Differentiator as Current Servo?

[Shanjaq]

Is it possible for an Active Differentiator to output Current proportional to a change in Input Voltage? So far all I've seen are Differentiators which have output in the form of Voltage, but I need to use the Current for downstream processes.

Thanks!

 

[Venkadesh_M]

Hi simply construct a active differentiator and follow it with a voltage to current convertor.....

 

[Shanjaq]

Hi simply construct a active differentiator and follow it with a voltage to current convertor.....

Is there a more direct method that does not involve additional op-amps? Specifically, a voltage differentiator which has push/pull current as output, using just 1 op-amp? I've seen op-amps used as precision current sources at low levels without the need for an external FET, but I'm not sure how it would look as a differentiator with gain.

 

[Venkadesh_M]

What is the amount of current you needed, you can choose two opamps in single package, usually its rare to find a current output opamp because your feedback circuit and input works with voltage.

 

[Shanjaq]

What is the amount of current you needed,

I would estimate a max of 15mA push/pull from the output, in response to a max of 150mV change on the input. I'm using the second half of my dual op-amp for a different purpose, so an ideal solution would use a single op-amp for the current-sourcing/sinking voltage differentiator stage.

 

[Venkadesh_M]

Hi never a voltage differentiator could result you a in current terms you can try a quad opamp or a FET or a high voltage output with high series resistance which is impossible, and for your small output current the best choice could be another cascaded opamp...

 

[LvW]

Depending on the required accuracy - perhaps a passice C-R high pass followed by an OTA (voltage-in and current-out) will do?