Re: Simple but precise ramp/triangle generator

From: legg (legg_at_nospam.magma.ca)
Date: 09/13/04 

Date: Mon, 13 Sep 2004 23:11:43 GMT

On Mon, 13 Sep 2004 16:22:38 +0200, Tilmann Reh
<tilmannreh@despammed.com> wrote:

>Hello,
>
>I am looking for a simple but reasonably precise ramp (sawtooth)
>or triangle generator. It is intended as part of a PWM circuit that
>must output constantly OFF for low input voltages and constantly ON
>for an input voltage of 5 V.

 It doesn't matter how well behaved the ramp and comparator are, the
will always be a discontinuity at the extremes. This is created by
non-zero delays from the control point through to the power train
functioning with real components and the tendency of this nonlinearity
to produce cycle skipping.

The condition is loosely chaotic, but as all known conditions are
typically non-destructive, providing linear operation of switches is
avoided, it's a matter of lumping it, in an imperfect world.

RL