Which MOSFET and Gate Driver should I buy?

smc241

I am working on a laboratory setup that requires fast high‑voltage switching, and I am interested in purchasing a suitable MOSFET along with a corresponding gate‑driver board.

The application involves applying high‑voltage pulses to a crystal. The system will be connected to a high voltage power supply (ORTEC 556H), and I need to generate pulses up to 1000 V with on‑times of up to 10 microseconds, followed by an off‑state at 0 V. It would be very helpful if I could vary both the pulse repetition rate (up to a practical limit) and the pulse duration.

If possible, I would appreciate your recommendations for a suitable MOSFET and compatible gate‑driver board for this type of operation. Guidance on any relevant trade‑offs or configuration considerations would also be very helpful. I am currently considering:

For the MOSFET: C3M0030170D

For the Gate Driver Board: one of:

CGD1700HB2M-UNA,CGD1700HB2M-UNA-R1, CGD1700HB2M-UNA-R2

Thank you and I look forward to your suggestions.

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ChrisN

Hello smc241,

Without knowing more specifics about your system, the parts that you selected are a good fit. The MOSFET voltage rating is suitable for 1000 V bus applications and the switching frequencies that you identified. These parts will be able to comfortably switch with a 10 us on time, and the CGD1700HB2M-UNA family of gate drivers are optimized for SiC devices such as the C3M0030170D that you selected. Wolfspeed offers LTspice models of all devices here if you would like to evaluate the device performance in a simulation environment.

There are a few additional steps that you should consider moving forward. First, simply hooking up the devices directly to a power supply will result in significant inductance due to the leads of the power supply. It is critical at these switching speeds and voltage levels that you have low inductance routing from DC+/- to your device. This is typically achieved by having your bulk capacitors very close to the switching device. More details about the influence of inductance can be found in PRD-08710. Second, I recommend using either the CGD1700HB2M-UNA or CGD1700HB2M-UNA-R1 gate drivers but not the CGD1700HB2M-UNA-R2. The CGD1700HB2M-UNA-R2 has nominal +18V/-4V output voltages which are not recommended for the C3M0030170D. The other two gate driver options are suitable. More information about the differences can be found in PRD-06992. Third, these gate drivers require differential signaling to communicate with them. I recommend also ordering the CGD12HB00D daughterboard to facilitate single-ended to differential communication. More information can be found in Section 7.1 of PRD-09301. Fourth, you will need to ensure you have suitable cooling for the part and will need to select your gate resistance based on acceptable power losses vs overshoot/ringing. Fifth, you will still need a controller to generate the repetition rate and pulse duration. You can roughly think of the gate driver as a buffer stage (it adds several additional necessary benefits such as isolation) which simply replicates an input signal. A controller is used to control the gate driver for modulating the power devices at the correct times.

Again, your component selection seems reasonable, and I hope this guidance helps you to continue to progress this project.

Thanks,

Chris N.

ChrisN

Hello smc241,

I hope that this answered your question. I will close this discussion for now but if you have a follow up question, please "Start a New Discussion" and we would be glad to support you further.

Thanks,

Chris N.