HB-LED driver based on single-inductor-dual-output switching converters in pseudo-continuous conduction mode

A kind of high-brightness light emitting diode (HB-LED) driver based on single-inductor-dual-output (SIDO) constant current sources Flyback converter operating in pseudo-continuous conduction mode(PCCM) is proposed in this paper. By adopting time-multiplexing control, the proposed converter can avoid cross-regulation in providing two independent voltages, which enables different outputs to be constructed by using different types of LED strings. The cost of the driver is reduced by using only one inductor. Compared with the converter operating in discontinuous conduction mode(DCM), the proposed converter operating in PCCM can handle larger current with a smaller current ripple, and also with the voltage stress on the power switch reduced. The control strategy is presented and the performance of the proposed method is verified by simulation results.