A Two-channel LED Driver with Automatic Current Balance and Soft-switching

In this paper, a stacked half bridge converter with automatic current balance and soft-switching is proposed. Here, an LED driver is taken as an example to analyze. Based on the ampere-second balance principle, the proposed LED driver can realize automatic current balance. The proposed converter adopts a small inductor to form a resonant tank, which achieves zero current switching (ZCS) in the discontinuous operation mode (DCM) and zero voltage switching (ZVS) in the continuous operation mode (CCM). By using frequency doubling technology, switching losses are reduced by half under the same hardware conditions. A 15.8W experimental prototype with 100V input voltage and 25V output voltage is established in the laboratory, verifying the feasibility of the stacked half bridge converter.