Investigation of buck DC-DC converter featuring active clamp absorption capability

In today's emerging new energy electric vehicles, silicon-based MOSFETs are an indispensable presence. Due to its extremely short switching time and very fast operating frequency, it generates large oscillations in the parasitic inductance and capacitance, which results in large transient voltages at the moment of turn-off. Voltage spikes can have a number of adverse effects on the system. It is important to suppress overvoltage or switching stress on power semiconductors connected in series and parallel. In this study, a spike voltage absorption circuit based on active embedding is proposed to reduce the spike voltage generated at the moment of mos turn-off in a step-down isolated automotive DC-DC power circuit with large spike voltage at the low voltage side. In this study, a classical doublepulse test topology, a circuit topology based on the active embedded absorption circuit, and the main power topology of an isolated automotive DC-DC are constructed based on LTSPICE, and the theoretical feasibility is analyzed, and the practical application of the circuit is also verified by simulation, and the simulation results show that the absorption circuit can inhibit the spike voltage of the mos very well.