4716B–AUTO–06/03
Watchdog IC
ATA6025
Features
Watchdog Adjustable
Over- and Undervoltage Detection of V
cc
= 5 V
Standby Modes On/Off via Ignition Pin VKL15
Internal Time Delay for Output Signal
Push-pull Output Driver
Interference and Damage Protection According to ISO/CD 7637
ESD Protection
Description
The ATA6025 is a monolithic circuit based on Atmel’s smart power BCD60-III technol-
ogy. It is a universal IC for monitoring basic functions of an automotive application. It is
possible to monitor the battery voltage (VKL15) and an external 5 V voltage regulator.
With the independent watchdog the correct function of a microcontroller can be
observed. If a failure occurs, the output NOTL switches to high after a time delay. Dur-
ing standby mode the current consumption is reduced to a minimum.
Figure 1. Block Diagram
GND
VCC
VB
VBG
VDD
5V regulator
POR & Bandgap
Reference
VBG
VDD
Short circuit
protectedBIAS
current
IBias
RREF
WD
VDD
Watchdog
OSC
CLK
oscillator
on chip
trimming
OSC
standby mode
up
&down
counter
400ms
failure
watchdog
fwd
VCC
over- & undervoltage
detection
POR
POR
NOTL
NL High
at counter end
NL Low
at counter zero
2.5 mA
High at counter
zero
standby mode
Input
Test mode 1 or 2
divided by 4
OSC
VCCL
VCCH
NVKL15
VB monitoring VBOK
VKL15
1