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