Therefore this circuit produces {HEAD ~ a digital ramp signal} with {TAIL ~ a slope} and frequency proportional to the numerical value of the input digital word 
with
Therefore this circuit produces { HEAD ~ a digital ramp signal } with { TAIL ~ a slope } and frequency proportional to the numerical value of the input digital word
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH