Single-Stage Electrolytic-Capacitors-Free AC-to-DC LED Driving Circuit with High-Power-Factor

This paper proposes a single-stage electrolytic-capacitors-free ac-to-dc driving circuit for light-emitting-diode (LED). A buck-boost power factor corrector (PFC) is integrated with a flyback converter. In this way, the presented circuit can provide not only high power factor (HPF) and low total harmonic distortion (THD). The electrolytic capacitors can be replaced by multi-layer ceramic capacitors (MLCCs) via the conversion circuit integration. Above 0.97 power factor (PF) and 82% efficiency are obtained from a 5W LED bulb driver prototype.