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