open-circuit output (of an integrated circuit)

A unipolar output whose only connection within the integrated circuit is through an active device, usually a transistor, to one of the supply voltages.

NOTE 1 For the purpose of this definition, the presence of any parasitic components and freewheeling, flyback, and clamp diode is ignored.

NOTE 2 When the active device is in its on state, the output voltage approaches the voltage of the supply to which it is connected (through the active device); when the device is in its off state, the output impedance to any other terminal of the integrated circuit is high and the output voltage is determined by the external circuit to which the output is connected.

NOTE 3 Outputs of this generic class are usually classified according to the name of the element of the active device to which they are connected within the integrated circuit, e.g., open-collector output, open-drain output, etc.

NOTE 4 For graphic symbols, see "sink driver" and "source driver".

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