The TPS3617 and TPS3618 are battery-backup supervisors that monitor 5 V supplies. They provide a battery-backup function ideal for applications that require data retention of CMOS RAM during fault conditions. When the voltage at VDD drops below a preset threshold (VIT), the active low push-pull RESET output asserts, and VOUT switches from VDD to VBAT. When VDD rises above the trip threshold, VOUT switches immediately from VBAT to VDD. The RESET output remains low until the delay time (td) expires. During power on, RESET is asserted when the supply voltage (VDD or VBAT) goes higher than 1.1 V.