BMI270: SPI current consumption

[peterl]

What is the expected current consumption when reading and writing via SPI to the BMI270?

We have noticed an increase in current consumption of roughly 1mA when reading sensor data from the BMI270 at a measurement rate of 50Hz. Is this expected?

Thank you very much.

[BSTRobin]

Hello peterl,

Current consumption depends on power mode, ODR, bandwidth, filter mode, noise mode.

For 1mA current consumption, which side you tested, MCU side or BMI270 side?

[peterl]

Thank you very much for your response. 

We tested the current consumption of the board, i.e. MCU (nRF52833) and BMI270 together. We were supprised to see the current consumption to increase by 1mA when we started reading the data acquired by the IMU. We were therefore wondering whether this is expected.

Looking at the datasheet of the MCU, the specified current consumption for the SPI reads/writes of the MCU seem to be much lower than the 1mA observed. 

Would you have any thoughts or estiamtes what the current consumption of the IMU is which is associated with the SPI data reads?

Thank you very much!

Peter

[Minhwan]

Hello peterl, 

Did you set low power mode for BMI270? 

Please check page 15 ~ 18 in our datasheet. 

bst-bmi270-ds000.pdf

I think you just run with performance mode. 

Thanks, 

[peterl]

Thank you very much for your quick response.

Our question centers around any additional power with the SPI interface.

We are running in lthe following mode 

sConfig.cfg.acc.odr = BMI2_ACC_ODR_25HZ;
sConfig.cfg.acc.range = BMI2_ACC_RANGE_2G;
sConfig.cfg.acc.bwp = BMI2_ACC_OSR4_AVG1;
sConfig.cfg.acc.filter_perf = BMI2_POWER_OPT_MODE;

The gyro and the AUX interface are in both in suspend mode.

When we are not communicating with the chip via SPI, the current consumption matches the datasheet. However, when we read sensor data from the chip using SPI the current consumption increases significantly. 

Is this expected? Is there any significant power consumption associated with reading the sensor data via SPI?

Thank you very much!

All the best

Peter