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UCC27211A-Q1: Minimum Bootstrap Charge Up time

Part Number: UCC27211A-Q1

hi Sir/Miss,

May I know what is the minimum Bootstrap Charge Up time for UCC27211A-Q1 HSD with 0.1uF capacitor?

I cannot find it anywhere in the datasheet.

regards

Wilson.

  • Hello Wilson,

    Thank you for the interest in the UCC27211A-Q1. The bootstrap charging path for the bootstrap capacitor is from the VDD capacitor thru the bootstrap diode to the HB-HS capacitor. Also the HS thru the low side FET is the charging path. So the boor diode resistance plus low side FET on resistance and the bootstrap capacitor results in a time constant. t= Cboot x (Rd + Rdson). The boot diode resistance is 0.5 Ohms and boot cap is 0.1uF. If we assume Rdson of 0.1 Ohms then the time constant is t=0.1uF x 0.6 Ohms = 0.06us to reach 67% of the charge voltage.

    Please confirm if this addresses your question or you can post additional questions on this thread.

    Regards,