TUSB8041A: Schematic review and questions

Tejas Gulur

Part Number: TUSB8041A
Other Parts Discussed in Thread: TPS74801, TUSB8041EVM, , TUSB322, TUSB542

Hi all,

I am learning PCB design and have done a few custom ESP32 board designs successfully. I wanted to do a USB hub design and wanted some feedback on this schematic which I have attached here. Here are some of my main questions that I had on top of any feedback that you all could provide:

1.) I wasn't sure what the difference between VDD11/BOARD_1P1V and VDD33/BOARD_3P3V, and even BOARD_5V. Are the BOARD tags meant for traces on the PCB and VDD is meant for the power planes itself? And if this is the case, how would one generate a VDD11 plane? Would it just jump from the VDD33 and you would use an LDO or voltage divider and then you would have a BOARD_1P1V and a VDD11 plane?

2.) I wanted the USB hub to be something that functions plugged into DC5V or via a USB cable. I wanted to get any further feedback on that section

3.) At the moment I lazily generated BOARD_1P1V using a voltage divider. Could anyone recommend a more stable method of generating the BOARD_1P1V part?

Thank you for all your feedback!

SCH_Schematic1_2023-12-10.pdf

4 months ago

0 Brian Zhou 4 months ago

TI__Guru** 105965 points

Tejas:

Q1:VDD33/VDD11 is supply name for hub device, BOARD5v and board_3p3v or board_1p1v are supply name generated from LDO on the board. VDD33/VDD11 are only for hub device, BOARD_xV are for all other devices on the board, like LDO, EEPROM. so you do need plan for both VDD33/VDD11, BOARD-xV supply. Please check hub layout for reference.

Q3: we use TPS74801 for 1.1v supply.

for Q2, I will discuss in svchematic review later.

Regards

brian

0 Tejas Gulur 4 months ago in reply to Brian Zhou

Prodigy 20 points

Thanks for your response Brian. Does this mean that there are 5 different power planes (VDD33, VDD11, Board_1P1V, Board_3P3V, Board_5V)? If there is an example of this I'd like to read up on it.

Please provide any further feedback in the schematic review. Thank you once again!

0 Brian Zhou 4 months ago in reply to Tejas Gulur

TI__Guru** 105965 points

this is the plane for TUSb8041EVM.

0 Brian Zhou 4 months ago in reply to Brian Zhou

TI__Guru** 105965 points

Attached is SCH review commands.

EasyEDA_8041a_review.pptx

0 Tejas Gulur 4 months ago in reply to Brian Zhou

Prodigy 20 points

Hi Brian, thank you for your feedback. I've attached a new schematic here with the MUX implementation using TUSB542 and TUSB322. Can you please check the schematic and see if it looks good? My only concern was on TUSB8041A there is no ID pin and INT# pin, but I felt it should still be okay. I've also used the TPS74801 to generate a 1.1V power, but wasn't sure about the implementation I've created. Please check that too. Finally, with regards to the comment on the paralleling supply, I just followed https://datasheet.lcsc.com/lcsc/2304140030_Analog-Devices-LTC4359IMS8-PBF_C580870.pdf page 10 figure 5. Could you go a little bit in-depth on your suggestion? More than happy to make the change anyway but just wanted to ask.

Regards,

Tejas

SCH_Schematic1_2023-12-12.pdf

0 Brian Zhou 4 months ago in reply to Tejas Gulur

TI__Guru** 105965 points

Tejas:

for TUSB542, you need 100nf AC cap on SSRX0_UP as well.

for TUSB322, you need to ground EN/N pin.

In this design, hub upstream is configured by TUSB322 as UFP, so TUSB322 schematic looks good

Regards

Brian

0 Tejas Gulur 4 months ago in reply to Brian Zhou

Prodigy 20 points

Thank you so much for all your feedback. Could you check the rest of the schematic quickly if there is anything else, especially the paralleling supply? I've implemented the feedback you have provided here.

Regards,

Tejas

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TUSB8041A: Schematic review and questions