LLC CURRENT RESONANCE TYPE SWITCHING POWER-SUPPLY DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an LLC current resonance type switching power-supply device that allows outputting two voltages and preventing oscillation.;SOLUTION: An LLC current resonance type switching power-supply device includes a transformer having a primary winding connected to a first switch element and a second switch element and two secondary windings, and an LLC control circuit generating first and second driving signals so as to alternately turn on/off the first and second switch elements. The LLC current resonance type switching power-supply device induces two AC voltages to the two secondary windings by oscillation operation of a current oscillation circuit, and then converts the two AC voltages into first and second DC voltages. The LLC control circuit controls each switching frequency of the first and second driving signals on the basis of a first feedback signal corresponding to the first DC voltage, controls each duty ratio of the first and second driving signals on the basis of a second feedback signal corresponding to the second DC voltage, and includes a variable resistor for oscillation prevention adjustment that applies a part of the first DC voltage to the second DC voltage.;COPYRIGHT: (C)2015,JPO&INPIT