Hi We have gone over CMOS 50 ohm line driving a bunch of times. Check the archives for all of the various opinions. A quick summary:
If you are driving CMOS, the output swing does not have to hit 99% of the supply. You can do a pretty good job with gates in parallel and no source termination. If you want both source and load termination *and* want 5V p-p on the load, you will need a 10V p-p source. Good luck if that source ever gets tied to a “normal” CMOS input. Something made from 2N3904’s and 2N3906’s is probably your best bet (along with dual supplies) if *really* want to do this. Source termination (open load) is the low power approach. Cable reflections are minimized and you don’t use a lot of power. === If all you are after is sine wave signals, a pair of gates running on 5V will give you 20 dbm without a lot of effort. There aren’t many applications in the timing world that need more power than that. Bob > On Mar 3, 2018, at 9:17 PM, David C. Partridge > <david.partri...@perdrix.co.uk> wrote: > > Brice said: > >> . Some fast CMOS devices (esp clock drivers) have an output R close to 50 > ohms as they are intended to drive 50 ohm source terminated transmission > lines. > > Any in particular that you'd recommend? I need to drive a 50ohm line and a > single gate inverter doesn't have the grunt to do so ... > > Thanks > David > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
