NRF_POWER->DCDCEN does not reduce power?

[nordicdev]

DCDC_testing.zip Hi, I am in the process of reducing power consumption in micro esb mode. I use the following code, just for testing. The following code consumes 18mA unlike specified in the spec(www.nordicsemi.com/.../nRF51822. I feel 18mA is way higher than the spec, sorry about that. There is no effect whether I turn the DCDC on or not. Code:(I checked in the debug mode: peripheral register for NRF_POWER did have the DCDCEN set to 1)

int main(void)

{

	NRF_POWER->DCDCEN = 1;

	NRF_RADIO->TASKS_RXEN  = 1;

	NRF_RADIO->TASKS_START = 1;

	while(1);

}

The current consumption of the above is 18mA. Current consumption of below is 18mA(no effect after commenting out DCDCEN.)

int main(void)

{

	//NRF_POWER->DCDCEN = 1;

	NRF_RADIO->TASKS_RXEN  = 1;

	NRF_RADIO->TASKS_START = 1;

	while(1);

}

Basically, I tried to follow the example given in: devzone.nordicsemi.com/.../ and devzone.nordicsemi.com/.../ but no luck with reducing power yet.

[Øyvind Karlsen]

What measurment equipment are you using to measure this?

Is this on the Development Kit?

[nordicdev]

Hi Oyvind, thanks for the reply. I measured using the oscilloscope and also confirmed this by noting down the current drawn in the power supply.

[nordicdev]

I am using nrf51822, sdk 10.0, s130 Radio RX only mode

[Øyvind Karlsen]

Hi,

Using the nRF52 Development kit pca10040 I have measured this just now.

• RXEN no DC/DC 14.54 mA
• RXEN with DC/DC 9.16 mA
• TXEN no DC/DC 15.57 mA
• TXEN with DC/DC 9.56 mA

On the nRF51 Development kit pca10028:

• RXEN no DC/DC 17.62 mA
• RXEN with DC/DC 14.83 mA
• TXEN no DC/DC 14.78 mA
• TXEN with DC/DC 12.58 mA

What board are you using? Is it configured in DC/DC mode?

Here is the code I used.

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

    //NRF_RADIO->TASKS_TXEN = 1;
    NRF_RADIO->TASKS_RXEN = 1;

    NRF_RADIO->TASKS_START = 1;

    while(1);
}

Note that this was measured using a cheap UT61D multimeter, so apply suitable tolerances to the measurements.

The hardware must be in DC/DC config to be able to use the DC/DC.

Best regards,

Øyvind

[nordicdev]

Hi Oyvind, thanks for your reply. I am using our custom board which uses N51822 QFAAHO 15301T. I have attached the proj I am using(DCDC_Testing.zip). With DCDCEN in the software current consumption is 17.4mA. Without DCDCEN in the software, it is 17mA. The hardware in my custom board doesn't have anything connected to DCC pin. I will configure the hardware to be in DC/DC mode and check. Thanks.