In variable commutation scheme, MCT8316A device switches dynamically between 120° and 150° trapezoidal commutation depending on motor speed. The device operates in 150° mode at lower speeds and moves to 120 mode at higher speeds. In 120° commutation, when motor phase is Hi-Z due to stored inductive current, there is torque ripple in phase current which leads to acoustic noise. In order to reduce the effect of torque ripple and improve acoustic noise, in a variable commutation mode MCT8316A device reduces the phase current by extending 120° driving time and gradually decreasing duty cycle prior to entering Hi-Z state. In this mode, phase is Hi-Z between 30° and 60° and this window size is dynamically adjusted based on speed, smaller window size gives best acoustic performance. Figure 2-8 shows the phase current and current waveform FFT in 150° commutation. Phase current shape is more sinusoidal waveform in 150° commutation mode.