Smart gate driver with trapezoidal commutation for three-phase BLDC motor applications

The Texas Instruments DRV8306 device is an integrated gate driver for three-phase BLDC motor applications. The device gives three half-bridge gate drivers, each able to drive high-side and low-side N-channel power MOSFETs. The device creates the proper gate drive voltages with an integrated charge pump for high-side MOSFETs and a linear regulator for low-side MOSFETs. The smart gate drive construction supports up to 150mA source and 300mA sink peak gate drive current, and 15mA rms gate drive current capability. The device gives an internal 120-degree commutation for the trapezoidal BLDC motor. The device has three Hall comparators using the input from the Hall elements for internal commutation. The duty cycle ratio of the phase voltage of the motor can be altered through the PWM pin. Extra brake (nBRAKE) and direction (DIR) pins are given for braking and setting the direction of the BLDC motor. A 3.3V, 30mA LDO regulator, is given to supply the external controller and Hall elements. A further FGOUT signal is offered which is a measure of the commutation frequency. This signal can be used for implementing the closed-loop control of BLDC motor. A low-power sleep mode is offered to deliver low quiescent current draw by shutting down most of the internal circuitry. Internal protection functions are offered for undervoltage lockout, charge pump fault, MOSFET short circuit, MOSFET overcurrent, gate driver fault, and overtemperature. Fault conditions are shown on the nFAULT pin.