What is PLL? Explain its operation with a block diagram.

What is PLL? Explain its operation with a block diagram.
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1 Answer

Answer :

PLL - A phase-locked loop or phase lock loop is a control system that generates an output signal whose phase is related to the phase of an input signal


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Block diagram 

PLL Operation:- The phase comparator compares the input frequency and the feedback frequency. And output DC Voltage is proportional to the phase difference between the two known as error voltage. This voltage is applied to low pass filter which removes high frequency noise. This DC level is input to voltage controlled oscillator. Output frequency of VCO is directly proportional to the input DC level. The VCO frequency is compared with the input frequency and adjusted until it is equal to the input frequency. The phase – locked loop goes through three states free running capture and phase lock.

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