The power supply monitor and reset circuit protects memory and system controllers during power up/down and against brownout conditions. Five reset threshold voltages support 5V, 3.3V and 3V systems. If power supply voltages are out of tolerance reset signals become active, preventing the system microcontroller, ASIC or peripherals from operating. Reset signals become inactive typically 200ms after the supply voltage exceeds the reset threshold level. With both active high and low reset signals, interface to microcontrollers and other ICs is simple. In addition, a reset pin can be used as debounced input for pushbutton manual reset capability.