SDAA266B March   2026  – May 2026 MSPM0C1104 , MSPM0C1106 , MSPM0G3507 , MSPM0L1306

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Block Diagram
    1. 2.1 Power Supply Module
    2. 2.2 Zero-Crossing Detection (ZCD)
    3. 2.3 Current Detection
    4. 2.4 MSPM0 Microcontroller
    5. 2.5 TRIAC
  6. 3Phase Angle Control
    1. 3.1 Operating Principle
    2. 3.2 Boundary Conditions and Special Cases
    3. 3.3 Implementation with MSPM0
  7. 4Soft-Start Feature
  8. 5Software
    1. 5.1 Software Workflow
    2. 5.2 Zero-Crossing Detection Implementation
    3. 5.3 Pulse Generation
    4. 5.4 Update Targeted Speed
    5. 5.5 Overcurrent Protection
    6. 5.6 User System Define
  9. 6Results
    1. 6.1 Scope Waveforms
    2. 6.2 Speed Change
    3. 6.3 Soft Start
    4. 6.4 Temperature
  10. 7Summary
  11. 8References
  12. 9Revision History

3.3 Implementation with MSPM0

This reference design implements three discrete speed levels to provide simple and intuitive motor control:

  • Speed High:1000μs delay (approximately 162° firing angle) – Maximum power delivery for highest motor speed.
  • Speed Middle:5000μs delay (approximately 90° firing angle) – Medium power for moderate speed.
  • Speed Low:7000μs delay (approximately 54° firing angle) – Minimum power for lowest operating speed.
  • The boundary setting for the firing angle is 30.6°.

The MSPM0 uses a high-resolution timer to precisely measure the AC period through zero-crossing detection. For each half-cycle, the microcontroller calculates the average period from the most recent two measurements to compensate for line frequency variations. Based on this period measurement and the selected speed mode, the control algorithm determines the delay time before generating a 1ms gate trigger pulse to turn on the TRIAC.