A novel power feeding circuit for LED buck driver

This paper provides a novel power feeding circuit. The circuit comprises two power MOSFETs. One can sustain line voltage, the other is built in chip with 40 V process. The new power feeding route is from the source node of high voltage power MOSFET through a regulator which is built inside the chip to charge a VCC capacitor. The proposed circuit turns power consumption of conventional startup resistor to LED lighting energy. Also, some switching loss in conventional LED buck driver can be reused as chip energy. Under the same operation current of control IC and output voltage is 40 V, the proposed circuit saves 26% under 156 V line voltage, and 12.5 % under 326 V voltage.