BHI360 VDD and VDDIO

[tizfreestyle]

I was reading the Datasheet of BHI360 link at Table 111, and realized that the VDD domain is up to 3.6V whereas the VDDIO only up to 1.89V.

I actually was expecting it to be the opposite, as e.g. for BMM350, which is useful as I would need the IO to work at 3.3V.

Can someone from Bosch confirm the BHI360 VDDIO is seriously limited to 1.89V and that VDD and VDDIO have not been mixed up in the datasheet please.

[BSTRobin]

Hi tizfreestyle,

It is recommended to use 1.8V to power the VDD and VDDIO of BHI360 and BMM350. Of course, the host MCU also needs to use 1.8V power supply.

We do not recommend using a power supply that exceeds the maximum voltage specified in data sheet for VDD and VDDIO. If the host MCU must use 3.3V power supply, then you need to add a bidirectional voltage conversion chip between the host MCU GPIO and the IO of BHI360 and BMM350 to prevent chip damage due to level mismatch.

[MartinXBcn]

Hello,

(VDD and) VDDIO max. 1.8V is clear.

But the data sheet does not say anything about a max. voltage for IO-input:
18.3 Electrical Characteristic Table
Voltage Input High Level VIH: "Max" is empty - my understanding is that BHI360 can be connected to 3.3V-I2C-bus.
Please confirm.

My Problem is if a "3.3V-host" - in my case an ESP32 - reads correctly the Voltage Output High Level VOAH of min. 0.8VDDIO = 0.8 x 1.8V = 1.44V whereas the ESP32 has a min. VIH of 75% VDD = 0.75 x 3.3V = 2.475V.
Anybody has experience if this works with an ESP32?

[TomTake]

Hello,
BMP388 is used in the prototype. A problem occurred where the sensor could not be read.
NG - 15pcs /using - 300pcs
I would like to analyze the sensor, but since I purchased the sensor in stock, I cannot request analysis from the agency. Is there any good way to analyze the sensor status? Analysis is for BMP388 single item.
The parts have been removed from the board. I want to know what is wrong with the sensor.

[BSTRobin]

Hi MartinXBcn,

You can see from BHI360 data sheet that VDD supplies power to the analog domain. VDD supplies power to the digital domain and includes IO. IO cannot communicate with 3.3V.