Power consumption of the nRF52832 (PCA10040 and custom board)

[jrg]

Hi,

We are troubleshooting high power consumption on a custom nRF52832 board. It has taken us down to just

1. Enable RTC,

2. Setup GPIOs,

3. With and without NRF_POWER->DCDCEN |= 1;

3. Go into a sleep loop (while(1) { __WFE(); __SEV(); __WFE(); }

Confirming the power consumption on a PCA10040 still keeps us in high 15 uA, with peaks up to 60 uA at ~40 Hz.

Also, not enabling the RTC and leaving all GPIOs in default states leaves us with these weird-looking spikes.

Running the same code on a custom nRF52811 leaves at a low 3-4 uA current consumption which is very expected.

We are testing with the current measurement probes on a DK10040, and are using SDK15.30 with armgcc.

int main(void)
{
	NRF_POWER->DCDCEN |= 1;
    while (1)
    {
        __WFE();
        __SEV();
        __WFE();
    }
}

Thanks

Johan

[Simonr]

Hi Johan

Do you see ~15uA on your custom board as well? How are the NFC pins configured now? As the product specification says, some increased leakage current between the two pins is to be expected if they are used in GPIO mode, and are driven to different logical values. To save power the two pins should always be set to the same logical value whenever entering one of the device power saving modes.

Can you try setting P0.09 and P0.10 back to NFC pins and see if the current consumption changes at all to confirm/dismiss this theory?

Best regards,

Simon

[jrg]

I will test again with the NFC-pins as configured to NFC pins and report back the current consumption.

For now they are both in the default setup - I believe this should be high impedance input so no current should flow between the pins.

Johan