[time-nuts] Interfacing a 8dBm sine output of an OCXO to adigital logic standard

Poul-Henning Kamp phk at phk.freebsd.dk
Fri Sep 16 12:31:25 EDT 2005

In message <432AF0A4.5060901 at onetel.net>, David Kirkby writes:
>Poul-Henning Kamp wrote:
>>>>	http://www.icst.com/datasheets/ics2305.pdf
>> Be aware they don't mean the same with "jitter" as you do: they
>> include production tolerances, so the 200ps is the worst case jitter
>> measured between two output pins on a large lot of chips, not the
>> jitter you would measure on a single output on a single chip.
>What you are describing sounds more like the 700ps "Device to Device Skew".

Hmm, could be, I just picked this datasheet as an example of the concept,
I didn't look at the actual numbers.

Newer devices are down below 50ps jitter or rather: newer memory
mandates that they be.

Just remember to stay well away from "spread spectrum" or disable
it if possible.  It's a 50-75 kHz FM to make the computer sneak
under the EMI masks.

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.

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