{HEAD ~ A bias circuit} selects the second external input voltage or {TAIL ~ voltage} obtained by adding bias voltage to the second external input voltage, according to the output voltage of the amplifying circuit, and outputs it as the voltage corresponding to second external input voltage 
selects
{ HEAD ~ A bias circuit } selects the second external input voltage or { TAIL ~ voltage } obtained by adding bias voltage to the second external input voltage , according to the output voltage of the amplifying circuit , and outputs it as the voltage corresponding to second external input voltage
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL 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 OTH OTH OTH OTH OTH OTH OTH OTH OTH