SLVSHC7 December 2023 DRV8334
PRODUCTION DATA
The bootstrap diode is necessary to generate the high-side bias and is included in the driver device. The diode anode is connected to GVDD through an internal resistor and cathode connected to BSTx. With the CBST capacitor connected to BSTx and the SHx pins, the CBST capacitor charge is refreshed every switching cycle when SHx transitions to ground. The capacitor value CBST is dependent on the gate charge of the high-side MOSFET and must be selected considering PWM control and voltage drop of the MOSFET gate. The boot diode provides fast recovery times, low diode resistance, and voltage rating margin to allow for efficient and reliable operation.