A High-Speed Multi-Channel Magnetic Isolated Driver Circuit With Overcurrent Protection for Nanosecond Marx Generators

Solid-state pulse generators (SSPGs) require drivers with high-voltage isolation, synchronization, and electromagnetic interference (EMI) immunity. Multi-channel magnetic isolated driver circuits (MCMIDCs) are widely used in SSPGs due to the advantages of simple structure and high-voltage insulation. However, limited driving capability hinders the rapid switching of semiconductor devices, fundamentally limiting the minimum pulse width to submicrosecond range. This study proposes a high-speed MCMIDC for pulse generators to generate nanosecond pulses with fast edges and short widths. Snubber circuits incorporating metal–oxide–semiconductor field-effect transistors (MOSFETs) are employed to enhance the source current and driver synchronization. The auxiliary precharged inductor branch strengthens the sink current. A desaturation circuit employs current limiting to suppress turn-offovervoltage, protecting MOSFETs from overcurrent/overvoltage breakdown. The operating principles are presented, and a 24-stage Marx generator prototype is developed. Simulation and experimental results show that the proposed driver circuit provides multichannel high drive currents above ±5 A and synchronization error within 4 ns. The prototype can generate 20-kV pulses with a minimum pulse width of 36 ns and a maximum current amplitude of 250 A over different resistive loads. Collectively, this proposed MCMIDC features ultrafast gate voltage transitions, high sink/source currents, and integrated overcurrent protection.