MCT8329A Sensorless Trapezoidal Control 3-Phase BLDC Gate Driver

Texas Instruments' MCT8329A provides a single-chip, code-free sensorless trapezoidal solution for applications requiring high-speed operation or very fast startup time for three-phase brushless DC (BLDC) motors. The device provides three half-bridge gate drivers, each capable of driving high-side and low-side N-channel power MOSFETs. The device generates correct gate drive voltages using an internal charge pump and enhances the high-side MOSFETs using a bootstrap circuit. A trickle charge pump is included to support a 100% duty cycle. The gate drive architecture supports peak gate drive currents up to 1 A source and 2 A sink.

The MCT8329A can operate from a single power supply and supports a wide input supply range of 4.5 V to 60 V. The sensorless trapezoidal control is highly configurable through the register settings in a non-volatile EEPROM (MCT8329A1I) ranging from motor start-up behavior to closed-loop operation, which allows standalone operation when it is configured. The motor current is sensed using an integrated current-sensing amplifier supporting a single external shunt resistor. The driver receives a speed command through the PWM input, analog voltage, variable frequency square wave, or I²C command. Multiple protection features are intended to protect the device, motor, and system against fault events.