The differential amplifier 110 amplifies voltage difference between the inputted reference voltage and the voltage at {TAIL ~ the node N7} and provides {HEAD ~ the amplified voltage} to the node N6 
The differential amplifier 110 amplifies voltage difference between the inputted reference voltage and the voltage at { TAIL ~ the node N7 } and provides { HEAD ~ the amplified voltage } to the node N6
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH