Sushanthhegde3 wrote on Jul 24th, 2015, 3:05am:Thank you for the explaination. I have another query.The bang bang phase detectors used in ADPLL can measure the phase of early or late signals.If the reference is leading then early will be at logic 1 and if the feedback is leading then the late signal will be at logic 1.In some literatures I came to know that the BBPD can measure the frequency difference too.Could you plz help me to understand?
Thanks in Advance
THis is the difference between a
Phase Detector (PD)
and a
Phase-Frequency Detector (PFD)
A PFD will tell the PLL to go up or down until the frequency is the same and then just adjust for phase.
A PD will give a mixture of up-down information depending on the instant phase relationship of the two signals.
I am sure there is some information out there on this. Look for timing diagrams of the PFD and PD to see a comparison.