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BQ25190: Concerned about heat dissipation - larger package available?

Jörg Pressel
Prodigy 20 points
Part Number: BQ25190

Tool/software:

Hi there,

the BQ25190 would be a perfect match for our setup (LifePO4 charging, 3V3 constant, another 3.3V, 1.8V and 5V switchable, I2C). I'm concerned regarding the heat dissipation when under full load and charging (I calculated about 1.3W in total). Any recommendations for a similar product with a larger package that would meet our needs? Any plans for a "BQ25190" in a larger package?

Thanks,

Jörg

  • 0
    TI__Genius 14055 points

    Hi Jorg,

    The BQ25190 isn't currently available in a larger package. The thermal dissipation can be an important item to take into consideration but there are many design guidelines, particularly with regards to board layout, that can greatly help to improve thermal performance with the device.

    What input voltages, charge currents, and load currents are you expecting from the charger and the various rails? Do you have control over your input expected input voltage?

    Best Regards,

    Juan Ospina

  • 0 in reply to Juan Ospina
    Prodigy 20 points

    Hi Juan,

    - Input: 5V USB-C
    - 1 LiFePO4 Cell, desired charging: 780mA (if necessary could lower to 500mA)
    - 3.3V rail (always on): 70-120mA (ESP32-S3)
    - 1.8V rail (switchable): 3mA (neglectable)
    - 3.3V rail (switchable): 4mA (neglectable)
    - 5V rail (switchable): 100mA

    A large ground plane, perhaps thicker copper and enough ground vias would certainly help. Or even a heat sink.

    Just go for it?

    Thanks,

    Jörg

     

  • 0 in reply to Jörg Pressel
    TI__Genius 14055 points

    Hi Jörg,

    I will try these settings using our EVM in-lab to provide an idea of typical behavior in a 25C ambient environment. This is to get an idea of the kind thermal dissipation you can expect to see assuming a similar board design consideration.

    Thicker copper and ground vias would definitely improve performance. A heat sink, if possible, would help as well.

    Best Regards,

    Juan Ospina

  • 0 in reply to Juan Ospina
    Prodigy 20 points

    That'll be great! I have to wait for availability of samples of the BQ25190 whatsoever ...

  • +1 in reply to Jörg Pressel
    TI__Genius 14055 points

    Hi Jörg,

    I was able to capture some temperature data relating to the IC with this set up:

    VIN = 5V

    VBAT = 2.9V

    VBUCK = 1.8V IBUCK = None

    VLDO1 = 3.3V ILDO1 = 120 mA (E-load)

    VLDO2 = 3.3V ILDO2 = None

    VBUBO = 5V IBUBO = 100mA (50 Ohms)

    With an ambient temperature of 21.8C I was able to gather these are the peak temperature values I captured from using the IC on its EVM with a thermal camera.

    - ICHG = 100 mA, peak temperature 33.8°C

    - ICHG = 250 mA, peak temperature 41.8°C

    - ICHG = 500 mA, peak temperature 55.4°C

    - ICHG = 780mA, peak temperature 70.4°C (71°C per the ADC).

    The EVM specifics can be seen on the user's guide. The board is 4-layer and 1 oz (1.4mil copper thickness).

    Best Regards,

    Juan Ospina

  • 0 in reply to Juan Ospina
    Prodigy 20 points

    Hi Juan,

    thanks a lot that should certainly work! I've ordered the EVM along with some BQ25190 from Digikey as it's now available. This chip is really a game changer, thanks again.

    Cheers,

    Jörg