PLLs work by continuously adjusting a voltage or current-driven oscillator to match (lock onto) the phase and frequency of an input signal. A circuit called a phase comparator causes the VCO to seek and lock onto the desired frequency, which is set via a Voltage Controlled Oscillator. When the VCO frequency differs from the reference frequency, the phase comparator produces an error voltage. Digital Phase locked loop (DPLL) is one of the most important devices in almost all the electronic systems.... Mehr