Need help with transconductance operational amplifier

[riie]

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!

 

[riie]

anyone?

 

[NascentOxygen]

Hi. You pdf seems to provide a lot of information. What application are you hoping to use this for?

 

[skeptic2]

What is your input voltage range and what output current range do you need?

 

[alphysicist]

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!