Re: [time-nuts] 100 MHz decade divider advice needed
I'd recommend good old ECL and related families for these sorts of things. It's a lot more RF-friendly. 116/216 type receivers and small RF transformers can work for I/O, the signals are reasonably-sized (<1 V pp), can be all differential, can operate over a wide impedance range, and is quiet, power supply-wise (no supply or ground glitches on transition). The 10H series should be nice for 100 MHz, and there are newer series like "EL" that can go much higher, and more functions are available. The downside is powering it up - whether it's regular ECL or PECL for +5 V, it's pretty power hungry, but can be well worth it. Since it's low-gain, non-saturating logic, you can have additional noise issues, but operating as ECL with very clean and proper -5.2 V should minimize it. Ed ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] 100 MHz decade divider advice needed
Am 30.11.19 um 02:10 schrieb Gerhard Hoffmann: Auto-follow-up: Why do you want crystal ovens in each stage when you lock it to something else anyway? Then something cheaper like these should do: < https://www.digikey.de/product-detail/de/crystek-corporation/CVHD-950-100.000/744-1213-ND/1644128 > My score on Morions from China was not so pleasant. .. and while I'm at it: < https://www.digikey.de/product-detail/de/nexperia-usa-inc/74LVC163PW118/1727-3097-1-ND/946754 > 150 MHz min @3V3, 200 MHz typ. Sorry, no DIL. 74ACT, 74F, 74AS are also dying. 74HCT is still there. regards, Gerhard ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] 100 MHz decade divider advice needed
Am 30.11.19 um 00:50 schrieb Perry Sandeen via time-nuts: Yo Bubba Dudes!, I'm considering attempting making a 10 MHz frequency difference meter sort of based on the Ticor 527. The design calls for using 100 MHz OCXO's and using the PLL difference to steer the EFC and then mix it with a PLL 90 MHz locked to the reference 10 MHz. Then that 10MHz difference is fed into the next stage PLL and the process repeated in the following stages. Hy problem is this. The only generally available 100MHz decade divider I've found is the 74LS196N. The problem arises that on the TI website it's advertised as going to 100 MHz BUT when one reads the data sheet it says that it only works to 85 MHz or so. I found on ebay the MC12080 100 MHz to 1.1GHz chip that can be configured to divide by 10. Now the ON units carried by the big name distributers are about $6. The Chicom no-brand-name units on ebay are less that $2 each. I'd really like to use the LS296 chip as it is a dip type and *genuine* ones sell for less than $2 on ebay. Since I need one OCXO for each decade stage plus one for the 90 MHz reference, at $50 each used on ebay this starts to get very expensive quickly. I did find some obscure 100 MHz decade counters on some design circuit on the net but I'd never heard of them and expect they will be unobtainum. The same seems to be true for the 74S and 74AC series. 74ls, 74s and mostly 74AC are all obscure now. 5V is mega-out, 3.3V is still standard but the trend goes to even less. 74LVC is mainstream. Not all chips of the old 74 series have been ported to 74lvc because nobody designs system around MSI function blocks any more. There are just the essentials: octal bus drivers, gates, flipflops (mostly only 1 gate/ff per pop in a tiny SO-8 or sot-23-5). There is still the 74LVC163 counter. I think there is no LVC191 whose precursor I have used a lot. These SSI/MSI chips only save as glue logic to make LSI ICs to fit together or to connect them to IO. Heavy functions that do not justify a full custom chip go to FPGAs or at least to CPLDs. I personally like the Xilinx Coolrunner-2 CPLDs as garbage collectors, but they are getting old also. The 74LVC163 + inverter should work for you, up to 200 MHz at least. But remember: with the speed come problems, too. Your output may be only 10 MHz, but rise and fall times are easily as fast as 500 ps. Good rf engineering is absolutely required. The lower-left quarter of the picture should work for you. There are more fast families, like Fairchild NC7SZ04P5X (04 = one inverter in sc70-5) or TI SN74LVC1G04DCKR (mostly the same) or ON Semiconductor NL17SZ74USG (D-type FF), Fairchild NV7SV74K8x or NXP 74LVC163PW ( counter ) as search strings for your google-foo, as typed from the anti-static bags in my drawer. If you find one of the family, the brothers are easy. local bed time now, Gerhard :-) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] 100 MHz decade divider advice needed
Hi 74AS161 / 163 are rated to 125 MHz. Bob > On Nov 29, 2019, at 6:50 PM, Perry Sandeen via time-nuts > wrote: > > Yo Bubba Dudes!, > I'm considering attempting making a 10 MHz frequency difference meter sort > of based on the Ticor 527. > The design calls for using 100 MHz OCXO's and using the PLL difference to > steer the EFC and then mix it with a PLL 90 MHz locked to the reference 10 > MHz. Then that 10MHz difference is fed into the next stage PLL and the > process repeated in the following stages. > Hy problem is this. The only generally available 100MHz decade divider I've > found is the 74LS196N. > The problem arises that on the TI website it's advertised as going to 100 MHz > BUT when one reads the data sheet it says that it only works to 85 MHz or so. > I found on ebay the MC12080 100 MHz to 1.1GHz chip that can be configured to > divide by 10. > Now the ON units carried by the big name distributers are about $6. The > Chicom no-brand-name units on ebay are less that $2 each. > I'd really like to use the LS296 chip as it is a dip type and *genuine* ones > sell for less than $2 on ebay. > Since I need one OCXO for each decade stage plus one for the 90 MHz > reference, at $50 each used on ebay this starts to get very expensive quickly. > I did find some obscure 100 MHz decade counters on some design circuit on the > net but I'd never heard of them and expect they will be unobtainum. The same > seems to be true for the 74S and 74AC series. > > So will the LS196 chip work reliably at 100 MHz or am I stuck with the MC > 12080 or is there a better chip that I could use? > Regards, > Perrier > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
[time-nuts] 100 MHz decade divider advice needed
Yo Bubba Dudes!, I'm considering attempting making a 10 MHz frequency difference meter sort of based on the Ticor 527. The design calls for using 100 MHz OCXO's and using the PLL difference to steer the EFC and then mix it with a PLL 90 MHz locked to the reference 10 MHz. Then that 10MHz difference is fed into the next stage PLL and the process repeated in the following stages. Hy problem is this. The only generally available 100MHz decade divider I've found is the 74LS196N. The problem arises that on the TI website it's advertised as going to 100 MHz BUT when one reads the data sheet it says that it only works to 85 MHz or so. I found on ebay the MC12080 100 MHz to 1.1GHz chip that can be configured to divide by 10. Now the ON units carried by the big name distributers are about $6. The Chicom no-brand-name units on ebay are less that $2 each. I'd really like to use the LS296 chip as it is a dip type and *genuine* ones sell for less than $2 on ebay. Since I need one OCXO for each decade stage plus one for the 90 MHz reference, at $50 each used on ebay this starts to get very expensive quickly. I did find some obscure 100 MHz decade counters on some design circuit on the net but I'd never heard of them and expect they will be unobtainum. The same seems to be true for the 74S and 74AC series. So will the LS196 chip work reliably at 100 MHz or am I stuck with the MC 12080 or is there a better chip that I could use? Regards, Perrier ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
