SLVAFZ3 December   2024 DRV8161 , DRV8162 , DRV8350 , DRV8350F , DRV8353 , DRV8353F

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2System Power Requirements
  6. 3Motor Current and MOSFET Selection
    1. 3.1 How Does a BLDC Motor Driver System Work?
    2. 3.2 Motor Current and QG Value Relation
    3. 3.3 Role of a Motor Driver
    4. 3.4 Can my MOSFET be Driven or Commutated?
      1. 3.4.1 Example 1 – Medium Power (4.8kW – 48V × 100A)
      2. 3.4.2 Example 2 – High Power (19.2kW – 48V × 400A)
  7. 4Motor Driver Specifications to Consider
    1. 4.1 DRV8353 - Internally Generated Gate Drive Supply
    2. 4.2 DRV8161/DRV8162 – Externally Generated Gate Drive Supply
  8. 5Advantages of TI’s BLDC Drivers With Smart Gate Drive
  9. 6Maximum Source and Sink Current and QGD
  10. 7Older Designs
  11. 8Summary
  12. 9References

3.1 How Does a BLDC Motor Driver System Work?

Brushless DC motors use electrical commutation to drive a three-phase motor. Modulated PWM signals are applied as input to the motor driver to control the torque and speed of the motor. A BLDC gate driver is used to control 3 sets of half bridges. The input commands from the controller get scaled through the driver’s power stage to generate gate driving voltage of the MOSFET. The commutation algorithm is used to supply power to the motor in the manner required by the application. The magnetic field on the stator coils, from the applied voltage, interacting with the magnetic field of the rotor, is used to spin the motor.

In a 3-phase BLDC motor driver system, Figure 3-1, the current is supplied from the battery to the motor using 6 N-type MOSFETs arranged in 3 pairs of H-Bridges.

Three-Phase BDLC Motor DriverFigure 3-1 Three-Phase BDLC Motor Driver