Schematic Review Request For Custom STM32MP13X PCB

[pegvin]

Greetings,

I have finished the schematics of my custom STM32MP13X based PCB, My aim with this PCB is to learn high speed digital circuit design & how the board bring up is done & various other things like loading RAM's timing information from an EEPROM to initialize RAM, etc.

I would appreciate if my schematics could be reviewed & any potential issues could be pointed out before I start my PCB design (or worse, produce the PCBs) because I’m a student who’s funding this project from my part time job & I really don’t want to make an expensive mistake.

The schematics are majorly based on STM32MP135-DK's reference schematics (MB1635) & I have attached the schematics (PDF) along with BoM file for package size information, etc.

I would also like to mention that the schematics have been designed to keep costs low, This is also why most of the components will be sourced via LCSC & This is also why there’s no eMMC on-board. I also omitted the termination resistors on DDR because in the “DDR memory routing guidelines for STM32MP13x product lines” (AN5692) document, It was mentioned that I can omit them if the DDR chip is very close to the MPU, which it will be. Although I don’t mind adding it if need be.

Thanks for your time.

Warm Regards,
Aditya M.

 

Edit: The “+3V3” entry in “Expected voltages at nodes/labels” note in “/Power Supply/” (Page 3) can be ignored because it was replaced with “3V3_AO” but I forgot to remove it from the note.

 

Schematic PDF Preview:

 

BoM Preview:

 

[pegvin]

Actually in an effort to save costs in PCB (i.e. keeping it to 4 layers only), I removed Ethernet because it made routing more complicated, whilst my aim with this project currently is to have a STM32MP1 based board up & running. Networking isn’t an priority right now.

So you can ignore the Ethernet part or review the updated schematics instead that I’ve attached below. Thank you <3

[PatrickF]

Hi ​@pegvin 

STMicroelectronics is devoted to provide as best support as possible, but customer design review is not part of main scope of a public community.

We anyway do such deep expertise support for few key-customer accounts (read 'large enough potential sales') identified by regions, mostly when they face issues during their bring-up or pre-production (as usually they have sufficient in-house expertise for usual design phases).

You could understand we did not have bandwidth to yearly check thousands of STM32 designs of all our customers.

Customer which does not have enough expertise or does not feel confident with MPU design are usually subcontracting it or uses 3rd party products (SOM or similar). Distributors could also give support.

You could contact your ST local sales to check further what kind of direct support could be possible in your case, regarding business opportunity.

https://www.st.com/content/st_com/en/contact-us.html

https://ols.st.com/s/

 

Otherwise, you could wait if there is community members looking to your post and willing to help you on schematics review.

 

Regards.

[pegvin]

Hi,

That is completely understandable.

Best Regards,
Aditya M.