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BQ25890: calculation power of BQ25890

Xiaoqiang Shen
Intellectual 420 points
Part Number: BQ25890

I calculate power based on below guide.

But missing MOSFET tr, tf, Qgate, vgs in datasheet.

Where can I get it?

BQ25890: Guideline for calculation total power dissipation - Power management forum - Power management - TI E2E support forums

  • +1
    TI__Mastermind 31090 points

    Hi Xiaoqiang Shen, 

    TI does not publish FET capacitances and turn-on/ turn-off switching times for internal switching FETs needed to compute switching power loss. Therefore if you are looking to calculate an estimation for switching loss use the first part of the equation you included for both the high side and low side switching FETs. Replace D with (1-D) in the equation for the low side FET.

    Alternatively you can calculate overall losses within the IC by measuring output and input power to determine efficiency and Ploss. efficiency (n) = Pout/Pin; Pin + Ploss = Pout, therefore Ploss = Pout(1-1/n).

    Regards,

    Garrett