High voltage differential input

[theblond]

Dear all!

I would like to ask an advice about building an input stage to my device.
It should handle at least 350V (0-to-peak).

I can do it in single ended, but it should be differential (avoding ground problems and for better cmrr).

It will convert the input voltage to level what can be handled easy.

Any comments are welcome.

 

[House_Cat]

What is the frequency, bandwidth, current requirement, etc? Is it digital, linear, or what?

With nothing else to go on, it sounds like your requirements would be met by a transformer.

Simply stating that the signal is differential doesn't give enough information for a meaningful reply to your question.

 

[theblond]

Hi,

You are right not a fully qualified question. This will be an input stage to my DSO. I want to measure higher voltage than 5V or 50V. I decided to extend the input voltage range to 350V (peak). Currently, the input bandwith roughly 1Mhz (2MSPS). Thus, I think the input bandwith can about 1Mhz .

Generally the transformer is a good choice, but in this case I think it doesn't have enough bandwith. Am I correct?

There is no critical current recuirement, it have to drive just the next amplifier stage. Thats all.

If I would know how to design this stage, later on I can extend its bandwith upper to fit my next design requirements.

 

[House_Cat]

It sounds like all you need is a conventional x10 scope probe - either single ended or differential design. Your 350V would then be scaled to 35V, and would easily be measurable on your 50V input attenuation setting.