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Summary: Bootstrap capacitor in FET gate driver plays an important role in the transient performance of the half bridge configured synchronous buck DC‐DC converter especially in the top switch. In this paper, a new bootstrap capacitor based GaN‐FET driver is proposed. This new GaN‐FET driver is tested in a synchronous buck converter for performance verification like dvdt immunity, transient response, and voltage ringing. A comparison study with the existing LM5113 (Texas Instrument)–based driver for GaN‐FET and IR2110‐based Si‐MOSFET driver on a DC‐DC converter is carried out to show the performance improvement using the proposed GaN‐FET driver. The simulation study is performed on spice‐based NI‐Multisim 14.1. Finally, the designed GaN‐FET driver is tested on a 60‐W synchronous buck DC‐DC converter in open‐loop and closed‐loop configuration. [ABSTRACT FROM AUTHOR]

Summary: In this paper, a novel analysis of a single switch boost‐flyback integrated DC‐DC converter is accomplished under mixed CCM‐DCM mode operation. Because of the impact of reverse recovery during CCM‐DCM mode operation, a large voltage stress appears on the devices in comparison with CCM‐CCM operation. The devices are required to be saved from the attack of such stresses with a proper snubber design. Thus, a complete realization of the voltage stress on the devices, required for effective snubber parameter design, is carried out in this article. Further, the effect of voltage stress on the devices under different mode of operation with variation in duty ratio and/or variation in coupled inductor energy releasing period is analyzed. Validation of this study is carried out with a prototype of 50 W capacity, operated with light load conditions to attain CCM‐DCM mode effectively. In this paper, voltage stress on semiconductor devices of a coupled inductor based dc‐dc boost converter under mixed CCM‐DCM operation is carried out. The possibility of transition from CCM to DCM is quite practicable for solar photovoltaic‐based applications leading to failure in snubber protection if snubber parameters designed considering CCM operation only. This study enables the designers to estimate the snubber parameters to achieve efficient and reliable operation of the converter. [ABSTRACT FROM AUTHOR]