Volt diff detection / comparator?

[emf42]

(Noob here)

I have 2 x 1.65v lines and need to detect an occasional brief difference between them (over 0.2v diff, for 200ms max), and generate an INT signal.

Are there comparator IC's for things like this? Or what is the circuit needed to do this please?

Thanks.

 

[AnalogKid]

What is the power source for the circuit?
If the INT signal goes to a uC, what is its power supply voltage?
Will the difference always be the same polarity? That is, when there is a difference will line 1 always be the one that is greater?
How fast do you need the INT signal generation to be? Can you tolerate a 1 millisecond delay between when the voltage difference happens and when the INT signal changes state?

If either input can be greater or less than the other, and you don't need nanosecond response time, then this can be done with one dual comparator IC like the LM393. The circuit output goes low on error.

ak

 

[emf42]

thanks for helping.

Pwr is 3.3v, output signal INT goes to a uC . INT speed not important.

Inputs are both 1.65, same polarity, with a brief difference of +0.2 to +0.4, for about 200ms. i.e. one side will move to 1.4v or 1.9v briefly.

We need to detect when input-A + 0.2v > input-B, or the other way around.


I read the LM393 sheet but I don't think that's it.
thanks again

 

[Alec_t]

Perhaps you could base the INT generator on a simple long-tail pair, something like this ;-

C and D could generate INTs directly if you have two INT-capable negative -triggered Schmitt trigger inputs on the MCU.