> I studied the LM3900 app notes a year or two ago, and came to the same
> conclusion about the Serge pulse divider. I'm as sure as someone who has
> never seen the insides of a Serge module can be that it's using a purely
> analog LM3900 staircase generator to do the dividing. And part of me
> respects the pure-analog-ness of that solution. ;-)
There is a chance that Serge started with a 3900 circuit and upgraded it
to something more involved later, of course.
My own pulse divider story goes like this: Read the Serge catalogue,
thought it was a cool feature, designed a mildly involved analogue
circuit with CMOS gates and opamps (also a charge pump design),
and discovered that National application note ∗later∗.
BTW, I wonder how Serge's phaser looks like, just for the sake of
curiousity.
I've once built the circuit from his patent (also LM3900-based, big
surprise),
and the effect was very interesting but not quite what I expected from a
phaser.
As the Serge phaser has a reputation for being very clean (and what I built
from the patent disclosure is the very contrary), I'm sure he's added a lot
of extra circuitry, or has switched to a different concept later.
JH.