Patent ID: 8072196

Claim:
A power supply control circuit comprising: a low drop out circuit comprising an operational amplifier, the operational amplifier having an output configured to be coupled to a low drop out transistor for generating a power supply output voltage at a first source/drain terminal of the low drop out transistor; a switcher circuit having an output configured to be coupled to a second source/drain terminal of the low drop out transistor and to provide a switcher operating voltage to the low drop out transistor; and control signal circuitry configured to regulate an operation of the low drop out circuit, the control signal circuitry further configured to turn off the low drop out circuit when the power supply output voltage is in a steady state condition; wherein the control signal circuitry is configured to generate (i) a low drop out enable signal controlling whether the operational amplifier is enabled or disabled and (ii) a bypass signal controlling whether a bypass transistor couples a gate of the low drop out transistor to ground.