Patent ID: 6353544
Filing Date: 2002-03-05
Classification: H02M,Y02B

Abstract:
A flyback converter with synchronous rectifier, comprising:a power source; a flyback switch circuit received the power source to output a high frequency pulse; a transformer having a primary coil coupled to the flyback switch circuit to receive the high frequency pulse, having two secondary coil for one is master source and the other is sub-source; a synchronous rectifier which outputs a driving pulse is coupled to the sub-source and a current sensor; a synchronous switch received the driving pulse and parallel connected with an output diode D2; an output diode with one side coupled to the master source, and the other side coupled to the load, the load further connected to an output capacitor in parallel; a current sensor coupled to the load in series connection to detect the load current, and transmitted the load current into the synchronous rectifier for comparing with a preset current level to regular the driving pulse; wherein, the current sensor detect the load current to make the synchronous rectifier output a regulated driving pulse when the output diode is on, then the synchronous switch turn on with the output diode simultaneously to bypass the current of output diode for reducing the component stress and switching loss.