Inductor Considerations for NRF 52832 DC/DC Converter

RE: Inductor Considerations for NRF 52832 DC/DC Converter

Håkon Alseth — Wed, 18 Jan 2023 09:31:34 GMT

Hi,

You're posting in a thread that is from 2015. You should follow our reference design.

Please create a new thread if you have questions.

Kind regards,

Håkon

RE: Inductor Considerations for NRF 52832 DC/DC Converter

Hossein Kasaei — Tue, 17 Jan 2023 19:34:58 GMT

Hi,

Should I choose the exact value 10uH and 15nH for these two inductors ? can't I use 10uH and 4.7nH?

RE: Inductor Considerations for NRF 52832 DC/DC Converter

YSR1991 — Sat, 28 Oct 2017 08:19:00 GMT

Hello, If nRF52832 is to be used for broadcast only, is it necessary to add 15nH inductor. Because it is required for Rx sensitivity performance and I m not going to receive anything. Please reply.. Regards Sharad

RE: Inductor Considerations for NRF 52832 DC/DC Converter

tomkawal — Thu, 13 Apr 2017 14:32:58 GMT

The 2nd question, as I see, was answered some time ago. https://devzone.nordicsemi.com/question/57305/nrf52-sensitivity-with-dcdc-enabled/ The answer is always 'it depends' on layout, components parasitic parameters and so on. I started using nRF52 just weeeks ago. For me, there's no point to test removing or changing the 15nH inductors until making anything ready for high volume production. Tomasz

RE: Inductor Considerations for NRF 52832 DC/DC Converter

FredrikK — Mon, 10 Apr 2017 16:28:28 GMT

I was not asking about the mechanism, I was asking about the quantitative difference in sensitivity if the 15 nH inductor is not mounted. The next question was whether the sensitivity when using DCDC is different than when running off the LDO.

RE: Inductor Considerations for NRF 52832 DC/DC Converter

tomkawal — Mon, 10 Apr 2017 14:31:13 GMT

How ignoring the inductor reduces sensitivity? My guess: 15nH has decent inductive reactance (over 200R) only at 2.45 GHz and above. It means it's placed for a reason - to reduce switching noise floor and help to receive weak signals. 10uH main inductor will become capacitive just beyond 10MHz!¬ I didn't find any ferrite offering me 10uH predictable inductance and low losses at 8MHz. 2 components are needed. On the other hand: many data lines ferrites may do much better filtering job than 15nH inductor.

RE: Inductor Considerations for NRF 52832 DC/DC Converter

FredrikK — Fri, 07 Apr 2017 16:27:22 GMT

How will not mounting the 15 nH inductor affect the sensitivity? And does using the DCDC, with recommended components, affect the sensitivity in any way?

RE: Inductor Considerations for NRF 52832 DC/DC Converter

Justas — Thu, 06 Apr 2017 21:00:20 GMT

What about using multilayer type instead of wirewound for the main 10 uH inductor? It can handle enough current, has low DCR and high SFR. Am I missing something?

RE: Inductor Considerations for NRF 52832 DC/DC Converter

tomkawal — Thu, 06 Apr 2017 13:10:31 GMT

I also think about using just one inductor - it can be ferrite, with approx 10 uH inductance and good Q at 8MHz of switching and losses rising well above that it should be OK. I'm not sure about performance at 2.4 GHz (any switching noise leaking may affect the receiver performance), as ferrites datasheets only sometimes extend beyond 1GHz. Regards Tomasz

RE: Inductor Considerations for NRF 52832 DC/DC Converter

Håkon Alseth — Fri, 06 Nov 2015 09:30:52 GMT

Hi,

The 10 uH is the main inductor for the DCDC buck regulator, and the smaller 15 nH is present to filter the signal. Both are required for optimal operation when using the DCDC.

If you open the nrf52832_qfaa_dcdc_schematic.pdf from our reference design .zip file, and click on the components, you will get a more detailed view of the components, with links to the datasheet etc:

Cheers, Håkon