Demystifying the PLL

As RF and microwave engineers we use a lot of frequency sources that are synchronized to reference oscillators. Doing so requires some form of phase-locked loop circuitry. Feedback and control circuits classes in college taught the basics that are simple enough to understand, but unless you happen to have designed a PLL circuit during your career - we more often buy packaged devices or modules that someone else designed - chances are the concept has become a bit fuzzy by now. This brief article in EDN runs over the basics of PLL operation.

Posted April 2013

RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a lady's voice announced "You've Got Mail" when a new message arrived...