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It doesn't seem to clearly say totem-pole, open-collector, open-drain, etc. I wanted to place a pull-up at the output to guarantee a default state, but I feel like this is a bad decision.

datasheet

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  • \$\begingroup\$ As an aside, the "nG" parts work exactly the same as the parts without, but with fewer gates. And "LVC" works similar to "HC" but with different voltage levels as thresholds (plus a few additional features). \$\endgroup\$ – Ignacio Vazquez-Abrams Aug 5 '15 at 18:18
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    \$\begingroup\$ For future reference the "04" suffix" usually indicates a totem-pole inverter as it is derived from the original SN7404. The equivalent one with open collector is "05". "06" and "07" are also open-collector buffers. These days some types do not follow the historic conventions though. \$\endgroup\$ – Kevin White Aug 5 '15 at 18:22
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It's push-pull output (as would be expected, unless otherwise stated). You can see how push-pull it is from the datasheet:

enter image description here

At 4.5V supply it can sink or source up to 32mA and (Table 7.5) the maximum/minimum voltages under those conditions will be 0.55V/3.8V. So, it's a little better at sinking current than at sourcing it (<550mV drop sinking 32mA and <700mV drop sourcing 32mA).

Adding a resistor will do nothing under normal operating conditions (chip is powered) but waste power when the output is low.

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On the datasheet, under "Recommended Operating Conditions", it lists "High Level Output Current" for various conditions. When its output is high, an open collector/drain part effectivly is disconnected from its output pin, so has no high level output current. So this part must have a "totempole" output circuit.

Under "Application Information", the datasheet shows the part driving an LED connected to ground - this won't work with an open collector part.

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