STM32F103C8 production board schematic

lk.dgironi · ‎2022-01-14

I'm working on a board design with a STM32F103C8. First time for me to build a PCB with STM32, I've always worked with "blue pill" boards.

Not sure about BOOT wiring. The firmware will be uploaded using STM32CubeProgrammer. The board should startup using the internal firmware.

Only HSE External Crystal is used, 8Mhz.

PROG connect is used for programming/debugging.

Can you confirm this design will work? Thanks!

Note: first post here, so excuse me if I'm doing wrong.

lk.dgironi · ‎2022-01-14

Solved.

Schematic attached.

lk.dgironi · ‎2022-01-14

Done below

Peter BENSCH · ‎2022-01-14

Now it looks ok.

Regards

/Peter

In order to give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.

Piranha · ‎2022-01-15

Take a note that on 2 layer boards the stray capacitance is significantly smaller than on 4 or more layer boards. My experience says that on 2 layer boards with short routes to crystal the Cs is typically only 1-2 pF.

We measured such a board with a crystal CL = 12 pF and tried a few capacitor values. Here are the resulting LSE frequency offsets relative to an external precision reference clock:

15 pF:  +25 ppm
18 pF:  +15 ppm
22 pF: +1,6 ppm

Indirectly it shows that a stray capacitance should be Cs = (2 * 12 pF - 22 pF) / 2 = 1 pF.

lk.dgironi · ‎2022-01-16

Thanks! Indeed I'm using a 2 layer board.

lk.dgironi · ‎2022-03-01

Quick update: design is loaded on PCB, I confirm it's working.