nRF52832 DK sleep mode current consumption too high

[James168]

NCS v2.8.0

nRF52832 DK & nRF52840 DK

peripheral_uart unmodified example

nRF52832 DK with peripheral_uart example has about 1.3 mA current when LED off and sleep mode, but nRF52840 DK with peripheral_uart example just about 600 uA.

How to reduce the nRF52832 DK current consumption to approach the "Online Power Profiler for BLE" value on the web.

[Simonr]

Hi

So, I talked about this with a colleague, and the reason for the difference between the nRF52832 and the nRF52840 DKs is mainly because there was some improvements to active current made on the nRF52840 DK. In nRF52832 DK, the RX UART will both have the HF clock and DMA bus running. 

However, it seems like you are measuring the current consumption of the entire DK here, and not just on the nRF52 SoCs, since we're also seeing the LEDs in the current measurements here.

We recommend that you start out with the device in system OFF mode so we can confirm that the setup is correct on your end. We have the system OFF sample project available here for reference.

Best regards,

Simon

[James168]

Hi,

1) I measured the current with system_off sample,

nRF52832 DK

average current is about 322uA

nRF52840 DK, sw6 in DEFAULT

average about 1.9mA

nRF52840DK, sw6 in nRF ONLY

average current about 5.2uA

2) The setup environment is power monitor connected to the External supply pins of the DKs with 3.0V power, 

and I don't have the PPK2 to compare.

3) I do some tests these days, disable the UART can reduce the current consumption, but I need to have both the NUS service AND low power mode.