AVR® 8-Bit RISC - Applications - Three-phase Brushless DC Motors

Back to Motor Control AVR Solutions

Three-phase Brushless DC Motors provide excellent performance characteristics with and without position sensors.
Sensor-based BLDC are used when initial load is unknown or varies, or when high initial torque is required.
Sensorless BLDC motors are typically used in fans where they save Hall sensors and wiring.

Typical applications:
- Power tools
- Refrigerators/Cooling (compressors)
- HVAC (e.g. Fan)

Sensor-based Control of Three-phase BLDC

Hall-sensor based control of three phase BLDC
- Hall-sensor inputs on IO with Pin-Change-Interrupt
- Speed controlled using PWM channels connected to low side drivers

Current monitoring: Using ADC or Analog comparator

Communication supported: TWI, SPI and UART

Target device: ATmega48/88/168, any AVR with three PWM outputs

Document	Software	Description
		AVR443: Sensor-based control of Three-phase Brushless DC motor (8 pages, revision A, updated 06/05)
		AVR447: Sinusoidal driving of three-phase permanent magnet motor using ATmega48/88/168 (26 pages, revision A, updated 06/06)
		AVR448: Control of High Voltage Three-phase BLDC Motor (10 pages, revision A, updated 07/05)
		AVR492: Brushless DC Motor control using AT90PWM3 (26 pages, revision A, updated 07/05)
		AVR493: Sensorless Commutation of Brushless DC Motor (BLDC) using AT90PWM3 and ATAVRMC100 (19 pages, revision A, updated 07/06)
		AVR452: Sensor-based Control of Three Phase Brushless DC Motors Using AT90CAN128/64/32 (10 pages, revision A, updated 03/06)

Sensorless Control of Three-phase BLDC

Control of three-phase sensorless BLDC Motor
- Rotor position determined by using differential ADC
- Speed controlled using PWM channels connected to low side drivers

Over-current monitoring: Using ADC or Analog comparator

Communication supported: TWI, SPI and UART

Target device: ATmega48/88/168, ATmega64, AT90PWM3

Document	Software	Description
		AVR444: Sensorless control of 3-phase brushless DC motors (14 pages, revision A, updated 10/05)