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From: Toaster <toaster@dne3.net>
Newsgroups: sci.electronics.design
Subject: Re: 50 ohm termination
Date: Tue, 18 Mar 2025 18:54:21 -0400
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On Tue, 18 Mar 2025 22:46:55 -0000 (UTC)
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

> Toaster <toaster@dne3.net> wrote:
> > On Mon, 17 Mar 2025 19:17:13 -0700
> > john larkin <jlArbor.com> wrote:
> > 
> >> On Mon, 17 Mar 2025 19:50:17 -0400, Toaster <toaster@dne3.net>
> >> wrote:
> >> 
> >>> Thank you for the advice. In my case I have a 10Mhz signal with
> >>> very sharp transitions (500ps, 5V) and wanted to make sure I did
> >>> things properly.
> >> 
> >> Interesting. What's generating the 5v signal? Lots of AC and Tiny
> >> Logic chips are that fast, but might strain to drive 50 ohms. We
> >> use several tiny triple buffers in parallel sometimes.
> >> 
> >> Regular thick-film surface-mount resistors are fine as terminators
> >> at 500 ps.
> >> 
> >> LVDS line receivers are great at the receive end.
> >> 
> >> 
> > 
> > I used a THS3111CD. Split up my project into a timing and driver
> > board, so i have some 50 ohm BNC cables between and wanted to be
> > extra safe about reflections at these higher frequencies.
> > 
> > 
> 
> Hmm. 5V in 500 ps is pretty good going for a part with 1300 V/us
> slew. ;)
> 
> Cheers 
> 
> Phil Hobbs 
> 

I'm an expert at misreading the divisions on my scope ill have you know
:)