GENERAL DESCRIPTION

The ADM8323/ADM8324 are supervisory circuits that monitor

power supply voltage levels and code execution integrity in

microprocessor-based systems. An on-chip watchdog timer checks

for activity within a preset timeout window. A reset signal can also

be asserted by an external push-button switch through a manual

reset input. The RESET output is either push-pull (ADM8323)

or open-drain (ADM8324).

A watchdog failure results in a low output on the RESET pin. A

failure can be triggered either by a fast watchdog error (watchdog

pulses too close together) or by a slow watchdog error (no watchdog

pulse within the timeout period). This effectively gives a window

to observe the watchdog pulse. The watchdog timeout is measured

from the last falling edge of the watchdog input (WDI). There are

eight different watchdog windows available, as shown in Table 5.

Each device is available in a choice of 26 reset threshold options

from 2.5 V to 5 V in 100 mV increments. There are also four reset

timeout options of 1 ms, 20 ms, 140 ms, and 1120 ms (minimum).

Not all device options are available as standard models. See the

Ordering Guide for details.

The ADM8323/ADM8324 are available in a 5-lead SOT-23

package and typically consume only 10 μA, making them suitable

for use in low power portable applications.

FEATURES

Windowed watchdog, 8 timeout options

26 reset threshold options

2.5 V to 5 V in 100 mV increments

4 reset timeout options

1 ms, 20 ms, 140 ms, and 1120 ms (minimum)

Manual reset input

Open-drain or push-pull RESET outputs

Low power consumption

Specified over wide temperature range (−40°C to +125°C)

Qualified for automotive applications

5-lead SOT-23 package

APPLICATIONS

Automotive

Microprocessor systems

Computers

Controllers

Intelligent instruments

Portable equipment