nRF52832 higher current consumption then nRF52840

[Elisa]

Hi all,

we developed a BLE/peripheral project starting from Nordic NUS example on both devices nRF52840 and nRF52832 and we added the following features:

- LESC security and bonding managing (with HW cryptography on 840  and with SW cryptography on 832)

- DIS service

- periodic ADC reading to support the  BAS

-internal FLASH management using FDS library (only at init)

- UART always enabled

and we remove 

- buttons and LEDs handling

We found a background consumption of around 900uA for nRF52840 vs 2,3mA for nRF52832. Is it correct? there is something we can do to reduce the power consumption of nRF52832 up to the one of nRF52840?

Regards

[Simonr]

Hi

This does not sound right, the nRF52832 should be slightly lower, if anything, in terms of current consumption compared to the nRF52840. Are you positive that all the same peripherals are kept running on both devices? Do you have a PPK or some other way to measure the current consumption graphically so we might get some information of the current consumption graph? 

You can also check out this current consumption guide for some of the most common ways to reduce current consumption. I know the guide is for the nRF51, but it is still relevant for the nRF52 series.

Best regards,

Simon

[Elisa]

Hi Simon, 

thanks for your quick reply. 

I attached the PPK graph of both devices.

Yes, we are quite positive that fw for the 2 devices has the same peripherals running.

We thought the bacground consumption depended mostly by the UART enabled. But could be different in the 2 devices?

[Simonr]

Are you seeing these different current consumption levels on development kits or are you testing on custom boards? If the latter is the case, I think I need some details on your hw configurations. Does, for example, one of the devices use the internal LFRC oscillator while the other one have an external crystal oscillator? Would it be possible to share the schematics of these custom boards? I can set this case to private mode if you'd like, so that only yourself and Nordic engineers will be able to see this case.

Best regards,

Simon