A phase locked loop tutorial explains the fundamentals, concepts and operating mechanisms of the phase locked loop. A free phase locked loop tutorial is available online at Radio-electronics.com, and it features text, diagrams and videos.
The phase locked loop is a circuit building block particularly noted for its flexibility. Electronics engineers use the phase locked loop for radio frequency applications, such as FM demodulation, frequency synthesizers and clock recovery. The phase locked loop is found in radio frequency equipment such as radio receivers and test equipment. Early radio equipment did not use the phase locked loop due to the many stages required. Later, the rise of radio frequency integrated circuits increased the viability and proliferation of the phase locked loop.