7. Digital phase-locked loop

7.1 General

• Schematic diagram

  The loop can be realized in digital form by sampling the input signal at frequency f _e = 1/T. One embodiment is shown in figure 13 .

  The input signal sampled at frequency 1/T is applied to one of the inputs of the phase comparator realized in this case by a multiplier followed by a low-pass filter (in some cases, low-pass filtering is realized by the loop filter), the other input being attacked by the cos sequence (Ψ _s [k ]) from a digital controlled oscillator (DCO). The digital controlled oscillator is controlled...