SLVSH53 December 2023 MCT8315Z
PRODUCTION DATA
Figure 8-34 shows the operation of AAR in PWM mode. As shown in this figure, a PWM is applied in a synchronous rectification to the high-side and low-side FETs. During the low-side FET conduction, for lower inductance motors, the current can decay to zero and becomes negative since low side FET is in on-state. This creates a negative torque on the BLDC motor operation. When AAR mode is enabled, the current during the decay is monitored and the low-side FET is turned off as soon as the current reaches near to zero. This saves the negative current building in the BLDC motor which results in better noise performance and better thermal management.