from http://techref.massmind.org http://www.microlet.com/yam/. Schematics for their early FPGA, which includes a Digital PLL implementation. All digital PLL is generally not a good choice to reduce jitter (unless your jitter's real bad to begin with). Jitter attenuators do the job, though http://www.dalsemi.com/DocControl/PDFs/2188.pdf... The Bell Labs tech journals from the mid 1970's have tons of articles on jitter in communication systems. The bible on analog PLLs theory is "Phaselock Techniques by Gardner (1979)" "Phase Locked Loops : Design, Simulation, and Applications" by Best has a very basic intro to DPLLs "Monolithic Phase-Locked Loops and Clock Recovery Circuits : Theory and Design" from the IEEE is more current, and has a good PLL theory section. http://www.infosite.com/%7Ejkeyzer/piclist/2000/Feb/1777.html Using a PLL and an integrator to measure the amplitude of a signal at a given frequency an reject noise (a one channel spectrum analyzer) --- James Newton mailto:jamesnewton@geocities.com 1-619-652-0593 http://techref.massmind.org NEW! FINALLY A REAL NAME! Members can add private/public comments/pages ($0 TANSTAAFL web hosting) -----Original Message----- From: pic microcontroller discussion list [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Peter Crowcroft Sent: Friday, March 17, 2000 01:05 To: PICLIST@MITVMA.MIT.EDU Subject: [OT] PLL's Can anyone tell me some websites with good introductions to PLLs on them? thank you, regards, Peter Crowcroft DIY Electronics (HK) Ltd PO Box 88458, Sham Shui Po, Hong Kong Voice: 852-2720 0255 Fax: 852-2725 0610 Email: peter@kitsrus.com Web: http://kitsrus.com ----------------------------------------------------------------------