Power-On-Reset (POR) circuit

摘要

A Power-On-Reset (POR) Circuit compares a logic supply voltage to a reference voltage and provides a logic voltage validity signal if the logic voltage is greater than the reference voltage; the circuit delays, on startup, the validity signal for a selected period and then provides a drive signal for driving a solid-state switch which provides an open circuit on the presence of the drive signal, indicating logic voltage validity, and a short circuit in its absence, indicating invalidity; and the circuit immediately disables the drive signal if the logic voltage falls below the reference voltage. The selected start-up delay period is independent of the supply voltage magnitude.