NO-LOSS CURRENT DETECTION IN BACKUP CONVERTER OPERATED WITH LOW-IMPACT COEFFICIENT AND HIGH CLOCK FREQUENCY

摘要

PROBLEM TO BE SOLVED: To realize a converter, which is operated with a high frequency and a low-impact coefficient and converts high voltage into low voltage. SOLUTION: A high-potential side switch and a low potential side switch are connected in series between an input voltage and the ground potential. An inductor and a capacitor are connected between the junction of both the switches and a load so as to compose a low-pass filter. The two switches are turned on and off complementarily, to control the charging period and discharging period of the filter in order to obtain a required output voltage. A 'trough current control' method, where current applied to the low potential side switch is monitored, and if the current is lowered to a value which is not higher than a predetermined reference value, the discharging period is finished and the charging period is started is employed, to realize a stable operation with a low impact coefficient.