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 push-button, 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