Patent ID: 8169204

Claim:
A voltage regulator, comprising: a P-typed power transistor, said transistor's source is receiving an unregulated first voltage source according a control signal and generating a regulated second voltage at its drain; a feedback circuit, generating a feedback signal according to a voltage division with respect to said second voltage; an operational amplifier, said amplifier's output is coupled to the gate of said power transistor, said amplifier's positive input terminal is coupled to said feedback circuit, and said amplifier's negative terminal is coupled to a reference voltage; and a protecting circuit, for being configured to limiting a first current flowing through said P-typed power transistor, and for enhancing the voltage at the gate of said power transistor when said first current exceeds a predetermined value comprising: a DC current mirror, comprising a pair of N-typed transistors, and said pair of transistors' gates are interconnected, and for one of the pair its gate and its drain are interconnected; a DC current source, outputting a predetermined current with a direction to the ground and interconnect an output terminal of said DC current mirror at a first intersection; a first P-typed transistor, said first P-typed transistor's source is coupled to said first voltage source, and said first P-typed transistor's gate is coupled to said first intersection, and said first P-typed transistor's drain is coupled to said P-typed power transistor's gate; and a second P-typed transistor, said second P-typed transistor's source is coupled to said first voltage source, and said second P-typed transistor's gate is coupled to said the gate of said P-typed power transistor, and said second P-typed transistor's drain is coupled to an input terminal of said DC current mirror.