Combined frequency and phase regulation loop, esp. for gigabit signals

摘要

The regulation loop has a phase detector, a low-pass filter and a voltage-controlled oscillator (VCO). An additional comparator stage (OP2) compares the output signal of the low-pass filter or the phase discriminator in the phase regulating loop with a reference voltage, to provide a control signal for the voltage-controlled oscillator. Pref. the output of the comparator stage is fed to the input of a window comparator (FK), the output of which is fed to the input of the low-pass filter in the phase regulating loop.