Rigado BMD-340 - NRF52840 sleep current

[VECA_LV]

Hi,

I'm trying to get my NRF52840 to minimum current in sleep, but got stuck around 440 uA. Reading through the various posts about sleep current for this type of device, the sleep current should be around 120 uA, which is 4x lower than what I obtain.

I already tried to turn of modules in the config file, without result.

Is there something I can change in the config file in order to go to a lower current?

The main loop just has

__WFE();
NRF_POWER->SYSTEMOFF = 1;

Here my config file:

sdk_config.h

[Turbo J]

The UART is enabled as NRF_LOG backand, and this triggers the HF clock being permanently turned ON. If you don't need UART logging, you can safely turn the UART support off.

[VECA_LV]

I turned off logging, without effects on the current drawn. 

[VECA_LV]

Second question: when the NRF52 is running in sleep, I get around 1.3mA of current drawn. Disabling SAADC lowers this value to 1.1 mA. Disbaling all UARTS, you would expect the device to drop the power consumption significantly. We only get it down to 950uA. We disbaled in the above sdk_config all NRF_LOG entries and disabled al UART channels. Any idea how to debug this further? Any inputs welcome...

[Simonr]

Hi

Please add a loop after calling SYSTEM OFF. Something like this should do the trick.

int main(void)
{
NRF_POWER->SYSTEMOFF = 1;

for(;;){__WFE();}
}

Best regards,

Simon

[VECA_LV]

In our application, we are running Openthread. Disabling the Openthread messaging, the current consumption drops from 1mA to a value around 500uA. Reading through this link, there have been issues on low power consumption with Openthread in the past, but should be solved with the newer openthread libraries. What we see is 1 mA of current consumption when openthread is enabled. Disabling drops this to 500uA. The libraries we are using is one of the latest (3.0.0). Unless there have been more issues related to Openthread and low power sleep current? Any input welcome