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Visitor II
March 16, 2021
Question

STM32H725 SMPS Issue

  • March 16, 2021
  • 2 replies
  • 1375 views

Hello,

I designed a motor controller with an STM32H725ZG, and I am having problems with

the SMPS. First, with the board just assembled, the stm32CubeIDE let me upload

a simple code (activating 25MHz crystal, debug, and blinking a led) one time.

After uploading it, the debugger shows "Target not found..."

"Shutting down..." and it can't be programmed never again. After some

measures I realized that the SPMS is throwing 0.06V, so I decided to bypass the

VDDLDO to 3V3 and after that it works perfectly.

Do I have to activate something in CubeIDE or in some register to use the SMPS?

Is there something wrong in the design? (PDF)

I put R107 as a jumper to switch between mode 1 and 2 described in datasheet. And none of this modes worked.

0693W000008x1XGQAY.png 

Thank you for your help.

    This topic has been closed for replies.

    2 replies

    Visitor II
    March 16, 2021

    Hey,

    Not sure about this chip, but on H747 there is a selection for linear or smps regulator on startup. If you have wrong power supply type and the opposite register init, it will never boot. To recover you have to use the BOOT1 pin to enter bootrom and reflash, then after make sure in whatever image you flash - start up init of the power domain to match you supply selection. Hope this helps.

    K.

    Visitor II
    July 26, 2021

    Hello,

    Is this issue resolved? I also have issue with H725, but worse, the board never boot-up. ST-Link always reports "cannot connect to the target".

    Technical Moderator
    July 27, 2021