SPI vs I2C power consumption differences on Steval-mki176v1 LSM6DS3H,

[Roumen K]

For a certain app that acquires at 1hz temperature and accelerometer data, I measure that SPI consumes 2.2% more power than I2C. How do I make SPI perform better as it is supposed to. My settings are 104Hz conversion, 4 lines SPI at 1mbps (781 kbps actual) or 2 line I2C (400 kbps) , +/-8g, 1 hz acquisition, 1.75V supply, 12kOhm SDA/SCL pullup for I2C.

[Eleon BORLINI]

Hi @Roumen K​ , if I well understood the issue... I think that if SPI is running at higher frequency than I2C (1Mbps instead of the 400kbps), it will naturally increase the device power consumption... you can try to decrease the SPI frequency, especially if you are running at ODR 104Hz and you app acquires at 1Hz. You can also decrease the ODR of the sensor to reduce power consumption. Regards

[Roumen K]

When I convert SPI to run at actual 400kbps, the current consumption drops to 8.3% below I2C. The noise floor lowers 14%. 

[Eleon BORLINI]

​And is this OK for you and your application? I2C will consume more especially if you are measuring the current consumption on Vdd and Vdd is tied together to VddIO, you will have part of the current flowing through pull-up resistors during the I2C clock and data transitions, resulting in a higher current consumption in the I2C case then in the SPI case, at the same frequency condition. Regards