Datasheet
2Atmel ATA5021 [DATASHEET]
9145G–AUTO–09/12
1. Description
The digital window watchdog timer, Atmel
®
ATA5021, is designed in Atmel’s state-of-the-art 0.8µm SOI technology
SMART-I.S.
™
1. In applications where safety is critical, it is especially important to monitor the microcontroller. Normal
microcontroller operation is indicated by a cyclically transmitted trigger signal, which is received by a window watchdog timer
within a defined time window.
A missing or a wrong trigger signal causes the watchdog timer to reset the microcontroller. The IC is tailored for
microcontrollers, which can work in both full-power and sleep mode. With an additional voltage monitoring (power-on reset and
supply voltage drop reset), the Atmel ATA5021 offers a complete monitoring solution for micro-systems in automotive and
industrial applications.
Figure 1-1. Block Diagram with External Circuit
Input signal
conditioning
OSC
POR
3
2
Power-on
reset
5
Mode
Trigger
RC
oscillator
State machine
POR
OSC
Reset
Micro-
controller
Test logic
1
Wake-up
External
switching
circuitry
4
7
Enable
GND
8
6
C
10nF
R
1
V
DD
OSC
C
1
V
DD
R
2