Patent ID: 8643350

Claim:
A self-driven synchronous rectification boost converter having high step-up ratio, wherein the self-driven synchronous rectification boost converter having high step-up ratio comprises: a first switch receiving a pulse driving signal and being repeatedly switched on/off according to the pulse driving signal; a first winding connected between an input voltage source and the first switch, storing energy when the first switch is switched on and having a reverse terminal voltage when the first switch is switched off; a second winding connected to first winding; an auxiliary winding connected to the second winding; a switch circuit connected to the auxiliary winding and having a diode and a third switch, and the anode of the diode is connected to a terminal of the auxiliary winding; the third switch is connected to the cathode of the diode, and when the terminal voltage of the auxiliary winding is a forward voltage, the diode is in an on state, the third switch is in an off state; when the terminal voltage of the auxiliary winding is a reverse voltage, the diode is in an off state, and the third switch is in an on state; and a second switch connected to the third switch of the switch circuit, wherein when the third switch is in an off state, the second switch is in an on state; when the third switch is in an on state, the second switch is in an off state.