The APL5151/2/3/4 is micropower, low noise, low dropout linear regulator. Operate from 3V to 6V input voltage and deliver up to 150mA. Typical output noise is just 60uVRMS with the addition of an external 0.33uF bypass capacitor in BP pin and typical dropout voltage is only 220mV at 150mA loading. Designed for use in battery-powered system, the low 50uA quiescent current makes it an ideal choice. Design with an internal P-channel MOSFET pass transistor, the APL5151/2/ 3/4 maintains a low supply current, independent of the load current and dropout voltage. Other features include reverse current protection, thermal-shutdown protection, current limit protection to ensure specified output current and controlled short-circuit current. The APL5151/2/3/4 regulators come in a miniature SOT23-5 package.