Designing a custom board with STM32H725ZGT3

[Ironman]

I designed a custom board using the STM32H725ZGT3. The references I followed include the datasheet, application note AN5419, and the STM32H745ZIT6 Nucleo board design, among others.

After powering up the board, I was able to connect to it via ST-Link using STM32CubeProgrammer, and successfully uploaded a simple blink code using STM32CubeIDE. The code worked, and the LED started blinking.

However, after a power cycle (i.e., turning the main power off and on again), the board stopped running the code, and the LED no longer blinked. I tried reconnecting with STM32CubeProgrammer, but I received a "Target not found" error.

After that, I connected the BOOT pin to 3.3V. This allowed me to connect to the board again using STM32CubeProgrammer, but I couldn’t upload code using STM32CubeIDE. I then changed a setting in the CubeIDE:

System Core → RCC → Parameter Settings → Power Parameters → PWR_LDO_SUPPLY

After this change, I was able to successfully upload the code. However, the LED no longer blinked as before. I tried connecting the BOOT pin to ground again, but it still didn’t work.

My Questions:

Is my schematic correct?

Is the MCU damaged?

If the code uploads successfully and the board connects, why is the LED not blinking? Could it

be a power issue?

[TDK]

PDR_ON should be tied to VDD.

VCAP caps should be 2.2 uF, not 0.1 uF.

I doubt anything is damaged.

[LCE]

I'm using the programming connector always with NRST.

Measure the voltage at VCAP, it should be close to the VOS you set (1.x V).

[FBL]

Hi @Ironman 

You might be able to recover your MCU by selecting power down mode or under reset while connecting to CubeProgrammer if it is stuck due to incorrect power configuration.

[Ironman · Accepted solution]

Thank you all

I finally I got the solution from 

https://community.st.com/t5/stm32-mcus/unable-to-connect-to-stm32h7-devices/ta-p/49296

It worked for me