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TPS65930 USB port in Host mode with VBUS current higher than 100mA

Bartlomiej Swierczek
Prodigy 100 points

Other Parts Discussed in Thread: TPS65930, DM3730

Hi,

 

I am working on very board space  efficient deign with DM3730 and TPS65930.

We need only one USB port  working in HOST mode but capable to power connected device with VBUS current higher than 100mA.

The target board dimensions are very small  so we want to use ULPI USB OTG PHY build in TPS65930 .

We have +5V power efficient supply on-board.

There is any suggested (hardware and software) way to use our +5V PS instead of TPS65930 charge pump to power VBUS line?

 

 

 

 

  • 0
    TI__Genius 15100 points

    Hi,

    You can power VBUS with external supply. Please ensure you disable the internal charge pump. If you need HOST only environment then you can ground ID pin. 

    Is this info helpful.

  • 0 in reply to Gandhar Dighe
    Prodigy 100 points

    Gandhar Dighe said:
    Please ensure you disable the internal charge pump

     

    By disabling internal CP You mean - writing 0 to the OTG_CTRL[5] DRVVBUS TPS65930 register?

    TPS65930  OTG_CTRL:

    bit 5 DRVVBUS Signals the internal charge pump to drive 5 V on VBUS
    0b: Do not drive VBUS.
    1b: Drive 5 V on VBUS. 


  • 0 in reply to Gandhar Dighe
    Prodigy 100 points

    Thanks for your answer.

    but,

    I've found similar topics on e2e board:

     

    http://e2e.ti.com/support/power_management/pmu/f/43/t/37488.aspx 

    and

    http://e2e.ti.com/support/embedded/f/354/p/84650/291976.aspx#291976

     

    do you have any solution for this problem?

  • 0 in reply to Bartlomiej Swierczek
    Intellectual 1000 points

    Gandhar,

    Has this issue ever been resolved? I have a design where OTG is always a host and I am using external 5V Power Supply that is connected to VBUS pin and to the connector. Since I will not use the integrated charge pump, I did not add any charge pump capacitors. Is this ok to do? 

    We disable the charge pump by writing to DRVVBUS bit, but somehow it gets set again. Not sure if this is done over ULPI by a driver.

    From what I have been reading, DM3730 uses Mentor Graphics OTG core. Is there any way to get register definitions for this? It would make it easier to figure out why DRVVBUS bit gets set again.

    Thanks,
    Alex 

  • 0 in reply to Alex Shpilsky
    TI__Intellectual 2045 points

    Alex,

    The DRVVBUS can be controlled directly by the USB LINK in the processor using ULPI.

    Please check how to disable this contril with Procesor's team.

     

    regards

  • 0 in reply to Alexis Piton
    Intellectual 1000 points

    Alexis - Thank you.

    I have a design where OTG is always a host and I am using external 5V Power Supply that is connected to VBUS pin and to the connector. Since I will not use the integrated charge pump, I did not add any charge pump capacitors. Is this ok to do? 

  • 0 in reply to Alex Shpilsky
    Intellectual 560 points

    Hi,

    I am facing the same issue. I am working on a DM3730 based custom Android platform and we are using TPS65930. We have external 5V power supply for vbus and would like to disable on board charge pump. I could not not set DRVVBUS bit to zero. Anyone found the solution on where else this bit gets changed.

    Thanks,

    Srinivas

  • 0 in reply to Alex Shpilsky
    Prodigy 190 points

    Hi.

    I also have a design where OTG is always a host and I am using external 5V Power Supply that is connected to VBUS pin and to the connector.

    In our products,charge pump capacitor is equipped. And when we use USB devise powerd by external 5V,an unexpected current flows into VBUS pin of TPS65930.

    For resolving this problem,we will remove charge pump capacitors.Is it OK?

    But if possible,we want to resolve this problem by changing software only.How can we resolve it?

    And we want to know whether it (i.e. internal charge pump and external 5V are on simultaneously) is fatal for TPS65930 or not.

    If an unexpected current flows into VBUS pin of TPS65930,is TPS65930 broken?

    Or is it safety for internal circuit of TPS65930?

     

  • 0 in reply to makoto fujimoto
    Intellectual 560 points

    Yes, it might damage PMIC. Unfortunately we could not turn off the internal charge pump using SW. Though you do it through registers, it is getting enabled back.

    To solve this issue we connected diode on the VBUS path which allows current flow in one direction.

    Thanks,

    Srinivas