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Instrumentation Amplifier or Current Sense Amplifier ?

A3JBNE

Hello friends, this is my first experience with the design of a precision ammeter for reading. I will use a shunt resistor (60mV/1500A)

I am confused as to the choice, to use an instrumentation amplifier or a current sense amplifier?


I think using the INA190A3 (CSA) has x100 gain, will this be the correct one? I just want to read the amperage very accurately similar to a professional ammeter.


I read that an instrumentation amplifier can do the same task as a current detection amplifier and better, that's why I'm a bit confused about the choice or it doesn't matter?

  • 0

    It probably boils down to cost. You can get an instrumentation amp with zero-drift circuitry for even better performance. You need to look closely at how the instrumentation amp performs when its inputs are at the rails - not all of them will perform well. I would use a CSA unless it couldn't meet accuracy requirements, because I find them simpler and cheaper.

  • 0

    Current sense amplifiers are typically intended to work well in systems where the bulk of the ciruitry is referenced to 0V and the current snese reistor at some positive voltage with respect to it. It will often only be able to cope with quite small sense voltages.

    There are many different kinds of device marketed as a current sense amplifier.

    An instrumentation amplifier is more general purpose type of differential amplifier. Some have very large common mode voltage ranges (much greater than supplies) and some have convenient reference ports.

    The INA190 is a nice zero drift current sense amplifier which can cope with the positive common mode voltage of 40V whille running on a 5V supply at a reasonable price. It also semes to be available.

    Without knowing a lot more about your application it's not possible to say if it is a good choice.

    MK