Only
1: A High or Low limit has been exceeded
0
IN0(+) & IN1(-) Error
Read Only
1: A High or Low limit has been exceeded
1
IN3(+) & IN2(-) Error
Read Only
1: A High or Low limit has been exceeded
2
IN4(+) & IN5(-) Error
Read Only
1: A High or Low limit has been exceeded
3
IN7(+) & IN6(-) Error
Read Only
1: A High or Low limit has been exceeded
4
Reserved
Read Only
5
Reserved
Read Only
6
Reserved
Read Only
7
Hot Temperature Error
Read Only
1: A High limit has been exceeded
0
IN0 Error
Read Only
1: A High or Low limit has been exceeded
1
IN1 Error
Read Only
1: A High or Low limit has been exceeded
2
IN2 Error
Read Only
1: A High or Low limit has been exceeded
3
IN3 Error
Read Only
1: A High or Low limit has been exceeded
4
IN4(+) & IN5(-) Error
Read Only
1: A High or Low limit has been exceeded
5
IN7(+) & IN6(-) Error
Read Only
1: A High or Low limit has been exceeded
6
Reserved
Read Only
7
Hot Temperature Error
Read Only
MODE 2
MODE 3
1: A High limit has been exceeded
Interrupt Mask Register — Address 03h
Default Value [7:0] = 0000_0000 binary
Bit
Bit Name
Read/Write
Bit(s) Description
0
IN0 Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
1
IN1 Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
2
IN2 Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
3
IN3 Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
4
IN4 Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
5
IN5 Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
6
IN6 Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
7
Temperature Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
0
IN0 Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
1
IN1 Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
2
IN2 Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
3
IN3 Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
MODE 0
MODE 1
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Bit
Bit Name
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Read/Write
Bit(s) Description
4
IN4 Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
5
IN5 Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
6
IN6 Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
7
IN7 Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
0
IN0(+) & IN1(-) Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
1
IN3(+) & IN2(-) Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
2
IN4(+) & IN5(-) Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
3
IN7(+) & IN6(-) Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
4
Reserved
Read Only
5
Reserved
Read Only
6
Reserved
Read Only
7
Temperature Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
0
IN0 Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
1
IN1 Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
2
IN2 Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
3
IN3 Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
4
IN4(+) & IN5(-) Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
5
IN7(+) & IN6(-) Mask
Read/Write
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
6
Reserved
Read Only
7
Temperature Mask
Read/Write
MODE 2
MODE 3
1: Mask the corresponding interrupt status from propagating to the interrupt
output pin, INT
Conversion Rate Register — Address 07h
Default Value [7:0] = 0000_0000 binary
Bit
0
1–7
Bit Name
Read/Write
Conversion Rate
Read/Write
Reserved
Read Only
Bit(s) Description
Controls the conversion rate:
0: Low Power Conversion Mode
1: Continuous Conversion Mode
Note: This register must only be programmed when the device is in shutdown
mode, that is, when the 'START' bit of the 'Configuration Register' (address 00h)
=0
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Channel Disable Register — Address 08h
Default Value [7:0] = 0000_0000 binary
• This register must only be programmed when the device is in shutdown mode, that is, when the ‘START’ bit
of the “Configuration Register’ (address 00h) = 0.
• Whenever this register is programmed, all of the values in the Channel Reading Registers and Interrupt
Status Registers will return to their default values.
Bit
Bit Name
Read/Write
Bit(s) Description
MODE 0
0
IN0 Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
1
IN1 Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
2
IN2 Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed
3
IN3 Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
4
IN4 Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
5
IN5 Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
6
IN6 Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
7
Temperature Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
0
IN0 Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
1
IN1 Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
2
IN2 Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
3
IN3 Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
4
IN4 Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
5
IN5 Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
6
IN6 Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
7
IN7 Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
0
IN0(+) & IN1(-) Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
1
IN3(+) & IN2(-) Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
2
IN4(+) & IN5(-) Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
3
IN7(+) & IN6(-) Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
4
Reserved
Read Only
5
Reserved
Read Only
6
Reserved
Read Only
7
Temperature Disable
Read/Write
MODE 1
MODE 2
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
MODE 3
30
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Bit
SNAS483E – FEBRUARY 2010 – REVISED MARCH 2013
Bit Name
Read/Write
Bit(s) Description
0
IN0 Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
1
IN1 Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
2
IN2 Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
3
IN3 Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
4
IN4(+) & IN5(-) Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
5
IN7(+) & IN6(-) Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
6
Reserved
Read Only
7
Temperature Disable
Read/Write
1: Conversions are skipped and disabled, value register reading will be 0, and
error events will be suppressed.
One-Shot Register — Address 09h
Default Value [7:0] = 0000_0000 binary
Bit
Bit Name
Read/Write
0
One-Shot
Write Only
1–7
Reserved
Read Only
Bit(s) Description
1: Initiate a single conversion and comparison cycle when the device is in
shutdown mode or deep shutdown mode, after which the device returns to the
respective mode that it was in
Deep Shutdown Register — Address 0Ah
Default Value [7:0] = 0000_0000 binary
Bit
0
1–7
Bit Name
Read/Write
Deep Shutdown Enable
Read/Write
Reserved
Read Only
Bit(s) Description
1: When 'START' = 0 (address 00h, bit 0), setting this bit high will place the
device in deep shutdown mode
Advanced Configuration Register — Address 0Bh
Default Value [7:0] = 0000_0000 binary
Note: Whenever the Advanced Configuration Register is programmed, all of the values in the Channel Reading
Registers and Interrupt Status Registers will return to their default values.
Bit
0
1
2
3–7
Bit Name
External Reference Enable
Mode Select [0]
Read/Write
Read/Write
Read/Write
Mode Select [1]
Reserved
Bit(s) Description
0: Selects the 2.56V internal VREF
1: Selects the variable external VREF
Mode Select [1]
Mode Select [0]
Mode
0
0
Mode 0
0
1
Mode 1
1
0
Mode 2
1
1
Mode 3
Read Only
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ADC128D818
SNAS483E – FEBRUARY 2010 – REVISED MARCH 2013
www.ti.com
Busy Status Register — Address 0Ch
Default Value [7:0] = 0000_0010 binary
Bit
Bit Name
Read/Write
0
Busy
Read Only
1: ADC128D818 is converting
Bit(s) Description
1
Not Ready
Read Only
1: Waiting for the power-up sequence to end
2–7
Reserved
Read Only
Channel Readings Registers — Addresses 20h – 27h
Address
Register Name
Read/Write
Register Description
MODE 0
20h
IN0 Reading
Read Only
Reading for this perspective channel
21h
IN1 Reading
Read Only
Reading for this perspective channel
22h
IN2 Reading
Read Only
Reading for this perspective channel
23h
IN3 Reading
Read Only
Reading for this perspective channel
24h
IN4 Reading
Read Only
Reading for this perspective channel
25h
IN5 Reading
Read Only
Reading for this perspective channel
26h
IN6 Reading
Read Only
Reading for this perspective channel
27h
Temperature Reading
Read Only
Reading for this perspective channel
20h
IN0 Reading
Read Only
Reading for this perspective channel
21h
IN1 Reading
Read Only
Reading for this perspective channel
22h
IN2 Reading
Read Only
Reading for this perspective channel
23h
IN3 Reading
Read Only
Reading for this perspective channel
24h
IN4 Reading
Read Only
Reading for this perspective channel
25h
IN5 Reading
Read Only
Reading for this perspective channel
26h
IN6 Reading
Read Only
Reading for this perspective channel
27h
IN7 Reading
Read Only
Reading for this perspective channel
20h
IN0(+) & IN1(-) Reading
Read Only
Reading for this perspective channel
21h
IN3(+) & IN2(-) Reading
Read Only
Reading for this perspective channel
22h
IN4(+) & IN5(-) Reading
Read Only
Reading for this perspective channel
23h
IN7(+) & IN6(-) Reading
Read Only
Reading for this perspective channel
24h
Reserved
Read Only
25h
Reserved
Read Only
26h
Reserved
Read Only
27h
Temperature Reading
Read Only
Reading for this perspective channel
20h
IN0 Reading
Read Only
Reading for this perspective channel
21h
IN1 Reading
Read Only
Reading for this perspective channel
22h
IN2 Reading
Read Only
Reading for this perspective channel
23h
IN3 Reading
Read Only
Reading for this perspective channel
24h
IN4(+) & IN5(-) Reading
Read Only
Reading for this perspective channel
25h
IN7(+) & IN6(-) Reading
Read Only
Reading for this perspective channel
26h
Reserved
Read Only
27h
Temperature Reading
Read Only
MODE 1
MODE 2
MODE 3
32
Reading for this perspective channel
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SNAS483E – FEBRUARY 2010 – REVISED MARCH 2013
Limit Registers — Addresses 2Ah – 39h
Address
Register Name
Read/
Register Description
MODE 0
2Ah
IN0 High Limit
Read/Write
High Limit
2Bh
IN0 Low Limit
Read/Write
Low Limit
2Ch
IN1 High Limit
Read/Write
High Limit
2Dh
IN1 Low Limit
Read/Write
Low Limit
2Eh
IN2 High Limit
Read/Write
High Limit
2Fh
IN2 Low Limit
Read/Write
Low Limit
30h
IN3 High Limit
Read/Write
High Limit
31h
IN3 Low Limit
Read/Write
Low Limit
32h
IN4 High Limit
Read/Write
High Limit
33h
IN4 Low Limit
Read/Write
Low Limit
34h
IN5 High Limit
Read/Write
High Limit
35h
IN5 Low Limit
Read/Write
Low Limit
36h
IN6 High Limit
Read/Write
High Limit
37h
IN6 Low Limit
Read/Write
Low Limit
38h
Temperature High Limit
Read/Write
High Limit
39h
Temperature Hysteresis Limit
Read/Write
Hysteresis Limit
2Ah
IN0 High Limit
Read/Write
High Limit
2Bh
IN0 Low Limit
Read/Write
Low Limit
2Ch
IN1 High Limit
Read/Write
High Limit
2Dh
IN1 Low Limit
Read/Write
Low Limit
2Eh
IN2 High Limit
Read/Write
High Limit
2Fh
IN2 Low Limit
Read/Write
Low Limit
30h
IN3 High Limit
Read/Write
High Limit
31h
IN3 Low Limit
Read/Write
Low Limit
32h
IN4 High Limit
Read/Write
High Limit
33h
IN4 Low Limit
Read/Write
Low Limit
34h
IN5 High Limit
Read/Write
High Limit
35h
IN5 Low Limit
Read/Write
Low Limit
36h
IN6 High Limit
Read/Write
High Limit
37h
IN6 Low Limit
Read/Write
Low Limit
38h
IN7 High Limit
Read/Write
High Limit
39h
IN7 Low Limit
Read/Write
Low Limit
2Ah
IN0(+) & IN1(-) High Limit
Read/Write
High Limit
MODE 1
MODE 2
2Bh
IN0(+) & IN1(-) Low Limit
Read/Write
Low Limit
2Ch
IN3(+) & IN2(-) High Limit
Read/Write
High Limit
2Dh
IN3(+) & IN2(-) Low Limit
Read/Write
Low Limit
2Eh
IN4(+) & IN5(-) High Limit
Read/Write
High Limit
2Fh
IN4(+) & IN5(-) Low Limit
Read/Write
Low Limit
30h
IN7(+) & IN6(-) High Limit
Read/Write
High Limit
31h
IN7(+) & IN6(-) Low Limit
Read/Write
Low Limit
32h
Reserved
Read Only
33h
Reserved
Read Only
34h
Reserved
Read Only
35h
Reserved
Read Only
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ADC128D818
SNAS483E – FEBRUARY 2010 – REVISED MARCH 2013
Address
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Register Name
Read/
Register Description
36h
Reserved
Read Only
37h
Reserved
Read Only
38h
Temperature High Limit
Read/Write
High Limit
39h
Temperature Hysteresis Limit
Read/Write
Hysteresis Limit
2Ah
IN0 High Limit
Read/Write
High Limit
2Bh
IN0 Low Limit
Read/Write
Low Limit
2Ch
IN1 High Limit
Read/Write
High Limit
2Dh
IN1 Low Limit
Read/Write
Low Limit
2Eh
IN2 High Limit
Read/Write
High Limit
2Fh
IN2 Low Limit
Read/Write
Low Limit
30h
IN3 High Limit
Read/Write
High Limit
31h
IN3 Low Limit
Read/Write
Low Limit
32h
IN4(+) & IN5(-) High Limit
Read/Write
High Limit
33h
IN4(+) & IN5(-) Low Limit
Read/Write
Low Limit
34h
IN7(+) & IN6(-) High Limit
Read/Write
High Limit
35h
IN7(+) & IN6(-) Low Limit
Read/Write
Low Limit
36h
Reserved
Read Only
37h
Reserved
Read Only
38h
Temperature High Limit
Read/Write
High Limit
39h
Temperature Hysteresis Limit
Read/Write
Hysteresis Limit
MODE 3
Manufacturer ID Register — Address 3Eh
Default Value [7:0] = 0000_0001 binary
Address
Register Name
Read/Write
Register Description
3Eh
Manufacturer ID
Read Only
Manufacturer's ID always defaults to 0000_0001.
Revision ID Register — Addresses 3Fh
Default Value [7:0] = 0000_1001 binary
Address
3Fh
34
Register Name
Read/Write
Revision ID
Read Only
Register Description
Revision's ID always defaults to 0000_1001.
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SNAS483E – FEBRUARY 2010 – REVISED MARCH 2013
REVISION HISTORY
Changes from Revision D (March 2013) to Revision E
•
Page
Changed layout of National Data Sheet to TI format .......................................................................................................... 34
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35
PACKAGE OPTION ADDENDUM
www.ti.com
11-Apr-2013
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
Lead/Ball Finish
(2)
MSL Peak Temp
Op Temp (°C)
Top-Side Markings
(3)
(4)
ADC128D818CIMT/NOPB
ACTIVE
TSSOP
PW
16
92
Green (RoHS
& no Sb/Br)
CU SN
Level-1-260C-UNLIM
-40 to 125
128D818
CIMT
ADC128D818CIMTX/NOPB
ACTIVE
TSSOP
PW
16
2500
Green (RoHS
& no Sb/Br)
CU SN
Level-1-260C-UNLIM
-40 to 125
128D818
CIMT
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability
information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that
lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between
the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight
in homogeneous material)
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4)
Multiple Top-Side Markings will be inside parentheses. Only one Top-Side Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a
continuation of the previous line and the two combined represent the entire Top-Side Marking for that device.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
Addendum-Page 1
Samples
PACKAGE MATERIALS INFORMATION
www.ti.com
21-Mar-2013
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device
ADC128D818CIMTX/NOP
B
Package Package Pins
Type Drawing
TSSOP
PW
16
SPQ
Reel
Reel
A0
Diameter Width (mm)
(mm) W1 (mm)
2500
330.0
12.4
Pack Materials-Page 1
6.95
B0
(mm)
K0
(mm)
P1
(mm)
8.3
1.6
8.0
W
Pin1
(mm) Quadrant
12.0
Q1
PACKAGE MATERIALS INFORMATION
www.ti.com
21-Mar-2013
*All dimensions are nominal
Device
ADC128D818CIMTX/NOP
B
Package Type
Package Drawing
Pins
SPQ
Length (mm)
Width (mm)
Height (mm)
TSSOP
PW
16
2500
349.0
337.0
45.0
Pack Materials-Page 2
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