View ds1816 datasheet:

DS1816 3.3V EconoReset with Open Drain Output www.maxim-ic.com FEATURES PIN ASSIGNMENT Automatically restarts a microprocessor after 3 power failure Maintains reset for 150ms after VCC returns to an in-tolerance condition Reduces need for discrete components Precision temperature-compensated voltage 1 2 reference and voltage sensor SOT-23 PACKAGE Accurate 5%, 10% or 20% power monitoring 20% tolerance for use with 3V systems 1 2 3 Low-cost TO-92 or space saving SOT-23 packages available 1 2 3 Efficient open-drain output with internal 5k pull-up resistor TO-92 PACKAGE See Mech. Operating temperature -40 C to +85 C Drawings Section PIN DESCRIPTION TO-92 1 RST Active Low Reset Output 2 VCC Power Supply 3 GND Ground SOT-23 1 RST Active Low Reset Output