The TL7757 is a supply-voltage supervisor designed for use in microcomputer and microprocessor systems. The supervisor monitors the supply voltage for undervoltage conditions. During power up, when the supply voltage, VCC, attains a value approaching 1 V, the RESET output becomes active (low) to prevent undefined operation. If the supply voltage drops below threshold voltage level (VIT), the RESET output goes to the active (low) level until the supply undervoltage fault condition is eliminated.