A voltage controlled oscillator is supplied with a part of {HEAD ~ the output} of {TAIL ~ the phase comparator} which controls its oscillation frequency 
A voltage controlled oscillator is supplied with a part of { HEAD ~ the output } of { TAIL ~ the phase comparator } which controls its oscillation frequency
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH