Analysis and Design of a Novel Single-Stage Switching Power Supply With Half-Bridge Topology

A novel single-stage switching power supply with half-bridge topology is presented in this paper. The proposed novel single-stage switching power supply is formed from integration of one half-bridge ac/dc power factor corrector (PFC) and one half-bridge dc/dc postregulator. The proposed switching power supply operations are verified and discussed, from which the inductor design criteria are resulted. In addition to output regulation, the proposed single-stage switching power supply has great power factor correction function with the PFC inductor operating in a discontinuous conduction mode (DCM). Compared to the conventional two-stage power supply, this configuration reduces cost and size, simplifies the design, and increases efficiency with both pulse-width-modulation (PWM) controller and switch integrations. The operating principles of the proposed switching power supply are analyzed. Simulations are performed to verify the operations and facilitate the design and implementation with the output specifications of 120 W and 48 V suitable for LED lamp drivers, piezoelectric element driver power systems or adapters. The experimental results show good conformation with the theoretical analysis in which the power factor and efficiency of the implemented single-stage switching power supply are above 0.97 and 0.88, respectively, and the efficiency is improved obviously compared to the conventional two-stage power supply.