{HEAD ~ The impedance} across the first and second devices is compared to provide {TAIL ~ the respective bit} of the corresponding digital output word 
{ HEAD ~ The impedance } across the first and second devices is compared to provide { TAIL ~ the respective bit } of the corresponding digital output word
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH