igbt gate driver ground

[deniz88]

Hi,

i am making an IGBT gate driver. Ground of the driver will have high voltage like 3000V and Vc of the driver will be 3015V.

there will be also FPGA which will read datas such as Ig, Uce, Uge... from ADC.

I am a bit confused how should be FPGA part of the circuit,
should it also has 3000V ground? it doesnt sound good because FPGA works with 3.3V and a small changes(harmonic etc..) on ground can damage circuit.

if FPGAs ground will be normal ground, will i need optocoupler between ADC and FPGA?
it would be also nice if you can suggest any documents about it.
thanks a lot,

Best regards

 

[Warpspeed]

Always best to keep as much of the circuit at true ground potential, for maintenance and debug, as well as for noise isolation.

At a very noisy 3 KV, I would be thinking about running fibre optics between ground and and an isolated gate driver contained within a small Faraday enclosure.

 

[brushhead]

Completely agree with statement about using optic fibre. It makes things a lot easier from a number of angles. Have a look at the POF range from Avago/Broadcom. Make sure the Optic Fibre is carbon free!!!