How to build a Frequency to Voltage converter without microcontrollers

Thread Starter


Joined Mar 23, 2017
We are supposed to construct a Frequency to Voltage converter without using any microcontrollers, or integrated circuits. Only op amps, comparators, resistors, capacitors,inductors, voltage regulators

We were told as an example if we input a 3khz frequency we should get 3 volts in return

Any suggestions?


Joined Sep 17, 2013
Since this is Homework, what thoughts have you had so far for solving the problem? We can give hints, but don't do your homework for you.


Joined Jan 8, 2017
Your question contradicts itself. You say NO integrated circuit but then you say you can use opamps. (Which will be integrated circuits unless you build them yourself using discrete components.) Another tip Google "charge pumps"



Joined Jun 17, 2014

A quick example which would be the most basic F to V converter is a one shot that outputs a very narrow pulse and that pulse is integrated with a fixed time constant and some leakage. The output voltage is related to the input frequency by a constant, although the linearity may not be as good as you want because of the narrow pulse and the leakage. This is the most basic way to do it but also probably the worst way to do it too.

You should try to figure this out too and see what makes sense to you.