The ADM9690 contains a voltage monitoring comparator and a watchdog timer monitor. It is designed to monitor the 5 V power supply to a microprocessor and the microprocessor operation via a watchdog function. The voltage monitoring comparator monitors the voltage on VMON. If it drops outside tolerance, as will happen during a power-fail, two reset signals are generated. Both reset signals go active (low) simultaneously. They will remain active while VMON is below the threshold, and for 50 ms (RESET(1)) or 60 ms (RESET(2)) after VMON climbs above the reset threshold. RESET(1) is intended to provide a power-on reset signal for the P while RESET(2) is used to hold additional circuitry in a reset state until the P has regained control following a power-up. The voltage monitoring circuitry remains operational with VCC as low as 2 V.