SLLA663 March   2025 MCF8315A , MCF8315C , MCF8315C-Q1 , MCF8315D , MCF8316A , MCF8316C-Q1 , MCF8316D , MCF8329A , MCT8315A , MCT8316A , MCT8329A

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2End Application Configuration Recommendation
    1. 2.1 Resynchronization
    2. 2.2 Reverse Drive
    3. 2.3 Coasting (Hi-Z)
    4. 2.4 Startup Brake
    5. 2.5 Direction Change Mode
  6. 3Tuning Guidance
    1. 3.1 Initial Speed Detection Module
      1. 3.1.1 Initial Speed Detection
      2. 3.1.2 ISD Times
      3. 3.1.3 Stationary Detect Threshold
    2. 3.2 Resynchronization
      1. 3.2.1 Forward Drive Resync Threshold
      2. 3.2.2 Reverse Drive
      3. 3.2.3 Reverse Acceleration Parameters
      4. 3.2.4 Reverse Drive Current Limits
      5. 3.2.5 Reverse Drive Handoff Threshold
      6. 3.2.6 Reverse Drive Open Loop Deceleration (REV_DRV_OPEN_LOOP _DEC)
    3. 3.3 Coasting (Hi-Z)
    4. 3.4 Brake
      1. 3.4.1 Brake Config (BRK_CONFIG)
  7. 4Feature Availability of MCx Devices
    1. 4.1 FOC Family (MCF83xx devices)
    2. 4.2 TRAP Family (MCT83xx devices)
  8. 5Summary
  9. 6References

2.5 Direction Change Mode

Decides whether direction change is executed through full pre-startup state machine or through reverse drive depending upon DIR_CHANGE_MODE configuration.

When recommended:

  • In end applications where direction change is expected during operation, DIR_CHANGE_MODE is set to 1b. This requires the reverse drive parameters to be tuned as reverse drive is used to change direction.
    • Example: In massage chair motors that frequently change direction, DIR_CHANGE_MODE to 1b.
  • In end applications where reverse drive is not common and can afford to stop the motor by coasting and applying brake before starting in opposite direction, set the direction change mode to 0b and disable reverse drive by setting RVS_DR_EN to 0b. This saves tuning effort for reverse drive.
    • Example: Server fans have fixed direction of spinning.
  • When RVS_DR_EN is set to 1b and reverse drive is tuned, DIR_CHANGE_MODE can be set to 0b as reverse drive is executed on direction change command.