TUSB8041: Can work with 3.0 device but 2.0 not

you mean HS_DP_DN3/HS_DM_DN3 connect to USBC connector?

Best

Brian

Yes, Both the SS_DN3 and HS_DN3 interfaces are routed to the Type-C connector (Type-C has DP/DM which are dedicated for USB 2.0, right?). HS_DN3 routed to TPS2750 too. And I have another HS_DN interface routed directly to an USB2.0 connector and it works well. So I guess the problem may at the combination of TPS25750 and TUS8041. But I can't figure out where the problem exactly is. May you give me some clues? 

Thanks.

DP/DM of TPS25750 is just for charging, Do you need charging for DN3?

Best

Brian

Yes, we intended to let the TPS chip to handle the charging. And we noticed that the TUSB chip has ability to handle the CDP/DCP too. May there are conflicts in my usage with the two chips? If it is, are there some workaround to solve, as both the two chips give some flexible configuration capability.

Best regards.

do you turn on BC on DN3 as well?

Best

Brian

We use the TUSB chip without eeprom and smbus control now. But we can change several external pullups/pulldowns. Pin45, 33 are floating now. I expect these configuration will disable the BC for dn3. Is this enough?

Thanks

IF PIN 45,33 floating, then BC is disabled.

can you send schematic for review?

Best

Brian

Brian Zhou I've sent you the schematics. 

Best

Ok, I will review before monday.

Best

Brian

Hi:

   Where is USB2_UP connected to? AL so I didn't see 5v for any downstream port.

Best

Brian

Hi,

USB2_UP is connected to the main processor.  5V is powered up before the USB device attached. Actually, the 5V is controlled by the TPS25750.

it's not on the schematic you sent?

Hi,

The 5V is routed to TPS25750's pin 34.35, with net name 'VSYS_5V0'. And indeed the 5V is switched out by TPS, when the USB device attached.

ok, which one is main processor?

Best

Brian

Brian Zhou I've sent you a PM. 

Best.

so hub upstream is connected to MCU and hub downstream port 3 is connected to USBC connector.

USBC is DFP port, Can MCU see hub USB2 upstream? 

Best

Brian

Hi,

Yes, both of the upstream USB2 and USB3 are routed to the MCU. And hub port3 routed to Type-C. You see we have other USB2 port of the hub routed to other USB2 connector directly (without TPS chip companion), and it worked well. So, it proves the USB2 upstream link is OK. 

Thanks.

This could be issue of PD controller TPS25750. Let me check schematic again.

Best

Brian

Move ticket to PD group.

PD guy:

    how to disable battery charging for TPS25750?

Best

Brian

Hi,

Do you think the BC communication on D+/D- will affect the following data USB protocol?

Thanks.

Hi,

No information from PD guys so far . 

Best.

Hi,

We use TUSB8041 and TPS25750 together, that means one port of TUSB8041's D+/D- pins are connected to TPS chip. But we find that port can't work with  USB2.0 device. As the other port without TPS chip companion work well with USB2.0 device, we suspect if the function from TPS chip side is conflict with TUSB chip. We need someone to give some suggestion, if the companion of TUSB and TPS chip can work flawless.

BTW, are there any way to completely disable the function on D+/D- by the configuration tools provide by TI?

Thanks.

Thanks for your answer.

We tried configuring the D+/D- to open drain, and set the initial value to 1 (IMHO, this will set the D+/D- to high impedance, right?) The problem is our board design is to let TPS to handle the VBUS source/sink, so in this case, the TPS won't enable VBUS, and the USB device attached won't be powered.

We assumed if we disable the charging function of TUSB, and it should work well with TPS chip handling the charging and sourcing, but the result is not so. Can you confirm this for me?

Best regards.

Hi,

It seems power switching and battery charging are two separate functions of TUSB8041. We may need to disable both the power switching and battering charging function, and let TPS chip to handle them. May you send me the EEPROM programme utility?

Thanks. 

Yes.

Finally, we resolved the problem. After disable the BC function of TUSB, it now works. TUSB only responsible for USB data communication, the power sourcing/sinking is handled by TPS. In our previous tries we removed a wrong bootstrap resistors.

Thanks for all you guys help,

BTW, where to get the EEPROM program utility for TUSB chip?

Best regards.

That I do not know... I will let Brian answer that!

Thanks,

Chris