For BLDC motor, square wave and sine wave are two different motor drive solutions, with its own advantages and disadvantages.
Square wave drive is widely used. Its advantages are of high torque, simple control, low cost. But its disadvantages are of torque fluctuation and large noise.
Due to complex algorithm, sine wave drive becomes one technical bottleneck many companies are trying their best to break through. Its advantages are of smooth torque, high efficiency and low noise. However its disadvantages are of complex control and high cost.
Therefore, customers should properly select BLDC motor drive solution according to product characteristics and application occasions.