PWM (Pulse Width Modulation) is the core method for achieving precise speed control in motor drive chips. It controls the average voltage and speed of the motor by adjusting the duty cycle. Modern chips support a wide frequency range of PWM input; for example, the SS6548D supports frequency adjustment from 0-50kHz, and the TB6612FNG supports PWM frequencies up to 100kHz, achieving efficient and quiet stepless speed regulation.
Field-Oriented Control (FOC) is an advanced control algorithm that is efficient, stable, and low-noise. By independently controlling the motor's magnetic field and torque components, it achieves precise torque and speed control across the entire speed range from low to high. It is suitable for three-phase brushless DC (BLDC) motors (such as the Melexis MLX81339). To improve processing speed and reliability, some manufacturers (such as PeakTech) adopt a hardware-based approach, implementing complex motor control algorithms (such as sensorless algorithms and vector control algorithms) at the hardware level through logic circuits during the chip design stage, forming a dedicated processor core.
