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BQ24133: System Voltage

Part Number: BQ24133
Other Parts Discussed in Thread: BQ25600, , BQ25713

Hi,

I am having trouble understanding how this part works. I am specifically trying to know the system voltage being output and whether/how this can be configured. Please also let me know how the system voltage will change depending on various power path management conditions. Directions towards applicable sections in the datasheet are also appreciated.

Thanks

  • Hi Daniel,

    The BQ24133 uses the powerpath selector architecture to pass through the input power supply voltage to the system. If there is no input power supply, then the system is provide by the battery. We have the NVDC powerpath topology ICs (for example, BQ25600) that provides a minimum regulated system voltage from the integrated buck converter to the system. Can your end application be powered from the input source (5V, 12V) or now higher than your max battery voltage (4.2V for 1S LiIon battery for example)?

    Regards,
    Jeff
  • I will be using a 3s Li-ion battery and charging will be via USB 2.0 or a USB power adapter. My circuit will require both a +12V and +/-5V regulated power output.

    I was originally looking at the BQ25713 for its NVDC regulated system voltage as you mentioned, but I decided to not use this as I prefer a standalone battery charging system (such as the BQ24133)  vs host controller as I am very limited on time to design my system as well as I would like a battery charger that is as simple to use as possible.

    Given what I have just said, would you suggest I use the BQ24133 along with 3 DC-DC converters to achieve 12V and +/-5V system voltages? (12V LM3478) (+5V TPS62122 -> -5V TPS60401)

    Thanks

  • Daniel,

    The BQ24133 charging is a buck only charger so its input voltage must be slightly larger than 3s LiIon ~=12.6V, not USB 5V. For USB 5V, you need a boosting charger. The only boosting charger TI has is BQ25713. If you can place a standalone boost converter from 5V to at least 13.5V in front of the BQ24133 then it will function. TI currently does not have a standalone boost charger.

    Regards,
    Jeff
  • I am trying to design my system to work with the BQ25713 now. In the typical application section of the datasheet it seems the resistors used are measured in wattage?
    Do you have any other examples that I could look at?
  • Hi Daniel,

    The datasheet has typos. The "W" are supposed to be the ohm symbol.

    regards,
    Jeff