POWER FACTOR COMPENSATION CIRCUIT FOR POWER SOURCE CONTROL DEVICE, CONTROL METHOD FOR SUCH CIRCUIT, AND LED ILLUMINATION DEVICE

摘要

This power factor compensation circuit comprises a booster PFC circuit and a digital control circuit. In the digital control circuit: an error is calculated from an output voltage and a target voltage; PI calculation is carried out using an error value obtained at a timing at which detected is a bottom voltage for which full-wave rectification is carried out on an AC input voltage using a full-wave rectifier; an ON time A is determined using the PI calculation high-order bit, such ON time A being a rising period of a triangular wave of an inductor current triangular wave; and a correction period tx is determined using a low-order bit. In the correction period tx determined using a low-order bit, control is carried out using an ON time A+1 for which an ON time is determined in advance and to which applied is a correction amount +1.