{HEAD ~ a comparison apparatus}, coupled to {TAIL ~ the output driver}, that generates a comparison output signal according to a reference voltage and the differential signal; and 
{ HEAD ~ a comparison apparatus } , coupled to { TAIL ~ the output driver } , that generates a comparison output signal according to a reference voltage and the differential signal ; and
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH