[time-nuts] SE880 GPSDO

Attila Kinali attila at kinali.ch
Mon Apr 25 19:36:53 EDT 2016


On Mon, 25 Apr 2016 23:34:52 +0200
Ilia Platone <info at iliaplatone.com> wrote:

> I selected this because of the CMOS output, since I didn't find any 
> Connor Winfield osc with these levels yet.

To get to CMOS levels, you usually add a simple inverter, with an
capacitor in front and a 1M resistor across the inverter (from input
to output).


> Actually  want to achieve less than around 78ps jitter at 125MHz. (this 
> should be achievable using this also: 
> http://www.digikey.it/product-detail/it/fox-electronics/FVXO-HC53B-125/FVXO-HC53B-125-ND/2153894)

I think you are mixing up a few things here:

Your logger might have very relaxed jitter requirements, but the
GPS module needs a low noise reference signal. If you feed it with
the noisy HC53 output, you will degrade your GPS receivers performance
severely. At the minimum, you should use a normal XO for the GPS modul.
You can of corse use a HC53 as the reference for your logger if its
jitter is ok for you.

And for comparison, for a XO you usually talk about jitter in the
order of 100fs to 1ps (10kHz-20MHz)



			Attila Kinali
-- 
Reading can seriously damage your ignorance.
		-- unknown


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