How Do You Convert A Square Wave To Sine Wave?
With passive elements, use a low pass filter, the square wave into a resistor in series with a capacitor tied to ground, the output to be taken across the capacitor. If the square wave has a DC offset add a large blocking capacitor in series with the input to the resistor. The sinusoidal frequencies comprising a square wave are at odd harmonics of the fundamental, so an RC time constant 50% or so shorter than the square wave fundamental will work fine. For variable square wave frequency, you can make the resistor variable accordingly. http://homepages.inf.ed.ac.uk/rbf/CVonli… .
