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Totem-Pole Output. A type of output structure used with integrated circuits in which one transistor drives the output high while another transistor connected below it pulls the output low.

Many ICs use Totem-Pole Outputs, in fact it's so common that the output structure isn't mentioned in the data sheet title. An IC with a Totem-Pole Output is the default condition. As opposed to an Open Collector Output which is always indicated in the title of the data sheet.

The circuit schematic shown below details the internal structure of a TTL triple input NOR gate with a Totem-Pole Output. The Totem-Pole is formed by transistors Q1 and Q2.

NOR gate with a Totem-Pole Output structure
Totem-Pole Output

The schematic and logic diagram are examples of 3-input NOR gates. The output structure will be some deviation of a Totem-Pole but the actual schematic will change depending upon the Logic Family used.
74HC27, 74HCT27, 54HC27, 54HCT27, 54AS27, 54ALS27, 54F27
Related page that covers all NOR Gates styles.

Another example of a 3-input NOR gate with a Totem-Pole Output. Although not labeled the Totem-Pole is formed by the two output transistors.

TTL 3-Input NOR Gate Structure

Note that the current paths are different between a high and low pulse. A totem-pole output sources current out to the load and sinks current in. Or an output high is derived from Vcc through Q1, and an output low is derived from Q2 to ground. So a rising pulse sees the impedance path of Q1 while a falling pulse see the impedance path of Q2. Depending on the logic function and the logic family there may be components in one or both paths in addition to the switching transistors Q1 and Q2. The different components and the different impedances of the transistors causes a difference between the rise time and the fall time of the output pulse.

When the IC has a Tri-state control pin, both output transistors may be placed in the off condition. Read more on 3-State Outputs.

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