{TAIL ~ a processing circuit} that controls the current control signal according to {HEAD ~ the comparison output signal} to calibrate the driving current, 
{ TAIL ~ a processing circuit } that controls the current control signal according to { HEAD ~ the comparison output signal } to calibrate the driving current ,
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH