TIDUF84 June   2024

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
    3. 2.3 Highlighted Products
      1. 2.3.1 UCC28810
      2. 2.3.2 MCF8315
      3. 2.3.3 MSPM0L
      4. 2.3.4 MSPM0C
  9. 3System Design Theory
    1. 3.1 MCF8315 Design
      1. 3.1.1 Power section
      2. 3.1.2 GPIO section
    2. 3.2 ACDC Design: Single Stage PFC
    3. 3.3 Host MCU Design
  10. 4Hardware, Software, Testing Requirements, and Test Results
    1. 4.1 Hardware Requirements
      1. 4.1.1 Hardware Overview
      2. 4.1.2 TIDA-010951 PCB
    2. 4.2 Software Requirements
    3. 4.3 Testing requirements
    4. 4.4 Test Setup
    5. 4.5 Test Results
      1. 4.5.1 Power Management in TIDA-010951
      2. 4.5.2 UCC28810 Based Single Stage PFC
      3. 4.5.3 BLDC Residential Fan Operation Using MCF8315C
        1. 4.5.3.1 Power-Up Sequence
        2. 4.5.3.2 Forward Windmilling (ISD Forward Resync)
        3. 4.5.3.3 Reverse Windmilling (ISD Reverse Resync)
        4. 4.5.3.4 Direction Reversal
        5. 4.5.3.5 Fan Acceleration/Deceleration
      4. 4.5.4 Thermal Performance
  11. 5Design and Documentation Support
    1. 5.1 Design Files
      1. 5.1.1 Schematics
      2. 5.1.2 BOM
    2. 5.2 Tools and Software
    3. 5.3 Documentation Support
    4. 5.4 Support Resources
    5. 5.5 Trademarks
  12. 6About the Author
  13. 7Recognition

4.5.3.4 Direction Reversal

MCF8315C-Q1 can reverse the direction of fan rotation without applying brake or relying on motor inertia to coast down. This is a useful feature to smoothly change the fan direction as seen in Figure 4-9. The fan is decelerated at a controlled slew rate to prevent voltage spike on 24V rail (using the AVS feature) and upon reaching zero speed is accelerated to set speed in the forward direction.

TIDA-010951 Direction Reversal Figure 4-9 Direction Reversal