GENERAL DESCRIPTION

The ADM823/ADM824/ADM825 are supervisory circuits that monitor power supply voltage levels and code execution integrity in microprocessor-based systems. In addition to providing power-on reset signals, an on-chip watchdog timer can reset the microprocessor if it fails to strobe within a preset timeout period. A reset signal can also be asserted by an external pushbutton, through a manual reset input. The three parts feature different combinations of watchdog input, manual reset input, and output stage configuration, as shown in Table 1.

FEATURES

Precision 2.5 V to 5 V power supply monitor

7 reset threshold options: 2.19 V to 4.63 V

140 ms (minimum) reset timeout

Watchdog timer with 1.6 sec timeout (ADM823, ADM824)

Manual reset input (ADM823, ADM825)

Push-pull output stages

RESET (ADM823)

RESET, RESET (ADM824/ADM825)

Low power consumption: 5 μA

Guaranteed reset output valid to VCC = 1 V

Power supply glitch immunity

Specified over automotive temperature range

5-lead SC70 and SOT-23 packages

APPLICATIONS

Microprocessor systems

Computers

Controllers

Intelligent instruments

Portable equipment