Patent ID: 7872842

Claim:
An overcurrent protection device for a power supply device, the overcurrent protection device comprising: a receiving end for receiving a current sensing signal; a compensating current unit for compensating the current sensing signal in order to generate a current sense compensation signal, the compensating current unit comprising: a compensating signal generator for generating a compensation signal, the compensating signal generator comprising: a triangular wave generator for generating a triangular wave signal; a second reference voltage generator for generating a second reference voltage; and a subtractor coupled to the triangular wave generator and the second reference voltage generator for performing a subtraction operation between the triangular wave signal and the second reference voltage to generate the compensation signal; and an adder coupled to the subtractor and the receiving end for performing an addition operation between the current sensing signal and the compensation signal to generate the current sense compensation signal; a first reference voltage generator for generating a first reference voltage; a comparator coupled between the adder and the first reference voltage generator for comparing the current sense compensation signal with the first reference voltage in order to generate a comparison result; and a control unit coupled to the comparator for controlling an on/off status of a power switch of the power supply device according to the comparison result.