CAT871, CAT872 are dual input reset generators designed to restart microprocessor and microcontroller based systems when the watchdog timer or other resetting mechanisms have become disabled or failed.CAT871, CAT872 monitor two inputs and output an active low reset pulse after both inputs have been active (logic low) for a factory preset minimum time. The reset pulse width is 2.2 ms for CAT871 and 70 ms for CAT872. Releasing either input from its active state before the minimum timeout period resets the internal timer and both inputs must return to being active before the timer will restart with a fresh count down.CAT871, CAT872's open drain output is capable of sinking up to 3 mA of current and may be wire-OR'd with other open drain devices to drive a common reset input.