Bob, Totally agree.
24mA of drive at 3.3V is pretty nice in a small footprint for the parts we are discussing. Of course as you have pointed out you can drive them at 5V too. Mini-circuits is a good place to look too - especially for us hobbyists: http://www.minicircuits.com/products/DesignerKits.shtml 73's, John AJ6BC On Thu, Sep 26, 2013 at 3:05 PM, Bob Camp <[email protected]> wrote: > Hi > > How clean is your clock source? If you have something that is -150 dbc at > 1 Hz, then you probably need some fancy analog gizmos. If you can make do > with "only" -110 to -120 dbc/Hz at 1 Hz, then properly driven LVC CMOS will > do just fine. That's true for a square or a sine output. Since you pretty > much can't find an OCXO better than -120 at 1 Hz, I'd bet you'll be ok. 5 > volt logic will be a little more quiet than 3.3V. More or less faster is > quieter as long as you stay with saturated silicon CMOS. Change materials > and all bets are off. > > For square wave cable drive you can parallel up a couple of the '125 or > '126 gates to get how ever much power you want to put into the cable. You > can source or load terminate (or both). If you source and load terminate, > your logic levels will be 1/2 the output. With either source only or load > only termination you can get full swing logic levels. More drive will > always be required with load termination (you are putting current into 50 > ohms). > > Logic IC's are cheap, easy to use, and simple to find. A low voltage > single supply drives them and they aren't current hogs unless heavily > loaded. What's not to like? > > Bob > > > On Sep 26, 2013, at 1:28 PM, Tom Minnis <[email protected]> wrote: > > > I am looking into various degrees of craziness. The source is CMOS and > there are plenty of 1 in to N out parts designed to drive clocks on a PCB > but not much is said about driving clocks on to a random length of coax to > another piece of equipment and what additional precautions that might > warrant. I am also considering making a sine wave output and maybe other > frequencies. > > Tom > > > > On 9/26/2013 4:34 AM, Bob Camp wrote: > >> Hi > >> > >> Standard high speed CMOS logic works pretty well. How crazy are you > trying to get? > >> > >> Bob > >> > >> On Sep 26, 2013, at 1:48 AM, Tom Minnis <[email protected]> wrote: > >> > >>> I am working on a small clock distributor and wanted to get some ideas > on what works best for 10MHz and 1PPS driver circuits. I remember sifting > through the archives a year or so ago and tripped on some discussion of > this but I can't find it anymore. > >>> Tom > >>> _______________________________________________ > >>> time-nuts mailing list -- [email protected] > >>> To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >>> and follow the instructions there. > >> _______________________________________________ > >> time-nuts mailing list -- [email protected] > >> To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >> and follow the instructions there. > >> > > > > _______________________________________________ > > time-nuts mailing list -- [email protected] > > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
