BOOT0 pin problem on STM32F302RE

[HAENEL.Cyril]

Hello, I use STM32 for years, and on a new board I use for the first time a F3 series : STM32F302RE

I use exactly the same schematic as all my previous board, and for the BOOT0 pin, I have a 2.2K pull-up pull-down, and a jumper to set the pin to 3.3V when I need to reflash it through UART1 with internal system bootloader. On this project I don't use this jumper because I use an stlink/V2 cable to flash.

On a board I work on, after some days with everything fine, with no reason the board stopped working. Read/write flash was OK but impossible to boot. I finally checked the BOOT0 pin, and found 1.6V on the pin, even with the 2.2K pull-down resistor ! Thus the BOOT0 pin now leaks ~700µA of current !!!

If I short the pin directly to the ground, the chip boot normally, but this behavior is not normal, I never see that in 8 years I use STM32.

What happened to this BOOT0 pin !?

Also, I worked on a second board, and some hours later I had the same problem.

It worry me a lot, because after production if the problem appears after delivery, the board will stop working because jumping on the internal system bootloader at power-up....

Regards

Cyril

[waclawek.jan]

Mount one chip from given batch onto a "known good" board - a Nucleo64 (properly jumpered) - and run the sleep test on it.

That's for the "chips are at fault" hypothesis. Now for the "board, connected stuff or working environment is at fault" - this is entirely upon you, but the usual debugging strategies apply: take a good sleep, take three steps back, think out of the box, formulate wild hypotheses and try to prove/disprove them, talk your girlfriend/wife/the cleaning lady/teddybear through the problem, etc.

JW

PS. N-layer boards with ground plane can have bad solder joints on various parts too.

[PVast.1]

I've the same identical problem on STM32L071CB. I've 2000 devices selled, the devices work fine for many months, but my customer return back after months some devices with no boot and I measured 1.6V on pin BOOT0, with a pull down resistore of 10k. With a direct GND connection the firmware start again. Also the issue on RST pin is present some times, with a 100nF capacitor to GND the program software said "STM32 held reset condition". The problem is resolved removing the capacitor. 

Paolo

[HAENEL.Cyril]

Hello, did you find a solution or explanation from ST for this boot0 problem ?

[PVast.1]

obviously no answer from ST.... no, I have not found any solution

[PVast.1]

any suggestions from ST for us?

[BBasn.1]

OMG~ the same problem is happening to my boards as well.

I am using STM32F103C8T6 chip and it's driving me crazy.

After using the board for 30 minutes or so BOOT0 pin goes high even its pulled low with 10K resistor. Sometimes NRST pin goes low after using a board for 30 minutes or so. What is happening????

I have to produce a lot of boards with the Chip and this is driving me crazy. I have checked everything with my board and couldn't find any faults with any PCB trace.

[Tesla DeLorean]

Sounds like a power or grounding issue.

Pay particular attention to analogue supplies.

Post salient portion of the schematics, least we have to raise dark forces..

Also a lot of fake parts on the market. A picture of the part, ideally high resolution, tight on part, perhaps slightly oblique, and in focus.

[JavierLopez]

Hello Cyril

I have seen your problem and the exact same thing happens to us.

We have started developing with the STM32F7 family since January 2024 and a few weeks ago we had this same problem. If you reprogram the microcontroller flash it is solved temporarily but after a few days it happens again.

As it has been a considerable time, I would like to know if you solved your problem? And if so, could you tell us how?

 

Regards

 

Javier