First and second comparator groups compare {HEAD ~ first and second analogue signals} applied thereto, respectively, with {TAIL ~ reference voltages} and convert the results of the comparison to binary signals to output the binary signals to an encoding circuit 
with
First and second comparator groups compare { HEAD ~ first and second analogue signals } applied thereto , respectively , with { TAIL ~ reference voltages } and convert the results of the comparison to binary signals to output the binary signals to an encoding circuit
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH