ESP32-S3 USB Connection

[bitflip]

I have a very simple PCB leveraging an ESP32-S3 to interface with an external component with a connector. The board contains a USB C connector in addition to a status LED. I've been able to program the board over the UARTO interface to flash the LED. However I can not a computer to recognize the board over USB C.

I've enabled the USB port as outlined in this doc:
https://docs.espressif.com/projects/esp ... nsole.html

• I'm using a USB C to A cable that I've confirmed works on other boards for flashing

• I've swapped out the USB protection IC

• I've probed the D+ and D- pins at the ESP32 and found D+ to be at a constant 3.3v while D- is at 0v. Holding EN low sends D+ to 0v.

I've attached my PCB schematic and layout. Ignore the bug with my EN pin always pulled low. I've fixed this with a cut trace and bodge wire on my PCB and again confirmed the ESP32 boots and can be programmed over UART0 by uploading a simple Hello World program to flash the LED on GPIO35.

Please suggest any other troubleshooting options I may have overlooked.

Thank you.

esp_bells_layout_v1.jpg (191.21 KiB) Viewed 898 times

esp_bells_schematic.jpg (77.6 KiB) Viewed 898 times

[bitflip]

I found that removing the USB protection IC (U4) from the PCB and bridging the pads so that the ESP32 is connected directly to the USB C D+ and D- pins fixed my connectivity. My computer now recognized the device and I can see my serial logs from my Hello World program. Can anyone spot the issue in my design? I'm using a USBLC6-2SC6 IC.

Details Here: https://www.digikey.com/en/products/det ... C6/1040559

[Sprite]

That is weird. Are you absolutely sure you got exactly that ESD component? I recall a situation where someone got a chip with a slightly different part number and an entirely different pinout and didn't notice. Perhaps check with a multimeter if the chip has the pins connected in the way you think it does. Also, do you only have one PCB or multiple? If you only have one and it misbehaves, it could be a soldering issue; if you have multiple it's a design thing.

While I'm going over the PCB and schematics, two remarks that may lead to issues later: first of all, your EN circuit is not correct (should be 3V3 - resistor - EN - capacitor - gnd), and secondly you want to remove C6 otherwise you'll have issues with your program not starting on powerup. Also, while I'm noticing stuff - your ground planes look super-messy (lots of interruptions); you might want to go in your DRC settings and adjust the values there to something a bit more closer to what your PCB provider can do because at the moment at least your track-to-track and track-to-via spacing seems to be huge.

[bitflip]

You're right, I accidentally ordered the 4sc6y variant. Thanks for the sanity check...

Yup I caught the EN issue and fixed it. Thanks for the note about C6.

I'll have to research more about your other remarks. Appreciate your review!