2021-08-21 09:52 AM
Hi guys,
I recently made a design based on nucleo wb55 dongle using STM32WB55CGU (48-UFQFN), but I cannot connect to it using SWD.
I believe it is not a schematic problem, so I am a bit stuck for debugging the situation. I soldered it using hot air station (< 250/260 deg celsius). The joints look okay, but I am not an expert on soldering QFN. So, my main guess is that I broke it while soldering.
Thank you very much for your time
SWD
MCU Schematics
VDD
External Clocks
2021-08-22 11:52 PM
Soldering a QFN with a hot air gun is very doable, but takes some amount of skill/experience. STM32 chips are quite robust. It's hard to damage them from temperature. Use flux, you should see it shift into place when solder begins to flow.
2021-08-23 03:54 AM
Thank you for your message. That's how i did it actually. Would you mind having a quick look at my schematic if you have some time please ?
Thanks again
2021-08-23 11:05 AM
I did. Seems fine to me but I'm not an expert with SMPS configuration. I would assume a fresh chip is configured to run in LDO mode for any relevant option bytes.
2021-08-23 02:18 PM
Thanks, any review is precious ahah. There are not so many STM32WB55CG left on sale online..