Where/How to find useful power/current consumption documentation?

RE: Where/How to find useful power/current consumption documentation?

Stian Røed Hafskjold — Thu, 14 Mar 2019 14:22:26 GMT

Sorry for not answering you, but yes, it is enough to just stop the peripheral to save power.

RE: Where/How to find useful power/current consumption documentation?

Andy — Thu, 14 Feb 2019 09:54:45 GMT

Hi Stian, thanks for your reply! I have a question regarding the "activity" you mentioned. In the case of the PWM peripheral for example: From what you say I understand that it's enough to just stop the peripheral (nrfx_pwm_stop()) and I don't need to deinitialize it (nrfx_pwm_uninit()) in order to save power?

RE: Where/How to find useful power/current consumption documentation?

Stian Røed Hafskjold — Wed, 13 Feb 2019 21:29:00 GMT

When I say "peripherals are active" I mean during the actual transaction. Just enabling the peripheral does not start the HF clock and DMA

RE: Where/How to find useful power/current consumption documentation?

Stian Røed Hafskjold — Wed, 13 Feb 2019 21:27:38 GMT

Hi, unfortunately the peripheral currents are not fully documented in the product specification because there are too many factors involved.

In general the HF clock needs to be started and the DMA bus needs to be running when the peripherals are active. These two combined is about 1.2mA or 2mA for DCDC enabled or disabled respectively. For peripherals without DMA, the current depends on how much the CPU is working during the transactions.

RE: Where/How to find useful power/current consumption documentation?

Andy — Wed, 13 Feb 2019 15:40:30 GMT

Hi Frankie,

Thanks for the link to the power profiler! I didn't know it. I know where to find the product specifications, but as I said I'm failing to find useful information there. I already checked those power chapters with no luck.

RE: Where/How to find useful power/current consumption documentation?

frankie_pham — Tue, 12 Feb 2019 18:04:15 GMT

hi Andy,

About Nordic's document, you can find all here.

Your question about power current consumption, I found that in Nordic there is a keyword "power profile". There is a online power profiler here. I see that this power profiler only supports for radio power.

in my opinion, power consumption of a particular peripheral depends on many factors. Your GPIO output pin drives 1KOhm resistor is different from driving 500Ohm resistor about current consumption! So, it's hard to make sure that how much power a peripheral uses. 2 chapters in Product Specification are "power and clock management" and "power" may help you.

Best Regards!

Frankie