What is the principle of phase-locked loop?

What is the principle of phase-locked loop?

A phase-locked loop or phase lock loop (PLL) is a control system that generates an output signal whose phase is related to the phase of an input signal. There are several different types; the simplest is an electronic circuit consisting of a variable frequency oscillator and a phase detector in a feedback loop.

What is the operating principle of PLL?

Initially, PLL operates in free running mode when no input is applied to it. When an input signal having some frequency is applied to PLL, then the output signal frequency of VCO will start change. At this stage, the PLL is said to be operating in the capture mode.

What are 3 running conditions in PLL?

Thus, a PLL goes through three stages (i) free running, (ii) capture and (iii) locked or tracking.

What are the components of phase-locked loop?

The Phase Locked Loop circuit consists of three parts. They are, (1) Phase sensitive detector, (2) Low Pass Filter, and (3) Voltage controlled Oscillator. The output signal is generated by a Voltage controlled Oscillator (VCO).

What is PLL used for?

The main purpose of a PLL circuit is to synchronize an output oscillator signal with a reference signal. When the phase difference between the two signals is zero, the system is “locked.” A PLL is a closed-loop system with a control mechanism to reduce any phase error that may occur.

What is phase lock loop PLL )? With simple block diagram explain a PLL operation What is the use of PLL?

The phase locked loop, PLL is a very useful building block, particularly for radio frequency applications. The PLL forms the basis of a number of RF systems including the indirect frequency synthesizer, a form of FM demodulator and it enables the recovery of a stable continuous carrier from a pulse waveform.

How does phase lock loop speed control scheme operate?

The phase-locked loop consists of a phase detector, a voltage controlled oscillator and, in between them, a low pass filter is fixed. The input signal ‘Vi’ with an input frequency ‘Fi’ is conceded by a phase detector. Hence, the PLL works like free running, capture, and phase lock.

What is the purpose of phase locked loop PLL?

What are PLL used for?

The PLL is widely used for a variety of purposes. It is used to recover the clock signal in some wireless applications. It is used to recover the original signal in frequency modulation radio. It is used to multiply a frequency by a fixed factor.

What is the working principle of a phase locked loop?

Block Diagram And Working Principle Of PLL. The phase locked loop consists of a phase detector, a voltage control oscillator and, in between them, a low pass filter is fixed. The input signal ‘Vi’ with an input frequency ‘Fi’ is conceded by a phase detector.

How is a phase locked loop similar to a servo loop?

A phase locked loop, PLL, is basically of form of servo loop. Although a PLL performs its actions on a radio frequency signal, all the basic criteria for loop stability and other parameters are the same. In this way the same theory can be applied to a phase locked loop as is applied to servo loops.

How is capture range related to phase lock?

The capture range is the range in which the Phase Locker Loops attains the Phase Lock. When the filter bandwidth is reduced, the response time increases .But this reduces the capture range. But it also helps in reducing noise and in maintaining the locked loop through momentary losses of signal.

What happens when the PLL is in lock?

When the PLL, phase locked loop, is in lock a steady state error voltage is produced. By using an amplifier between the phase detector and the VCO, the actual error between the signals can be reduced to very small levels.