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Gabor , 06-30-2025, 07:58 PM

Hi everyone,
I’m a beginner and I’ve started building a streamer using a TDA1541 DAC chip together with a Raspberry Pi.

I’d like to ask for advice regarding the PCB ground plane design. I’ve read so many different opinions – from star grounding to using a full ground plane – that I’m feeling completely uncertain about which approach to choose.

I’ve made a small diagram to show roughly how the streamer is set up. According to the TDA1541 datasheet, the analog and digital grounds of the chip need to be connected together, but I’d like to confirm the best way to do this.

My other big question is about the power transformers: I have three transformers in total, two of which are center-tapped (dual secondary) and one that is a simple single secondary transformer. In this case, what is the proper way to handle grounding and connections?

Thank you very much in advance for your help!

Best regards,
Gábor

⸻

QDrives , 06-30-2025, 08:15 PM

So far the best Gnd solution is a single Gnd.
The trick is seperation - so keep the analog part at a distance from the power and digital sections.

Gabor , 07-01-2025, 05:58 AM

Thanks for the explanation!
So it’s okay to have a continuous GND layer, but I just need to keep enough spacing between the analog and digital components, right?
How much distance should I leave between them?
Can the Raspberry Pi’s ground be connected to the other grounds as well?

QDrives , 07-01-2025, 01:30 PM

Since your ADC is connected to both digital and analog section, you cannot have more distance than that device allows.
The distance also depends on your layer stack-up.
And yes, the Pi can connect to the same Gnd. Especially if the layout is like you drawn: analog -> ADC -> Pi.

Gabor , 07-01-2025, 05:33 PM

It will be two layers.

On the bottom layer there will be the GND, and on the top the rest. Is it a problem if I sometimes route one or two traces to the GND layer? It might not be physically possible to connect everything on the top side.

QDrives , 07-01-2025, 09:59 PM

As for the distance: https://www.youtube.com/watch?v=9lEtkysFGGg
As for traces on you Gnd layer: as long as you add Gnd traces on the top too jumping the gap.