[sdiy] Low Frequency Square to Sine Waveshaper

[Paul Perry]

Just overdriving the input diff pair, I believe.

Perhaps you would be able to use an OTA as a variable gain stage, and make a
square to sine thusly:

1. run a square wave to an integrator. 
This gives a triangle (of unspecified amplitude).

2. run the triangle into an OTA, detect the level of the output, compare it
to a reference, and use the result to adjust the gain of the OTA so that the
triangle is amplified to just reach the amplitude of the desired sine.

Paul perry Melbourne Australia

-----Original Message-----
From: David Moylan 
>Is the overdrive characteristic of the OTA just an extension of 
>overdriving the input differential pair or is there a different 
>phenomenon which makes them good for creating sines?