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AD215 suitable for scope floating measuements?

Question asked by TripleX on Dec 22, 2014
Latest reply on Dec 23, 2014 by TripleX

Dear people of Analog,

 

I have an earth referenced scope and the BNC jack grounds are also connected together (earth potential).

 

On first sight it seems possible to use the AD215 to make an input isolation adapter (not sure if that is the right term) -little box between the BNC input and the probe BNC output- for the scope to be able to tie the black probe lead to any voltage in the circuit under test as long as the common-mode voltage rating is met of 1500 * sqrt(2) = 2121V.

 

If so, I bet I'm not the only person with the desire to make such a thing. Any suggestion to develop that circuit with the AD215 would be highly appreciated. It would be a lot cheaper than buying a active differential probe I think.

 

However I might want to measure frequencies higher than the 120 kHz. But with a common mode signal much closer to earth. Like 20 V for example. The scope I have has a bandwidth of 200 MHz. Would any of the high speed differential amplifiers Analog has to offer be suitable for this application?

 

Thank you very much for your attention and time!

Best Regards,

Maarten Verhage

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