A Flicker-Free Single-Stage LED Driver with Its Optimized Design

Conventional single-stage LED driver suffers from serious twice-line-frequency output current ripple and large electrolytic capacitors have to be used. This paper gives a flicker-free single-stage LED driver based on energy distribution with power factor correction. The LED driver consists of a half bridge LLC converter and a ripple compensation circuit. Compared with conventional single-stage LED driver, the LED driver achieves constant output current, flicker-free and small capacitance while high power factor. A 120 W (150V/0.8A) simulation prototype is designed in PSIM to verify the capability and excellent performance of the circuit and its strategy.