As a driver, you can look at the RS-485 drivers. Some have very temperature stable and well controlled delays in the 10nS range, and they can drive relatively low impedances. I do not have the P/N on hand, but if you can't find one, let me know and I'll send you the P/N from home.
Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -----Original Message----- From: Michael Tharp <[email protected]> Sender: [email protected] Date: Thu, 17 May 2012 19:35:24 To: <[email protected]> Reply-To: Discussion of precise time and frequency measurement <[email protected]> Subject: [time-nuts] Buffering a PPS signal Greetings, As I mentioned briefly a few days ago I'm working on an interface board for the Trimble Resolution SMT carrier board to provide a convenient way to get power in and PPS/serial out. The PPS output is a 3.3v, 125 microsecond long pulse and I'd like to buffer it with something that can drive a 50 ohm terminated line. What's the best way to go about doing this? I've looked at using a MOSFET driver like FAN3111ESX but most of these have a moderate (30-50ns) delay with a moderate temperature coefficient, but perhaps I'm expecting too much. For people interested in buying the board, it will have USB and RS-232 (with PPS on the Carrier Detect line) plus the 50 ohm PPS output on BNC. Physically, it's the same size and shape as the RSMT board itself and will fit directly on top. Total cost should be about 20 USD. Current schematic is here, comments welcome: http://partiallystapled.com/~gxti/circuits/2012/05/17-piggyv2.png Cheers, -- m. tharp _______________________________________________ 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.
