Flicker-Free Resonant LED Driver With High Power Factor and Passive Current Balancing

A flicker-free resonant LED driver with high power factor (PF) and passive current balancing is proposed analysed in this paper. The are composed a buck correction (PFC) unit dc-dc by sharing an active switch. Based on topology, the low output ripple can be achieved via small voltage bulk capacitor fast voltage-mode control loop. By charge balance for capacitor, of each string balanced. In half line cycle, owing to pre-stage output, duty cycle switch almost constant. Therefore, when inductor PFC operates discontinuous conduction mode, PF realized. Moreover, as resonance existed between leakage transformer, diodes achieve zero-current turn-off. Thus, efficiency improved. Finally, 82W prototype three-output built verify studied results.