The first comparator group 10a and the second comparator group 10b each have a plurality of comparators for comparing {HEAD ~ the input analogue signal} with {TAIL ~ a reference voltage} 
with
The first comparator group 10a and the second comparator group 10b each have a plurality of comparators for comparing { HEAD ~ the input analogue signal } with { TAIL ~ a reference voltage }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL