The digital processing circuitry converts the output of {HEAD ~ the comparator} 113 to a digital signal, averages the digital signal, and generates {TAIL ~ a multi bit digital bias signal} 
The digital processing circuitry converts the output of { HEAD ~ the comparator } 113 to a digital signal , averages the digital signal , and generates { TAIL ~ a multi bit digital bias signal }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL