Single stage switched capacitor LED driver with high power factor and reduced current ripple

Abstract

This paper presents a switched capacitor-based converter to drive high power light emitting diodes (LEDs). Unlike the traditional switched capacitor based one, the proposed converter uses an inductor to avoid the forced charging and discharging operation reducing stress current in circuit. The proposed converter provides inherent power factor correction (PFC) and the switched capacitors are used as isolation capacitors. The proposed converter also uses a LC filter to reduce the output current ripple through LED array instead using a bulk electrolytic capacitor. The basic description of the topology is presented and a laboratory prototype of 48 W has been implemented. The experimental results presented demonstrate the technical feasibility of the proposed converter applied as LED driver.

An LLC Converter with Capacitive Insulation

“…Many previous studies have presented circuit architectures using Class Y capacitors as isolation components and these capacitors replace transformers as energy transfer compo-nents. However, this is only for LED lighting [2][3][4][5][6][7][8] or electric vehicle chargers [9,10], and is characterized by the fact that the secondary side is not in contact with the human body.…”