BMA456 CBS Pin issue

[mgchoi]

 Hi,BOSCH

I am sending you an email because I have an inquiry while using BMA456 in the I2C method.

Questions

Define the status of the CSB pin when using BMA456 in I2C mode

Marked differently depending on the version of the published datasheet.

Document version of the BMA456 datasheet

It says….CSB is VDDIO.

However, it was provided earlier

Document says….CSB is Float or VDDIO.

All existing BMA253 products are CSB Float.

When using BMA456, which uses the latest wafer, there is no problem if you float against the CSB pin setting...
(If CSB is changed to VDDIO, the existing product needs to change PCB. -> There was no problem with the recent test (CSB Float)

I would like to ask if there is a problem with checking the function.

Pre-review history states that changes have occurred in 6.2.

Thanks

[BSTRobin · Accepted solution]

Hi mgchoi,

After internal check, CSB pin has a weak pull-up resistor. In order to ensure the stability of protocol selection when using I2C, BMA456 data sheet recommends connecting the CSB to VDDIO since 2019.

For BMA253, PS pin is the rithgt pin for protocol selection. When using I2C for communitation, CSB pin was not used, so it could be floating.

[mgchoi]

Thank you for your answer!!

[BSTRobin]

Welcome, mgchoi.