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TPS2511: 10W charging vs 1.5A standard for DCP

Jared Becker
Genius 11845 points
Part Number: TPS2511

Hi Team,

I am looking at the TPS2511 datasheet and am seeking clarification on a couple of tables..

Assuming I am supplying 5V to my device for charging..

In the first table, a DCP is specified to provide 1.5A:

5V @ 1.5A = 7.5W

However, there is a 10W setup available:

With 5V at the output, this means I am not charging at 2A..

To achieve this 10W output, does that mean I have to increase my voltage output to >5V since the standard for DCP is 1.5A? I am a little confused on the industry standard for fast charging at 5V. Any clarification would be super.

Thanks in advance.

Jared

  • 0
    TI__Mastermind 42795 points

    Hi Jared,

    Table 1 in the datasheet shows the maximum allowable current drawn by the portable device and not the current sourced by the charging port (DCP or CDP). This is per the BC1.2 specification section 4.6. You can see this below along with CDP and DCP current sourcing requirements.

    Table 2 in the datasheet shows the charging schemes supported by TPS2511. Divider and 1.2V are proprietary modes (not per BC1.2) supported by two large suppliers of portable devices. TPS2511 supports these modes and BC1.2 DCP mode for a better user experience. So, as long as the TPS2511 current limit is set for the highest expected portable device current draw (maybe 2A for a divider 2 device such as iPad) then TPS2511 can charge at 5V.

    If you use the cable droop compensation with the DC/DC converter, the nominal 5V will be slightly higher under load but usually will be < 5.5V.

  • 0 in reply to Eric Wright
    TI__Genius 11845 points
    Hi Eric,

    A couple quick questions for you. I am using the TPS2511 in my circuit and need to test it, but I am not seeing a voltage at the output with 5V connected to the input. I believe this is because I have nothing connected to D+ or D-, so the auto-detect feature is not allowing a voltage at the output.

    1. Is my assumption regarding D+ and D- correct?
    2. If it is, what should I apply to D+ and D- to allow the device to output 5V @ 2A?

    Thank you!
    Jared
  • 0 in reply to Jared Becker
    TI__Mastermind 42795 points

    Jared,

    You should have 5V on the OUT pin with nothing connected to D+/D- as long as EN is active (high).