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