Patent ID: 6980442

Claim:
A 384X-based burst mode PWM controller, comprising: an oscillator for generating a pulse signal of a constant frequency; an output circuit for generating an output signal based on the pulse signal and sending the output signal to an external circuit; an error amplifier for receiving a voltage feedback signal from the external circuit and generating an amplified error signal; a comparator having a current sense input on one end to receive a voltage of a current sense signal from the external circuit and another end to receive the amplified error signal, and comparing the voltage of the current sense signal with the voltage of the amplified error signal to generate a comparison signal; and a PWM latch for responding the pulse signal and generating a pulse control signal based on the comparison signal to control the output circuit on and off; wherein the output circuit turns on when the voltage of the current sense signal is smaller than the voltage of the error signal; the output circuit turns off when the voltage of the current sense signal is greater than the voltage of the error signal; wherein the burst mode PWM controller further including a logic control current source which has an output end connecting to the current sense input of the comparator; wherein the pulse control signal generated by the PWM latch controls the logic control current source and the output circuit in opposite conditions of turning on and off.