[sdiy] filtering out a saw-reset glitch in a triangle shaper

[David G. Dixon]

One would probably have to hand-pick the zener for accuracy.  If this were
impractical, then Antti's method is to be preferred.


> > I'm actually liking the active full-wave rectifier plus 5.1V zener
> > method
> > more and more.  Slap a 15pF cap across the feedback loop of the
> > final level
> > shifting and inverting opamp, and the final -5 to +5V triangle looks
> > virtually perfect.
> 
> Haven't followed the thread too closely, so I don't know the details
> of this circuit; but did you take the tolerance of the zener voltage
> into account? Looking at the data sheet of a random 5.1 volts zener
> diode (1N5231B), the voltage can vary between 4.845 and 5.355 volts.
> So if you're unlucky, either a bit of the glitch will still be there,
> or your triangle gets quite mis-shaped. Or you need to trim the
> amplitude or offset of the triangle.