A jitter attenuating PLL can be used to filter noise from the input clock and produce a low jitter output clock. Reducing the loop filter bandwidth increases the amount of jitter attenuation on the reference clock, transferring less jitter from the input to the output.
What is the purpose of the loop filter in a PLL?
The loop filter removes the unwanted high-frequency components of the error signals. The output of the loop filter (vlf (t) in Figure 23-11) is used to control the output frequency of the VCO and serves as the demodulated output of the PLL FM detector.
What is bandwidth of a PLL?
PLL bandwidth is the measure of the PLL's ability to track the reference clock and its associated jitter. ... A high-bandwidth PLL provides a fast lock time and tracks jitter on the reference clock source, passing it through to the PLL output. A low-bandwidth PLL filters out reference clock jitter, but increases lock time.
