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TPS65982: Support of charge through audio as a UFP

Rolf Wendt
Intellectual 480 points
Part Number: TPS65982

I would like to implement the TPS65982 as a DRP.  In this mode, I would like to support the charge through audio feature.  The unit will be connected to a USB-C PD device operating in DFP mode.  The audio jack will be configured as depicted in the USB PD Spec (appendix A).  Can the presence of <Ra be sensed on CC1 and CC2 in this mode?  Furthermore, can the register bit be exposed as a GPIO to actively switch between data and audio on DN DP?

A second mode will be required as well, negotiated from a DRP.  In this mode, there will be the afformentioned USB-C PD DFP power source, but with the TPS65982 acting as a host to a USB type A port.

A third mode will be the same as above, with no USB-C PD device attached.  In this mode, the TPS65982 will act as a data host and power source to a USB type A port

The final mode will be where the TPS65982 is acting as a power sink, and data client.

There will be a external processor available, but it would be best if it wasn't directly involved, particularly in the fourth mode.  In the first mode, I imagine that there will need to be external processor involvement to react to the presence of Ra on the CC, and to generate a switch from data to audio.  It would be a slam dunk if no involvement. 

  • 0
    TI__Mastermind 36756 points
    Hi Rolf,

    The TPS65982 supports audio accessory mode. When <Ra is present on CC1 & CC2, the TPS65982 will enter Audio Accessory mode when it is enabled in the device configuration. No MCU is required for this feature. As far as the USB Data, the TPS65982 only acts as a MUX for the D+/D- lines and does not control the data present on those lines. " Furthermore, can the register bit be exposed as a GPIO to actively switch between data and audio on DN DP?" Can you expand on this? I'm not quite sure what you mean by this.

    The TPS65982 can be a DFP, UFP, Power Source, & Power Sink. You can set the device behavior in the Control Configuration register in the Application Customization Tool. If you want to adjust the behavior during the device run-time, a host MCU will have to write to the I2C Host Interface Registers of the TPS65982.

    Thank you,
    Eric
  • 0 in reply to Eric Beljaars
    Intellectual 480 points
    As for the GPIO, I imagine there needs to be an external mux or switch that can switch the audio into the DN/DP lines, since in audio device these carry the L/R audio signals. I was envisioning a external switch to do this, since there is no evidence of an internal switch to do this. I might be missing something...
  • 0 in reply to Rolf Wendt
    TI__Mastermind 36756 points
    Hi Rolf,

    We do not have a GPIO Event for entering audio accessory mode. However, you can use your host MCU to read the Status register (0x1A) and check the CONNSTATE bits. This is highlighted on page 18 of the technical reference manual: www.ti.com/.../slvuan1a.pdf
    The Status register will tell you when an audio accessory has been connected. You can use this to determine when to mux the audio signals over D+/D-.

    Thank you,
    Eric