A feedback control system that generates an output signal related to an input signal’s phase. It is a versatile electronic circuit used in a wide range of applications, including:
- Frequency Synthesis: PLLs are commonly used to generate stable and precise output frequencies. They can be found in devices like clock generators for microprocessors and digital communication systems.
- Clock Recovery: In data communication, PLLs recover the clock signal from a data stream, ensuring accurate data reception.
- Frequency Modulation and Demodulation: In FM modulation and demodulation, PLLs play a critical role in maintaining the carrier signal’s phase and recovering the modulating signal.
- Frequency Tracking: PLLs are used in radio receivers to track and tune to the desired frequency, ensuring the reception of a clear and stable signal.
- Phase Alignment: They are employed in applications requiring precise phase alignment or synchronization, such as in telecommunications and radar systems.
- Frequency Multipliers/Dividers: PLLs can multiply or divide input frequencies, making them useful for various frequency-related tasks.