Mobile QR Code QR CODE : The Korean Institute of Power Electronics
Title Non-Dissipative Snubber for High Switching Frequency and High Power Density Step-Down Converters
Authors Jung-Min Shin ; Chul-Wan Park ; Sang-Kyoo Han
Page pp.345-352
ISSN 1229-2214
Keywords Step down converter ; Non-dissipative snubber ; High frequency ; High power density ; Loss analysis
Abstract In this paper, a non-dissipative snubber for reducing the switching losses in the step down converter is proposed. The conventional step down converter, e.g., buck converter, suffers from serious switching losses and consequentially heat generation because of its hard switching. Thus, it is unsuitable for high switching frequency operation. Reduction of the reactive components’ size, such as an output inductor and capacitor, is difficult. The proposed snubber can slow down the increasing current slopes and switch voltage at turn-on and turn-off transients, thereby significantly reducing the switching loses. Additionally, the slowly increasing current during switch turn-on transition, can effectively solve the output rectifier diode reverse recovery problem. Therefore, the proposed non-dissipative snubber not only leads to the efficiency of converter operation at high switching frequency but also reduces the reactive components size in proportion to the switching frequency. To confirm the validity of the proposed circuit, theoretical analysis and experimental results from a 150 W, 1 MHz prototype are presented.