Re: fast discrete PHEMT one-shot

On 17/05/2024 2:46 am, John Larkin wrote:

On Fri, 17 May 2024 00:40:32 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
 

On 16/05/2024 11:15 am, John Larkin wrote:

On Wed, 15 May 2024 22:46:27 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
>

John Larkin <jjSNIPlarkin@highNONOlandtechnology.com> wrote:

>
https://www.dropbox.com/scl/fi/agatzclr8pvr5470g6mc4/Phemt_One_Shot_1.jpg?rlkey=cwnx0qd7ajgnh8otf627x5lku&raw=1
>
Regular monostables are terribly slow. This one has low prop delay and
high rep-rate, if the sim is to be believed.
>
SAV541 is mostly specified as an RF part, but it's a dynamite switch.
>
I can post a link to the files if anybody wants to play with this. All
my values are first guesses, no math involved, and it works!
>
My SAV541 Spice model is a revision of Phil Hobbs' original.
Mini-Circuits is adamant that they will never provide Spice models, a
typical RF-bigot attitude.
>
>

>
Yay! Eccles-Jordan ride again.

>
1918!
>
I think that was a bistable. I don't know when the monostable was > invented.

>
https://en.wikipedia.org/wiki/Multivibrator
>
has a two quotes from 1942 one from 1943 and two from 1949 which make it
clear that monostable had been invented by then. It sees it as a cut
down bistable, so Eccles-Jordan is probably a good name.
>
Since the first multivibrator circuit, the astable multivibrator
oscillator, was invented by Henri Abraham and Eugene Bloch during World
War I, it probably isn't the right name.
>
https://apps.dtic.mil/sti/tr/pdf/AD0410225.pdf
>
is a 1963 Ph.D. on the bistable circuit.
>

People tend to roll eyes when I use one-shots in logic designs. I
can't see why.

>
You can't trigger a one-shot immediately after it has been triggered,
and the pulse width you get can be reduced if you re-trigger it too soon
after it has generated it's pulse, when it hasn't entirely recovered.

 The SN74123 retriggerable one-shot, and a Fairchild equivalent, are
over 50 years old.

But you don't get a new pulse when you retrigger a retriggerable monostable - you just stretch the one you had already started.

And "it's" is not the possessive form. It's means "it is."

I do  know that but produce the mistake as a typo from time to time, as you are well aware.
And you've snipped the rest of my post, without marking the snip.
--
Bill Sloman, Sydney