> One option is to use just the programmable divider part of a PLL IC, > such as those from National Semiconductors or Analog Devices. Or, use a > Hittite HMC394 programmable counter preceded by a fast /2 flip flop. > The PLLs will need serial programming via a micro-controller or other > logic device; the HMC394 uses parallel programming so is easier to > implement. > > Neither the PLLs nor the HMC394 counter need external edge conditioning > - they will work with sine wave inputs.
... at high input frequencies. The Hittite parts *hate* sine-wave inputs below about 100 MHz. Sensitivity drops like a rock (and presumably jitter performance does too, but I haven't looked closely at that). The NatSemi/ADF PLL chips are fine with whatever you give them, sensitivity-wise, although they are quieter if you don't rely on them to do their own edge conditioning. > These solutions won't give you as good a phase noise performance as a > regenerative divider, but if you want something that you can just plug > together then they will work for relatively little effort. And you > don't need to worry about -ve supply voltages which some ECL devices need. The Zarlink SP8401 and SP8402 are also worth investigating. They are the quietest VHF/UHF divider chips I'm aware of. http://products.zarlink.com/product_profiles/SP8402.htm -- john, KE5FX _______________________________________________ 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.
