PMIC I2C 2 is floating (Bug #153)


Added by Matthijs van Duin about 2 years ago. Updated almost 2 years ago.


Status:New Start date:10/17/2015
Priority:Normal Due date:
Assignee:- % Done:

0%

Category:-
Target version:-

Description

According to the TPS659037 FAQ, if the secondary (AVS) i2c port of the pmic is unused, it should not be left floating but should be tied to the primary i2c or pulled up to VIO.

It is left floating in the x15 schematic, since R18/R19 are marked DNI.

Reference:
https://e2e.ti.com/support/applications/automotive/w/design_notes/3268.which-i2c-bus-should-be-used


History

Updated by Gerald Coley almost 2 years ago

Per the datasheet, it recommends that these pins be left floating if not used. It has been used this way for three years now. Not sure what the FAQ is all about. Will contact TI for an explanation on conflicting direction on the design implementation.

Updated by Gerald Coley almost 2 years ago

Here is the response from the TI product group:

Either is ok. In general, it’s best practice to pull up unused I2C, but it’s ok to leave floating as well. I’ve updated the E2E post to reflect that.
For future designs, we recommend to pull them up or connect to I2C1 if possible.

On the next revision, we will make those two resistors pullups and have them copulated.

This issue should be closed.

Also available in: Atom PDF