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