[sdiy] OTA VCO bad or not!

[René Schmitz]

Hi Mark and all,

mark verbos wrote:
> I assume the offset voltage is what makes the symetry problem. No? Could 
> you add a symetry trim by mixing in a fixed voltage with the triangle 
> before it goes to the comparator?

Might just be that the squarewave levels that come out of the comparator 
are unsymmetrical if you just use a passive pull up. Buffering it with a 
CMOS gate or a push-pull emitter follower helps. Adding a symmetry trim 
prior to the comparator also is a solution.

Cheers,
  René

-- 
uzs159 at uni-bonn.de
http://www.uni-bonn.de/~uzs159