FOR ABOVE 10KHz
Above this range, frequency have less influence in boot capacitor design
CAPACITOR VALUE = TOTAL GATE CHARGE / VOLTAGE DROP ACROSS BOOTSTRAP DIODE
EXAMPLE
- mosfet – CSD19534KCS
- BOOTSTRAP DIODE – UF4007
from data sheet
TOTAL GATE CHARGE = 16.4 nC
VOLTAGE DROP ACROSS BOOTSTRAP DIODE = 0.7
C = 16.4 nC / 0.7 = 23nF