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Want a SMALL solution for the battery charger.

Jiwei Fan
Prodigy 10 points
Other Parts Discussed in Thread: UCC28700, TPS2511

Just want to know which part can give us a smallest solution for a 5V 2A battery charger. The input voltage is 100-240V 50/60Hz. 

Thanks, 

  • 0
    Prodigy 5 points

    Hello Jiwei,

    Thank you for posting.

    PMP8286 on TI.COM is a perfect small size solution for a charger.

    This reference design uses the UCC28700 in a quasi-resonant flyback to generate an isolated 5V at up to 2.1A. The UCC28700 implements primary-side regulation, eliminating the need for an opto-coupler and reducing the total component count. This results in a compact and cost effective design. The populated circuit boards in this design occupy the space of a 1" by 1" by 1" cube. The TPS2511 USB power switch also offers the data line control to charge most smart phones and tablets. The energy saving features of the UCC28700 allow this design to consume less than 30mW when plugged into the wall with no device attached to the USB port.

    All materials for creating this design are available at the link.

    This design hardware is not available for purchase.

    Here is a  picture of what it looks like;

    If this answers your question please confirm with the THIS RESOLVED MY ISSUE button.

  • 0 in reply to Ed Walker
    Prodigy 10 points
    Hi Ed,
    This is a very good information. Does Ti have any transformerless solutions for the same spec?
    I would imagine the overall dimension will be much smaller than the design with transformers.

    Thank you,
    Best Regards,
    Rui
  • 0 in reply to Rui Zhang
    Prodigy 5 points
    Hello Rui,
    Since the input voltage is 100-240V 50/60Hz, the output must be safety isolated from the AC input.
    Otherwise an extreme shock hazard is realized.

    And due to the large stepdown ratio, the transformer turns ratios make the conversion possible.
    240VAC = 340V peak DC, converting 340V to 5V requires a very narrow duty cycle of 5/340= 1.4%
    This low duty cycle is not realistic for a stepdown converter.

    There is no other way to do an AC input design like this.