The function of a low pass filter in phase locked loop is ______________.

Explanation:

The function of a low-pass filter in a phase-locked loop (PLL) is to remove the high-frequency noise present. This statement can be elaborated upon by explaining the concepts of PLLs and low-pass filters, and how they interact within the system.

Phase-Locked Loop (PLL):

Definition: A phase-locked loop (PLL) is an electronic control system that generates an output signal whose phase is related to the phase of an input signal. It is widely used for synchronization purposes in communication systems, where it locks the phase of a local oscillator to the phase of an incoming signal.

Components of PLL:

• Phase Detector: Compares the phase of the input signal with the phase of the output signal and produces a signal proportional to the phase difference.
• Low Pass Filter (LPF): Filters the output of the phase detector to remove high-frequency noise and produces a smooth error signal.
• Voltage-Controlled Oscillator (VCO): Generates an output frequency that is controlled by the filtered error signal.
• Feedback Path: The output of the VCO is fed back to the phase detector to close the loop.

Low Pass Filter in PLL:

The low-pass filter in a PLL plays a crucial role in ensuring stable operation and high performance of the system. Its main function is to remove high-frequency noise from the output of the phase detector. This noise can arise from various sources, including thermal noise, power supply variations, and other electromagnetic interferences. By filtering out this noise, the LPF produces a smooth and stable error signal, which is then used to control the VCO. This ensures that the VCO output closely tracks the phase of the input signal, achieving the desired synchronization.