TPS25751: TPS25751 and USB 2.0/3.0 Support TUSB1142

Clayton Ferrazzo

Part Number: TPS25751
Other Parts Discussed in Thread: TPS25763-Q1, TUSB1146

I have a Jetson Orin module communicating with a USB Type-C port that has 27W PD. I've implemented a TPS25751, and being new to PD, discovered that there is some nuance with supporting both USB 3.2/3.1/3.0 AND 2.0 on the same port. The datasheet suggest the use of a superspeed mux to handle the SS signals.

The block diagrams in figures 9.11 and 9.12 are confusing though. Are the D+/D- lines supposed to connect BOTH to the TPS25751 GPIO AND the Host controller (an NVIDIA module in my case) D+/D- lines? Or should I be routing the D+/D- only to the host module. I guess I'm confused beccause I didn't see a data output set of signals for USB comms on the TPS25751, and my only experience so far has been with USB 2.0 hubs with take in multiple D+/D- lines and spit out a singla D+/D- pair to the host device.

If my understanding is correct I need D+/D- >> Host with a t-connection to the TPS25751, which seems very odd to have 3 devices on one port.

Type C Mux.png

9 months ago

0 Raymond Lin 8 months ago

TI__Mastermind 37666 points

Hi Clayton,

TPS25751 supports BC1.2 enumeration on the D+/D- line, if your system requires BC1.2 then you can route the D+/D- pin from the Type-C connector to the PD controller, otherwise this connection is needed (only route D+/D- to your host, no need to connect to PD controller).

Let us know if you have any further questions or concerns!

Thanks and Regards,

Raymond Lin

0 Clayton Ferrazzo 8 months ago in reply to Raymond Lin

Prodigy 20 points

Got it thank you, I'll plan to route D+/D- only to my host device for this application since no battery charging is implemented, only USB2.0/3.0 and keep the Mux.
A further question would be about configuring the GPIO between the PD controller and the TUSB11432, but I would guess the technical reference manual for the 1142 will have that information.

0 Clayton Ferrazzo 8 months ago in reply to Raymond Lin

Prodigy 20 points

I'm also now realizing that for a 27W PD application, I am going to need an external PD converter to communicate with the TPS25751D, this may not be the best fit for my application as a source only PD device...
I'm wondering if I need to just shift to the TPS25763-Q1 and use an on-board 10VDC or 20VDC regulator with the TUSB 1142 mux.

0 Raymond Lin 8 months ago in reply to Clayton Ferrazzo

TI__Mastermind 37666 points

Hi Clayton,

TPS25751 does not have integrated DCDC so an external converter will be needed to provide the correct output voltage/current on PPHV. What Source PDOs (voltage/current ratings) are required for your application?

Thanks and Regards,

Raymond Lin

0 Clayton Ferrazzo 8 months ago in reply to Raymond Lin

Prodigy 20 points

27W (9V, 3A) is the minimum required, I wouldn't mind making it more flexible (say 60W) but presently I only have 1V8, 3V3, 5V, 24V and raw battery available (48VDC nominal), so picking a DC/DC for USBC PD is annoying since most of them max out at 20VDC in.

The general setup is USB-C PD, D+/D- support, and USBSS (3.0) support. Doesn't look like there is one IC that can support all 3 of those but any recommendations are welcome here.

0 Clayton Ferrazzo 8 months ago in reply to Clayton Ferrazzo

Prodigy 20 points

Wanted to follow up, I'm planning to use USBC-to-TUSB1146. TPS25763 will connect to TUSB1146 and the USBC receptacle. The host will provide DP source, USB3.0 PHY, and USB2.0 data in/out. This config seems to be the correct method for getting USB-C with DP and PD @ 27W.