Operational Amplifiers - Technical MCQs

Q1:

What three subcircuits does a phase locked loop (PLL) consist of?

A phase comparator, comparator, and VCO

B phase comparator, bandpass filter, and VCO

C phase comparator, bandpass filter, and demodulator

D phase comparator, low-pass filter, and VCO

ANS:D - phase comparator, low-pass filter, and VCO

PLL - A Phase-Locked Loop (PLL) is an electronic circuit with a current-driven oscillator that constantly adjusts to match the frequency of an input signal, often used in wireless systems.

PLLs are used to generate, stabilise, modulate, demodulate, filter or recover a signal from a "noisy" communications channel where data has been interrupted.