The CMPWR150 is a low dropout regulator that delivers up to 500mA of load current at a fixed 3.3V output. An internal threshold level (typically 4.1V) is used to prevent the regulator from being operated below dropout voltage. The device continuously monitors the input supply and will automatically disable the regulator when VCC falls below the threshold level. When the regulator is disabled, the control signal "Drive" (Active Low) is enabled, which allows an external PMOS switch to power the load from an auxiliary 3.3V supply.