Faselåseløkker

Faselåseløkker, also known as phase-locked loops (PLLs), are electronic circuits that generate an output signal whose phase is related to the phase of an input signal. Essentially, a PLL synchronizes an oscillator's output signal with the phase of a reference input signal. This synchronization is achieved through a feedback control system.

A typical PLL consists of three main components: a phase detector, a loop filter, and a voltage-controlled oscillator (VCO). The phase detector compares the phase of the input reference signal with the phase of the VCO's output signal. Any difference in phase generates an error voltage. This error voltage is then fed through the loop filter, which smooths out the voltage fluctuations and removes unwanted high-frequency components. The filtered error voltage then controls the frequency of the VCO. If the VCO's frequency is too high, the error voltage will cause it to decrease, and vice versa. Through this continuous feedback process, the VCO's output signal eventually locks in frequency and phase with the input reference signal.

PLLs are widely used in various electronic applications. They are crucial in communication systems for demodulating signals, in frequency synthesizers for generating precise frequencies, in clock recovery circuits for extracting timing information from data streams, and in motor control systems for speed regulation. Their ability to lock onto and track signals makes them indispensable in modern electronics.