During conversion, the analog input voltage is applied to a first device and a selected one of {HEAD ~ the predetermined digital control words} is applied to a second device which is coupled to {TAIL ~ the first device} through an amplifying feedback network 
During conversion , the analog input voltage is applied to a first device and a selected one of { HEAD ~ the predetermined digital control words } is applied to a second device which is coupled to { TAIL ~ the first device } through an amplifying feedback network
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 HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH