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BQ24747 MOSFET Qg

Ankit Thakkar
Prodigy 90 points
Other Parts Discussed in Thread: BQ24747

Hi,

I am designing a LI-ION battery charger based on bq24747.

Regarding the gate charge drive capacity of bq24747, I did not find anything in the datasheet of BQ24747.

Any one having idea about gate charge capacity of BQ24747?

I appreciate your help.

Regards,

Ankit Thakkar

  • 0
    TI__Intellectual 2295 points

    1) on pg8 of bq24747 d/s. There's spec for the driver resistance (6Ohm on and 1Ohm off) and dead-time (30ns).

    2) cos all gate driver energy comes from VDDP, please check pg6 for the LDO capability (80mA@5V). And I_driver = Qg_total × fs, Qg here is total gate charge at 6V of siwtching MOSFET and Fs is the switching frequency.

    3) PICLoss_driver = VIN ×Qg_total × fs, please take the IC loss due to the VDDP LDO for consideration.