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Associate III
April 3, 2026
Question

Set up PWR_SMPS_1V8_SUPLLY_LDO STM32H755ZIT6

  • April 3, 2026
  • 2 replies
  • 284 views

Dear al!

i need your help, i design PCB use STM32H755ZIT6, i set up mode PWR_SMPS_1V8_SUPLLY_LDO via STM32CubeMX 6.12.1. I expect core M7's clock is 400Mhz, M4's clock is 200Mhz. I measure voltage after L2 is 1.8V, at each Vcap pin is 1.0V, The MCU warmed up to about 35 degrees Celsius and chip didn't run. can you share me my mistake, this is the first time which i handle with SMPS block

2 replies

AScha.3
Super User
April 3, 2026

Hi,

just...

- vbat not connected , connect to vdd.

Bildschirmfoto_2026-04-03_10-11-44.png

- what is vddio ?  should be 3v3 .

- whats on nrst ? should be 100nF to gnd.

+

What happens (if these voltages correct) on connecting in CubeProgrammer with st-link ?

show pic.

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Associate III
April 3, 2026
VDDIO is 3.3V, i can connect stm32Prog via STlink, and Vbat pin is
floating,
AScha.3
Super User
April 3, 2026

So connection to H755 cpu seems fine ? ...then cpu running.

Can you flash the cpu with success ?

So what means >chip didn't run< ?  Your prog dont work ?

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Technical Moderator
April 3, 2026

Hi @khanhcong861989 

Could you please confirm:

  1. Can you erase and program the MCU with STM32CubeProgrammer without errors?
  2. After programming your firmware, what exactly happens on the board?
    • Do any of the GPIOs you configured toggle or stay at a fixed level?
    • If you pause the core from the debugger after reset, where is the PC. Is it in Reset_Handler, main(), or a fault handler?
  3. Can you check your HSE 16MHz used on your board to narrow down the issue?
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.Best regards,FBL
Associate III
April 4, 2026
  1. Can you erase and program the MCU with STM32CubeProgrammer without errors?--> i did it, after download new FW, MCU has alittle hot.
  2. Do any of the GPIOs you configured toggle or stay at a fixed level? --> i have 3 output by Led, but ii didn't run.
  3. Can you check your HSE 16MHz used on your board to narrow down the issue?-> current i usse internal crystal