[time-nuts] Distribution amplifier (again!) - now mostly ok but has gain peaking
davidwhess at gmail.com
Sun Jan 29 02:11:46 EST 2017
On Sat, 28 Jan 2017 13:58:27 +0200, you wrote:
>The picture gallery also shows a pulse distribution amp for 1PPS. It has an
>LT1711 comparator feeding an 74AC14 buffer with length-matched traces to
>74AC04's at the outputs. So far my length-matching didn't give zero
>output-skew between the outputs - I see around 150-200ps skew which I tried
>to tune a bit with wires and 0R resistors - without very much success.. any
>ideas for improving this - or just leave it at 200ps skew?
200ps of skew is consistent with long traces on board material like
standard FR4 because of uneven dielectric constant produced by uneven
fiberglass weave. One way to ameliorate this is to route traces at a
diagonal compared to the fiberglass weave.
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