3-Phase Brushless DC Motor Sensorless Control Reference Design Using 56F801X

This reference design is for 3-phase sensorless brushless DC (BLDC) motors for fans, pumps, and compressors based on the low-cost NXP Drive® 56F801X digital signal controller (DSC). The concept is a closed-loop speed-controlled BLDC drive that requires no position or speed sensors It is a reference design for a sensorless BLDC motor control system, ideal for fan, pump, and compressor applications The power stage used in the application is designed for a 12V DC line voltage and 3A or 8A output current The reference manual provides a detailed description of the application, including design features for both hardware and software Three-Phase Brushless DC Motor Sensorless Driver Designed for fan, pump, and compressor applications Uses the 56F8013 32 MIPS digital signal controller Can be used with two power stages and two motors Input supply voltage +12 VDC for the power stage Control techniques include: Sensorless, trapezoidal control of the three-phase BLDC motor with back-EMF sensing ADC zero-crossing detection for sensorless control Closed-loop speed control using a PI controller Adjustable DC bus current limit PI controller Driving modes Both directions of rotation Speed ranges: 200-2000 and 800-8000 RPM (depending on the motor used) Manual interface (RUN/STOP switch, UP/DOWN buttons) FreeMaster interface for monitoring, control, and tuning Fault protection (DC bus overcurrent, DC bus undervoltage, DC bus overvoltage) Automatic calibration of phase back EMF measurement 20 kHz PWM switching frequency Easy to adjust to different power levels and motors.