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INA118: amplify the RF signal with 50hz frequency and 400uv amplitude

Part Number: INA118

Hi Team, 

Good day. I am posting this inquiry on behalf of the customer.

"I want to amplify the RF signal with 50hz frequency and 400uv amplitude by using INA118 instrumentation amplifier, which will be fed with +-12vdc, by making a single signal input (non-differential). So, I'm aiming to amplify the rf signal by connecting it to pin 3 and connecting pin 2 to the ground. Is it possible for such amplifiers to upgrade without performing a differential connection?
I'm trying to find out what kind of difference it makes.
Can someone with knowledge on this issue help?"

Please help to advise. Thank you for extending your help.
Kind regards, 
  • Hi Marvin,

    yes, you can do this, but you can do it easier with a single OPAmp. Instrumentation amplifiers like the INA118 are designed for a high balance between the two inputs in order to achieve a very high common mode rejection. But in your application your input signal is purely differential and there's no need for an instrumentation amplifier.

    Having said that, the INA118 offers another feature: You can easily shift the output voltage by an offset when connecting the "REF" pin to a suited potential Relaxed This can be very helpful in certain applications.

    If you don't need this offset shifting, I do not see an advantage of using the INA118 instead of a single OPAmp.


  • Hi Marvin,

    Agreed with Kai, this should be easily done with a single amplifier.  The INA118 can be used as well as dozens of our devices, but picking the right one will involve a deeper understanding.  Without any further information, we can't support this with much additional detail.  The first major question is; what is the source of this input signal?  The second is; what will the amplifier drive at the output?  Is it intended to go to an ADC, or some sort of analog output?

    Best Regards,