Can't locate/ID.this chip for the life of me. Anyone care to take a crack at it?

[FloridaCaveDiver]

I have spent hours trying to ID and locate this chip. I need to replace one to complete a repair.

I have attached a photo... any help would be VERY appreciated.  There are two of them located on the back of a Keychron V8D2 keyboard mainboard.

I believe it is 22C31WB0c e3

Thank you in advance for any help!

[amyk]

If you can figure out the pinout, that would help narrow it down as I suspect it's an MCU but there are tons of them in QFN40.

[fzabkar]

If you can figure out the pinout, that would help narrow it down as I suspect it's an MCU but there are tons of them in QFN40.

I can't think why one would need two identical (?) MCUs on a keyboard? Am I living in the Dark Ages? :-?

[darkspr1te]

Are there any other chips ? these could be identical MCU's , one is the io keyboard sense side the other could hand the USB side &/or rgb. i would make sense if you already have a build environment and ran out of IO on one chip and didnt want to use a IO expander,
Now if you have maybe 3 chips on the pcb then one could be the actual MCU and the other could be IO expanders. these are just my guess though, 


darkspr1te

[gamalot]

Looks like a customized EFR32BG22 series MCU.

[m k]

I can't think why one would need two identical (?) MCUs on a keyboard? Am I living in the Dark Ages? :-?

PC and Mac?

[fzabkar]

I can't think why one would need two identical (?) MCUs on a keyboard? Am I living in the Dark Ages? :-?

PC and Mac?

I recall PC keyboards where you could select XT mode or AT mode via a switch. They still had a single MCU. I don't think the data transfer rate (2 bytes per second?) has improved since then.

[Haenk]

Now *that* was easy.

"MCU: Ultra-low-power ARM Cortex-M4 32-bit STM32L432 (128KB Flash)"

"The open-source firmware means endless possibilities for keyboard layouts, shortcuts, backlight effects, and more."

https://www.keychron.com/pages/firmware

[fzabkar]

Now *that* was easy.

"MCU: Ultra-low-power ARM Cortex-M4 32-bit STM32L432 (128KB Flash)"

"The open-source firmware means endless possibilities for keyboard layouts, shortcuts, backlight effects, and more."

https://www.keychron.com/pages/firmware

That's a 32-pin package. :-?

https://www.st.com/resource/en/datasheet/stm32l432kb.pdf

[Haenk]

That's a 32-pin package. :-?

That's from the product description page, so don't blame the messenger
At least it should help to understand the technology used, maybe they switched to a chinese clone (chip shortage?) - it should still be possible to flash these with their software.

[fzabkar]

I can't see a crystal or oscillator in the OP's photo ...

Could we see a photo of the whole PCB?

[m k]

More surrounding components would be better.

My take is that 1 is not 1, so 22C3|W[DBO0][O0]c e3.
1st C can be 12, so made 22/2023.

Is lower part of a logo 'together' (hé sī).

E,
obviously C is 12.

[ArdWar]

If there are wireless version of this keyboard family there might be merit into suspicion that it's a clone of STM32WB series. Not necessarily a full clone, but at least functionally similar. That's what Chinese OEM supplier often do (e.g. STM32WB-like peripherals but using 51 core etc)

[m k]

What's 0c then, different package and mask ROM, of version e3?

[fzabkar]

https://electronics.stackexchange.com/questions/2428/what-does-the-e3-or-e4-printed-on-an-ic-mean

"e3" is most probably an RoHS mark.

[m k]

Maybe end part is a diversion and a real thing is 30ce.

What is that missing pin marking of end of 1st side?
If that last marking is real all sides have hiding pins.