Comparative Analysis of CoolGaNTM BDS and B2B UDS Dynamic On-Resistance and Switching Loss Performance

Abstract:
In applications employing back-to-back (B2B) switches to create a BiDirectional Switch (BDS), a single monolithic GaN BDS can replace two Unidirectional Switches (UDS), improving both power density, performance while reducing cost. Using state-of-the-art dynamic Rss(on) and switching loss measurement techniques, we report an application-relevant comprehensive comparison between CoolGaN(TM) BDS and B2B UDS GaN devices. It was found that CoolGaN(TM) BDS has superior performance in both soft and hard switching conditions. In soft switching, the dynamic Rss(on) is practically equivalent to its static RSS(on) value, and the soft switching loss for the 35 mOmega B2B UDS is approximately 25% higher than that of the 55 mOmega BDS at 10 A turn off, 400V switching. In hard switching, the dynamic RSS(on) of the Cool-GaN(TM) BDS is significantly affected by switching frequency and the B2B UDS exhibited 5-6% higher hard-switching losses than the BDS at 400V, while the BDS showed 15% lower hard-switching losses than the B2B UDS at 200V. These results highlight the significant advantages of the CoolGaN(TM) BDS in reducing switching losses, particularly at lower output voltages, making it an ideal choice for high-performance applications requiring both soft and hard switching.