Using OTA as voltage-controlled current source with OPA860

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riie
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Hi all,

Does anyone know how do I connect an OTA if I want to use it as a voltage-controlled current source, meaning that it will ouput an AC current when i supplied an AC voltage?
Any guide I can refer to?

And how do I adjust the gain or transconductance, gm?

For example, OPA860 with pinout E,C,B, Iq.
http://www.ti.com/lit/ds/symlink/opa860.pdf

Thanks!
 

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Hi. You pdf seems to provide a lot of information. What application are you hoping to use this for?
 
What is your input voltage range and what output current range do you need?
 


Hello,

To use an OTA as a voltage-controlled current source, you will need to connect the input voltage to the non-inverting input and the output current to the inverting input. This will create a negative feedback loop, which will regulate the output current based on the input voltage. The gain or transconductance can be adjusted by changing the value of the feedback resistor. A higher value feedback resistor will result in a higher gain or transconductance, while a lower value will result in a lower gain or transconductance.

As for a guide, I recommend referring to the datasheet for the specific OTA you are using. In this case, the OPA860 datasheet you provided has a section on using the device as a voltage-controlled current source. It also includes a formula for calculating the transconductance based on the feedback resistor value. Additionally, there are many online resources and tutorials available on using OTAs as voltage-controlled current sources that you may find helpful.

I hope this helps. Good luck with your project!