TPS25814EVM: No VBUS connection at UFP port

Ravi Parmar

Part Number: TPS25814EVM
Other Parts Discussed in Thread: TPS25814, TPS65988

Hello,

I am currently developing the design for a USB dock that incorporates three ports. One port will serve for charging an Android tablet, the second port will be designated for a USB camera, and the third port will function as a USB power input to supply power to the system. The USB camera will draw power from the tablet/USB dock. I want to simultaneously transfer data to the tablet, allowing for tablet charging during data transfer.

To achieve this, I plan to employ the TPS25814 IC and have consulted the TPS25814EVM for reference. According to the above block diagram, the tablet must be linked to the DFP port for charging, while the UFP port will be connected to the USB camera, requiring a power supply. It's worth noting that in this configuration, there is no VBUS connection at the UFP port. I require assistance in resolving this matter. Would it be advisable to directly connect or short the VBUS between the UFP and DFP?

over 1 year ago

0 Raymond Lin over 1 year ago

TI__Mastermind 34676 points

Hi Ravi,

The UFP port (J3) on TPS25814EVM is a sink-only port and cannot be use to charge the USB camera. The purpose of J3 port is to provide pass-through data from a host device (i.e. laptop, computer, etc.) to the DFP source port (J2) which simulates a Type-C source port that supports USB data and 5V/3A (15W) power output. The EVM itself is powered from the barrel jack, for design details refer to page 13 in the user guide: https://www.ti.com/lit/ug/slvuc37/slvuc37.pdf?ts=1702495725820&ref_url=https%253A%252F%252Fwww.ti.com%252Ftool%252FTPS25814EVM

Thanks and Regards,

Raymond Lin

0 Ravi Parmar over 1 year ago in reply to Raymond Lin

Prodigy 30 points

Hi Raymond,

Thanks for the response.

I've already reviewed the EVM design details from page 13, but my question revolves around modifying that design to suit my specific application. If the TPS25814 doesn't seem suitable for this modification, could you recommend an alternative component that would be better suited to my needs?

Thanks.

0 Raymond Lin over 1 year ago in reply to Ravi Parmar

TI__Mastermind 34676 points

Hi Ravi,

I would not advise shorting VBUS between ports J3 and J2 since this can potentially cause overcurrent draw from both ports (if both devices are drawing some power) and would cause VBUS to be live on both ports if one port is already sourcing. Based on Type-C specifications, VBUS should not have any voltage on VBUS pins until a proper connection is made.

TPS25814 is a single-port Type-C solution, if you want to implement dual port I recommend using either another TPS25814EVM (to simulate the second port) or you can take a look at the TPS65988 PD controller, however this part might be an overkill depending on your application.

Thanks and Regards,

Raymond Lin

0 Ravi Parmar over 1 year ago in reply to Raymond Lin

Prodigy 30 points

Hi Raymond,

Thanks for the help.

Best Regards,

Ravi Parmar

0 Raymond Lin over 1 year ago in reply to Ravi Parmar

TI__Mastermind 34676 points

Hi Ravi,

No problem, I'll go ahead and close this thread. If you need additional support please open a new thread so we have better tracking!

Thanks and Regards,

Raymond Lin

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TPS25814EVM: No VBUS connection at UFP port