Opвђ“amp Circuits Manual. Including Ota Circuits -

: Because the output can be "turned off" by setting IABCcap I sub cap A cap B cap C end-sub

The fundamental relationship governing an OTA is defined by its transconductance, which relates the output current ( Ioutcap I sub o u t end-sub ) to the differential input voltage ( Op–Amp Circuits Manual. Including OTA Circuits

: An OTA can simulate a resistor whose value is determined by the bias current, allowing for digital or analog control of resistance in a circuit. Understanding Operational Transconductance Amplifiers | PDF : Because the output can be "turned off"