Re: The emitter-coupled monostable as slow differential amplifer

On Sat, 20 Jul 2024 15:29:58 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:

About a month ago John Larkin dismissed the emitter coupled monostable
with "It's really a slow diffamp, not a one-shot."
>
If you feed a really slow pulse into it, it can look that way.
The 3.3pf capacitor at C1 doesn't feed through much current if you drive
the input with a slow edge
>
The simulation below demonstrates it working exactly that way.
>
No sensible circuit designer would deliberately drive it with a very
slowly rising and falling pulse  - if you want it to work as a
monostable pulse stretcher, you have to drive it with a pulse that is
narrower than the one you want to get out.
>
Integrated circuit monostables don't have that limitation, but they are
more complicated, and slower. There was an ECL monostable that went down
to 10nsec, but the emitter-coupled monostable lets you get down to
1nsec, if you use it right.
>

That wasn't my point. My comment wasn't about the trigger risetime but
that if you put in a long trigger, you get a long output. It's hardly
a one-shot.  The input and output levels are weird too.

If course a proper one-shot should fire cleanly on a fast or slow
rising edge.

https://www.dropbox.com/scl/fi/idliehdrx7dr5fnffr4f9/28S505A.pdf?rlkey=gkmhx0r2fe4clu4qf98qoig03&dl=0