RDDSCSENSORLESSBLDC: 3-Phase Brushless DC Motor Sensorless Control Reference Design using 56F801X

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• Overview
• Features
• Block Diagram
• Board
• Design Resources

Overview

This reference design is a 3-phase brushless DC (BLDC) motor sensorless drive for fans, pumps and compressors based on the low-cost NXP® 56F801x digital signal controllers (DSCs).

• The concept is a closed-loop speed-controlled BLDC drive with no need for position or speed sensors
• AIt serves as a reference design for a BLDC motor sensorless control system, ideal for fan, pump and compressor applications
• Power stages used by the application are designed for 12V DC line voltage and 3Aor 8A output current
• The reference manual provides a detailed description of the application, including design of the hardware and the software

Features

• 3-phase brushless DC motor sensorless drive
• Designed to fit into fan, pump and compressor applications
• Uses 56F8013 32 MIPS Digital Signal Controller
• Available for two power stages and two motors
• Input power supply voltage +12 VDC for power stages
• Control techniques incorporate:
  • Sensorless, trapezoidal control of 3-phase BLDC motor with back-EMF sensing
  • ADC zero crossing sensing for sensorless control
  • Closed-loop speed control using PI controller
  • Adjustable DC-bus current limitation PI controller
  • Motoring mode
  • Both directions of rotation
• Speed range: 200-2000 and 800-8000 RPM (depending on the motor used)
• Manual interface (RUN/STOP switch, UP/DOWN pushbuttons)
• FreeMaster interface for monitoring, controlling and tuning
• Fault protection (DC-bus over-current, DC-bus under-voltage, DC-bus over-voltage)
• Automatic calibration of phase back-EMF measurements
• 20 kHz PWM switching frequency
• Easy to tune for different power stages and motors.

Block Diagram

Board

Design Resources