This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS65981: Issues Interfacing with a USB Type C Hub Adapter that Supports USB Type C PD Power/Data Passthrough

Part Number: TPS65981
Other Parts Discussed in Thread: PCM2705,


We have a design that uses a TPS65981 to act as a Dual Role Port that provides 5V @3A power to a 2020 12.9" Ipad Pro while simultaneously connecting the Ipad USB audio to a PCM2705 DAC chip.  The design works as intended in all scenarios except one.

In one of our setups we need to use a USB Type C Hub Adapter that breaks out ethernet from the Ipad:

34184 from Monoprice (

This 34184 adapter plugs into the Ipad and has a USB Type C PD port that supports Power/Data Pass through. This port is what is plugged into our design and we expected the Ipad to charge and provide the ipad USB audio, will the Hub Adapter breaks out the ethernet.

The issue is that the iPad does not charge in this scenario.  The ethernet works and the iPad USB audio from the PCM2705 is successfully negotiated from the TPS65981 DRP.

The exact same behavior is observed using a different Targus branded USB Type C Hub adpater.

Are there any specific TPS65981 firmware settings that need to be selected in the Application Customization Tool to allow the TPS65981 to work with a USB Type C Adapter Hub (VGA,ethernet,USB etc.) that has a USB PD power and data pass through port?


Ben Schroeder