Analysis and design of a half-bridge series-parallel resonant converter operating in discontinuous conduction mode

A half-bridge series parallel resonant converter (SPRC) operating in discontinuous mode is analyzed in detail to provide a straightforward model and easy-to-use design tools. Closed-form solutions for the SPRC are derived under steady-state conditions. The gate pulse width requirement and criteria for resonant component selection are provided. Various design parameters derived from the results of the analysis are presented in the form of normalized design graphs to directly determine the component ratings. Using these design graphs, a step-by-step design procedure for a 250 kHz, 150 W, multioutput switching power supply is given and implemented for verification of the theoretical results.<<ETX>>