The Gate resistors R_HO and R_LO are sized to reduce ringing caused by parasitic inductances and capacitances and also to limit the current coming out of the gate driver.  For this design 3.01Ω resistors were selected.

• R_HO/R_LO: External gate resistors
• V_BOOT: Forward voltage drop of external bootstrap diode
• R_OL/R_OH: Gate driver pulldown/pullup resistance from datasheet
• R_NMOS: Effective resistance of pullup NMOS in hybrid structure
• R_{G_int}: Power transistor internal gate resistance, found in power transistor datasheet

Maximum HO Drive Current (I_HO(src)):

Maximum HO Sink Current (I_HO(sk)):

Maximum LO Drive Current (I_LO(src)):

Maximum LO Sink Current (I_LO(sk)):

The external gate driver resistors, R_HO and R_LO, are used to:

1. Limit ringing caused by parasitic inductances/capacitances in the gate drive loop.
2. Limit ringing caused by high voltage/current switching dV/dt, dI/dt, and body-diode reverse recovery.
3. Fine-tune gate drive strength, for example peak sink and source current to optimize the switching loss.
4. Reduce electromagnetic interference (EMI) related to switching.