Patent ID: 7274176

Claim:
A voltage regulator, comprising: an output node configured to be coupled to a load circuit; a first power transistor having a first conduction terminal coupled to a voltage source and a second conduction terminal coupled to the output node; a second power transistor having a control terminal, a first conduction terminal coupled to the voltage source, and a second conduction terminal coupled to the output node; and a control circuit configured to sense an output voltage at the output node and provide control signals to control a conduction capacity of each of the first and second power transistors such that the output voltage remains approximately equal to a selected output voltage, the control circuit further configured to hold the second transistor in an off state unless a load current drawn from the output node exceeds a threshold current, the control circuit having: a biasing transistor coupled between the control terminal of the second power transistor and a circuit ground, and a biasing resistor circuit coupled between the first voltage source and the control terminal of the second power transistor and having a biasing resistance configured to vary inversely relative to a biasing current flowing therethrough.