Hi The TBolt is designed to drive 50 ohms on the 10 MHz output. Level is above 7 dbm on the ones I have looked at.
Bob -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Greg Broburg Sent: Thursday, March 24, 2011 5:20 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Squaring Tbolt 10Mhz output what is the output drive circuit and what is the drive level / source impedance from the Thunderbolt? Greg On 3/24/2011 2:10 PM, Hal Murray wrote: >> I'm not sure everything can handle the 10Mhz signal. > Bingo. > > LM339 (National data sheet) > Response time: 0.5 us > > CD4049B/CD405B (from TI data sheet) > Rise time is 80 ns > Fall time is 30 ns > Those are typicals at 5 V with a 5V input signal. > > > The LM399 says "low power" which usually means low speed. > > I occasionally go "oops" when I sanity check the speed on a circuit I'm about > to build using HC/LS parts. They aren't very fast, and the old 4000 logic is > even slower. > > 10 MHz is about the corner for HC. I use the HC163 (4 bit binary counter) as > an example. It has a max clock frequency of 25 MHz, so you think "no > problems" at 10 MHz. But the setup times are 30-40 ns and the clock-out are > 40-50 ns so doing anything interesting at 10 MHz gets tight. > > > _______________________________________________ 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.
