Resonant DC-DC converter capable of controlling by pulse width modulation

摘要

In a resonant DC-DC converter for converting a d.c. input voltage into a d.c. output voltage, a main switching element (3) switches the d.c. input voltage under control of switching pulses to supply an a.c. voltage to a primary side of a transformer (4). A resonant circuit (5) is provided at a secondary side of the transformer. A clamp circuit is connected to the main switching element and comprises a first capacitor (2-1) and an auxiliary switching element (2-2) serially connected to the first capacitor. The main and the auxiliary switching elements are alternately put into an on state under control of the switching pulses.