Patent ID: 8129965

Claim:
A quick-start low dropout regulator, comprising: an error amplifier; an N-type depletion MOSFET having a source coupled to a negative input terminal of the error amplifier; a first switch having a first terminal coupled to a drain of the N-type depletion MOSFET, a second terminal coupled to an input voltage source, and a third terminal coupled to an output of the error amplifier; a second switch having a first terminal coupled to the source of the N-type depletion MOSFET, having a second terminal coupled to ground, and having a third terminal coupled to the output terminal of the error amplifier; a low-pass filtering resistor having a first terminal coupled to a gate of the N-type depletion MOSFET, and having a second terminal coupled to the negative input terminal of the error amplifier; and a low-pass filtering capacitor having a first terminal coupled to the negative input terminal of the error amplifier, and having a second terminal coupled to ground; wherein when an output signal generated at the output terminal of the error amplifier is at a high voltage level, the first switch is switched on so as to have the drain of the N-type depletion MOSFET be coupled to the input voltage source, and the second switch is switched on so as to have the source of the N-type depletion MOSFET be coupled to ground.