Each current control stage includes first, second, and third terminals, and means for conducting current between the first and second terminals in {HEAD ~ response} to a control signal present at {TAIL ~ the third terminal} 
Each current control stage includes first , second , and third terminals , and means for conducting current between the first and second terminals in { HEAD ~ response } to a control signal present at { TAIL ~ the third terminal }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL