nRF52833 - SAADC driver power consumption

[Katie Newell]

Hi Nordic team, 

I noticed that SAADC driver is consuming most of the power in Sleep state. In my application, the processor is in SYSTEM OFF state for 80% of the time (runs only for 4h over a 24h period). However, it's draining all the battery during in about 18hours. While investigating, I found that the SAADC is consuming the most. I am using this driver to read the battery voltage which my application and sends over BLE. 

What do you recommend to reduce the power consumption? Do I need to disable the driver before entering SYSTEM OFF?

Many thanks for your help

Kind regards

[Simonr]

Hi

What battery is this you're using, and what does the application do once awake? Have you measured that it is the SAADC peripheral drawing most of the current?

Also, how exactly do you go into System OFF mode in your application? It is recommended to do something like the sleep_mode_enter() function does in our ble examples, where the device is prepared for sleep to make sure that no peripherals are left running. If you're not using a SoftDevice in your application, it might be better to check out the pwr_mgmt example that shows off the most common ways of putting an nRF52 in various sleep modes.

Best regards,

Simon