[time-nuts] Sub-ps delay line

ed breya eb at telight.com
Wed Feb 8 01:28:44 EST 2017

Even presuming this system is for clocking within a single-board 
environment, that seems like a fairly tall order for setting resolution 
and long-term stability. It could be tough to keep these numbers with 
temperature and supply variations in all the circuitry involved, 
including the parts that ultimately receive the various clock signals. 
On the other hand, making it adjustable delay-wise should be fairly easy 
- almost anything you do to tweak the operating conditions of this 
essentially analog system will change the delays. The trick will be to 
compensate for the unwanted effects, and consistently control certain 
things to set the delay.

I'd recommend using differential signals throughout, if possible, with 
coarse delays set by sections of on-board transmission line, and fine 
adjustment by tweaking DC bias at various points. I don't think you need 
to add any extra variable delays such as varicap circuits - you should 
be able to affect enough control and compensation just with the normal 
part characteristics.


More information about the time-nuts mailing list