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BNO055 High current draw at suspend mode ~180uA

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TrickyNekro:
Hello to everyone and happy new year!

I´ve made a design with Bosch´s BNO055 for a handheld device, unfortunately as the title suggests I get a horrifically high current draw when in suspend mode.

The design is textbook, same as the one suggested by Bosch in their datasheet.

PS0 = 0V, PS1 = 0V, ADD = 0V, bootloader inditor pin shunted at 0V (as indicated by datasheet, but later found out it is wrong, on their forums)

I know the add pin has a weak pull-up, I removed the address pin to ground, no change (address changed normally so I would guess it´s not my soldering)
I also dug out the bootloader pin, again no change.

In between I changed also boards and IMUs to be sure that either is shot by a bad connection. Still the same...  |O

I also changed the suggested internal regulator value from 100n to 1u as indicated, still no luck.

I am at a loss as of what might be the problem. The suggested current consumption when in suspend mode is 40uA, having 3 times as much is a bit unacceptable,
as it brings the battery life from 5 - 6 months to barely 1.5 months at stand-by. (the rest of the board consumes 9 - 10uA when in suspend mode).

I am currently starting to suspect a batch problem as many other people have reported same issues on Bosch´s forums:
https://community.bosch-sensortec.com/t5/MEMS-sensors-forum/High-current-consumption-of-BNO055/td-p/8364

Still, If anyone has any idea on probable causes of the problem, it would be quite helpful!

Thanks a lot in advance!
Lefteris

mikerj:
Is your micro powered from the same rail that is connected to Vddio?  I2C pull-ups connected to the same rail?

TrickyNekro:

--- Quote from: mikerj on January 03, 2020, 12:18:24 pm ---Is your micro powered from the same rail that is connected to Vddio?  I2C pull-ups connected to the same rail?

--- End quote ---

Yup all same 3.3V rail, that was the point to begin with, no extra regulators or switches.

Edit: Everything connects to a power plane (6 layer PCB), I had a "no buried / blind vias" rule to keep the cost down, but that made the board look like Swiss cheese, leaving little room for extras,
or else I would have just powered the device from a single gate / buffer. Getting the BNO055 to work on the board was like a secondary mission, so I just followed the text-book design, expecting
everything to work, even the low power part. Since it´s such a highly integrated SoC, as soon as I was getting orientation data out of the damn thing, I gave it green light.

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