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From: john larkin <jl@650pot.com>
Newsgroups: sci.electronics.design
Subject: Re: another fast one-shot
Date: Wed, 12 Jun 2024 11:11:28 -0700
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On Wed, 12 Jun 2024 17:22:49 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:

>On Wed, 12 Jun 2024 09:33:17 -0700, john larkin wrote:
>
>> Here's another idea for a fast one-shot. This is the just-apply-money
>> version and should get close to 1 ns pulse width and should easily
>> trigger at 150 MHz.
>> 
>> https://www.dropbox.com/scl/fi/1okfo8964bw5m53mjmxs6/
>Pecl_One_Shot_1.jpg?rlkey=dwus6qjyqsynl2rv6uje2xxtj&raw=1
>> 
>> I can use the other half of the dual comparator elsewhere. This one has
>> programmable hysteresis too. 
>
>Exposing my contemptworthy ignorance here no doubt, but what exactly is it 
>that is fast about this design, John? And what would its application be?

It would have a leading-edge prop delay of 350 ps, a minimum pulse
width just over 1 ns, and would easily trigger at 150 MHz. Integrated
one-shots, xxx123 types, are always terrible, even the obsolete ECL
ones.

It would be a programmable delay in a number of possible products,
including some optical modulators. Just playing right now.

More dollars could certainly do something faster, but as long as
customers connect boxes with cables, faster isn't worth a lot. Light
just moves too slow.

Any suggestions for a faster one-shot?