Patent ID: 8847438

Claim:
A power controlling circuit comprising: first power transistor having a first electrode and a second electrode, one of the first and second electrodes being coupled to a load and the other of the first and second electrodes being coupled to a first terminal of a first shunt resistor having a second terminal coupled to receive a supply voltage; a first voltage source circuit having an output coupled to a control electrode of the first power transistor and operable to maintain the first power transistor in a fully-turned-on condition; a first current sensing circuit coupled to the first shunt resistor for producing a first control signal and a second control signal each proportional to a first load current contribution flowing in the first shunt resistor; and a first control amplifier for producing a third control signal in response to a difference between the first control signal and the second control signal, wherein the third control signal overrides the output of the first voltage source circuit if the difference exceeds a predetermined level, so as to increase a resistance of the first power transistor.