Regulator and Ferrite Bead Components for SGTL5000 Design

grinch

Well-known member
Hi, I am incorporating an SGTL5000 codec into a larger PCB design. I'm basing my schematic and layout on the SGTL5000 breakout board: https://www.pjrc.com/store/teensy3_audio.html

I wanted to share my schematic to confirm I got the design correct and also ask for advice on selecting 2 components.

For the digital power supply regulator, the shared schematic specifies AP7313, but this is a family of several parts at different voltage levels. I selected the AP7313-18SAG-7 with 1.8V output, is this what I should be using?

What parameters should I be searching to find the right ferrite bead component? These are always quite vaguely described when I see them schematics and have a bunch of different parameters so it's hard to tell what is relevant and what will work for a given application. Is there a specific ferrite bead component I should use or a specific set of parameters the component I select should match?

Lastly, does the rest of my schematic look okay? TYIA!

Screenshot 2025-02-20 at 8.50.46 AM.png
 
Yes, 1,8V is fine for that regulator. There exist different packages with different pin assignments. V_DDD has to be between 1.1 and 2.0V according to the datasheet.

As far as I see everything looks correct.

The 100k resistors at the line in an out are not on the audio board - you probably are aware of that and have a reason to add it.

I have worked on a PCB design where I had choosen the following ferrite bead, but I don't remember the details and I cannot guarantee that this is the same as on the board. I remember that from my research this one looked to be closely enough to the used one.
 
100k are to stop thumps with plugging in, i.e. draining the capacitor charge. Its always good design practice in audio to stop such thumps as they can break loudspeakers in the worse scenario! I2C pullups are usually 4k7 or 10k unless the device supports faster than 400kHz bus.
 
100k are to stop thumps with plugging in, i.e. draining the capacitor charge. Its always good design practice in audio to stop such thumps as they can break loudspeakers in the worse scenario! I2C pullups are usually 4k7 or 10k unless the device supports faster than 400kHz bus.

Yah this is why! I've always been confused as to why so many of these open source audio designs leave out the ground reference 🤔
 
I have worked on a PCB design where I had chosen the following ferrite bead, but I don't remember the details and I cannot guarantee that this is the same as on the board. I remember that from my research this one looked to be closely enough to the used one.

Ty for component rec, this is very helpful!

So for Ferrite bead the 600 refers to 600 ohm at 100MHz?
 
Last edited:
Back
Top