Re: 50 ohm termination

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!