For current sensing on a high voltage negative line (say -30V), can I use the AD8210 by connecting Vs to 5V, and GND to my negative supply (maybe -48V)? Any thoughts?
The absolute maximum rating for the AD8210 supply voltage is 12.5V. With 5V at Vs and -48V at GND, this specification would be violated, so I do not think you would able to do it this way. Could you elaborate on what you are planning to sense? Any additional information about your application would help me give you a better solution for this.
In the meantime, you can check the reference design at this link as an option.
Looks like you can close this out.
FYI, the customer wrote:
The problem with the AD8479 & AD629 is that they are differencing amplifiers, as John pointed out, and input current will be a big problem in my application as I am sensing very small currents (100µA). Although - if I buffered the input to the HV differencing amplifier then there should be no problem… I’ve showed this in my hand sketch. That makes sense, right? I’ll just make an instrumentation amp with HV buffers and a HV diff amp.
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