LLC RESONANT DC/DC CONVERTER WITH MULTI-OUTPUT, POWER SUPPLY UNIT AND BACK LIGHT UNIT

摘要

PURPOSE: A multi-output LLC resonant DC/DC converter, a power supply unit and a backlight unit are provided to obtain ideal regulation for each output voltage by controlling a switching frequency in a controller based on a second output voltage. CONSTITUTION: A switch part(10') provides power by alternately switching DC power. A conversion part(30') converts primary side power into secondary side power having a voltage level according to a predetermined turns ratio. A rectifier(150,250) outputs a first voltage level and a second voltage level by rectifying the secondary AC power. A controller(70') feeds back the dual outputs. The controller changes one voltage level by controlling a switching frequency of the switch part according to one voltage level between the dual outputs. The controller changes other voltage level by controlling a synchronized duty ratio to the frequency according to other voltage level. [Reference numerals] (70) Controller