nrf54h20 usb D+ and D- routing

RE: nrf54h20 usb D+ and D- routing

ketiljo — Thu, 04 Sep 2025 14:01:39 GMT

Ordinary FR4 is fine for most designs as traces and transmission lines are normally very short.

RE: nrf54h20 usb D+ and D- routing

Samno — Tue, 02 Sep 2025 15:57:52 GMT

Interesting I have never seen polypropylene used as prepreg before. So an RF substrate was not necessary for the 2.4 GHz radio?

RE: nrf54h20 usb D+ and D- routing

ketiljo — Fri, 29 Aug 2025 13:40:41 GMT

PP is polypropylene and the core is FR4, I don't have more information than that.

RE: nrf54h20 usb D+ and D- routing

Samno — Wed, 27 Aug 2025 15:31:40 GMT

Thanks do you have the actual materials used for PP-010 and Core-042 so I can see if my pcb manufacturer can get them?

RE: nrf54h20 usb D+ and D- routing

ketiljo — Wed, 27 Aug 2025 14:05:54 GMT

Here's the full stackup for the DK PCB:

RE: nrf54h20 usb D+ and D- routing

Samno — Wed, 27 Aug 2025 13:50:52 GMT

Ah I see I thought the grey wider circle was also part of the via. Have you published the layer stackup for the H20 DK so we can see what materials and thicknesses were used?

RE: nrf54h20 usb D+ and D- routing

ketiljo — Wed, 27 Aug 2025 13:43:27 GMT

RE: nrf54h20 usb D+ and D- routing

Samno — Wed, 27 Aug 2025 13:31:58 GMT

Even in your original image what is the clearance from the track to the via? 0.03mm? This is not realistic.

RE: nrf54h20 usb D+ and D- routing

ketiljo — Wed, 27 Aug 2025 13:30:15 GMT

True. So either use a different stackup or use vias. 10 mil prepreg is a lot.

RE: nrf54h20 usb D+ and D- routing

Samno — Wed, 27 Aug 2025 13:26:39 GMT

Which cannot be routed on the same layer correct? I will have to do it on an inner layer with vias. It seems the pin layout for this chip was not well thought out.

RE: nrf54h20 usb D+ and D- routing

ketiljo — Wed, 27 Aug 2025 07:40:27 GMT

The nRF54H20-DK uses PCB laminate with 0.084mm prepreg (3.3 mil). Width a thicker prepreg you have to use wider tracks.

RE: nrf54h20 usb D+ and D- routing

Samno — Tue, 26 Aug 2025 14:10:07 GMT

How are you achieving the 90 ohm impedance matching with such thin traces? I have 3 mils track to track spacing and 10 mils dielectric thickness with RF dielectric (3.48 Dk) and 1 oz copper and it's still telling me track thickness should be around 16 mils

RE: nrf54h20 usb D+ and D- routing

ketiljo — Tue, 26 Aug 2025 12:02:35 GMT

Like so:

Else, follow general USB high speed design rules, like equal track length on D+ and D-, impedance control etc.