SELF-EXCITING SWITCHING POWER SUPPLY

摘要

PROBLEM TO BE SOLVED: To provide a self-exciting switching power supply having a low switching loss and a small number of components.;SOLUTION: In the quasi-resonance RCC type switching power supply, a capacitor 15, a resistive element 16, and an inductor 8 are connected in series between one terminal of a feedback winding 14 of a transformer 11 and the gate of a main switching element 9, and a capacitor 7 is connected between a node N4 between the resistive element 16 and the inductor 8 and the source of the main switching element 9. When the voltage at the node N4 changes sharply, the inductor 8 is turned into a high impedance state and a delay is generated by the capacitor 7 in that state, causing the gate-to-source voltage Vgs of the main switching element 9 to change smoothly.;COPYRIGHT: (C)2011,JPO&INPIT