AVERAGE CURRENT CONTROLLER, AVERAGE CURRENT CONTROL METHOD AND BUCK CONVERTER USING THE AVERAGE CURRENT CONTROLLER

摘要

The present invention relates to an average current controller, an average current control method, and a buck converter using the average current controller. The average current control method comprises a step for determining whether or not a current level of a main switch reaches an average current level by comparing the current level of the main switch with the average current level; a step for generating average switching period (TAVG) signals when the current level of the main switch reaches the average current level; a step for generating signals (CH_ON) for charging and discharging a capacitor by using one or more TAVG signals; a step for charging and discharging the capacitor by receiving the capacitor charging and discharging signals (CH_ON) and capacitor charging and discharging currents from the outside; and a step for determining whether the voltage (Vc) between both ends of the capacitor after being charged and discharged during one period is positive (+) or negative (-). The present invention is provided to only compare the average currents and perform control to satisfy T2 (time to reach from Iavg to Ipeak)+Toff/2=T/2 (T is a switching period), thereby solving a problem that small on-time makes current control difficult and a problem that the average current level varies due to delays generated in two comparators of an existing average current controller.