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.

BQ25820: Request for Schematic and Technical Support for 20A, 48VDC Charger Design Using BQ25820

Part Number: BQ25820

Tool/software:

Dear Texas Instruments Technical Support,

We are reaching out regarding the BQ25820 battery charger IC. We are currently evaluating this device for a high-current application and have reviewed the datasheet, which suggests support for flexible system voltages and currents. However, the official BQ25820 evaluation module (EVM) appears to be rated for 10A only.

We are interested in developing a battery charger system with the following key requirements:

  • Output current: 20A continuous (or higher, if possible)
  • System voltage: 48VDC (10S Li-ion configuration)
  • Compact, reliable design

We would like to request the following:

  1. A reference schematic or application note for a 20A, 48VDC charger using the BQ25820, including guidance on sizing external components (inductor, capacitors, PCB layout, thermal design, etc.).
  2. Clarification of the BQ25820’s absolute maximum current and voltage limits when used with upgraded external passives, as the datasheet’s example designs are only up to 5A and the EVM is only rated for 10A.
  3. Any specific recommendations or best practices for safely implementing high-current charging in this topology, or, if the BQ25820 is not intended for such applications, suggested TI charger ICs and design resources better suited to >20A, 48VDC battery charging.

We are keen to align our design with best practices and TI’s recommendations, and your advice or technical documentation would be greatly appreciated.

Thank you in advance for your support.

  • Hello Pacvac,

    A reference schematic or application note for a 20A, 48VDC charger using the BQ25820, including guidance on sizing external components (inductor, capacitors, PCB layout, thermal design, etc.).

    I would recommend using our BQ25820 EVM as a starting point. The official EVM is only guranteed for 10A, but I have ran tests above 20A, and had no major issue. The only issue I observed was heat dissapation, you will need a find a way to increase the heat dissipation on the switching FETS/IC.

    My recommendation would be to increase copper pad under the switching FETS and inductor, and add many thermal vias under the IC. Another option is to change out the Switching FETs. I've seen other customers application that go up to 20A use IAUT165N088s5N029, but I have not tested them myself.

    Best Regards,

    christian.