Re: 50 ohm termination

On 18/03/2025 10:50 am, Toaster 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.

Doing things properly may not be too difficult. Light travels at about one foot (30cm) per nanosecond. Longer electromagnetic waves travels at about two thirds of the pace in coax insulation, so 500psec is about 10cm.
You don't have have to make you terminating resistors all that compact to have them behave predictably with those sorts of relatively slow edges.
Faster stuff can call for symetrical arrangements of compact surface mount resistors and that can get messy.
Double termination - at both source and destination - will give you the nicest looking waveforms, and since you would only see 2.5V at the destination the 125mW you'd have to dissipate at the source and the destination shouldn't be hard to cope with.
--
Bill Sloman, Sydney