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From: Toaster <toaster@dne3.net>
Newsgroups: sci.electronics.design
Subject: Re: 50 ohm termination
Date: Tue, 18 Mar 2025 18:59:44 -0400
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On Tue, 18 Mar 2025 16:02:45 -0700
john larkin <jl@glen--canyon.com> wrote:

> On Tue, 18 Mar 2025 18:29:42 -0400, 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.
> 
> Is the signal some analog thing, or a 10 MHz clock? The THS is an
> opamp, but they can make good cable drivers too, even for clocks.
> 
> Lately I'm enamored of BUF602, a unity-gain 1 GHz beast.
> 

I had a really hard time finding a good line driver. I might look into
this chip.

Thank you!