DOES 3.3v and gnd short circuit brick stm32 ?

[Kishan Joshi]

I have custom board with minimal design only stm32 chip is there and couple necessary capacitors and due to some soldering issue, i got shorted with 3.3 and gnd .. accidentaly i powered it on and for debuging it was connected like this for 2 minutes. now stm32 is not communicating through swd. Did it brick stm32 by shorting 3.3 and gnd for a minute ?

[Simon.B94]

Hi,

normally this should not brick your device since shorting VDD to GND would lead to the STM32 no seeing any voltage at all. The only thing probably dying by this could be your LDO if it has no protective features (current limit, thermal shutdown, etc.)

In my personal experience stm32s are not that easy to kill.

When connecting your programmer, what voltage does it show for VDD?

Greetings

Simon

[Kishan Joshi]

Yes now after removing that solder ldo is now working and there is no short circuit. And this is the empty chip. And i am booting it first time. Stm32f765vit6 is the chip. And voltage is 3.265 from the stlink. Do i need to do anything before swd to work?

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Thank you so much simon for your help please guide me through this is my first stm32 custom board. I have worked with many nucleo but i wanted to give a shot for a custom designed board. Basically it only has some caps and usb there are no sensors or anything at all on the board.​ Very minimal design

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[Simon.B94]

Hi,

if its an empty chip you should be able to connect when connecting the SWDIO to PA13 and the SWCLK to PA14 as with all STM32.

Additionally PB3 to SWO if you want to use the SWV (but not needed for simply programming the STM) and the NRST to the Reset-Pin

Best practice is to select Connect under Reset but this shouldn't matter if its a blank chip.

Greetings

Simon

[Kishan Joshi]

Yeah that's what i have done and again the voltage is updated now it is at 3.258847

[Kishan Joshi]

what should do to check if the stm32 is working or not is there any pin where can i check voltages ?

[TDK]

> my first stm32 custom board

Post your schematic. High chance something there is wrong.

VDDA connected?

[Kishan Joshi]

Yes sure here it is. yes vdda is connected

[Kishan Joshi]

please ignore the sensor part since they are just berg strip for breakout board. Those are not soldered. And crystal is not connected since i want to use HSI First after that if it will work i will move on to the HSE

[Tesla DeLorean]

What STM32? Lets narrow this down a bit.

VDDA powers PLL/POR circuits.

Check level on NRST

Check level on VCAP pins, if applicable

Pull BOOT0 Low

[Kishan Joshi]

It is Stm32f765vit6. what level should it be on nrst and vcap ? . yes. boot0 pin is low.