Series MOSFETs for HV switching

MarcW

Hello,

We design high voltage, low current DC power supplies for X-ray industry and others.

I would like to take 2 of our units , a +9kVDC supply and a -9kVDC supply, and use MOSFET switching to create a +/-9kV square wave, 400hZ, 5mA.

As I know of no FET that will block the full 18kV differential, I would need several FETs connected in series.

Do you have any reference designs or suggestions for using FETs in series for blocking high voltage?

Thanks, Marc

jshao

Hi Marc,

It is extremely challenging to make MOSFET in series in HV. We don't have any reference design on this topic. There are some research work in universities such as Virginia Tech. You can find some literature like this https://ieeexplore.ieee.org/document/9236192.

Do you have to be square waveform? Have you thought about using step up transformer?

Thanks,

Jianwen

jshao

Hi Marc,

Do you have any follow up questions? Thanks.

Jianwen