Patent ID: 8837184

Claim:
A secondary side synchronous rectification control circuit, comprising: an inverted amplifier having an input end for receiving a drain source voltage signal from a synchronous rectification transistor, and for outputting an inverted amplification signal; a first comparator for receiving the inverted amplification signal and a first reference voltage, and for outputting a first comparison signal; and a driving unit for receiving the first comparison signal and generating a driving signal according to the first comparison signal, in order to control a conduction status of the synchronous rectification transistor, wherein the driving unit is coupled to a power supply end for receiving a direct current voltage, and the driving unit comprises: a second comparator for receiving the inverted amplification signal and a second reference signal, and for outputting a second comparison signal; a first SR flip flop for generating the driving signal according to the first comparison signal and the second comparison signal; and a peak waveform elimination circuit having a delay unit which generates a delay signal according to the first comparison signal, for eliminating a peak waveform of the second comparison signal generated at the time when the synchronous rectification transistor is turned off, wherein the peak waveform elimination circuit comprises: a first AND gate for receiving the second comparison signal and the delay signal, and for generating a first output signal; a second SR flip flop for receiving the first comparison signal and the first output signal, and for generating a second output signal and a third output signal which are complementary to each other; the delay unit for receiving the second output signal, and for generating the delay signal; and a second AND gate for receiving the second comparison signal and the third output signal, and for generating a fourth output signal, wherein the first SR flip flop receives the first comparison signal and the fourth output signal for generating the driving signal.