SPI power consumption + nrf9160 + BMA400

[Marcin]

Hello,

On my custom board based on nrf9160, I'm using the BMA400 accelerometer sensor.

I'm trying to get as low consumption on sleep mode as possible. 

While I have SPI_3 configured as a protocol to communicate with the Accel, I cannot get better results than 290uA.

Without initializing the SPI_3, I have around 10-20uA (as documentation).

Is there a way to decrease the power consumption of the SPI interface or put it into sleep mode as well while it's not transmitting anything on the lines? 

Thank you for your help!

[Stian Røed Hafskjold]

Is it possible that the SPI lines are powering the external accelerometer? What is the current consumption if you enable SPI and do not connect anything on the pins? Do you have any pull resistors on the lines? The nRF91 should go back to normal idle current after the transaction is finished.