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BQ24160: BQ24160 USB Detection and MCU which requires USB Communication to PC

MohammedAl-Amin
Intellectual 540 points
Part Number: BQ24160
Other Parts Discussed in Thread: BQ25895M, TS3USB221A, BQ25895, BQ24392, BQ24072T

Hello,

I am having some trouble in an implementation which can include my Audio MCU which would communicate when connected to a PC/MAC.

The problem is that the Audio MCU, has two processes (process 1 runs on battery only and process 2 runs on USB only) and it has no proper USB detection, (the only detection it has to switch between the USB and battery is USB 5V detection but it does have enumeration).

The problem occurs that the Audio MCU detects 5V power and immediately switches to process 2 even if its a dedicated charger, but I would like the Audio MCU to continue process 1 during dedicated charging and only go to process 2 when a PC/MAC is detected.

This is why I went with the BQ24160 with its USB detection, but I was wondering can another PHY/USB Audio MCU be connected to the data lines while it is also connected to the BQ24160 for USB detection.

And if so are there extra precautions we need to take on hardware or programming side? 

I have attached an simple block image to help understand the idea.

Best regards

Mo

  • 0
    TI__Mastermind 25800 points

    Hey Mo,

    In regards to the shared data lines, I believe that may affect the DPDM detection (as per USB BC1.2) that the charger runs when on USB power.

    I would suggest a part like the bq25895M (Please note: Default battery regulation voltage for this part is 4.352V. Just be aware of your battery spec and change the VREG bits to match) that runs D+D- detection, and includes a DSEL pin that can be tied to the SEL pin of a USB Mux/Switch like the TS3USB221A. This allows the part to release the data lines to your Audio MCU in the event a non-DCP is detected.

    Only the non-DCP port types (SDP, CDP) will release the data lines to you. However, I think one issue is that your Audio MCU automatically switches when it detects 5V USB, which is when any USB port is connected.

    Do you have any other way to detect valid data communication through the MCU?


    Regards,
    Joel H

    EDIT: Changed bq25895 to bq25895M

    EDIT2: Comment about default VREG

  • 0 in reply to Joel Hernandez II
    Intellectual 540 points

    Hello Joel,

    The only way I can see to control the switchover would be if there is a pin which only activates when SDP and CDP are active so the SPST switch which locks out the 5V USB power supply to the audio MCU activates when the pin is pulled.

    I am considering another option which may reduce cost of BOM seeing as the original reason for using the BQ24160 was to daisy chain it with a Gas Gauge from BQ27530-G1, was to go with a hardware only option, using BQ24392 detection switch with passthrough and BQ24072T charger with BQ27421 Gas Gauge.

    But have an issue about the charger, BQ24072T and its regulated voltages, the link to that question is here.

    e2e.ti.com/.../567808

    I think you have answered this post, thank you, and with the other chip you mentioned if I tie that SEL pin to the SPST switch control it should sort out the power switch over issue.

    Also, I would be really greatfull if you would be able to provide me answer to the problem with the other charging IC, I have attached the url link.

    Best regards

    Mo

  • 0 in reply to MohammedAl-Amin
    TI__Mastermind 25800 points
    Hey Mo,

    I just want to slightly change my recommendation from the bq25895 to the bq25895M.

    And I will look into your other post, or try at least find someone on our team with more experience with specific charger.


    Regards,
    Joel H
  • 0 in reply to Joel Hernandez II
    Intellectual 540 points

    That is much-appreciated thank you Joel