Question about the input signal of OTA (DC and AC)

[bhl777]

Hi All, I have two DC signals and their difference is around 0.05V DC. I am wondering that can I use them as the two inputs of an OTA, and generate a output current that is proportional to (Vin1-Vin2)?
I am a little bit confused about this. For the opamp what we want is keep both input the same in DC, and amplify their difference in AC. Is OTA the same as this? If OTA is the same, that means I cannot use it to generate the current I want, is that correct?
If I cannot use OTA, could anyone tell me how can I obtain a current or voltage signal that is proportional to the difference of two voltage signal?
Thank you very much!

 

[nitishn5]

What you need is a difference amplifier. Look that up in a book and you will get your answers.

In a simple circuit, use a difference amplifier to generate Vout1 = (Vin1-Vin2)
And use Vout1 to generate a proportional current.
I think you should be able to use a simple OTA t do this.