VanMoof S3 e-bike teardown; datasheet unknown chip?

[artelse]

Hi,
Magnet fishers here in Amsterdam pulled a few VanMoof e-bikes out of the canal. I took one home for inspection. Electronics beyond repair, the STM32 microcontroller lost some legs due to corrosion, etc. The LED matrix display came out ok, but am wondering what the U4624 3742A LED driver chips are, I cannot find a datasheet.
See photo's. If some like to see more pictures of the VanMoof S3 electronics, let me know.

[thm_w]

Looks around 24 channels per IC?
Can you scrape some of the white plastic off so you can see how many pins the IC is (or measure), and if its TQFP or QFN.

Might be custom marking.

Can you post a photo of the STM32 board please

[artelse]

It's a 48 pin TQFP package. Any idea what chip it might be?

Here are some photo's of the front of the board. As you can see, pretty much eroded. The motor drive of the S3 is a pretty standard TI job with a TMS320F28054FPNT and companion chip to drive the mosfets for a three phase PM motor. Can post back of board as well if you like.

[thm_w]

Lumissil Microsystems has some ICs with similar functionality: https://www.lumissil.com/products/led-driver/fxled

They even have a 3742A, but its QFN not TQFP: https://www.lumissil.com/assets/pdf/core/IS31FL3742A_DS.pdf


TMS320 and STM32F4, wurth caps, not much expense spared here.

[artelse]

Thanks! That datasheet is from January 2021 while the manufacturing date of the bike is the same, so the TQFP might be from an earlier date. I looked briefly at the pin topology and it roughly matches the datasheet; ISET resistor, I2C and decoupling caps on the right pins. Nice chip btw, each LED can be individually controlled with PWM and current.

[nickuk]

Hi - hopefully someone on this thread is still on! I'm from Boost (boostbike.uk); we engineer all our own motor drive systems and are designing replacement VanMoof circuit boards to prolong the life of the bikes in the market, whatever happens to the VanMoof system. VanMoof uses an STM32, our system used Nordic bluetooth chips with super low resistance automotive MOSFETs.

If anyone has any old or broken VanMoof main circuit boards that would be useful, so we can use the physical profile for ours for various VanMoof versions. We're also up for buying end-of-life VanMoof bikes for testing purposes.