SYNCHRONOUS RECTIFICATION TYPE DC-DC CONVERTER

摘要

PROBLEM TO BE SOLVED: To provide a synchronous rectification type DC-DC converter having a simple configuration at a low cost and capable of stopping ON-OFF operations of a main switching element by detecting an over-voltage on a secondary output side and transmitting an alarm signal. SOLUTION: This DC-DC converter comprises a switching element 50 connected to a tertiary coil 33 of a transformer 30, an output voltage detection circuit 19 for detecting an output voltage from the tertiary coil 33; a switching element driving circuit for performing driving control for the switching element 50 based on a detected voltage of the output voltage detection circuit 19; an overvoltage detection circuit 60 for detecting the over-voltage on the secondary output side by directly generating voltage with the tertiary coil 33 and monitoring the voltage; an alarm signal generation circuit for generating an alarm if the over-voltage is detected; and a main switching element controlling circuit for stopping on-off operations of the main switching element 1 corresponding to the detection of the over-voltage. COPYRIGHT: (C)2005,JPO&NCIPI