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Graduate
November 12, 2025
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STM32F405RGT6 custom board review

  • November 12, 2025
  • 2 replies
  • 393 views

Hello everyone, this is my first post on the forum. I'm starting to learn STM and have created a custom board using the STM32F405RGT6. This is the first board I've created, and I wanted to check for any errors before sending it to production. So I've uploaded a PDF of the connection diagram. I'd be very grateful if you could review it and let me know if there are any mistakes.

    This topic has been closed for replies.
    Best answer by mƎALLEm

    Hello,

    Need to re-check this part of LSE:

    mALLEm_0-1763034793828.png

    Did you check if the crystal is compatible with the STM32? did you calculate the gain margin based on the crystal characteristics and the load capacitors?

    Read How to select a compatible crystal and load capacitors for STM32 with layout guidelines

    18pf CL looks a bit high compared to the CL recommended for LSE for STM32 in the AN2867

    mALLEm_0-1763035265288.png

    2 replies

    Super User
    November 12, 2025

    Welcome to the forum.

    Please see How to write your question to maximize your chances to find a solution for best results.

     


    @ekremtrn wrote:

     I'm starting to learn STM .


    Do you have experience with any other microcontroller(s) ?

    Before leaping into a custom hardware design, I would strongly recommend that you prototype & gain experience on a development board - far cheaper & easier to find & fix issues than on a custom design!

     

    Did you study Application note AN5093Getting started with STM32G4 Series hardware development boards?

     

    I don't see any programming/debug connector ?

    Have you considered how you will program, debug & test your design ?

    See Design For Debug ...

     

    PS:

    It would also help to give details on the intended application of this board, and what environment it will operate in - these will affect the design

    Super User
    November 12, 2025

    Looks okay except:

    How do you plan to program/debug without a programming header?

    ekremtrnAuthor
    Graduate
    November 13, 2025

    Thank you. I intentionally did not add a programming header because I wanted to design a small card. I plan to program it by removing the RTX and CTX from the 10-pin header and connecting it to the USB-A header with an external cable.

    mƎALLEmAnswer
    Technical Moderator
    November 13, 2025

    Hello,

    Need to re-check this part of LSE:

    mALLEm_0-1763034793828.png

    Did you check if the crystal is compatible with the STM32? did you calculate the gain margin based on the crystal characteristics and the load capacitors?

    Read How to select a compatible crystal and load capacitors for STM32 with layout guidelines

    18pf CL looks a bit high compared to the CL recommended for LSE for STM32 in the AN2867

    mALLEm_0-1763035265288.png