• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 64 subscribers
  • Views 171 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.

BQ24259: Inquiries about the operation of BQ24259

JH Shin
Mastermind 8815 points
Part Number: BQ24259

Hello,

My customer plans to design a power supply block using TI's devices as shown below.

The customer has some questions about the operation of the BQ2459.

1. If they used a 317ohm resistor on the ILIM pin of the BQ24259 to limit the current to 1.5A, would the total supply wattage be 7.5W?

2. Is it possible to output the rest of the power source except for the battery charging in the BQ24259 as a bypass?

3. Is it possible to send all input power to the output when no battery is connected to the bQ24259?

4. Can the customer turn the BQ24259 output on/off while charging the battery?

Thank you.

JH

  • 0
    TI__Guru 52301 points

    JH,

    1. The actual input current limit is the lower one set by ILIM and by I2C REG00[2:0]. It will be related to the input source power capability and if DPM (8.3.2.2 Dynamic Power Management) limits the input power.

    2. The charger may support VSYS only.

    3. Yes

    4. The charger may support VSYS only without charging the battery. If VSYS is shutdown, the device can't charge neither.

    Thanks,

    Ning.

  • 0 in reply to Ning T
    Mastermind 8815 points

    Hello Ning,

    Thank you for your reply.

    The customer has additional questions about the BQ24259.

    1. The following register map shows that the input current can also be set via the PSEL pin and the OTG pin.

        What is the difference between using the ILIM pin?

    2. Is it possble to leave the ILIM pin open if they used the PSEL pin and OTG pin to set the input current?

    Thank you.

    JH

  • 0 in reply to JH Shin
    TI__Guru 52301 points

    JH,

    1. The actual input current limit is the lower one set by ILIM and by I 2C REG00[2:0]. Please refer to 8.3.5.1 Input Current Limit on ILIM on the d/s for the details.

    2. If ILIM pin is short, the input current limit is set by the register.

    Thanks,

    Ning.