SLVAES1A June   2020  – May 2022 DRV8300

 

  1.   Trademarks
  2. 1Motor Considerations and Why Brushless DC Motors?
  3. 2Motor Driver Architecture
    1. 2.1 Gate Driver vs Integrated FET Driver: Power, Voltage, and Current Requirements
    2. 2.2 Three Use Cases: Speed, Torque, or Position:
    3. 2.3 Control Methods: Trap, Sine, or FOC
      1. 2.3.1 Trapezoidal
      2. 2.3.2 Sinusoidal
      3. 2.3.3 Field-Oriented Control
    4. 2.4 Sensored Versus Sensorless
      1. 2.4.1 Sensored
      2. 2.4.2 Sensorless
    5. 2.5 Current Sense Amplifiers
    6. 2.6 Interface
    7. 2.7 Power Integration
    8. 2.8 100% Duty Cycle Support
  4. 3Texas Instruments' Brushless-DC Motor Drivers
    1. 3.1 Gate Drivers: DRV8x and DRV3x family
      1. 3.1.1 DRV8x Family
      2. 3.1.2 DRV3x Family
    2. 3.2 Integrated MOSFET: DRV831x Family
    3. 3.3 Control and Gate Driver: MCx Family
    4. 3.4 Full Integration: MCx831x and DRV10x Family
      1. 3.4.1 MCx831x Family
      2. 3.4.2 DRV10x family
  5. 4Conclusion
  6. 5Revision History

2.3 Control Methods: Trap, Sine, or FOC

Many Brushless-DC motor commutation methods can be used to satisfy specific system requirements. Commutation methods vary largely on the motor type, application, and solution needed for the system. Each motor control method can be implemented from an external microcontroller or integrated into the motor driver. TI's BLDC motor drivers provide a wide portfolio of integrated trapezoidal, sinusoidal, and Field-oriented control in the Control & Gate Driver and Full Integration portfolios.

Motor construction should be the main factor of choosing a control method. Brushless DC motors are wound trapezoidally or sinusoidally, determined by their Back-EMF (BEMF) waveform. To maximize torque and efficiency, the current driving the motor should match the shape of the Back-EMF waveform. Application type (torque, speed, or position) should also be considered when selecting a control method to optimize performance parameters.

A high-level overview of control method performance parameters are listed in Table 2-2.

Table 2-2 Comparison of Control Methods
Trapezoidal Sinusoidal Field-Oriented Control
Algorithm complexity Low Medium High
Motor efficiency (MTPA) Low Medium High
Maximum speed High Low Medium (Standard FOC)
High (Field Weakening)
MOSFET switching losses Low High High
Torque ripple High Medium Low
Audible noise High Low Low

For more detailed information on how each control method works and their advantages, visit TI's Precision Lab Videos on BLDC Motor Drivers.