I'm not sure "HOW" this would work, but what I think you really want is a
Phase Locked Loop.  I believe a very informative discussion can be found
in the Tab Book called "The CMOS Cookbook"


On Thu, 20 May 1999, erik wrote:

> I would like to phase shift a square wave pulse train. Retard it by 90
> degrees.
>
> I can't seem to think of any way to do this. I had read that an or gate
> would retard it some.
> I'd need quite a few of them though and the shift would vary for
> different frequencies.
>
> Actually, I'm still trying to figure out how to multiply a clock pulse.
> If I take my clock pulse, xor it with it's 90 degree retartded friend, I
> would double my
> original clock.
>
> Just can't seem to figure out how I'm going to get "more" out of
> something than what I'm putting in.
> (similar project in the works concerning my wallet. that's not going so
> well either):)
>
> Erik
>
>
>
> Nigel Orr wrote:
> >
> > At 06:22 20/05/99 -0500, you wrote:
> > >I'm looking for a means of phase shifting a square wave clock pulse by
> > >90 degrees.
> >
> > If it is a constant frequency, then just add a delay, of t/4, where t is
> > the period of the pulse.
> >
> > If it could be some unknown frequency, it's more difficult- more details
> > would be needed.
> >
> > Nigel
>