** NOTE **
This FAQ is in reference to push-pull output devices. Open-drain outputs will
inherently have slower operating frequencies due to the lack of a positive side driver.
Clock speed is not characterized for devices that do not include a clock input. This includes typical combinational logic gates (AND, OR, NAND, NOR, XOR, XNOR), line drivers (buffers, inverters, transceivers), and other combinational logic devices (encoders, decoders, logic multiplexers, etc.).
The maximum operating frequency can be estimated by finding a clocked device in the same logic family.
For example, the SN74LVC1G34 is a logic buffer, and does not include a maximum operating frequency. The SN74LVC1G79 is a D-type Flip-Flop in the same logic family (LVCxG), and it includes an fmax value in the datasheet of 160 MHz (minimum). This indicates that the SN74LVC1G34 can operate at 160 MHz also.