These devices provide essential functions such as supply voltage supervision by asserting a reset output during power-up and power-down as well as during brownout conditions. An auxiliary voltage monitor is provided for detecting power failures warning the system of low battery conditions or presence detection. In addition, an independent watchdog timer helps to monitor microprocessor activity every 1.6s (typical). An active-low manual reset is offered and reset signals remain asserted until VDD returns to proper operating levels.