The gate driver accepts the low-voltage PWM signal and level shifts it to drive a high-current, full-bridge, power-FET stage. The device uses proprietary techniques to optimize EMI and audio performance.

The gate-driver power-supply voltage, GVDD, is internally generated and a decoupling capacitor is connected at pin 9 and pin 10.

The full H-bridge output stages use only NMOS transistors. Therefore, bootstrap capacitors are required for the proper operation of the high side NMOS transistors. A 1-µF ceramic capacitor of quality X7R or better, rated for at least 16 V, must be connected from each output to the corresponding bootstrap input (see the application circuit diagram in Figure 10-2). The bootstrap capacitors connected between the BST pins and corresponding output function as a floating power supply for the high-side N-channel power MOSFET gate drive circuitry. During each high-side switching cycle, the bootstrap capacitors hold the gate-to-source voltage high keeping the high-side MOSFETs turned on.