stm32h725 doesn't work.

[sangmin]

Hello, I looked at AN5419 and configured the stm32H725igk6 power supply circuit as shown in the following figure, but the external osc does not work and the st link is not connected to the MCU.

Is this product a model that must be configured using SMPS to operate?

[LCE]

SMPS is not a must, afaik.

More info, please...

So, you say you configured, so you have a custom board?

Please show the relevant schematics: power supply, crystal, ST-Link IO, Boot pin

And the relevant clock configuration code.

[TDK]

Also clarify "doesn't work" here. Can you connect via STM32CubeProgrammer (if not, what is error message)? Does it report a target voltage?

SMPS is optional.

If it's a custom board, most likely answer is a schematic or hardware issue.

[Michal Dudka]

Let me guess. You've generated project by CubeMX and forgot to properly set up power managment. Default CubeMX configuration uses SMPS. After power up, your MCU switch its power supply to SMPS,and lost power. Therefore you can't connect with St-link. That can be easily verified - just measure voltage at VCAP pins. If there isn't voltage between 1.0V to 1.3V... if not, simply connect external 1.2V source to that point, connect St-link and do chip erase.

[sangmin]

OSC

Thanks for the various answers. Above is the circuit connected to the MCU.
STlink detects 3.2V voltage.
As a result of further confirmation, the circuit is configured using a 25MHz clock, but it is not oscillating.

Vcap voltage comes out as 1.0V..!

[zulqarnainjabbar99]

Additionally, could you provide more details about the nature of the "doesn't work" situation? Are you able to establish a connection using STM32CubeProgrammer? If not, could you share any error messages you're encountering? Does it display the target voltage information?

Please note that the use of SMPS is discretionary.

If your setup involves a custom board, the most probable explanation could be a schematic or hardware-related problem.

[sangmin]

These pictures are the phenomena that appear when I try to connect the board through stlink.

What I did was change the setting value in the stlink utility.
I changed the access port / SWD frequency / Mode / Rest Mode.
All didn't work.

[FBL]

Hello @sangmin 

You can refer to STM32H735G-DK schematic as a reference. Sheet 4 out of 19 in MB1520C (st.com) explains the LDO mode in the following configuration:

•  SB19, SB3, SB1: Fitted
• SB20, SB2, SB18, SB16, SB21: Not Fitted 

Also refer to the datasheet for Vcap operating conditions.

[sangmin]

I set it up like the previous picture, but it doesn't work.
The smps are all connected to GND like the picture before I sent. Will this be a problem?

[TDK]

Use STM32CubeProgrammer, not the ST-Link Utility.

R130 looks like a potential problem. Inrush current will definitely make that voltage drop below the allowable.

The SMPS pins are fine if you're not using SMPS.