SPRAD12A July   2022  – February 2023 TMS320F280021 , TMS320F280021-Q1 , TMS320F280023 , TMS320F280023-Q1 , TMS320F280023C , TMS320F280025 , TMS320F280025-Q1 , TMS320F280025C , TMS320F280025C-Q1 , TMS320F280033 , TMS320F280034 , TMS320F280034-Q1 , TMS320F280036-Q1 , TMS320F280036C-Q1 , TMS320F280037 , TMS320F280037-Q1 , TMS320F280037C , TMS320F280037C-Q1 , TMS320F280038-Q1 , TMS320F280038C-Q1 , TMS320F280039 , TMS320F280039-Q1 , TMS320F280039C , TMS320F280039C-Q1 , TMS320F280040-Q1 , TMS320F280040C-Q1 , TMS320F280041 , TMS320F280041-Q1 , TMS320F280041C , TMS320F280041C-Q1 , TMS320F280045 , TMS320F280048-Q1 , TMS320F280048C-Q1 , TMS320F280049 , TMS320F280049-Q1 , TMS320F280049C , TMS320F280049C-Q1 , TMS320F28075 , TMS320F28075-Q1 , TMS320F28076 , TMS320F28374D , TMS320F28374S , TMS320F28375D , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376D , TMS320F28376S , TMS320F28377D , TMS320F28377D-EP , TMS320F28377D-Q1 , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28378D , TMS320F28378S , TMS320F28379D , TMS320F28379D-Q1 , TMS320F28379S , TMS320F28384D , TMS320F28384D-Q1 , TMS320F28384S , TMS320F28384S-Q1 , TMS320F28386D , TMS320F28386D-Q1 , TMS320F28386S , TMS320F28386S-Q1 , TMS320F28388D , TMS320F28388S , TMS320F28P550SJ , TMS320F28P559SJ-Q1 , TMS320F28P650DH , TMS320F28P650DK , TMS320F28P650SH , TMS320F28P650SK , TMS320F28P659DK-Q1

 

  1.   Abstract
  2.   Trademarks
  3. 1 Introduction
  4. 2 SysConfig
  5. 3 Time-Base (TB) Submodule
    1. 3.1 Setting the Frequency
    2. 3.2 Applying a Phase Shift
    3. 3.3 Setting up the Synchronization (Sync) Scheme
  6. 4 Counter-Compare (CC) and Action-Qualifier (AQ) Submodules
    1. 4.1 Calculating the Duty Cycle
  7. 5 Deadband (DB) Submodule
    1. 5.1 Setting up Signal Pairs
  8. 6 Verifying the Output
    1. 6.1 Checking the Duty Cycle and Dead-Time Insertion
    2. 6.2 Checking the Phase Shift Applied
  9. 7 Trip-Zone (TZ) and Digital Compare (DC) Submodules
    1. 7.1 Drive Outputs Low for an ePWM Cycle Upon Trip Condition Set Through CMPSS
    2. 7.2 Drive Outputs Low Until Cleared Through Software Upon Trip Condition set Through GPIO
  10. 8 Event-Trigger (ET) Submodule
    1. 8.1 Setting Up Time-Base Interrupts
  11. 9 Global Load
    1. 9.1 Applying Global Loading and One-Shot Load Feature
    2. 9.2 Linking the ePWM Modules
    3. 9.3 Updating Action Qualifier Settings and Counter Compare Values Through Global Loading
  12. 10Summary
  13. 11References
  14. 12Revision History

3.2 Applying a Phase Shift

The next area of interest is applying a phase shift between EPWM1, EPWM2, and EPWM3. This is also accomplished through the TB submodule.

To calculate the time-base phase shift (TBPHS) value, use the formula shown in Equation 12:

Equation 12. T B P H S =   T B P R D * D e s i r e d   P h a s e   D e g r e e 360 °

The sync source is EPWM1, meaning it drives the sync signal to EPWM2 and EPWM3. EPWM2 has a phase shift of 120° from EPWM1.

Equation 13. T B P H S =   125 * 120 ° 360 ° = ~ 42

EPWM3 has a 240° phase shift from EPWM1:

Equation 14. T B P H S =   125 * 240 ° 360 ° = ~ 83