An Error Amplifier Scheme to Reduce Compensation Capacitor for Boost PFC Converter

An error amplifier (EA) scheme to reduce type-I compensation capacitor for boost power factor correction (PFC) converter is proposed in this article. Compared to traditional EA scheme, the compensation capacitance is significantly reduced by applying a switch network to sample the output feedback signal. In this way, the compensation capacitance can be reduced to 10 pF and easily fabricated on chip. Therefore, the control circuit combined with the proposed EA scheme can reduce the cost and improve the reliability of the boost converter. Detailed theoretical analysis has been presented and a boundary conduction mode (BCM) boost converter with constant on-time (COT) control and proposed EA scheme has been designed. Finally, an 80-W experimental boost PFC prototype has been built up and experimental results show that the converter can maintain good performance with the proposed EA scheme.