The first circuit uses the clock signal received at the first input node to control {HEAD ~ the frequency} of {TAIL ~ the oscillator} 
of
The first circuit uses the clock signal received at the first input node to control { HEAD ~ the frequency } of { TAIL ~ the oscillator }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL