Patent ID: 7414865

Claim:
A controller for a power converter, comprising: a first circuit coupled to a current sense device of said power converter to generate a first signal in response to a switching current of a transformer of said power converter; a second circuit coupled to said transformer to generate a second signal in response to a discharging time of said transformer; a third circuit generating a third signal by integrating said first signal with said second signal; and a switching circuit generating a switching signal in response to said third signal and a reference voltage, wherein said switching signal is used to switch said transformer for regulating an output current of said power converter, said switching circuit including: an amplifier receiving said reference voltage and said third signal to generate an error signal; a comparator receiving said error signal and a ramp signal to generate a second reset signal; and an output circuit turning on said switching signal in response to a set signal, and turning off said switching signal in response to a first reset signal or said second reset signal.