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BQ25890: Recommendations for Converting from USB 2.0 to USB-C

Ryan
Prodigy 80 points
Part Number: BQ25890
Other Parts Discussed in Thread: TS3USB221, TUSB422, TPS2121

Our existing solution for charging a device via USB 2.0 is a combination of the following:

  • BQ25890 and
  • TS3USB221 for switching the data to the Micro-controller for communication.

(This setup is as described in the BQ25890 EVM schematics)

However we would like to change the port to USB-C, for reversibility and to take advantage of higher current allowed on this port.

What is the easiest way to convert this design to USB-C?

Is it simply a matter of replacing the TS3USB221?

Best regards, R

  • 0
    TI__Guru**** 166596 points

    Hi Ryan,

    The 221 is a multiplexer which allows you to disconnect the charger from the USB bus after the charger has finished using the bus.  It actually isn't required as the charger as long as no other ICs use the D+/D- lines while the charger is using it (first 2 seconds after charger has input power and if the host does a force D+/D- detection) because the charger's D+/D- lines go HiZ when not in use.

    For USB type C compatibility you would need an IC like TUSB320LHI or TUSB422. 

    You can still use the charger's D+/D- to keep compatibility with the legacy USB ports. 

    You might want to add a TPS2121 power mux before the charger to protect against a user connecting both a legacy USB source and type C source at the same time.

    Regards,

    Jeff

  • 0 in reply to Jeff F
    Prodigy 80 points

    Hi Jeff,

    Thanks for the quick reply. The TUSB320LHI looks like a very good option.

    About the TPS2121: how would a user end up connecting both a legacy USB source and type C source at the same time?

    (Our device only has one port.)

    I can't picture what kind of configuration would need this protection.

    Thanks and best,

    Ryan

  • 0 in reply to Ryan
    TI__Guru**** 166596 points

    Hi Ryan,

    If you had two ports, one type C and another legacy USB then you might need TPS2121.  Years ago, when legacy USB wasn't legacy, many devices had a USB port and a power adapter port (barrel type, etc.).  I suspect initially some manufacturers will put USB type C and legacy USB for backward compatibility.  

    Regards,

    Jeff