Regardless of how it is illustrated or defined, the OTA has a high impedance terminal (B); a low
impedance terminal (E) that can be considered either as an input or an output depending on the circuit;
and a output current source terminal (C). The output current source terminal is high impedance. Looking
at the transconductor, any voltage that appears between B and E will generate a current that flows out of
C. For the balance of this document, however, we will consider circuits. The first circuit that demonstrates
how an OTA operates is shown in Figure 2.