The CS8151 is a 5V, 100mA micro-power voltage regulator with very low quiescent current (400µA typical at 200µA load). The 5V output is accurate within ±2% and supplies 100 mA of load current with a typical dropout voltage of 400mV. Microprocessor control logic includes Watchdog, Wake Up and . This unique combination of low quiescent current and full microprocessor con- trol makes the CS8151 ideal for use in battery operated, microprocessor con- trolled equipment. The CS8151 WAKE UP function brings the microprocessor out of Sleep mode. The microprocessor in turn, signals its WAKE UP status back to the CS8151 by issuing a WATCHDOG signal. The WATCHDOG logic function mon- itors an input signal (WDI) from the microprocessor. The CS8151 responds to the falling edge of the WATCH- DOG signal which it expects at least once during each wake-up period. When the correct WATCHDOG signal is received, a falling edge is issued on the wake-up signal line. is independent of VIN and operates correctly to an output voltage as low as 1V. A signal is issued in any of three situations. During power up the is held low until the output voltage is in regulation. During operation if the output voltage shifts below the regulation limits, the toggles low and remains low until proper output voltage regulation is restored. And finally, a is issued if the regulator does notsignal receive a WATCHDOG signal within the WAKE UP p