The TL7702B, TL7705B, and TL7733B are integrated-circuit supply-voltage supervisors designed for use as reset controllers in microcomputer and microprocessor systems. The supply-voltage supervisor monitors the supply for undervoltage conditions at the SENSE input. During power up, the RESET output becomes active (low) when V_CC attains a value approaching 1 V. As V_CC approaches 3 V (assuming that SENSE is above V_T+), the delay-timer function activates a time delay, after which outputs RESET and RESET go inactive (high and low, respectively). When an undervoltage condition occurs during normal operation, outputs RESET and RESET go active. To ensure that a complete reset occurs, the reset outputs remain active for a time delay after the voltage at the SENSE input exceeds the positive-going threshold value. The time delay is determined by the value of the external capacitor C_T : t_d ≈ 2.6 × 10⁴ × C_T , where C_T is in farads (F) and t_d is in seconds (s).

An external capacitor (typically 0.1 µF) must be connected to REF to reduce the influence of fast transients in the supply voltage.