Datasheet
AS8650
High-efficient Power Management Device with High-speed CAN
Interface
1 General Description
2 Key Features
DCDC converter for 5V output with very high efficiency
The AS8650 is a companion IC which combines power management
functions and a fully conforming high speed CAN Transceiver in one
high performance analog device for automotive applications. The
AS8650 is powered by the battery, provides 4 output voltage levels
of which 3 outputs can be individually programmed in the range of
1.8V to 3.3V with a maximum current consumption up to 120mA at
the LDO voltage regulator outputs. An integrated DCDC converter
with a very high efficiency for the 5V output supplies the 3 voltage
regulators and ensures a voltage stability of ± 2.5%. The
combination of DCDC converter with low-drop-out voltage regulators
makes the AS8650 suitable for all Automotive Control Units where
power efficiency is a must.
2 programmable voltage regulators in the range of 1.8V to 3.3V
High-speed CAN interface (ISO 11898) with remote wake-up
Comprehensive voltage monitoring
Configurable watchdog functions for start-up, operation, and
standby
Automatic thermal shutdown protection
Excellent EMC performance with outstanding switching
technology for the DCDC converter
Ambient temperature range from -40°C to +105°C in maximum
load conditions
The AS8650 provides a high-speed CAN interface up to 1Mbps
communication rate conforming to ISO 11898. The AS8650 provides
wake-up via remote wake-up at CAN bus lines and a local wake pin.
The watchdog unit provides three different timing functions: start-up,
window- and time-out watchdog; configurable via the SPI and I2C
interface.
Lead-free 36-pin QFN (6x6x0.9) package
3 Applications
The AS8650 provides high efficient and flexible power supply
together with state-of-the-art high speed CAN Interface for
automotive control units.The device is pin compatible with AS8550
(LIN interface) in order to change from CAN to LIN easy.
Voltage monitoring is implemented for the battery supply, DCDC
output and the 3 LDO regulator outputs. Undervoltage will be
signalled on the INTN pin to the microcontroller. All diagnostics and
status flags can be accessed with the SPI interface.
The product is available in a 36-pin QFN (6x6x0.9) package.
Figure 1. AS8650 Block Diagram
VSUP
AS8650
I2C_EN
FB
CSSPI
SCLKI2C / SCLKSPI
SDAI2C / SDISPI
I2C
SPI
DC / DC Converter 5V
LX
SDOSPI
INTN
Configurable
Voltage
Regulator
CANH
SPLIT
CANL
RxD
High-speed
CAN
Transceiver
Digital
Logic
TxD
RESET
Configurable
Voltage
Regulator
Configurable
Voltage
Regulator
Watchdog
WAKE
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Revision 1.0
V5V_LDO1
V5V_LDO2
V5V_LDO3
VREG
VREG
VREG
GND
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AS8650
Datasheet - C o n t e n t s
Contents
1 General Description ..................................................................................................................................................................
1
2 Key Features.............................................................................................................................................................................
1
3 Applications...............................................................................................................................................................................
1
4 Pin Assignments .......................................................................................................................................................................
4
4.1 Pin Descriptions....................................................................................................................................................................................
4
5 Absolute Maximum Ratings ......................................................................................................................................................
6
6 Electrical Characteristics...........................................................................................................................................................
7
6.1 Electrical System Specification.............................................................................................................................................................
8
6.2 DCDC Converter ..................................................................................................................................................................................
8
6.3 Low Drop Out Regulators .....................................................................................................................................................................
9
6.4 CAN Transceiver ................................................................................................................................................................................
10
6.4.1 Timing Diagrams........................................................................................................................................................................ 12
6.5 Undervoltage Detection ......................................................................................................................................................................
7 Detailed Description................................................................................................................................................................
14
7.1 Operating Modes and States..............................................................................................................................................................
7.1.1
7.1.2
7.1.3
7.1.4
13
Normal Mode .............................................................................................................................................................................
Receive-only Mode ....................................................................................................................................................................
Standby Mode............................................................................................................................................................................
Sleep Mode................................................................................................................................................................................
14
14
14
14
14
7.2 Power Management Strategy .............................................................................................................................................................
14
7.3 State Diagram.....................................................................................................................................................................................
17
7.4 Initialization Sequence........................................................................................................................................................................
17
7.5 DCDC Converter ................................................................................................................................................................................
19
7.6 Voltage Regulator LDO1.....................................................................................................................................................................
19
7.7 Voltage Regulator LDO2.....................................................................................................................................................................
19
7.8 Voltage Regulator LDO3.....................................................................................................................................................................
19
7.9 Over-Temperature Monitor .................................................................................................................................................................
19
7.10 Undervoltage Reset..........................................................................................................................................................................
19
7.11 Reset Block......................................................................................................................................................................................
20
7.12 CAN Transceiver ..............................................................................................................................................................................
7.12.1
7.12.2
7.12.3
7.12.4
7.12.5
7.12.6
BUS Driver...............................................................................................................................................................................
Normal Receiver ......................................................................................................................................................................
Low Power Receiver................................................................................................................................................................
Operating Modes .....................................................................................................................................................................
Local Wake-up Event...............................................................................................................................................................
Remote Wake-up.....................................................................................................................................................................
7.13 Internal Flags....................................................................................................................................................................................
7.13.1
7.13.2
7.13.3
7.13.4
7.13.5
7.13.6
7.13.7
7.13.8
VSUP_UV_flag ........................................................................................................................................................................
VSUP_POK_flag......................................................................................................................................................................
V5V_UV_flag ...........................................................................................................................................................................
V5V_POK_flag.........................................................................................................................................................................
VLDO2_UV_flag ......................................................................................................................................................................
VLDO2_POK_flag....................................................................................................................................................................
VLDO3_UV_flag ......................................................................................................................................................................
VLDO3_POK_flag....................................................................................................................................................................
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21
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21
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22
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AS8650
Datasheet - C o n t e n t s
7.13.9 BUS Wake_up Flag .................................................................................................................................................................
7.13.10 Local Wake_up Flag ..............................................................................................................................................................
7.13.11 OVT_Warning Flag ................................................................................................................................................................
7.13.12 OVT_Recover Flag ................................................................................................................................................................
7.13.13 Bus Failure Flags...................................................................................................................................................................
7.13.14 Local Failure Flags ................................................................................................................................................................
7.14 Watchdog (WD) ................................................................................................................................................................................
23
24
24
24
24
24
25
7.14.1 Start-up Watchdog Behavior.................................................................................................................................................... 25
7.14.2 Window Watchdog Behavior.................................................................................................................................................... 25
7.14.3 Time-out Watchdog Behavior .................................................................................................................................................. 26
7.15 Interrupt Generation .........................................................................................................................................................................
26
7.16 Status Registers ...............................................................................................................................................................................
27
8 Application Information ...........................................................................................................................................................
28
8.1 Serial Peripheral Interface ..................................................................................................................................................................
28
8.1.1 SPI Write Operation................................................................................................................................................................... 29
8.1.2 SPI Read Operation................................................................................................................................................................... 30
8.1.3 SPI Timing Diagram................................................................................................................................................................... 31
8.2 Inter-Integrated Circuit (I2C) Interface................................................................................................................................................
32
8.2.1 I2C Write Operation ................................................................................................................................................................... 32
8.2.2 I2C Read Operation................................................................................................................................................................... 33
8.3 Digital Timing Specification ................................................................................................................................................................
34
8.3.1 System Specification and Timings............................................................................................................................................. 37
8.4 Register Space ...................................................................................................................................................................................
38
9 Package Drawings and Markings ...........................................................................................................................................
43
10 Ordering Information.............................................................................................................................................................
45
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AS8650
Datasheet - P i n A s s i g n m e n t s
4 Pin Assignments
LX
LX
FB
V5V_LDO2
V5V_LDO3
V5V_LDO1
VLDO3
36
LX
Figure 2. Pin Assignments (Top View)
35
34
33
32
31
30
29
28
VSUP
1
27
VLDO3FB
VSUP
2
26
VLDO2
VSUP
3
25
VLDO2FB
GND_DCDC
4
24
VLDO1FB
GND
5
23
VLDO1
WAKE
6
22
RESERVED
CANH
7
21
RESERVED
CANL
8
20
RESERVED
GND_CAN
9
19
RESET
AS8650
QFN 6x6x0.9
13
14
15
16
17
18
SCLKI2C (SCLKSPI)
CSSPI
RxD
INTN
TxD
I2C_EN
12
SDOSPI
11
SDAI2C / SDISPI
10
SPLIT
GND
(Exposed pad)
4.1 Pin Descriptions
Table 1. Pin Descriptions
Pin
Pin Name
1, 2, 3
VSUP
4
GND_DCDC
5
GND
6
WAKE
7
CANH
Analog Input / Output high-voltage High level CAN bus line
8
CANL
Low level CAN bus line
9
GND_CAN
10
SPLIT
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Pin Type
Description
Power Supply Input
Power Supply
Local wake request (high-voltage input)
Power Supply Input
Power supply
Analog Input / Output high-voltage Common-mode stabilization output
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AS8650
Datasheet - P i n A s s i g n m e n t s
Table 1. Pin Descriptions
Pin
Pin Name
Pin Type
11
I2C_EN
Digital Input
12
SDAI2C / SDISPI
Digital Input/Output
/ Digital Input
13
SDOSPI
Digital Output
14
SCLKI2C / SCLKSPI
Description
I2C/SPI select signal (High = I2C, Low = SPI)
Unidirectional for SPI, Bidirectional for I2C
SPI data out
Serial clock (Multiplexed for I2C and SPI) unidirectional
Digital Input
15
CSSPI
Digital input with pull-up
SPI chip select
16
RxD
Digital output with pull-up
CAN Transceiver receive signal
17
INTN
Digital Output
18
TxD
Digital input with pull-up
19
RESET
Digital Output
CAN Transceiver transmit signal
Digital Output referenced to VLDO1, active low
Pin with Digital / Analog Input /
Open-Drain-Output
20
21
Active low interrupt to µC. Generated if status/ diagnostic is
updated.
Reserved
Reserved
Analog Input / Output
22
23
VLDO1
Power Supply Input
24
VLDO1FB
Pin with Digital / Analog Input /
Open-Drain-Output
25
VLDO2
Power Supply Input
26
VLDO2FB
27
VLDO3FB
Pin with Digital / Analog Input /
Open-Drain-Output
28
VLDO3
29
V5V_LDO1
30
V5V_LDO3
31
V5V_LDO2
32
FB (DCDC)
33, 34, 35
LX (DCDC)
0
GND
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Regulated voltage output
Regulated voltage feedback
Regulated voltage output
Regulated voltage feedback
Regulated voltage feedback
Regulated voltage output
Power Supply Input
Step-down converter 5V output, supply for LDO1
Step-down converter 5V output, supply for LDO3
Step-down converter 5V output, supply for LDO2
DCDC output voltage feedback
Analog Input
Power Supply Input
DCDC output
Exposed pad (GND)
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AS8650
Datasheet - A b s o l u t e M a x i m u m R a t i n g s
5 Absolute Maximum Ratings
Stresses beyond those listed in Table 2 may cause permanent damage to the device. These are stress ratings only. Functional operation of the
device at these or any other conditions beyond those indicated in Electrical Characteristics on page 7 is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
Table 2. Absolute Maximum Ratings
1
Parameter
Min
Max
Units
Voltage at positive supply pin (VVSUP)
-0.3
40
V
Voltage at pin V5V_LDO1, V5V_LDO2,
V5V_LDO3, VLDO1, VLDO2, VLDO3, FB,
VLDO1FB, VLDO2FB, VLDO3FB
-0.3
7
V
Voltage at pin CANH, CANL, SPLIT
-40
+40
V
Voltage at pin LX, WAKE
-0.3
VVSUP + 0.3
V
Voltage at pin RESET, INTN, RxD, TxD, CS,
SCLK, SDO, SDA/SDI, I2C_EN
-0.3
4.5
V
1
V/µs
Notes
Electrical Parameters
Input Supply slew-rate (Vsup_slew)
Input power supply ramp rate
Electrostatic Discharge
Electrostatic discharge voltage
AEC-Q100-002 human body model standard
(ESD)
All pins except VSUP, GND, CANH, CANL,
WAKE, SPLIT
±2
kV
±4
±8
Latch-Up Immunity
VSUP, GND, WAKE, SPLIT
CANH, CANL
-100
+100
mA
AEC-Q100-004
1.2
W
170
ºC
+125
ºC
30
ºC/W
SEMI G42-88
ºC
The reflow peak soldering temperature (body
temperature) specified is in accordance with IPC/
JEDEC J-STD-020 “Moisture/Reflow Sensitivity
Classification for Non-Hermetic Solid State
Surface Mount Devices”.
The lead finish for Pb-free leaded packages is
matte tin (100% Sn).
Continuous Power Dissipation
Maximum power dissipation (Ptot)
Temperature Ranges and Storage Conditions
Junction temperature (TJ)
Storage temperature (Tstg)
-50
Thermal resistance MLF package (Rthj_36)
Package body temperature (TBODY)
Moisture Sensitivity Level
260
3
Represents a maximum floor life time of 168h
1. All voltages mentioned above are referred with respect to ground reference voltage VGND.
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AS8650
Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
6 Electrical Characteristics
Table 3. Electrical Characteristics
Symbol
Parameter
Conditions
Min
VSUP
Positive supply voltage
Normal operating condition
6
GND
Ground
In reference to all the voltages
0
TAMB
Ambient temperature
Junction temperature (TJ) ≤ 150ºC
(at full-load)
-40
Typ
Max
Units
18
V
Operating Conditions
Isupp
Supply current, normal mode
V
105
VSUP = 6V, LDOs at full load,
DCDC load = 390mA,
CAN dominant
425
VSUP = 18V, LDOs at full load,
DCDC load = 390mA,
CAN dominant, not production tested.
150
VSUP = 16V, LDOs at full load,
CAN dominant
170
ºC
mA
CS
Vt-
Negative-Going Threshold
Vt+
Positive-Going Threshold
Ilil_cs
Pull up current
VOH
High level output voltage
VOL
Low level output voltage
IO
Output drive current
VLDO1 = 3.3V
In CS pad, Pulled up to VLDO1
1.12
1.52
V
1.77
2.23
V
-60
-15
µA
SDO
2.5
VSUP ≥ 6V
V
0.4
V
4
mA
SDA / SDI
0.7*
VLDO1
VIH
High level input voltage
VIL
Low level input voltage
0.3*
VLDO1
V
VOL
Low level output voltage
0.4
V
V
SCLK
VIH
High level input voltage
VIL
Low level input voltage
Open-drain, external 500Ω pull-up
0.7*
VLDO1
V
0.3*
VLDO1
V
RESET, INTN
VOH
High level output voltage
VOL
Low level output voltage
IO
Output drive current
VIH
High level input voltage
VIL
Low level input voltage
IO
Output drive current
2.5
VSUP ≥ 6V
V
0.4
V
4
mA
TxD
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2.0
VSUP ≥ 6V
Revision 1.0
V
0.8
V
1
mA
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AS8650
Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
Table 3. Electrical Characteristics
Symbol
Parameter
Conditions
Min
Ilil
Pull-up current
TxD pulled up to VLDO1 with control
RxD pulled up to VLDO1
-60
VOH
High level output voltage
VOL
Low level output voltage
IO
Output drive current
VSUP ≥ 6V
Ilil
Pull-up current
TxD pulled up to VLDO1 with control
RxD pulled up to VLDO1
Typ
Max
Units
-15
µA
RxD
2.5
V
0.4
V
1
mA
-15
µA
Typ
Max
Units
-60
6.1 Electrical System Specification
-40°C < TJ < 150°C
Table 4. Electrical System Specification
Symbol
Parameter
Conditions
Min
IDDnom
Current consumption normal mode
No load, VSUP = 12V, CAN recessive
3.5
6
mA
IDDrecv
Current consumption receive-only mode
No load, VSUP = 12V, CAN recessive
1
2
mA
IDDstby
Current consumption standby mode
No load, VSUP = 12V
135
270
µA
IDDsleep
Current consumption sleep mode
No load, VSUP = 12V
75
150
µA
Min
Typ
Max
Units
6.2 DCDC Converter
-40°C < TJ < 150°C; all voltages are with respect to ground, normal operating mode, unless otherwise mentioned.
Table 5. DCDC Converter
Symbol
Parameter
Conditions
VSUP
Battery Voltage Range
6
12
18
V
V5V
Output Voltage
4.75
5
5.25
V
ILXS
LX current limit
0.8
1
1.25
A
IV5V
DCDC output current
500
mA
RON
LX switch on-resistance
0.8
1
Ω
VFB
Reference Voltage for FB
5
5.25
V
For inductor 22µH and capacitor 100µF
(bondwire resistance included)
4.75
Lireg_dc
Line regulation
Step from VIN = 6V to VIN2 = 18V,
ILOAD = 100mA
Lireg = 100*(VOUT1-VOUT2) /
[VOUT2*(VIN1-VIN2)]
Loreg_dc
Load regulation
ILOAD step from 90mA to 10mA
VSUP = 12V
Loreg = 100*(V_90mA-V_10mA) / V_90mA
LX_ind
Output inductor
10
22
µH
V5V_cer1
Output ceramic capacitor 1
10
100
µF
V5V_esr1
ESR of ceramic capacitor 1
0
0.05
Ω
V5V_cer2
Output ceramic capacitor 2
100
220
nF
V5V_esr2
ESR of ceramic capacitor 2
0.01
Ω
100
µF
1
Ω
Csup
Csup_esr
Input capacitor (ceramic)
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X7R type
For EMC suppression
Revision 1.0
-0.1
+0.1
%/V
-0.9
+0.9
%
22
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AS8650
Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
6.3 Low Drop Out Regulators
-40°C < Tj < 150°C; all voltages are with respect to ground, normal operating mode, unless otherwise mentioned. The LDO block is a linear
voltage regulator, which provides a regulated (band-gap stabilized) output voltage from the DCDC converter output voltage (V5V).
1
Table 6. VLDO1 Block Specifications
Symbol
Parameter
V5V
Input Voltage Range
IOUTLDO1
Output current
VLDO1
Output Voltage Range
ICC_SH
Output Short Circuit Current
Normal mode
dVLDO1
Line Regulation
ΔVLDO1/ΔV5V (static) for the input range,
ILOAD = 100mA
LOREG_NM
Load Regulation
ΔVLDO1 (for 100mA > ILOAD > 1mA),
V5V = 5V
tldo
Start-up time
Guaranteed by design
(includes start-up time of DCDC converter)
CL2
Conditions
Guaranteed by design.
Not production tested.
Output Capacitor (Ceramic)
CL1
Typ
Max
Units
4.75
5
5.25
V
100
mA
3.383
V
300
mA
-8
8
mV/V
-0.15
+0.15
mV/mA
80
ms
2
5
µF
0.02
0.1
Ω
100
220
nF
0.01
Ω
0
3.217
X7R type
ESR2
Min
X7R type
3.3
ESR1
1. Please note that the VLDO1 is not programmable.
1
Table 7. VLDO2 Block Specifications
Symbol
Parameter
V5V
Input Voltage Range
IOUTLDO2
Output current
Guaranteed by design.
Not production tested.
0
VLDO2
Output Voltage Range
VOUT (typ) depends on the trim code as in
OTP register mapping.
Default code gives 2.8V
0.975*
VOUT
ICC_SH
Output Short Circuit Current
Normal mode
dVLDO2
Line Regulation
ΔVLDO2/ΔV5V (static) for the input range,
ILOAD = 100mA
LOREG_NM
Load Regulation
ΔVLDO2 (for 120mA > ILOAD > 1mA)
tldo
Start-up time
Guaranteed by design
(includes start-up time of DCDC converter)
CL2
ESR2
CL1
Conditions
X7R type
Output Capacitor (Ceramic)
X7R type
ESR1
Min
Typ
Max
Units
4.75
5
5.25
V
120
mA
1.025*
VOUT
V
300
mA
-8
8
mV/V
-0.15
+0.15
mV/mA
80
ms
2
5
µF
0.02
0.1
Ω
100
220
nF
0.01
Ω
VOUT
1. 3.3V to 1.8V output.
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AS8650
Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
1
Table 8. VLDO3 Block Specifications
Symbol
Parameter
V5V
Input Voltage Range
IOUTLDO3
Output current
Guaranteed by design.
Not production tested.
0
VLDO3
Output Voltage Range
VOUT (typ) depends on the trim code as in
OTP register mapping.
Default code gives 1.8V
0.975*
VOUT
ICC_SH
Output Short Circuit Current
Normal mode
dVLDO3
Line Regulation
ΔVLDO3/ΔV5V (static) for the input range,
ILOAD = 100mA
LOREG_NM
Load Regulation
ΔVLDO3 (for 100mA > ILOAD > 1mA)
tldo
Start-up time
Guaranteed by design
(includes start-up time of DCDC converter)
CL2
Output Capacitor (Ceramic)
ESR2
CL1
Output Capacitor (Ceramic)
Conditions
X7R type
X7R type
Min
Typ
Max
Units
4.75
5
5.25
V
100
mA
1.025*
VOUT
V
300
mA
-8
8
mV/V
-0.15
+0.15
mV/mA
80
ms
2
5
µF
0.02
0.1
Ω
100
220
nF
0.01
Ω
VOUT
ESR1
1. 3.3V to 1.8V output.
6.4 CAN Transceiver
6V < VSUP < 18V; -40°C < Tj < 150ºC; all voltages are with respect to ground; 4.75V < V5V_LDO1 < 5.25V; RL=60Ω.
Table 9. DC Electrical Characteristics
Symbol
Parameter
Conditions
Dominant Output Voltage
V_TxD = 0V
Min
Typ
Max
Units
3
4.25
V
0.5
1.75
V
-0.1
0.15
V
45Ω < RL < 60Ω,
V_TxD = 0V (dominant)
1.5
3
V
No load; V_TxD = VLDO1 (recessive)
-50
50
mV
V_TxD = VLDO1; No bus load,
Normal mode
2
3
V
No bus load, Stand-by mode
-0.1
0.1
V
V_TxD = 0V, V_CANH = 0V
-160
-50
mA
V_TxD = 0V, V_CANL = 40V
+50
+160
mA
-27V < V_CAN < 40V
-2.5
+2.5
mA
-12V < V_CANH < 12V
-12V < V_CANL < 12V
Receive only mode (CAN receiver)
0.5
0.9
V
-12V < V_CANH < 12V
-12V < V_CANL < 12V
Stand-by mode (low-power receiver)
0.4
1.15
V
Driver
CANH_dom
CANL_dom
VO_dom_m
Matching Dominant Output Voltage
V5V_LDO1-V_CANH-V_CANL
VO_diff
Differential output voltage
V_CANH-V_CANL
VO_rec
Recessive output voltage
V_CANH, V_CANL
IO_short
Short circuit output current
IO_rec
Recessive output current
Receiver
V_RxD_th
Differential receiver threshold
voltage
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AS8650
Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
Table 9. DC Electrical Characteristics
Symbol
Parameter
Conditions
Min
V_RxD_hys
Differential receiver hysteresis
voltage
-12V < V_CANH < 12V
-12V < V_CANL < 12V
Receive only mode (CAN receiver)
I_RxD_LEAK
Input leakage current
R_IN_cm
Max
Units
20
130
mV
V5V_LDO1 = 0V;
V_CANH = V_CANL = 5V
100
250
µA
Common mode input resistance
Tested in Receive only mode
15
35
kΩ
R_IN_cm_m
Common mode input resistance
matching
V_CANH = V_CANL
(Tested in Receive only mode)
-3
+3
%
R_IN_diff
Differential input resistance
Tested in Receive only mode
25
75
kΩ
VO_SPLIT
Output voltage on split pin
Normal mode
-500µA < I_SPLIT < 500µA
0.3*
V5V_LDO1
0.7*
V5V_LDO1
V
Stand-by mode
0V < V_SPLIT < 35V
(Not production tested)
-5
+5
µA
Stand-by mode
-22V < V_SPLIT < 0
(Not production tested)
-1
+1
mA
Max
Units
IL_SPLIT
Leakage current on split pin
Typ
Table 10. AC Electrical Characteristics
Symbol
Parameter
Conditions
Min
Typ
t_TxD_BUS_on
Delay TxD to bus dominant
10
110
ns
t_TxD_BUS_off
Delay TxD to bus recessive
10
140
ns
t_BUS_on_RxD
Delay bus dominant to RxD
15
115
ns
t_BUS_off_RxD
Delay bus recessive to RxD
20
160
ns
t_TxD_RxD
Propagation Delay TxD to RxD
40
255
ns
Dominant time for wake-up detection
via bus
0.75
5
µs
WAKE UP via BUS
t_BUS_WR
BUS Diagnostic
t_OC_CANH
Time to detect over current CANH
V_TxD = 0V, V_CANH = 0V
(Not production tested)
60
µs
t_LC_CANH
Time to detect low current CANH
V_TxD = 0V, V_CANH = 40V
(Not production tested)
60
µs
t_OC_CANL
Time to detect over current CANL
V_TxD = 0V, V_CANL = 40V
(Not production tested)
60
µs
t_LC_CANL
Time to detect low current CANL
V_TxD = 0V, V_CANL = 0V
(Not production tested)
60
µs
Table 11. Temperature Limiter
Symbol
Parameter
Conditions
Min
Typ
Max
Units
Tjshut
Shut down temperature
Junction temperature when IC shuts down
150
170
185
ºC
Tjrecv
Recovery temperature
Junction temperature below which state
machine returns from shutdown/warning
125
140
155
ºC
Tjwarn
Over-temperature warning flag set
Junction temperature beyond which the
warning flag is set
140
157
175
ºC
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Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
6.4.1
Timing Diagrams
Figure 3. Timing Diagram and Hysteresis of CAN Receiver
TxD
CANH_dom
Vo_rec
CANL_dom
0.9V
Vin_diff
0.5V
2.5V
RxD
0.4V
t_TxD_BUS_on
t_TxD_BUS_off
t_BUS_off_RxD
t_BUS_on_RxD
t_TxD_RxD
V_RxD
t_TxD_RxD
V_RxD_hys
V_RxD_th (low)
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V_RxD_th (high)
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Vin_diff
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AS8650
Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
6.5 Undervoltage Detection
Table 12. Undervoltage Detection
Symbol
Parameter
Conditions
Min
Typ
Max
Units
VSUP_POR
VSUP Power on Reset threshold on
Rising edge of VSUP
5.09
5.5
5.91
V
VSUP_RESET
VSUP Power on Reset threshold off
(Master Reset for Device)
4.49
4.85
5.21
V
VSUP_POKTH
VSUP undervoltage threshold off
VSUP rising edge.
(Brown out reset threshold)
4.95
5.35
5.75
V
VSUP_UVTH
VSUP undervoltage threshold on
(CAN bus in recessive state)
VSUP falling edge.
(Brown out reset threshold)
4.625
5.0
5.375
V
V5V_POKTH
V5V undervoltage threshold off
Rising edge of V5V
4.16
4.5
4.84
V
V5V_UVTH
V5V undervoltage threshold on
Falling edge of V5V
3.8
4.1
4.4
V
VLDO_POKTH
LDO undervoltage threshold off
(VLDO1, VLDO2 and VLDO3)
Percent value is with respect to LDO
output. Rising edge of LDO
87
89
91
%
VLDO_UVTH
LDO undervoltage threshold on
(VLDO1, VLDO2 and VLDO3)
Percent value is with respect to LDO
output. Falling edge of LDO
78
80
82
%
trr
Spike filter on VLDO1
To remove disturbance
2
4
8
µs
tRes
Reset delay time
4
8
12
ms
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Datasheet - D e t a i l e d D e s c r i p t i o n
7 Detailed Description
The AS8650 consists of the following components on chip:
DCDC converter with 5V outputs that supplies the three LDO voltage regulators and the CAN Transceiver
One voltage regulator for 3.3V output voltage and two programmable voltage regulators in the range of 3.3V to 1.8V
CAN bus Transceiver according to ISO 11898
Integrated RESET unit with a power-on-reset delay and a programmable watchdog time
7.1 Operating Modes and States
The AS8650 provides four main operating modes normal, receive only, standby, and sleep. In normal mode, the CAN Transceiver can be
disabled in case of over-temperature condition. The detailed transition table for each mode is shown in the subsequent pages.
7.1.1
Normal Mode
In normal mode DCDC converter, the three voltage regulators, BUS Transceiver, and Window Watchdog are turned on with full functionality. All
the LDO regulators are capable of delivering maximum load current possible as per their respective ratings. The BUS Transceiver is capable of
sending the TxD data from the microcontroller to the CANH at the maximum rate.
7.1.2
Receive-only Mode
In this mode, the CAN transmitter is disabled. The CAN receiver, the three voltage regulators, and over-temperature monitor circuit are enabled.
7.1.3
Standby Mode
This is the mode after power up. The Standby mode is a functional low-power mode where the CAN Transceiver is disabled. The bus wake-up
(low power receiver) circuit, LDO1, and over-temperature monitor circuit are enabled. Both LDO2 and LDO3 can be enabled or disabled (default
state) using the host command. The AS8650 can enter normal mode, sleep mode or receive only mode through host command.
7.1.4
Sleep Mode
Sleep mode is the current saving mode that is entered by host command or by over-temperature condition. The DCDC converter, the three
voltage regulators, CAN Transceiver, the reset, and window watchdog unit are all switched off. The bus wake-up (low power receiver) circuit,
oscillator, and over-temperature monitor circuit are active. The bus is in recessive state (high). The only wake-up possible is through remote
wake-up (through the bus lines) or local wake up (through the WAKE pin) as described in the WAKE specification. In the case of entering sleep
mode due to over-temperature condition (T > Tjshut), the device can come out of sleep only after the temperature falls back below the return
temperature Tjrecv and any one of the wake up events mentioned above.
7.2 Power Management Strategy
The detailed block diagram and the power management strategy are shown in Figure 4.
Internal Regulator. This module is powered externally by the VSUP. All the critical modules that needs to be kept always on, work on this
supply. Some of the important modules among them are Over-temperature monitor, Local Wake block, Internal Power-on Reset module, Internal
Oscillator, complete mode-control unit, Undervoltage comparators of three external LDOs.
DCDC Converter. This is the main supply regulator for all the internal blocks. A step-down hysteretic buck converter is used to generate 5V
output from VSUP. This 5V output is then used to generate all the three LDOs. This high-efficiency step-down DCDC converter contains the
following features:
Current limited operation
Thermal shutdown
LDO1. This is the main I/O supply. This is generated internally from the 5V DCDC converter output and gives a regulated 3.3V output to powerup the external micro-controller. All the I/Os that interface with the micro-controller work on this supply.
LDO2 and LDO3. These are two regulators that are generated from the 5V DCDC converter output. Both the LDOs can be programmed via
I2C or SPI settings in the range from 3.3V to 1.8V.
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Figure 4. Power Management Strategy
VSUP GND
WAKE
CANH
SPLIT
CANL
Local WAKE
CAN
Transceiver
LX
ldo1_uvb
otm_160
otm_170
otm_en
ldo2_en
loc_wake
tx_en
tx
rx_en
rx
flags
ldo1_en
ldo2_uvb
ldo3_en
Mode Control / Reset
Generation
ldo3_uvb
AS8650
Datasheet - D e t a i l e d D e s c r i p t i o n
Level Shifter
Definer
Window
WatchDog
Digital
Interface
V5V
LDO1
(100mA)
V3P3
UV Comp
LDO2
(120mA)
Revision 1.0
OTM
FB
DCDC Converter 5V
V2P8
UV Comp
LDO3
(100mA)
V1P8
UV Comp
OTP
Level Shifter
Level Shifter
Definer
Level Shifter
RESET
INTN
TxD
RxD
Definer
Definer
Definer
Level Shifter
Definer
CSSPI
SCLKI2C / SCLKSPI
SDAI2C / SDISPI
SDOSPI
I2C_EN
LDO1
Pre-reg
DCDC 5V
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Osc
start
done
Pre-Reg
3.3V &
5.0V
por
clk
osc_en
POR
AS8650
Datasheet - D e t a i l e d D e s c r i p t i o n
Table 13. Power Management Strategy for AS8650
Control States
Analog Blocks
Power-up
Normal
RX Only
Standby
Sleep
DCDC Converter
ON
ON
ON
ON
OFF
Oscillator
ON
ON
ON
ON
ON
Internal Regulator
ON
ON
ON
ON
ON
1
OTM
ON
ON
ON
ON
ON
LDO1
ON
ON
ON
ON
OFF
LDO2
OFF
ON
LDO3
OFF
ON
2
2
ON
2
OFF
1
OFF
ON
2
OFF
1
OFF
CAN TX
OFF
ON
OFF
OFF
OFF
CAN RX
OFF
ON
ON
OFF
OFF
Low Power RX
OFF
OFF
OFF
ON
ON
LOCAL WAKE
OFF
OFF
OFF
ON
ON
OFF
ON
ON
ON
ON
WWD
OFF
ON
ON
ON
OFF
Digital Interface
OFF
ON
ON
ON
OFF
SPLIT Generation
Digital Blocks
1. Can be turned ON using Device configuration register
2. Can be turned OFF using Device Configuration register
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Datasheet - D e t a i l e d D e s c r i p t i o n
7.3 State Diagram
Figure 5. State Machine Model
VSUP_UV_flag = 1 OR V5V_UV_flag =1
à BUS transceiver disabled
VSUP_UV_flag =1 OR
V5V_UV_flag= 1 à BUS transceiver
disabled
Host command (go to ReceiveOnly)
Normal
Receive Only
an
d
(g
o
to
No
rm
a
l)
Ho
st
st c
Ho
m
om
(go
and
co
p)
lee
to S
mm
an
d(
go
t
oS
tan
db
y)
Sleep
Standby
3P
OR
O timeo
ut
wat R
c hd
og
tim
eou
t
=0
up
Power-up
Power Off
Normal OR
Receive_only OR
Standby state
ET
=
star
t
TEMP< Tjrecv AND BUS Wake
OR
Local Wake
V3P
3
V 3p
_RE
SET
== 1
Rese &
t tim
e ou
t
Host command (go to Sleep)
TEMP > Tjshut à BUS wake
disabled
From any state
Host command (go to Standby)
Host command (go to Sleep)
BUS transmitter will be enabled on
TEMP < Tjrecv
om
m
_P
UP
VS
=
ET
ES
_R
OR
V3
P3
_R
ES
TEMP>Tjwarn à BUS transmitter
disabled
Host command (go to ReceiveOnly)
Host command (go to Normal)
Ho
st
c
=0
7.4 Initialization Sequence
After this, DCDC converter is switched ON, on receiving PG (power good) signal from DCDC converter, LDO1 regulator is switched ON. If
VLDO1 > VLDO1_POKTH threshold, VLDO1_RESET is generated. After this, active-low PORN_2_OTP is generated. The rising edge of
PORN_2_OTP loads contents of fuse onto the OTP latch after load access time TLoad. The LOAD_OTP_IN_PREREG signal loads the content of
OTP latch into the pre-regulator domain register. The Reset timeout is also started. The RESET signal is de-asserted after Reset timeout period
TRes. After the RESET is high, startup watch dog will start. If microcontroller gives trigger within startup window the device enters into Standby
mode. If microcontroller misses the trigger, RESET signal is generated and again Reset timeout will start. If microcontroller misses to give the
startup watchdog trigger for 3 consecutive times, then the device enters into Sleep mode. On receiving Normal mode command from
microcontroller, device turns ON the LDO2 and LDO3 regulators. When VLDO2 and VLDO3 reach their respective power-ok (POK) threshold
values, device interrupts microcontroller. The circuit is designed such that the state machine initializes correctly even for very slow ramp rates on
VSUP of the order of 0.5V/min.
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Datasheet - D e t a i l e d D e s c r i p t i o n
The power initialization sequence diagram is shown in Figure 6.
After activating the power supply on VSUP pin, the VSUP_POR_RESET flag becomes inactive (high) while the voltage exceeds the
VSUP_POR threshold.
The DCDC output voltage V5V exceeds the V5V_POKTH thresholds after the DCDC settling time and the first voltage regulator (LDO1) will
be activated with the V5V_POK set.
If the voltage output at LDO1 (set to 2.5V on power-up) reaches the VLDO1_POKTH threshold, the PORN_2_OTP flag is set and OTP
register setting for the LDO1 is read. Consequently the output voltage will be regulated to the actual OTP settings.
The initialization phase of the device is terminated after the preset output voltage level threshold is exceeded and the reset timeout is
expired.
After entering Stand-by mode the host controller can switch the device in any operation mode through the I2C or SPI interface.
Figure 6. Initialization Sequence
VSUP_POR
VSUP
VSUP_POR_RESET
V5V_POKTH
V5V
Tdcdc = DCDC settling time
V5V_POK
VLDO1_POKTH
VLDO1
VLDO1_POKTH
Tldo = LDO settling time
VLDO1_RESET
PORN_2_OTP
6 Cycles of
RC- Oscillator
LOAD_OTP_IN_
PREREG
RESET
Tres = Reset Timeout
DEVICE
STATE
INITIALIZATION
STARTUP
WATCHDOG
STANDBY
MODE
NORMAL MODE
VLDO2_POKTH
VLDO2
VLDO3_POKTH
VLDO3
INTN
Tldo = LDO settling time
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Datasheet - D e t a i l e d D e s c r i p t i o n
7.5 DCDC Converter
The high-efficiency, high-voltage, hysteretic step-down DCDC converter, operates in asynchronous mode and delivers 500mA of output load to
drive the three internal LDOs and the CAN Transceiver. The low-power architecture extends hold-up time in battery-backed and critical
applications where maximum up-time over a wide input supply voltage range is needed, while still providing for high efficiencies of up to 90%
during peak current demands.
7.6 Voltage Regulator LDO1
The stability of the voltage output is below ±2.5% over the full input range and temperature for load current up to 100 mA at 3.3V. Power Input to
this LDO is the V5V_LDO1 pin. This LDO is activated in Normal, Receive only or Standby mode. It is switched OFF in Sleep mode.
7.7 Voltage Regulator LDO2
The stability of the voltage output is below ±2.5% over input range and temperature for load current up to 100 mA. The voltage regulator is
programmable between 3.3V and 1.8V via I2C or SPI interface. Power Input to this LDO is the V5V_LDO2 pin. LDO2 is activated in Normal and
Receive Only mode.
7.8 Voltage Regulator LDO3
The stability of the voltage output is below ±2.5% over input range and temperature for load current up to 100 mA. The voltage regulator is
programmable between 3.3V and 1.8V via I2C or SPI interface. Power Input to this LDO is the V5V_LDO3 pin. LDO3 is activated in Normal and
Receive Only mode.
7.9 Over-Temperature Monitor
In Normal mode, if the junction temperature reaches the over-temperature threshold Tjwarn, a warning flag is set in the diagnostic register which
can be accessed via the I2C and the SPI interface and an interrupt is signalled on INTN pin. The CAN transmitter is disabled and the device
remains in Normal mode. If the junction temperature falls below Tjrecv, the CAN transmitter is enabled. The warning flag is cleared in the
diagnostic register and an interrupt is signalled at the INTN pin. If the junction temperature exceeds the over-temperature threshold Tjshut, the
device enters sleep mode irrespective of the current mode and bus wake receiver (Low power receiver) is disabled. As soon as the temperature
falls below Tjrecv, the bus wake receiver (Low power receiver) is switched on.
7.10 Undervoltage Reset
Undervoltage on VSUP (Brown out Indication). If VSUP voltage falls below VSUP_UVTH threshold, the VSUP_UV_flag is set and an
interrupt at INTN is generated. In this case the device enters into the Stand-by mode. The LDO1 voltage regulator remains activated. Two
scenarios are possible at this stage:
VSUP is recovering: If VSUP exceeds the VSUP_POKTH threshold, the VSUP_POK_flag is set and the device remains in Stand-by mode.
VSUP is still falling: In this case the device continues to stay in Stand-by mode. If voltage falls below VSUP_RESET threshold, then the
device enters Power-Off and the logic is reset.
Undervoltage on V5V. If the V5V falls below V5V_UVTH threshold, the V5V_UV_flag is set. Once V5V returns to V5V_POKTH threshold
value, V5V_POK_flag is set. In case a flag is set, an interrupt is generated at the INTN pin. If undervoltage on V5V occurs in Normal or Receive
only modes then CAN Transceiver is disabled and the device remains in its operation mode.
Undervoltage on LDO1. If the voltage level of LDO1 falls below the VLDO1_UVTH threshold value and device is not in Sleep mode, the
device enters into power-up state while RESET signal is asserted and the voltage regulator is still active. Once the VLDO1_POKTH threshold is
reached, RESET signal is de-asserted after reset timeout period and device enters into Standby mode.
Undervoltage on LDO2. If the voltage level of the LDO2 falls below the VLDO2_UVTH threshold value a VLDO2_UV_flag is set. An
indication is given to microcontroller by setting a bit in interrupt register and giving interrupt on INTN pin. Once VLDO2 returns to
VLDO2_POKTH threshold value, VLDO2_POK_flag is set. An indication is given to microcontroller by setting a bit in interrupt register and giving
interrupt on INTN pin.
Undervoltage on LDO3. If the voltage level of the LDO3 falls below the VLDO3_UVTH threshold value a VLDO3_UV_flag is set. An
indication is given to microcontroller by setting a bit in interrupt register and giving interrupt on INTN pin. Once VLDO3 returns to
VLDO3_POKTH threshold value, VLDO3_POK_flag is set. An indication is given to microcontroller by setting a bit in interrupt register and giving
interrupt on INTN pin.
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Datasheet - D e t a i l e d D e s c r i p t i o n
Figure 7. Power-up and Undervoltage Sequence
VLDO2_POKTH
VSUP_POR
VLDO2_UVTH
VSUP_POKTH
VSUP_RESET
VSUP_UVTH
VSUP
VLDO2
VSUP_POR_RESET
VSUP recovering
VSUP_UV_flag
VLDO2_POK_flag
VSUP still falling
VSUP recovering
VSUP still falling
VSUP_POK_flag
VSUP Supply
V5V_POKTH
VLDO2_UV_flag
LDO2 Supply
VLDO3_POKTH
V5V_UVTH
V5V
VLDO3_UVTH
VLDO3
V5V_POK_flag
VLDO3_POK_flag
V5V_UV_flag
VLDO3_UV_flag
DCDC Supply
LDO3 Supply
VLDO1_POKTH
VLDO1_UVTH
VLDO1
VLDO1_RESET
LDO1 Supply
7.11 Reset Block
The reset block generates an external RESET signal to reset the microcontroller and all other external circuits. The reset functionality is
explained in Figure 8. The reset block consists of a digital buffer at the output. The RESET signal is affected by VLDO1_RESET (during
overload, reset on VLDO1) and watch dog output. All conditions which cause a drop of the VLDO1 voltage will be detected from the low voltage
reset unit which in-turn generates a reset signal.
Figure 8. Reset Block Functional Waveform
VVSUP_UV
VSUP
T>Tjshut
T<Tjwarn
t<trr
VLDO1_POR
VLDO1_UV
VLDO1
tRes
tRes
tRes
trr
tuv_VSUP
MISSING
WATCHDOG
ACCESS
tRes
tRes
RESET
Initialization
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Thermal shutdown
Spike VSUP
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Low voltage VSUP
Current limitation active
(Overload)
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AS8650
Datasheet - D e t a i l e d D e s c r i p t i o n
7.12 CAN Transceiver
The AS8650 provides an advanced interface between the protocol controller and the physical bus in a Controller Area Network (CAN) node. This
is intended for automotive high-speed CAN application (up to 1 Mbit/s), providing differential transmit capability to the bus and differential receive
capability to the CAN controller. It is fully compatible to the ISO 11898 standard and offers excellent Electromagnetic Compatibility (EMC)
performance. The CAN is a high speed, low complexity protocol with improved EMI and EMC performance. The CAN is a serial communication
protocol efficiently supporting the control of mechatronic nodes in a distributive automotive application. The basic blocks of the CAN Transceiver
are described below:
7.12.1 BUS Driver
This driver has the basic functionality of relaying the data from the microcontroller on to the CAN bus. The data on the CAN needs to have a
controlled slew to reduced EMI. A low side driver is used which has an inherent reverse polarity protection. It has a Short-Circuit current
limitation.
7.12.2 Normal Receiver
It relays the data from the CAN bus to the microcontroller in Normal mode.
7.12.3 Low Power Receiver
It relays the data from the CAN bus to the microcontroller in low power mode state.
7.12.4 Operating Modes
The CAN Transceiver provides the following operating modes:
NORMAL: Non low power mode
RECEIVE ONLY: Non low power mode
STANDBY: Low power mode
SLEEP: Low power mode
Normal Mode. In this mode the Transceiver is able to send and receive data signals on the bus. RxD reflects the bus data.
Receive Only Mode. In this mode the Transceiver has the same behavior as in normal mode but the transmitter is disabled.
Standby Mode or Sleep Mode. In this mode the Transceiver is not able to send and receive data signals from the bus, but the wake up
detector is active. The power consumption is significantly reduced respect the non low power operation modes. The WAKE_REMOTE reflects
the remote wake up detector output; WAKE_LOCAL reflects the input signal on WAKE pin.
Table 14. Operating Modes
TxD
Transmitter
Normal
Receiver
Low Power Receiver
Bust State
L
Enabled
Enabled
Disabled
Dominant
H
Enabled
Enabled
Disabled
Recessive
REC ONLY
X
Disabled
Enabled
Disabled
(CANH, CANL are not driven)
STANDBY
X
Disabled
Disabled
Enabled
(CANH, CANL are not driven)
SLEEP
X
Disabled
Disabled
Enabled
(CANH, CANL are not driven)
State
NORMAL
7.12.5 Local Wake-up Event
In all low power modes, if the voltage on the WAKE pin falls below V_LWUTH for longer than TLW_filter, WAKE_LOCAL falls down. At the same
time the biasing of the pin is switched to pull-down. If the voltage on the WAKE pin rises above V_LWUTH for longer than TLW_filter,
WAKE_LOCAL rises up. At the same time the biasing of the pin is switched to pull-up. In current application wake pin is initially pulled-down to
ground using external resistor on power up. For valid wake-up, the WAKE pin needs a rising edge.
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Datasheet - D e t a i l e d D e s c r i p t i o n
Figure 9. Wake Input Pin Behavior
PULL DOWN
PULL UP
PULL UP
TLW_filter
TLW_filter
VSUP
V_LWUTH
WAKE
TL_wake
TL_wake
WAKE_LOCAL
Local wake detected
Local wake detected
7.12.6 Remote Wake-up
In all low power modes, if the differential voltage on the bus becomes recessive for longer than t_BUS_WR, WAKE_REMOTE rises up. If the
differential voltage on the bus becomes dominant for longer than t_BUS_WR, WAKE_REMOTE falls down as shown in Figure 10.
Figure 10. Remote Wake-up Event
V_RxD_h
Vin_diff
V_RxD_l
VIO
WAKE_REMOTE
t_BUS_WR
t_BUS_WR
A remote wake request is detected after two dominant pulses with each pulse separated by a recessive pulse of at least Trec (wake). The remote
wake detection circuit is active in sleep and standby modes. The wake message pattern is shown in Figure 11.
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Figure 11. Wake Message Pattern
CANH
Dominant
Reccessive
Dominant
Reccessive
CANL
WAKE_remote
>Tdom(wake)
>Trec(wake)
>Tdom(wake)
WAKE_remote_flag
>Trec(wake)
Remote wake
detected
7.13 Internal Flags
The AS8650 supports internal flags to indicate the failures in the system. If any of these flag is set an interrupt is generated on INTN pin.
7.13.1 VSUP_UV_flag
This is a VSUP undervoltage flag. This flag is set when VSUP falls below the VSUP_UVTH threshold. When this flag is set the device enters into
standby mode and BUS Transceiver is switched off to save power. When VSUP recovers and raises above VSUP_POKTH threshold the
VSUP_UV_flag is reset.
7.13.2 VSUP_POK_flag
This is a VSUP power ok flag. This indicates the VSUP recovery from undervoltage condition. When the VSUP rises above VSUP_POKTH
threshold, this flag is set. This indicates the microcontroller that undervoltage condition on battery is cleared.
7.13.3 V5V_UV_flag
This is a V5V undervoltage flag. This flag is set when V5V falls below the V5V_UVTH threshold. When this flag is set the device enters into
Standby mode and BUS Transceiver is switched off to save power. When V5V recovers and raises above V5V_POKTH threshold the
V5V_UV_flag is reset.
7.13.4 V5V_POK_flag
This is a V5V power ok flag. This indicates the V5V recovery from undervoltage condition. When the V5V rises above V5V_POKTH threshold,
this flag is set. This indicates the microcontroller that undervoltage condition on DCDC converter is cleared.
7.13.5 VLDO2_UV_flag
This is a VLDO2 undervoltage flag. This flag is set when VLDO2 falls below the VLDO2_UVTH threshold. When VLDO2 recovers and raises
above VLDO2_POKTH threshold the VLDO2_UV_flag is reset.
7.13.6 VLDO2_POK_flag
This is a VLDO2 power ok flag. This indicates the VLDO2 recovery from undervoltage condition. When the VLDO2 rises above VLDO2_POKTH
threshold this flag is set. This indicates the microcontroller that undervoltage condition on LDO2 is cleared.
7.13.7 VLDO3_UV_flag
This is a VLDO3 undervoltage flag. This flag is set when VLDO3 falls below the VLDO3_UVTH threshold. When VLDO3 recovers and raises
above VLDO3_POKTH threshold the VLDO3_UV_flag is reset.
7.13.8 VLDO3_POK_flag
This is a VLDO3 power ok flag. This indicates the VLDO3 recovery from undervoltage condition. When the VLDO3 rises above VLDO3_POKTH
threshold this flag is set. This indicates the microcontroller that undervoltage condition on LDO3 is cleared.
7.13.9 BUS Wake_up Flag
The BUS Wake_up flag is set when the device detects a remote wake-up (BUS message) request. The remote wake-up request is detected
when pattern shown in Figure 11 is found on wake_remote port of low power receiver. This indicates the microcontroller about the Bus wake
event.
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7.13.10 Local Wake_up Flag
The Local Wake_up flag is set when the device detects a local wake-up request on WAKE pin. A local wake-up request is detected when a logic
state change on pin WAKE as shown in Figure 9. This indicates the microcontroller about the local wake event.
7.13.11 OVT_Warning Flag
The OVT_Warning flag is set when temperature exceeds Tjwarn. This indicates the microcontroller about temperature exceeding warning levels.
7.13.12 OVT_Recover Flag
The OVT_Recover flag is set when temperature falls back below Tjrecv. This indicates the microcontroller about temperature falling back below
recovery levels.
7.13.13 Bus Failure Flags
The bus failure flag is set if the CAN Transceiver detects a bus line short-circuit condition to VSUP, V5V_LDO1 or GND. Such possible conditions
are indicated to microcontroller through these flags. All these flags are cleared on microcontroller read. If the fault condition still exist after
microcontroller read, the particular flag is set again. The device still be working in the current state. The microcontroller takes appropriate action
on reading of these flags.
CANH_short_GND. This flag indicates Over Current condition on pin CANH. For example short to ground on pin CANH. When the output
current on pin CANH exceeds the threshold OC_CANH_th then the output OC_CANH switches on high level after a filter time t_OC_CANH.
CANH_short_VSUP. This flag indicates Low Current on pin CANH. For example open load or short to VSUP on pin CANH. When the output
current on pin CANH falls below the threshold LC_CANH_th then the output LC_CANH switches on high level after a filter time t_LC_CANH.
CANL_short_VSUP. This flag indicates Over Current on pin CANL. For example short to VSUP on pin CANL. When the output current on pin
CANL exceeds the threshold OC_CANL_th, then the output OC_CANL switches on high level after a filter time t_OC_CANL.
CANL_short_GND. This flag indicates Low Current on pin CANL. For example open load or short to ground on pin CANL. When the output
current on pin CANL falls the threshold LC_CANL_th then the output LC_CANL switches on high level after a filter time t_LC_CANL.
7.13.14 Local Failure Flags
The AS8650 prevents the system from four kinds of local failures without disturbing the BUS network. The four failures are TxD dominant
clamping, RxD recessive clamping, TxD & RxD short, and bus dominant clamping. All these failures are indicated to microcontroller through
flags.
TxD_Dom_Clamp flag. A permanent LOW-level on pin TxD (due to a hardware or software application failure) would drive the BUS into a
permanent dominant state, blocking BUS network communication. If pin TxD remains at a LOW level for longer than the TxD dominant time-out
period TTxDC(dom), the device disables the transmitter of BUS Transceiver and TxD_Dom_Clamp flag is set. The device prevents such BUS
network lock-up by disabling the transmitter of the Transceiver. The device will not change the functional state. The transmitter remains disabled
until the local failure flag is cleared by host command. The flag is cleared on microcontroller read.
RxD_Rec_Clamp flag. If pin RxD is shorted to VLDO1, the RxD pin is permanently clamped to recessive state. The BUS controller can not
see the bus dominant state and start sending message thinking bus is idle. This disturbs the BUS. This RxD recessive clamping is detected by
the device when BUS is at dominant state. On detection of this a failure RxD_Rec_Clamp flag is set and the transmitter is disabled. The flag is
cleared on microcontroller read. The transmitter is enabled by host command.
TxD_RxD_Short flag. The TxD_RxD short circuit would result in a dead-lock situation clamping the bus dominant. For example the
Transceiver receives a dominant signal, RxD outputs a dominant level. Because of the short circuit, TxD reflects a dominant signal, retaining the
dominant bus state. As a result TxD and the bus are clamped continuously dominant. The resulting effect is the same as for the continuously
clamped dominant TxD signal. The TxD dominant timeout interrupts the deadlock situation by disabling the transmitter and the TxD_RxD short
condition is differentiated. The bus becomes recessive again and TxD will be recessive if it is not driven by microcontroller. However, the failure
scenario may still exist and with the next dominant signal on the bus the described procedure will start again.
The device keeps the transmitter off after detection of TxD_RxD short fault and keeps updating this flag status. The microcontroller has to send
2 consecutive low pulses of duration 500ns with high period of 500ns in-between, in regular intervals to check short circuit recovery. This way a
local TxD/RxD short circuit will not disturb the communication of the remaining bus system.
BUS_Dom_Clamp flag. In the case of a short circuit from BUS to GND, the circuit for the BUS receiver senses dominant signal continuously
even if there is no dominant transmitting node. The result may be a permanently dominant clamped bus. The device detects and reports a Bus
Dominant Clamping situation to microcontroller through BUS_Dom_Clamp flag. If the receiver detects a bus dominant phase of longer than the
bus dominant time out TBUSC(dom) BUS_Dom_Clamp flag is set. The flag is cleared on microcontroller read.
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7.14 Watchdog (WD)
The WD has the following three monitory timing functions:
Start-up watchdog: Gives opportunity to microcontroller to initialize the system.
Window watchdog: Detects too early or too late microcontroller software response (loops and hangs).
Time-out watchdog: Detects too very long response from microcontroller.
7.14.1 Start-up Watchdog Behavior
Following any reset event the watchdog is used to monitor the ECU start-up procedure. Once the reset is released the watchdog counter will
start. In case the watchdog is not properly served (a trigger from microcontroller) within TWD(init), another reset is forced on RESET pin and the
monitoring procedure is restarted. The watchdog will give three opportunities to microcontroller to initialize the system. In case the watchdog is
not properly served for three times, then the system enters into sleep mode.
7.14.2 Window Watchdog Behavior
Whenever the device enters Normal mode, the Window mode of the watchdog is activated. This ensures that the microcontroller operates within
the required speed; a too fast as well as a too slow operation will be detected. Watchdog triggering using the Window watchdog is illustrated in
Figure 12.
Figure 12. Window Watchdog Triggering
Twwd_period
Twd_no_trig
Twd_trig
NON-TRIGGER WINDOW
TRIGGER WINDOW
Trigger
restarts
period
SPI
TRIGGER
Last
Trigger
Point
50%
100%
Latest
Trigger
Point
Earliest
Trigger
Point
Trigger restarts period
( with new period if desired)
New Period
NON-TRIGGER WINDOW
TRIGGER WINDOW
50%
SPI
TRIGGER
Unwanted Trigger
(RESET generated,
watchdog enter Start-up
mode)
Earliest
Trigger
Point
100%
Latest
Trigger
Point
The AS8650 provides 8 different period timings. This timing can be changed through digital interface when desired. The period can be changed
within any valid trigger window. Whenever the watchdog is triggered within the window time Twd_trig, the timer will be reset to start a new period.
The watchdog window is defined to be between 50% and 100% of the nominal programmed watchdog period. Any too early (trigger in nontrigger window) or too late watchdog trigger will result an immediate system reset on RESET pin and watchdog entering Start-up watchdog
mode. During undervoltage condition on VLDO1 the watchdog timer is disabled.
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7.14.3 Time-out Watchdog Behavior
Whenever the AS8650 operates in Standby mode, active watchdog operates in Time-out watchdog mode. The watchdog has to be triggered
within the actual programmed period time Twd_tout_period. The device provides 8 different possible periods for programming through digital
interface. If the microcontroller fails to trigger the watchdog within trigger range then the system reset is generated on RESET pin and watchdog
enters into Start-up watchdog mode. The time-out watchdog function is illustrated in Figure 13.
Figure 13. Time-out Watchdog Triggering
Twwd_period
Twd_no_trig
Twd_trig
NON-TRIGGER WINDOW
TRIGGER WINDOW
Trigger
restarts
period
SPI
TRIGGER
Last
Trigger
Point
50%
100%
Latest
Trigger
Point
Earliest
Trigger
Point
Trigger restarts period
( with new period if desired)
New Period
NON-TRIGGER WINDOW
TRIGGER WINDOW
50%
SPI
TRIGGER
Unwanted Trigger
(RESET generated,
watchdog enter
Start-up mode)
Earliest
Trigger
Point
100%
Latest
Trigger
Point
7.15 Interrupt Generation
The pin INTN is an interrupt output. The INTN is forced LOW if one bit in the Interrupt register is set. The Interrupt register bits are cleared when
the microcontroller clears the corresponding interrupt source register. The Interrupt register will also be cleared during a system reset (RESET
LOW). As there are microcontrollers with level sensitive or edge sensitive interrupt port, pin INTN will be HIGH for at least TINTN after any of the
interrupt source register is cleared. The Interrupt source register is cleared through write operation by overwriting 1 in to respective set bits
position. Without further interrupts within TINTN pin INTN stays HIGH, otherwise it will revert to LOW again.
The Interrupt register indicates the cause of an interrupt event. There are two levels of interrupt registers. First level register indicates the source
region of interrupt and the second level register indicates the exact source of interrupt. With this structured interrupt, the microcontroller can trace
source of interrupt by two read operations instead of polling for source of interrupt and also interrupts can be prioritized by microcontroller. The
interrupt register structure is given in Figure 14. The register is cleared through digital interface write operation and upon any reset event. The
hardware ensures no interrupt event is lost in case there is a new interrupt forced while reading the register.
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Figure 14. Interrupt Register Structure
R
D5
R
R
I3
I2
I1
D4
D3
CANH_Short_VCC
RxD_Rec_Clamp
D6
CANL_Short_VCC
TxD_RxD_Short
D7
CANH_Short_GND
BUS_Dom_Clamp
D0
TxD_Dom_Clamp
Wake_up
D1
CANL_Short_GND
Local Wake_up
D3 D2
BUS and Local failure Interrupt
R
R
wake-up, temperature and LDO timeout Interrupt
R
R
Supply Related interrupt
Interrupt Register
R
OVT_Recovery
R
OVT_Warning
D0
Reserved
D1
Reserved
Reserved
D2
Reserved
D3
VSUP_UV_flag
D4
VSUP_POK_flag
V2P8_UV_flag
D5
V5V_UV_flag
V2P8_POK_flag
D7 D6
V5V_POK_flag
V1P8_UV_flag
V1P8_POK_flag
Interrupt Source Registers
D2
D1
D0
7.16 Status Registers
The AS8650 has three Flag status registers and one RESET reason register. The Flag status registers indicate the current status of flags which
are related to respective interrupt source registers. The Flag status registers are Bus status register, Temperature status register and Supply
status register. The microprocessor can read these registers any time to check the status of device. The function of each flag is listed in register
space description in subsequent sections.
A RESET reason register indicates the reasons for RESET generation. Once the RESET pin goes low, the reason of this reset event is stored in
RESET reason register. When RESET is released microprocessor can read this register to know the cause for last RESET signal. The RESET
reason register is cleared once microprocessor reads this register through read operation. The bits functionality of this register is explained in
register space description table.
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8 Application Information
Device Interfaces. There are two ways to communicate with AS8650, one is 4 wires SPI and other is I2C. The selection between these two
interfaces is through I2C_EN pin, as shown in Table 15. The pins CS, SCLK, SDI, and SDO are used for SPI interface. For I2C interface, SCLK
is used as I2C Clock and SDA is used as I2C data line. Pins SCLKI2C / SCLKSPI and SDAI2C / SDISPI are multiplexed for both SPI and I2C
interface. Since I2C_EN is a digital input pin, it has to be connected either to VLDO1 or GND.
Note: I2C_EN should not be changed during a I2C/SPI Read/Write operation. Maximum switching delay between I2C and SPI is 8µs.
Table 15. Device Interface Selection
I2C_EN
Description
LOW
Interface is 4-wire SPI
HIGH
Interface is I2C
8.1 Serial Peripheral Interface
The Serial Peripheral Interface (SPI) provides the communication link with the microcontroller. The SPI is configured for half-duplex data transfer.
The SPI provides access to configuration registers, control registers, and diagnostic registers. The modes of the AS8650 are changed by writing
required code in to mode control register through SPI. The SPI is also used to enter into test and OTP modes. This interface is only slave
interface and only master can initiate SPI operation.
The SPI can work on both the clock polarities. The polarity of the clock depends on the value of SCLK at the falling edge of CS. At the falling
edge of CS if SCLK is “1” then the SPI is positive edge triggered and if the SCLK is “0” then SPI is negative edge triggered logic (see Table 16).
Table 16. SPI Clock Polarity
CS
SCLK
Description
LOW
HIGH
Serial data is transferred at falling edge and sampled at rising edge of SCLK
LOW
LOW
Serial data is transferred at rising edge and sampled at falling edge of SCLK
The SPI protocol frame is divided in to two fields, the header field and the data field. The header field is 1 byte long containing a read/write
command bit, 5 address bits and 2 reserved bits. The data field is of one data byte. The SPI frame format is shown in Figure 15. In the data
phase MSB is sent first and LSB is sent last.
Figure 15. SPI Frame Format
Header Field
Data Field
1 byte
R/W
0
0
A4
Reserved
Bits
0–
1–
A3
A2
A1
A0
D7
D6
D5
D4
D3
D2
D1
D0
5 bits
Address
WRITE
READ
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8.1.1
SPI Write Operation
The SPI write operation begins with clock polarity selection at negative edge of CS, given in Table 16. Once the clock polarity is selected the SPI
write command is given by providing ‘0’ in R/W bit of the header field in first sampling edge at SDI pin. The 5 bits address of register to be written
is provided at SDI pin in next five consecutive sampling edges of SCLK. The first 2 bits in header fields are reserved and set to 0. The data to be
written is followed by last bit of header field. With each sampling edge a bit is sampled starting from MSB to LSB. During complete SPI write
operation the CS has to be low. The SPI write operation ends with positive edge of CS. The wave form for SPI write operation with single data
byte is shown in Figure 16 and Figure 17.
Figure 16. SPI Write Operation with Negative Clock Polarity and 1 Byte of Data Field
CS
SCLK
SDI
R1
R0
A4
A3
A2
A1
A0
D7
D6
D5
D4
D3
D2
D1
D0
SDO
Sampling Edge
High Impedance Sate
Figure 17. SPI Write Operation with Positive Clock Polarity and 1 Byte of Data Field
CS
SCLK
R1
R0
A4
A3
A2
A1
A0
D7
D6
D5
D4
D3
D2
D1
D0
SDI
SDO
Sampling Edge
High Impedance Sate
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8.1.2
SPI Read Operation
The SPI read operation also begins with clock polarity selection at negative edge of CS, given in Table 16. Once the clock polarity is selected the
SPI read command is given by providing ‘1’ in R/W bit of the header field in first sampling edge at SDI pin. The 5 bits address of register to be
read is provided at SDI pin in next five consecutive sampling edges of SCLK. The first 2 bits in header fields are reserved and set to 0. The read
data is followed by last bit of header field on SDO pin. With each sampling edge a bit can be read on SDO pin starting from MSB to LSB. During
complete SPI read operation the CS has to be low. The SPI read operation ends with positive edge of CS. The wave form for SPI read operation
with single data byte is shown in Figure 18 and Figure 19.
Figure 18. SPI Read Operation with Negative Clock Polarity and 1 Byte of Data Field
CS
SCLK
SDI
R1
R0
A4
A3
A2
A1
A0
D7
SDO
D6
D5
Sampling Edge
D4
D3
D2
D1
D0
D1
D0
High Impedance Sate
Figure 19. SPI Read Operation with Positive Clock Polarity and 1 Byte of Data Field
CS
SCLK
SDI
R1
R0
A4
A3
A2
A1
A0
D7
SDO
Sampling Edge
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D6
D5
D4
D3
D2
High Impedance Sate
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8.1.3
SPI Timing Diagram
Figure 20. Timing Diagram for SPI Write Operation
CS
...
tCPS
tCPHD
tSCLKH
tSCLKL
tCSH
CLK
polarity
SCLK
...
tDIH
tDIS
SDI
DATAI
...
DATAI
DATAI
...
SDO
Figure 21. Timing Diagram for SPI Read Operation
CS
tSCLKL
tSCLKH
SCLK
SDI
DATAI
DATAI
tDOHZ
tDOD
SDO
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8.2 Inter-Integrated Circuit (I2C) Interface
I2C is a bidirectional 2 line bus interface with a serial data line (SDA) and a serial clock line (SCLK) for inter IC control. This interface is only slave
interface and only microcontroller can start and stop the I2C operation. The overview of I2C protocol is shown in Figure 22. A HIGH to LOW
transition on SDA line while SCLK is HIGH is the START (S) condition and a LOW to HIGH transition on SDA line while SCLK is HIGH is the
STOP (P) condition, as shown in Figure 22. The START and STOP conditions should always be generated by the microcontroller. After the
START condition, microcontroller has to make sure that data on SDA line must be stable during the HIGH period of SCLK. The data should only
change when SCLK line is LOW. The Bus is busy after the START condition and it is free after the STOP condition. Any number of data bytes
can be transmitted between START and STOP. Each byte is followed by an acknowledgement (which is the ninth bit). The data transmitter
always receives an acknowledgement from the data receiver at end of each byte. The data transmitter releases the SDA bus at start of LOW
period of 8th clock pulse and data receiver acknowledges by pulling the SDA to LOW during the LOW period of the SCLK. The Data receiver
releases the bus at start of LOW period of 9th clock pulse of the SCLK and data transmitter gets the data bus.The AS8650 does not support
general call address, START byte and high-speed mode.
Figure 22. I2C Bus Protocol
SDA
MSB
S
SCLK
1
LSB
2
3
4
5
6
8
7
1
9
3
2
7 bit Slave address
5
6
8
7
9
1
2
3
4
5
6
8
7
S
or
P
9
8 bit Data
8 bit Data
R/W
8.2.1
4
ACK
ACK
ACK
I2C Write Operation
After the START condition, microcontroller has to send, in the first byte, the 7-bit slave address and 0 into the R/W bit as shown in Figure 23. The
microcontroller has to send the address of the register to be written in the second byte. The first 3 MSB bits are reserved and remaining 5 bits are
used as address bits. The data is sent starting from MSB to LSB. The AS8650 sends acknowledgement on 9th clock pulse. In the next byte (3rd
byte) microcontroller has to send the data to be written into addressed register. If it is a single write operation, after receiving the
acknowledgment from AS8650, microcontroller has to send START or STOP condition, as shown in Figure 23. In case of auto increment write
operation, microcontroller should not generate START or STOP condition after the third byte. If microcontroller continuously writes then address
pointer rolls back to the starting register address after reaching the last register address. Data bytes coming from the microcontroller are written
at the consecutive address locations, starting from the address sent in first data byte. After each data byte, direction of the bus line changes and
AS8650 acknowledges by pulling the SDA line LOW. To terminate the write operation microcontroller has to generate STOP or repeated START
condition. For details, see Figure 24.
Figure 23. I2C Write Operation
acknowledge
from slave
Slave address
A
SDA
MSB
SCLK
S
1
acknowledge
from slave
register address
A4
A3 A2
A1 A0
A
8
9
data to register
acknowledge
from slave
A
LSB
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
1
2
3
4
5
6
7
8
9
S
or
P
R/W
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Figure 24. I2C Auto-increment Write Operation
acknowledge
From slave
Slave address
SDA
Master
transmitter
SCLK
A
MSB
S
1
acknowledge
From slave
register address
A3 A2
A4
A1 A0
A
8
9
data to register
acknowledge
From slave
data to register + n
A
LSB
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
1
2
3
4
5
6
8
7
S
or
P
9
R/W
8.2.2
I2C Read Operation
After the START condition, microcontroller has to send, in the first byte, the 7-bit slave address and 0 into the R/W bit as shown in Figure 25. The
microcontroller has to send the address of the register to be written in the second byte. The first 3 MSB bits are reserved and remaining 5 bits are
used as address bits. The data is sent starting from MSB to LSB. After receiving the acknowledgement on the 9th clock pulse, microcontroller
has to send on the SDA line repeated START or STOP, as shown in Figure 25. If microcontroller sends STOP then microcontroller has to send
START again. If microcontroller sends repeated START then there is no need to generate START again. The microcontroller again has to send
the 7-bit slave address and writes 1 into the R/W bit (8th bit). Now AS8650 sends data of the corresponding addressed register in the next eight
clock cycles. In case of single read, microcontroller does not acknowledge on the 9th clock pulse and generates START or STOP condition after
the ninth clock pulse. If it is an auto increment read operation, microcontroller acknowledges on the 9th clock pulse and AS8650 sends data from
the consecutive address locations, see Figure 25. If microcontroller continuously reads then address pointer rolls back to the starting register
address after reaching the last register address. In the data phase MSB is sent first and LSB is sent last. After each data byte, microcontroller
has to send the acknowledgement. The microcontroller can terminate the auto read operation by not generating acknowledgement for the last
byte that was sent by the AS8650 and generates STOP or repeated START condition after the 9th clock pulse.
Figure 25. I2C Read Operation
acknowledge
from slave
Slave address
SDA
MSB
SCLK S
1
0
A
8
9
acknowledge
from slave
register address
A4
A3 A2 A1 A0
A
LSB
2
3
4
5
6
7
1
2
3
4
5
6
7
8
9
S
or
P
W
acknowledge
from slave
SDA
MSB
SCLK S
1
1
A
8
9
acknowledge
from master
Data byte
Slave address
A
LSB
2
3
4
5
6
7
1
2
3
4
5
6
7
8
9
S
or
P
R
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Revision 1.0
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AS8650
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
Figure 26. I2C Auto-increment Read Operation
0
A
7 8
9
SDA
MSB
SCLK S
1
acknowledge
register address from slave
acknowledge
from slave
Slave address
A
4
LSB
2
3
4
5
6
1
2
3
4
A
3
5
A
2
6
A
1
A
0
A
7
8
9
S
or
P
W
acknowledge
from slave
Slave address
1
A
7 8
9
SDA
MSB
SCLK S
1
Data byte 1
acknowledge
from master
Last data byte
Data byte n
No
acknowledge
from master
A
A
LSB
2
3
4
5
6
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
S
or
P
R
8.3 Digital Timing Specification
SPI Protocol.
Table 17. SPI Timing Parameters
Symbol
Parameter
Conditions
Min
Typ
Max
Units
1
Mbps
General
BRSPI
Bit rate
TSCLKH
Clock high time
500
ns
TSCLKL
Clock low time
500
ns
Write Operation Parameters
tDIS
Data in setup time
20
ns
tDIH
Data in hold time
10
ns
TCSH
CS hold time
40
ns
Read Operation Parameters
tDOD
Data out delay
tDOHZ
Data out to high impedance delay
Time for the SPI to release the SDO bus
80
ns
80
ns
Timing Parameters for SCLK Polarity Identification
tCPS
Clock setup time
(CLK polarity)
Setup time of SCLK with respect to CS
falling edge
20
ns
tCPHD
Clock hold time
(CLK polarity)
Hold time of SCLK with respect to CS
falling edge
20
ns
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AS8650
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
I2C Protocol. Electrical characteristics of SDA & SCLK bus lines for F/S mode
Table 18. I2C Electrical Parameters
Standard
Fast
Symbol
Parameter
VIL
VLDO1related input levels
VIH
VLDO1-related input levels
Vhys
Hysteresis of Schmitt trigger input
VOL1
LOW level output voltage (open drain or
open collector) at 3mA sink current
0.4
tof
Output fall time from VIHmin to VILmax
with a bus capacitance from
250
tSP
Pulse width of spikes which must be
suppressed by the input filter
n/a
n/a
Ii
Input current of each I/O pin with an
input voltage between 0.1VLDO1 and
0.9VLDO1 maximum
-10
10
Ci
Capacitance for each I/O pin
Min
Max
LOW level input voltage:
HIGH level input voltage:
Min
0.3V*LDO1
0.7V*LDO1
n/a
n/a
Units
Max
0.3V*LDO1
0.7V*LDO1
V
0.05V*LDO1
V
0.4
20 + 0.1Cb
V
250
(see Footnote 2) (see Footnote 1) (see Footnote 2)
10pF to 400pF
V
ns
(lab tested
only)
ns
50
10
-10
µA
(see Footnote 3) (see Footnote 3)
10
pF
(guaranteed
by design)
10
1. Cb = capacitance of one bus line in pF.
2. The maximum tf for the SDA and SCLK bus lines quoted in Table 19 (300ns) is longer than the specified maximum tof for the output
stages (250ns). This allows for any series protection resistors to be connected between the SDA/SCLK pins and the SDA/SCLK bus
lines without exceeding the maximum specified tf.
3. I/O pins of Fast-mode devices must not obstruct the SDA and SCLK lines if VLDO1 is switched off.
Characteristics of the SDA and SCLK Bus Lines for F/S Mode I2C Bus.
Table 19. I2C Timing Parameters
Standard
Symbol
Parameter
fSCLK
Fast
Min
Max
Min
Max
(see Footnote 1)
Units
SCLK clock frequency
0
100
0
400
kHz
tHD_STA
Hold time (repeated) START condition.
After this period, the first clock pulse is
generated
4
-
0.6
-
µs
tLOW
LOW period of the SCLK clock
4.7
-
1.3
-
µs
tHIGH
HIGH period of the SCLK clock
4.0
-
0.6
-
µs
tSU_STA
Set-up time for a repeated START
condition
4.7
-
0.6
-
µs
tSU_DAT
Data set-up time
250
-
100
(see Footnote 2)
-
ns
tHD_DAT
Data hold-time
tr
Rise time of SDA and SCLK signals
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0
0
3450
900
(see Footnote 5) (see Footnote 3) (see Footnote 5) (see Footnote 3)
-
Revision 1.0
1000
20+
0.1Cb
(see Footnote 4)
300
ns
ns
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AS8650
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
Table 19. I2C Timing Parameters
Standard
Symbol
Parameter
tf
Fast
Min
Max
Min
Max
(see Footnote 1)
Units
Fall time of SDA and SCLK signals
-
300
20+
0.1Cb
(see Footnote 4)
300
ns
tSU_STO
Set-up time for STOP condition
4.0
-
0.6
-
µs
tBUF
Bus free time between a STOP and
START condition
4.7
-
1.3
-
µs
Cb
Capacitive load for each bus line
-
400
-
400
pF
VnL
Noise margin at the LOW level for each
connected device (including hysteresis)
0.1V*LDO1
-
0.1V*LDO1
-
VnH
Noise margin at the HIGH level for each
connected device (including hysteresis)
0.2V*LDO1
-
0.2V*LDO1
-
1. All values referred to VIHmin and VIlmax levels (see Table 18).
2. A fast mode I2C bus device can be used in Standard mode I2C bus system, but the requirement tSU_DAT ≥ 250ns must then be met.
This will automatically be the case if the device do not stretch the LOW period of the SCLK signal. If such a device does stretch the
LOW period of the SCLK signal, it must output the next data bit to the SDA line trmax. TSU_DAT = 1000 + 250 = 1250ns (according to
standard mode I2C bus specification) before the SCLK line released.
3. The maximum tHD;DAT has only to be met if the device does not stretch the LOW period (tLOW) of the SCLK signal.
4. Cb = total capacitance of one bus line in pF. If mixed with Hs-mode devices, faster fall-times according toTable 18 allowed.
5. This device internally provides a hold time of at least 300ns for the SDA signal to bridge the undefined region of the falling edge of the
SCLK.
Figure 27. Definition of I2C Timing Parameters
SDA
tf
SCLK
tr
tLOW
tr
tf
tSU_DAT
tHD_DAT
tBUF
tSP
S
tHD_STA
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tHIGH
tSU_STA
Revision 1.0
Sr
tSU_STO
P
S
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AS8650
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
8.3.1
System Specification and Timings
Table 20. System Timing Parameters
Symbol
Parameter
Conditions
Min
Typ
Max
Units
Wake-up Timing
Tdom(wake)
Minimum dominant pulse for CAN
wake-up detection (remote wake)
5
µs
Trec(wake)
Minimum recessive pulse for CAN
wake-up detection (remote wake)
5
µs
TL_wake
Time between edge on WAKE pin to
local wake detection
TLW_filter
Time between edge on WAKE pin to
WAKE_LOCAL signal
(Filter on WAKE pin)
TR_wake
Remote wake detection time from the
valid pattern detection
TINTN
INTN pin high time
7
V_LWUTH
Local WAKE threshold input
2
32
0.75
µs
5
24
µs
µs
µs
4
V
Local Failure Related Timing
TTxDC(dom)
TxD dominant time-out period
600
1000
1400
µs
TBUSC(dom)
BUS dominant clamping time-out period
600
1000
1400
µs
Watchdog Timing & Timeouts
TWD(init)
Start-up Watchdog time-out
(initialization time)
Twd_trig
Window watchdog Trigger window
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300
Twwd_period is defined in WWD
register
Revision 1.0
0.375
0.5
ms
0.625
Twwd_period
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AS8650
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
8.4 Register Space
The AS8650 register space consists of configuration registers, control registers and diagnostic registers. All of these registers are accessible
through SPI or I2C commands.
Table 21. Configuration Registers
Addr
Register Name
POR Value
0x00
Reserved
Reserved
0x01
Reserved
Reserved
0x02
WD Access Control
Register
0000_0000
POR_VLDO1
Bit
D[7:0]
Type
R/W
Description
0101_10 WD Configuration Register access Enabled
10
Else WD Configuration Register access disabled
01
D[7:6]
WD disabled
Else WD enabled
Time-out Watchdog mode Window period Twd_tout_period.
(Accuracy of the timings is ±25%)
D[5:3]
0x03
WD Configuration
Register
0000_1001
POR_VSUP
R/W
000
80 ms
001
160 ms
010
320 ms
011
480 ms
100
800 ms
101
1000 ms
110
2000 ms
111
4000 ms
Window Watchdog mode Window period Twwd_period
(50% of above value is trigger window)
D[2:0]
D[7:1]
0x04
WD Trigger Register
0000_0000
POR_VLDO1
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D[0]
000
10 ms
001
40 ms
010
80 ms
011
120 ms
100
160 ms
101
240 ms
110
320 ms
111
400 ms
Reserved
W
Watchdog trigger bit. The microcontroller set this bit within the
required window of watchdog timer. After this internal counter is
reset and this bit is cleared internally.
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AS8650
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
Table 21. Configuration Registers
Addr
Register Name
POR Value
Bit
Type
Description
D[7]
D[6]
D[5]
0x05
Device
Configuration
Register
D[4]
0110_1101
POR_VSUP
R/W
D[3]
D[2]
D[1]
D[0]
0
LDO3 disable in Standby mode
1
LDO3 enable in Standby mode
0
LDO3 disable in Receive only mode
1
LDO3 enable in Receive only mode
0
LDO3 disable in Normal mode
1
LDO3 enable in Normal mode
0
LDO2 disable in Standby mode
1
LDO2 enable in Standby mode
0
LDO2 disable in Receive only mode
1
LDO2 enable in Receive only mode
0
LDO2 disable in Normal mode
1
LDO2 enable in Normal mode
0
DCDC disable in sleep mode
1
DCDC enable in sleep mode
0
BUS with low slew rate
1
BUS with high slew rate
D[7:6]
Reserved
Device state (Read-only values)
D[5:4]
0x06
Mode Control
Register
0000_0000
POR_VSUP
D[3:2]
R/W
D[1:0]
0
Device in STAND BY Mode
1
Device in NORMAL Mode
10
Device in RECEIVE ONLY Mode
Reserved
00
STAND BY Mode
01
NORMAL Mode
10
RECEIVE ONLY Mode
11
SLEEP Mode
D[7:3]
Reserved
D[2]
0x07
Interrupt Register
0000_0000
POR_VSUP
D[1]
No Interrupt
1
Supply Related Interrupt. The source of interrupt is
known by reading interrupt source register 3
0
No Interrupt
1
Wake-up & temperature Related Interrupt. The
source of interrupt is known by reading interrupt
source register 2
0
No Interrupt
1
BUS & Local Failure Related Interrupt. The source of
interrupt is known by reading interrupt source
register 1
R
D[0]
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0
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AS8650
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
Table 21. Configuration Registers
Addr
Register Name
POR Value
Bit
Type
D[7]
D[6]
D[5]
D[4]
0x08
Interrupt Source
Register 1
0000_0000
POR_VSUP
R/W
D[3]
D[2]
D[1]
D[0]
Description
0
No Interrupt
1
Interrupt due to BUS clamped to dominant
0
No Interrupt
1
Interrupt due to short TxD & RxD pins
0
No Interrupt
1
Interrupt due to RxD pin clamped to Recessive
0
No Interrupt
1
Interrupt due to TxD pin clamped to Dominant
0
No Interrupt
1
Interrupt due to CANL pin shorted to VCC
0
No Interrupt
1
Interrupt due to CANL pin shorted to GND
0
No Interrupt
1
Interrupt due to CANH pin shorted to GND
0
No Interrupt
1
Interrupt due to CANH pin shorted to VCC
D[7:4]
Reserved
D[3]
0x09
Interrupt Source
Register 2
0000_0000
POR_VSUP
D[2]
D[1]
D[0]
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Revision 1.0
0
No Interrupt
1
Interrupt due to junction temperature falling back
below Tjrecv
0
No Interrupt
1
Interrupt due to junction temperature exceeding
Tjwarn
0
No Interrupt
1
Interrupt due to Local Wake up event on WAKE pin
0
No Interrupt
1
Interrupt due to Wake up by BUS message (remote
wake)
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AS8650
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
Table 21. Configuration Registers
Addr
Register Name
POR Value
Bit
Type
D[7]
D[6]
D[5]
D[4]
0x0A
Interrupt Source
Register 3
0000_0000
POR_VSUP
R/W
D[3]
D[2]
D[1]
D[0]
0x0B
0x0C
0x0D
0x0E
Reserved
BUS Status
Register
Temperature Status
Register
Supply status
Register
0000_0000
POR_VSUP
0000_0000
POR_VSUP
0000_0000
POR_VSUP
1010_1010
POR_VSUP
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Description
0
No Interrupt
1
Interrupt due to VLDO3_POK_flag set
0
No Interrupt
1
Interrupt due to VLDO3_UV_flag set
0
No Interrupt
1
Interrupt due to VLDO2_POK_flag set
0
No Interrupt
1
Interrupt due to VLDO2_UV_flag set
0
No Interrupt
1
Interrupt due to V5V_POK_flag set
0
No Interrupt
1
Interrupt due to V5V_UV_flag set
0
No Interrupt
1
Interrupt due to VSUP_POK_flag set
0
No Interrupt
1
Interrupt due to VSUP_UV_flag set
D[7:0]
Reserved
D[7]
BUS clamped to dominant
D[6]
TxD & RxD pins short
D[5]
RxD pin clamped to Recessive
D[4]
D[3]
R
TxD pin clamped to Dominant
CANL pin shorted to VCC
D[2]
CANL pin shorted to GND
D[1]
CANH pin shorted to GND
D[0]
CANH pin shorted to VCC
D[7:2]
Reserved
D[1]
R
OTM 140 Recovery flag
D[0]
OTM 160 Warning flag
D[7]
VLDO3_POK_flag
D[6]
VLDO3_UV_flag
D[5]
VLDO2_POK_flag
D[4]
D[3]
R
VLDO2_UV_flag
V5V_POK_flag
D[2]
V5V_UV_flag
D[1]
VSUP_POK_flag
D[0]
VSUP_UV_flag
Revision 1.0
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AS8650
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
Table 21. Configuration Registers
Addr
Register Name
POR Value
Bit
Type
Description
These bits are cleared on microcontroller read
0x0F
RESET Reason
Register
0000_0000
POR_VSUP
D[7]
Reserved
D[6]
SLEEP Mode exit by Local Wake up on WAKE pin
D[5]
SLEEP Mode exit by Remote wake
D[4]
R
Window Watchdog failure
D[3]
Timeout Watchdog failure
D[2]
Start-up Watchdog failure
D[1]
Undervoltage on VLDO1
D[0]
OTM Shutdown flag
0x10
D[7:0]
OTP_BITS[32:25] / MCU Backup Data
0x11
D[7:0]
OTP_BITS[40:33] / MCU Backup Data
0x12
D[7:0]
OTP_BITS[48:41] / MCU Backup Data
0x13
0x14
Backup Register
0000_0000
POR_VSUP
D[7:0]
D[7:0]
R/W
OTP_BITS[56:49] / MCU Backup Data
{1’b0,OTP_BITS[63:57]} / MCU Backup Data
0x15
D[7:0]
{2'd0, Slave address[6:1]}/MCU Backup Data
0x16
D[7:0]
10bit_slave_address[3:0]/MCU Backup Data
0x17
D[7:0]
MCU Backup Data
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AS8650
Datasheet - P a c k a g e D r a w i n g s a n d M a r k i n g s
9 Package Drawings and Markings
The device is available in a 36-pin QFN (6x6x0.9) package.
Figure 28. Drawings and Dimensions
AS8650
YYWWIXX
Symbol
A
A1
A3
L
L1
b
D
E
e
D2
E2
aaa
bbb
ccc
ddd
eee
fff
N
Notes:
Min
0.80
0
0.35
0
0.18
4.60
4.60
-
Nom
0.90
0.02
0.20 REF
0.40
0.25
6.00 BSC
6.00 BSC
0.50 BSC
4.70
4.70
0.15
0.10
0.10
0.05
0.08
0.10
36
1. Dimensions and tolerancing conform to ASME Y14.5M-1994.
2. All dimensions are in millimeters, angle is in degrees.
3. Dimension b applies to metallized terminal and is measured between 0.25 and
0.30mm from terminal tip. Dimension L1 represents terminal full back from package edge up to 0.15mm is acceptable.
4. Coplanarity applies to the exposed heat slug as well as the terminal.
5. Radius on terminal is optional.
6. N is the total number of terminals.
Max
1.00
0.05
0.45
0.15
0.30
4.80
4.80
-
Marking: YYWWIXX.
YY
WW
I
XX
Last two digits of the current year
Manufacturing Week
Assembly plant identifier
Assembly traceability code
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AS8650
Datasheet - R e v i s i o n H i s t o r y
Revision History
Revision
Date
Owner
Description
1.0
29 Nov, 2010
hgl
Initial release
Note: Typos may not be explicitly mentioned under revision history.
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AS8650
Datasheet - O r d e r i n g I n f o r m a t i o n
10 Ordering Information
The devices are available as the standard products shown in Table 22.
1
Table 22. Ordering Information
Ordering Code
Marking
Description
Delivery Form
Package
AS8650-ZQFP-0001
AS8650
AS8650 Power Management device with high-speed
CAN Interface (standard configuration)
Tape & Reel
36-pin QFN
(6x6x0.9)
1. The AS8650 provides various configuration options during production. For more information, please contact our sales office.
Note: All products are RoHS compliant and austriamicrosystems green.
Buy our products or get free samples online at ICdirect: http://www.austriamicrosystems.com/ICdirect
Technical Support is available at http://www.austriamicrosystems.com/Technical-Support
For further information and requests, please contact us mailto: [email protected]
or find your local distributor at http://www.austriamicrosystems.com/distributor
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AS8650
Datasheet - C o p y r i g h t s
Copyrights
Copyright © 1997-2010, austriamicrosystems AG, Tobelbaderstrasse 30, 8141 Unterpremstaetten, Austria-Europe. Trademarks Registered ®.
All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of
the copyright owner.
All products and companies mentioned are trademarks or registered trademarks of their respective companies.
Disclaimer
Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale.
austriamicrosystems AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding
the freedom of the described devices from patent infringement. austriamicrosystems AG reserves the right to change specifications and prices at
any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with austriamicrosystems AG for
current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature range,
unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment are
specifically not recommended without additional processing by austriamicrosystems AG for each application. For shipments of less than 100
parts the manufacturing flow might show deviations from the standard production flow, such as test flow or test location.
The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However, austriamicrosystems AG shall not
be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use,
interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing,
performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of
austriamicrosystems AG rendering of technical or other services.
Contact Information
Headquarters
austriamicrosystems AG
Tobelbaderstrasse 30
A-8141 Unterpremstaetten, Austria
Tel: +43 (0) 3136 500 0
Fax: +43 (0) 3136 525 01
For Sales Offices, Distributors and Representatives, please visit:
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