Each current control stage includes an operational amplifier , {TAIL ~ a pass transistor} , {HEAD ~ a sense resistor} , and a feedback resistor  
Each current control stage includes an operational amplifier , { TAIL ~ a pass transistor } , { HEAD ~ a sense resistor } , and a feedback resistor
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH