Hello,
I'm looking at 74AUP2G14DW-7 (<- Datasheet) and I'm a bit confused.

The absolute ratings read:
Continuous Output Current = +/-20mA
Output Clamp Current = -50mA

But in the recommended section the Maximum High/Low-Level Output Current = +/-4mA .

So my choices are, it allows -50mA +/-20mA or +/-4mA. Which is correct?

Also, the device has no Power Dissipation spec nor any Rth JA. Am I missing something or did they omit it by accident?

Thanks!

 

So my choices are, it allows -50mA +/-20mA or +/-4mA. Which is correct?

They are all "correct" within their definitions.
The 50mA and 20mA are absolute maximum ratings that should never be exceeded.
4mA is the maximum nominal current where it meets it's input and output logic voltage limits.

the device has no Power Dissipation spec nor any Rth JA. Am I missing something or did they omit it by accident?

The device is a very low power device, so normal operation will not require any calculation of the power dissipation.
How would you expect it to dissipate significant power?

If you use it in an application that will dissipate significant power, then you should use a device designed for higher power operation.

 

Thanks!

Could you also please explain what "Additional Supply Current" is for? Like, you have normal supply current, so why would you need additional supply current?

 

Could you also please explain what "Additional Supply Current" is for? Like, you have normal supply current, so why would you need additional supply current?

Not sure what that's from.
It is indeed a curious parameter.
You might have to contact the manufacturer for an answer to that.

 

Ah! I found the answer!

When the inputs transition between logic levels there is an excess current that is drawn due to the internal PNP and NPN transistors both being semi-on at the same time. This can damage the part if the logical input signal oscillates or is kept at an invalid logic state for too long.

The solution to this is to keep your transition times consistent with the datasheet specs, bearing in mind the input capacitance. You should also add pull-up/down resistors to the inputs if there is a chance that they will enter a floating state. Alternately, some TI parts have a built in pull-up/down stage that auto-transitions based on what the logic input voltage level is at thus allowing you to save power compared to using resistors which can prove useful, for example, in battery powered applications.