Description

The MAX792/MAX820 microprocessor (µP) supervisory circuits provide the most functions for power-supply and watchdog monitoring in systems without battery backup. Built-in features include the following: µP reset: Assertion of RESET and active-low RESET outputs during power-up, power-down, and brownout conditions. Active-low RESET is guaranteed valid for VCC down to 1V. Manual-reset input. Two-stage power-fail warning: A separate low-line comparator compares VCC to a presetthreshold 120mV above the reset threshold; the low-line and reset thresholds can be programmed externally. Watchdog fault output: Assertion of active-low WDO if the watchdog input is not toggled within a preset timeoutperiod. Pulsed watchdog output: Advance warning of impending active-low WDO assertion from watchdog timeout thatcauses hardware shutdown. Write protection of CMOS RAM, EEPROM, or other memory devices.The MAX792 and MAX820 are identical, except the MAX820 guarantees higher low-line and reset threshold accuracy (±2%).ApplicationsComputers: Desktop, Workstation, ServerControllersCritical µP MonitoringIntelligent Instruments