Patent ID: 7683693

Claim:
A circuit that limits currents comprising: a pass transistor having a first input, a first output and a first control, wherein the input is connected to an input voltage, the first output delivers an output current to a load; a sense transistor having a second input, a second output and a second control, wherein the second input is connected the first input, and the second control is connected to the first control, the second output delivers a first mirror current of the first output current to the load; a charge pump that powers a current source that drives the first and the second controls high which, in turn, turns on the pass and the sense transistors; a current mirror circuit that accepts the first mirror current and produces a second mirror current thereof; a comparator that compares the second mirror current to a reference current derived from the input voltage and generates a signal indicating which current is higher; a control transistor that receives the signal from the comparator, and, when the second mirror current exceeds the reference current, turns on the control transistor, wherein the control transistor drives the first and the second controls turning off the pass and the sense transistors.