Re: Chip for fast pulses

On Sat, 18 Jan 2025 00:23:18 +0100, Jeroen Belleman
<jeroen@nospam.please> wrote:

On 1/17/25 23:43, Cursitor Doom wrote:

On Fri, 17 Jan 2025 14:26:46 -0800, john larkin <jl@glen--canyon.com>
wrote:
 

On Fri, 17 Jan 2025 17:47:04 +0000, Cursitor Doom <cd@notformail.com>
wrote:
>

Gentlemen,
>
What's available these days for generating well-defined pulses with
really sharp rise times? I admit to being like 40 years behind when it
comes to what ICs can do (and proud of it!) Would 50pS cut the mustard
or is that dog-doo slow nowadays?
>
Thanks,
>
CD

>
50 ps edges are pretty fast. I tell people that 1 ns starts to be
interesting and 100 ps starts to be hard.
>
Some CMOS parts make 200 ps edges.
>
Eclips Lite (EL series) and GigaComm (NB7) are fast ECL logic
families. Some Giga parts have 35 ps rise and fall, but tiny swings.
>
There are some interesting laser drivers around, like the SY88022.
>
There were some really fast Russian parts but I don't know if they
still can be had.
>
Step-recovery diodes and NLTLs (shock lines) make the fastest
all-electrical pulses. Laser stuff gets truly fast, fs and as optical
pulses.

 
Interesting. I'm seeing a *lot* of adverts on Ebay currently for
"optical TDRs" which must be challenging to produce (to my VHF mindset
anyway). So yeah, I'm perfectly certain SRDs would be more than
adequate for anything I wanted to do. NLTLs I'm not familiar with so
gonna have to look 'em up.

>
Optical TDRs have VHF bandwidths. It's the /modulation/ they show.
They certainly don't have the 600-odd THz bandwidth you seem to imply.
>
Jeroen Belleman
not

Ah - well that would explain a great deal! Thanks.