[time-nuts] Re: General query about disciplining circuitry

[Carsten Andrich]

Hi Jim,

there are a bunch of fairly low-complexity designs on EEVblog. Just to 
name a few:
https://www.eevblog.com/forum/projects/lars-diy-gpsdo-with-arduino-and-1ns-resolution-tic/
https://www.eevblog.com/forum/projects/diy-gpsdo-project-w-stm32-tdc7200/
https://www.eevblog.com/forum/projects/yet-another-diy-gpsdo-yes-another-one/
https://www.eevblog.com/forum/projects/gpsdognssdo-stm32g4-u-blox-zed-f9t-tdc7200/ 
(disclaimer: my personal, currently stalled project)

Depending on your desired time tagging resolution, using an MCU timer 
capture (with the timer driven by your oscillator) may already suffice. 
Various STM32 advertise <10 ns capture resolution. If you require higher 
resolution I'd suggest to use a TDC7200. For that extra effort to 
amortize, I believe you need to rely on a dedicated timing GNSS receiver 
and to implement time pulse quantization (sawtooth) correction.

Best regards,
Carsten

On 10.02.23 03:57, AC0XU (Jim) via time-nuts wrote:
> Thanks to all for the various comments.
>
> My question was really about how to make accurate phase measurements of an oscillator at the 1 PPS time tag output from a GNSS radio. There are some methods I can think of, but I am not finding one that has clear advantages of accuracy, immunity to all forms of noise on the oscillator output, and low complexity and power. I was hoping that someone out there had the perfect solution...
>
> Thanks!
> Jim