Patent ID: 7778051

Claim:
An output current control circuit for a power converter, comprising: a current-detection circuit, coupled to a current sense device, for generating a primary-current signal in response to a primary-side switching current of a transformer; a voltage-detection circuit, coupled to the transformer, for generating a period signal and a discharge-time signal in response to a reflected voltage of the transformer; a signal-process circuits, for generating a current signal in response to the primary-current signal, the period signal and the discharge-time signal; a switching control circuit, coupled to the signal-process circuit, for generating a switching signal in response to the current signal; and a pulse generator, coupled to the voltage-detection circuit, for generating a sample-pulse signal in response to the period signal, wherein the switching signal is utilized to switch the transformer and regulate the output current of the power converter; the period signal is correlated to the switching period of the switching signal, the discharge-time signal is correlated to the duty cycle of a secondary-side switching current of the transformer; the current signal is correlated to the output current of the power converter; the sample-pulse signal is used to control sampling of the signal-process circuit.