• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 65 subscribers
  • Views 233 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

TPS25840-Q1: Current draw of more than 1.5A

Danilo A.
Mastermind 27680 points
Part Number: TPS25840-Q1

Hi Team,

We would like to ask your help regarding the customer's inquiry.

We are currently using this chip on our system; it is a 5 V, 3.5 A USB Type-A converter with BC1.2

However, when we plug in USB devices, the maximum current a device will draw is 1.5 A; how can we draw a higher current (rated 3.5A) from that converter?

Per the datasheet, it appears that there are a few modes the converter can operate in, shown in Table 10-5. In all port types, the maximum allowable current drawn by portable equipment is limited at 1.5 A or lower

If that is the case, why is the converter rated for 3.5 A? Are there cases where we can draw more current than 1.5 A?

Just to make sure I got my concern addressed correctly: I want to know if there are any commercial devices that could ignore the BC1.2 and draw more than 1.5 A. (With an electronic load, I was able to draw more than 3 A). However, commercial products like phones/tablets seems to be limited to 1.5A. If that is the case, could we potentially make 2 USB ports in parallel for a single converter, since we operate in DCP (dedicated charging port).

Regards,

Danilo

  • 0
    TI__Expert 3890 points

    Hi Danilo,

    How much current the mobile phone can draw and how much current the 840 can output are separate.

    The maximum output of 840 is 3.5A (this is determined by DCDC), and how much current the mobile phone can draw is determined by the mobile phone and the charging protocol.

    BC 1.2 (DCP/CDP) can support up to 1.5A, 1.2-V Mode (Samsung) supports 2A, and Divder 3 (Apple) supports 2.4A. So for the 840, it can support Apple devices up to 2.4A.

    Regards,

    Ansel

  • 0 in reply to Ansel Song
    TI__Mastermind 27680 points

    Hi Ansel,

    Thank you for this information. Another question that he asked is,

    "If that is the case, could we potentially make 2 USB ports in parallel for a single converter, since we operate in DCP (dedicated charging port)."

    Regards,

    Danilo

  • 0 in reply to Danilo A.
    TI__Expert 3890 points

    Hi Danilo,

    No, because the current is limited by portable devices (mobile phone) that means the  portable devices cannot draw the large current not IC.

     

    Regards,

    Ansel