Electronic – If a datasheet doesn’t state I2C address pins have pull-up/down resistors, does that mean I must connect them

i2c

I've got a handful of DS75S+ temperature sensors. They're SO-8 and I'm going to solder them onto prototyping boards for use with a Raspberry Pi.

I want to set the addresses sequentially so I have the option of using as many as I like on one Pi (up to 8, but I only have 5). The datasheet says nothing about internal pull-up/down resistors on the address inputs, so does this mean they're floating? Tying them high is trivial, tying them low might be a little messy. But I don't want to set it floating only to find later that I've caused a problem (especially as, once tested, I'll probably pot them in epoxy).

The "Detailed pin description" says "7 A0 Address input pin." etc., there's no typical circuit and the block diagram has nothing of any help.


I've seen how do you typically tie the address pins and WP pin of I2C device? Do these lines need a pull-up/down resistor or just tied directly (closed) which has a helpful answer that unfortunately starts "Completely dependent on the specific IC you are using, and would be listed in the data sheet. " which isn't true here

Best Answer

I had a quick check of the datasheet (No I did not read the complete sheet but looked at every instance of the text 'address').
The data sheet does not mention anything like pull-ups/downs or defaults thus you must assume the worst case: you have to tie each pin either high or low.