RE: nRF52840 Reference Design

GriffinNiles — Wed, 10 Dec 2025 05:23:41 GMT

Egy jól dokumentált referencia-terv sok időt spórol, akárcsak a legális magyar online kaszinók esetében az átlátható működés. A megbízhatóság minden technikai projekt alapja.

RE: nRF52840 Reference Design

mavenboard — Fri, 05 Dec 2025 20:50:26 GMT

Wow, thanks for the detailed answer. I will follow the design ref. 3, and skip C9. Thank you yet again.

RE: nRF52840 Reference Design

Asbjørn — Fri, 05 Dec 2025 12:29:48 GMT

Hello,

Q1: There are seven configurations given in the reference design to show combinations possible with regard to power supply and setup. You want to start on configuration #3 probably. It has USB and a single voltage supply on VDD otherwise. You can combine as you think is useful for you. There's a little table for every configuration showing what is available and what is not:

https://docs.nordicsemi.com/bundle/ps_nrf52840/page/ref_circuitry.html#ariaid-title4

The RF match from the ANT pin to the antenna is the same for each variant of the package. So there's a component selection and layout for aQFN, WLCSP and for the QFN package, but all seven configuration using the aQFN will have the same component selection and layout from ANT in to the 50Ohm point. With the antenna we recommend following the guides from the antenna manufacturer, but most of the time we see customers adding a pi network of tuning components after the C22 in this example:

This screen shot is from the aQFN73-QIAA package variant. After C22 we recommend components for tuning the antenna input impedance to 50Ohm. See the antenna section here: https://devzone.nordicsemi.com/guides/hardware-design-test-and-measuring/b/nrf5x/posts/general-pcb-design-guidelines-for-nrf52-series

Q2: You can skip the C9 as long as you ensure that the nRF52840 components you are buying is from version F or later. Version F was started in 2021, so unless you have old stock on inventory you are buying from, it's not a problem. You should specify with HW revision you want from the source and then the C9 component can be skipped.

Best regards

Asbjørn