Features
Driver Stages
Four DMOS 150 mA Low-side Relay Drivers with Current Limitation
One Gate Driver for External N-channel FET with Charge Pump and Bootstrap
Two Universal Outputs (10 mA High Side and 60 mA Low Side)
One 20 mA Warning Lamp Driver
Power Supplies
5V/150 mA Linear Regulator
5V/30 mA Linear Regulator (also Active in Standby Mode)
Internal Power Supply
Switchable System Supply Voltage Output
Monitoring and Protection
12V Monitoring
Watchdog with Reset
Two Comparators for Current Measurement
Adjustable Undervoltage Warning Level
Overtemperature Protection with Hysteresis
Two 5V Comparators
Wide Supply Voltage Range from 5.8V up to 26V
8-bit SPI Interface
Low Current Consumption in Standby Mode 80 A
TTL and CMOS Compatible Inputs
2 kV ESD Protection
Transient Protection According to ISO/TR 7637-1 Level 4 (Except Load Dump)
Applications
As an Automotive Failsafe System IC, the ATA6814 is ideal for driver and monitoring
functions in ambitious solutions with increased safety requests such as parking
brakes, power steering, and other applications with DC motor control.
Automotive
Failsafe System
IC
ATA6814
Preliminary
Rev. 4849BAUTO09/05
2
4849BAUTO09/05
ATA6814 [Preliminary]
1.
Description
The ATA6814 is a monolithically-integrated multi-functional IC designed in Atmel's
state-of-the-art 0.8 m BCDMOS technology. With its built-in driver stages, voltage supplies and
monitoring functions, it is an ideal cost saving failsafe system IC.
The communication with an external microcontroller is provided by an 8-bit SPI interface.
Four protected and current limited driver stages are available to control relays and additionally
there is a gate driver including charge pump and bootstrap to control an external FET.
Three LEDs for status information can be controlled via three separate outputs: The high-side
driver at pin OUTP has monitoring functions for overcurrent and current threshold. The low-side
drivers at the pins WLN and OUTN also have monitoring functions for overcurrent, current
threshold, and voltage monitoring.
Two internal bandgap references control and monitor two independent 5V supply voltages. In
standby mode the internal IC-supply is provided by one of them; the other one is switched off, in
order to reduce the power consumption to a minimum. All internal blocks are supplied by a spe-
cific internal voltage regulator.
The system supply voltage and all internally-generated voltages are monitored and in case of
over or undervoltage all drivers are switched off. Via the SPI the system supply voltage can be
switched to provide power for external components.
The car battery voltage (KL 30) is monitored by an adjustable monitoring function.
An oscillator with an external RC circuitry and a fully-integrated auxiliary oscillator which can be
set via the pin RREF are the clock references for the watchdog and all other time constants.
Both oscillators monitor each other.
The independent watchdog circuitry monitors the microcontroller's correct operation.
Two differential amplifiers support the use of external A/D converters for current measurement.
Two comparators are provided to monitor the 5V supply of external devices like sensors.
3
4849BAUTO09/05
ATA6814 [Preliminary]
Figure 1-1.
Block Diagram
V12S
CtrL
Control
Logic
8-Bit
SPI
12V switch
CtrL
WLP
UVM
WLN
RREF
GND
L
A
P
TEST
OUTN
OUTP
C2I
C2O
BSC
TCFET
RD1
RD4
RD3
RD2
CtrL
Enable
Test
12V Over/
undervoltage
monitor
Battery
undervoltage
monitor
Universal
lowside
Driver
CtrL
CtrL
CtrL
B2CI
B2CG
B2CO
Auxiliary
5V voltage
regulator
Main
5V voltage
regulator
Bandgap
reference
Bandgap
reference
Internal
voltage
regulator
Fully integrated
main
oscillator
Overtemperature
monitor
Watchdog
oscillator
Current bias
for all blocks
Watchdog
with reset
function
Universal
lowside
Driver
Universal
highside
driver
Highside
gate driver
with charge
pump
Lowside
driver
Lowside
driver
Lowside
driver
CtrL
Lowside
driver
Voltage
monitoring
Current
measurement
comparator
Current
measurement
comparator
Voltage
monitoring
comparator 1
Voltage
monitoring
comparator 2
CtrL
CtrL
(CtrL)
CtrL
CtrL
CtrL
CtrL
CtrL
CtrL
CtrL
CtrL
CtrL
CtrL
CtrL
I
REF
B1CI
B1CG
B1CO
V12
DO
VRE
EK15
E5
B5
V5
B5A
RCOS
V5A
RESAN
RESN
WDT
RSTN
VI
CLK
DI
CSN
ERD
UVR
UVW
C1I
C1O
4
4849BAUTO09/05
ATA6814 [Preliminary]
Figure 1-2.
Application Circuit
P
VI
WLN
10
F
47
F
P
P
ERD
C1I
C2I
C2O
C1O
DO
P
P
P
P
P
P
P
P
P
P
P
P
P
100 nF
CV5
CK30
DK30
QU5
STD1802
4.7
F
CV5A
QU5A
BC817-40
100 nF
DWLN
CVI
47 nF
CBS1
RREF
EK15
RSTN
RESAN
CSN
DI
CLK
RESN
WDT
E5
GNDA
GNDL
B1CO
RWLN
2.7 k
RUVM
510
10 k
RREF
100 k
RUV2
2.5 k
RUV1
1 k
47 nF
CBS2
DOUTN
DK15
RTC2
10 k
RTC1
10 k
ROUTN
2.7 k
OUTP
TEST
VRE
GNDP
V12S
VI
WLN
TCFET
BSC
V5A
B5A
V5
B5
WLP
OUTN
K15ext
K15
K30
K30P
K30
DOUTP
ROUTP
2.7 k
V12
VI
UVR
RCOS
UVM
UVW
B1CG
B1CI
RD2
1 k
RL12
1 k
RL14
ADC
ADC
20 k
RL15
0.01
RL13
20 k
RL11
MR34
MR12
M1
8.2
RL1
RL2
RL1
MTCFET1
RD1
K30P
M
B2CO
B2CG
B2CI
RD4
1 k
RL22
1 k
RL24
20 k
RL25
0.01
RL23
20 k
RL21
8.2
RL2
MTCFET2
COS
ROS
1 nF
M2
RL4
RL3
RD3
K30P
M
5
4849BAUTO09/05
ATA6814 [Preliminary]
2.
Pin Configuration
Figure 2-1.
Pinning QFN48
C1I
RD2
RD1
V12S
WLN
OUTP
V12
RD4
GNDP
RD3
C2I
OUTN
ATA6814
CLK
CSN
RCOS
E5
EK15
UVM
TEST
UVR
GNDA
RREF
RESN
RSTN
DI
DO
VRE
C10
GNDL
C20
B1CO
B2CO
B2CI
B2CG
B1CG
B1CI
VI
B5
V5A
B5A
WDT
UVW
RESAN
WLP
ERD
V5
BSC
TCFET
24 23 22 21 20 19 18 17 16 15 14 13
37 38 39 40 41 42 43 44 45 46 47 48
25
26
27
28
29
30
31
32
33
34
35
36
12
11
10
9
8
7
6
5
4
3
2
1
Table 2-1.
Pin Description
Pin
Symbol
Function
1
RSTN
Reset input
2
RESN
Reset output
3
RREF
Reference resistor
4
GNDA
Analog ground
5
UVR
Undervoltage reference input
6
TEST
Test
7
UVM
Undervoltage measurement input
8
EK15
Enable (K15 based)
9
E5
Enable (5V based)
10
RCOS
Resistor-capacitor oscillator
11
CSN
Chip-select input
12
CLK
Clock input
13
DI
Data input
14
DO
Data output
15
VRE
External voltage regulator output
16
C1O
Comparator 1 output
17
GNDL
Logic ground
18
C2O
Comparator 2 output
19
B1CO
Bridge 1 current output
20
B1CI
Bridge 1 current input
21
B1CG
Bridge 1 current ground
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