I2C bus pull-up resistor sizing, is 3mA min or max ?_?

[ANTALIFE]

Hey All

For you I2C gurus out there, can you tell me if the bus pull-up resistor (Rp) should be chosen such that the sink current is >3mA or <3mA for Standard-mode?

If I dig through the NXP golden document "NXP - I²C bus specification and user manual.pdf" on I2C use it says that you need to have a sink current of at least 3mA to be within spec for Standard-mode. But then if I look at say the datasheet for TMP1075 then I am told not to exceed 3mA

[ataradov]

At a minimum device should be able to sink 3 mA to meet the spec requirements, it may do more.

With this guaranteed number, when selecting the resistors your best bet is to be at or below 3 mA. This will give you the best compatibility with an abstract worst case scenario device. Most real devices are much more capable, of course.

[Siwastaja]

I think you have a perspective issue.

"You have to sink at least 3mA", "you" refers to the chip designer. So their I2C compatible device needs to sink at least 3mA while respecting the voltage specs.

Hope this helps make sense.