Square to Sine converter using Active fillter

[nagaya]

I have a variable frequency square wave generator based on 16F628A.Now I have to convert it to a sine wave 0-10kHz.I thought to use an active low pass fillter at 10kHz passband to fillter odd harmonics and get the fundemental frequency from the square wave.I've designed 8th order fillter for this.Will it generate almost pure sine wave?will I have to change pass band freequency for different ranges of input,anyone have similar experience?

 

[FvM]

will I have to change pass band frequency for different ranges of input

Yes, obviously. This fact doesn't suggest the method for a variable frequency sine generator, I think. The filter definition would be based on a specification of acceptable sine THD. An 8th order filter also requires to tune 8 filter elements, so a lower order filter seems more reasonable. Considering the said problems, most people would prefer different methods of variable frequency sine generation, I guess.