View max6443-max6452 datasheet:

19-2656; Rev 0; 10/02 µP Reset Circuits with Long Manual Reset Setup Period General Description Features The MAX6443–MAX6452 low-current microprocessor Single- or Dual-Supply Voltage Monitors reset circuits feature single or dual manual reset inputs Precision Factory-Set Reset Thresholds from with an extended 6.72s setup period. Because of the 1.6V to 4.6V extended setup period, short switch closures (nuisance resets) are ignored. Adjustable Threshold to Monitor Voltages Down On all devices, the reset output asserts when any of the to 0.63V (MAX6449–MAX6452) monitored supply voltages drops below its specified Single or Dual Manual Reset Inputs with Extended threshold. The reset output remains asserted for the 6.72s Setup Period reset timeout period (210ms typ) aft