DCDC - Which peripherals use it other than BLE?

[snoopy20]

Couldn't find it documented anywhere.

[Håkon Alseth]

Hi,

 

The system will use DCDC when it is effective to use it, and automatically switch between LDO operation and DCDC, as described in the POWER chapter of the datasheet:

https://docs.nordicsemi.com/bundle/ps_nrf52810/page/power.html

 

CPU will use DCDC for instance:

https://docs.nordicsemi.com/bundle/ps_nrf52810/page/_tmp/gluon/autodita/CURRENT/parameters.id_current_cpu.html

 

Kind regards,

Håkon

[snoopy20]

In my case ADC performance worsens when DCDC is enabled, but I'm unsure if it's because DCDC is starting/stopping and the noise from it. I thought I could optimise by forcing DCDC on all the time (using previously supplied code) when I know which peripherals are active and using it.

[snoopy20]

Looked everywhere and can't find it, could I ask for the code which forces DCDC on all the time?

[Håkon Alseth]

Hi,

 

The DCDC is controlled via hardware. Once enabled in its NRF_POWER->DCDCEN register, the hardware will control the different power states based on consumption.

Here's the place where its set in NCS:

https://github.com/nrfconnect/sdk-zephyr/blob/v4.0.99-ncs1/soc/nordic/nrf52/soc.c#L37

 

Here's how to set up DCDC in device tree:

&reg {
	regulator-initial-mode = <NRF5X_REG_MODE_DCDC>;
};

And LDO:

&reg {
	regulator-initial-mode = <NRF5X_REG_MODE_LDO>;
};

 

PS: You can set the register on/off at runtime if desired.

 

Kind regards,

Håkon