Fast and precision current comparator

[jan.didden]

Thank you Jan, but I need as less of errors right in the point of comparison, as possible, that's why I decided to use an inverting connection and feed both signals to the same point. Such a way both signals meet the same capacitance, the same non-linearities, the same delay.

True, although you can easily insert both currents into one -input of course. That takes care of that. You can servo out any offset current with a voltage servo to the +input. These circuits look funny but have to be tried to be believed. They really are blindingly fast and challenge your test equipment for speed and accuracy. My error correction power amp has several of them.

jd

 

[Wavebourn]

True, although you can easily insert both currents into one -input of course. That takes care of that. You can servo out any offset current with a voltage servo to the +input. These circuits look funny but have to be tried to be believed. They really are blindingly fast and challenge your test equipment for speed and accuracy. My error correction power amp has several of them.

Yours have half of a unity gain frequency than what I wanted to use, but 4 times higher slew rate. And they drive 50 Ohm pretty well also.

Thanks, I'll consider them!

 

[jan.didden]

I think the SR matters most in your app.
The simplest is like this: