This document introduces the characteristics of IGBTs in resonant converters, and how to select IGBTs
This document serves as a guide for designers selecting Insulated Gate Bipolar Transistors (IGBTs) for use in resonant converters. It addresses the challenges of using IGBTs in soft-switching applications, where switching losses are minimized but current and voltage ratings are higher than in conventional hard-switching systems.
The note characterizes IGBT behavior by examining the effects of key parameters such as current slope (di/dt), voltage rise delay time, and junction temperature on power losses. It compares different IGBT types (low saturation voltage, standard, and fast) and analyzes their performance in Zero-Current (ZC) and Zero-Voltage (ZV) converter topologies through experimental results and waveform analysis.
IGBTs are becoming more attractive due to their higher current density, lower saturation voltages, and high reliability compared to MOSFETs.
In soft-switching applications, the switching losses of the IGBT can be reduced significantly if the switching times required are longer than the minority carrier lifetime.