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BQ51050B: How to selection R (FOD), R(term), R (ILIM), R(RECT).

Part Number: BQ51050B

as Reference data:  tidraz7.pdf and data sheet(8.3.4.3 Battery Charge Current Setting Calculation)

It is too complex on spec description on selection R (FOD), R(term), R (ILIM), R(RECT). Can you calculate it for me?

My operation is Li-Pol Battery (100mAH, 50mA charge, 20mA discharge), system operation using 5mA.

tidraz7.pdfbq51051b.pdf

6 Replies

  • The FOD calculation is determined by measurements with an FOD TX designed for this purpose. I cannot calculate it.
    If you are NOT going to Qi certify the unit and only operate with your TX you may have other options.

    Best Regards,

    Bill Johns,  Applications Engineer

    Texas Instruments Inc

    Dallas, Texas

    Please click "This resolved my issue" button if this post answers your question.

    For more information on Battery Charger Solutions see Link

  • In reply to Bill Johns:

    BQ51050B is receiver chip. your replay do not answer my question on the chip resister value.

    BQ51050B: How to selection R (FOD), R(term), R (ILIM), R(RECT).

  • In reply to user4104025:

    For a unit that will be certified to Qi standard see below application not on how to measure then calculate the FOD resistor value, R(FOD) and R(OS).
    www.ti.com/lit/zip/sluc577

    R(term) and R(ILIM) setting can be found in the data data sheet section 8.3.4.3.1 and 8.3.4.3.2.

    Best Regards,

    Bill Johns,  Applications Engineer

    Texas Instruments Inc

    Dallas, Texas

    Please click "This resolved my issue" button if this post answers your question.

    For more information on Battery Charger Solutions see Link

  • In reply to Bill Johns:

    It is too complex on spec description on selection R (FOD), R(term), R (ILIM), R(RECT). Can you calculate it for me?

    My operation is Li-Pol Battery (100mAH, 50mA charge, 20mA discharge), system operation using 5mA.
  • In reply to user4104025:

    Hi there,

    The datasheet specifies the calculation equations and we encourage you to calculate and understand the relationship of parameters and design considerations.

    Regards,

    Eric

    Texas Instruments

    Battery Charger Solutions

  • In reply to ezhao:

    My operation is Li-Pol Battery (100mAH, 50mA charge, 20mA discharge), system operation using 5mA.
    I will use WPC Qi TX standard.
    1. bq51051b.pdf page 8, the Ibuck parameter min is 500mA, can I use the chip direct charge the battery?
    2. how is Rfod?
    3. please help to provide R(term), R (ILIM), R(RECT) base on battery charging 50mA

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