VOLTAGE LEVEL SENSING POWER-UP RESET CIRCUIT

摘要

A power-up reset circuit for providing a reset signal for resetting circuit elements such as filp-flops upon the application of power to the circuit includes a CMOS pair output section and a capacitor coupled to the gates of the CMOS transistors. The capacitor is charged up by the power supply to switch the reset signal to a low level after the resetting operation has been achieved. In order to accommodate slow ramping power supplies, circuitry operating as a voltage sensitive switch is included to prevent the capacitor from charging until the power supply voltage has reached a level to ensure proper operation.