AM263x MCU+ SDK  09.02.00
EPWM Chopper

Table of Contents

Chopper Submodule

The PWM chopper submodule allows a high-frequency carrier signal to modulate the PWM waveform generated by the action-qualifier and dead-band submodules. This capability is important if pulse transformer-based gate drivers to control the power switching elements are needed.

Key Funcitonalities include...

  • Programmable chopping (carrier) frequency
  • Programmable pulse width of first pulse
  • Programmable duty cycle of second and subsequent pulses
  • Can be fully bypassed if not required

Example Description

this example demonstrates the Chopper functionality of EPWM. Configurations

  1. EPWM 0 (EPWM_NO_CHOPPER)
    • No Chopper enabled (Chopper bypassed)
    • 50% duty Cycle with Period 100 uS
  2. EPWM 1 (EPWM_CHOPPER_1_8TH)
    • Chopper enabled (Chopper bypassed)
      • first Pulse width 8/(EPWMCLK/16)
      • Chopper Duty Cycle : 1/8
    • 50% duty Cycle with Period 100 uS
  3. EPWM 2 (EPWM_CHOPPER_6_8TH)
    • No Chopper enabled (Chopper bypassed)
      • first Pulse width 8/(EPWMCLK/16)
      • Chopper Duty Cycle : 2/3
    • 50% duty Cycle with Period 100 uS
  4. EPWM 3 (EPWM_CHOPPER_4_8TH_WITH_DB)
    • No Chopper enabled (Chopper bypassed)
      • first Pulse width 8/(EPWMCLK/16)
      • Chopper Duty Cycle : 1/2
    • 50% duty Cycle with Period 100 uS
    • DeadBand added.
      • output A is RED with 50 EPWM TBCLKs
      • output B is FED with 50 EPWM TBCLKs

External Connections

  1. Probe EPWM 0A for Reference waveform
  2. Probe EPWM 1A,2A,3A,3B for the Chopper enabled waveforms.

On AM263x CC/ AM263Px CC with HSEC Dock,

Probe HSEC pins 49,53,50,54,56 respectively for EPWM 0A, 1A, 2A, 3A and 3B

On AM263x LP/ AM263Px LP,

Probe J4 11, J2 37, J2 39, J6 77, J6 78 respectively for EPWM 0A, 1A, 2A, 3A and 3B

Supported Combinations

Parameter Value
CPU + OS r5fss0-0 nortos
Toolchain ti-arm-clang
Board am263x-cc, am263x-lp
Example folder examples/drivers/epwm/epwm_chopper/

Steps to Run the Example

  • When using CCS projects to build, import the CCS project for the required combination and build it using the CCS project menu (see Using SDK with CCS Projects).
  • When using makefiles to build, note the required combination and build using make command (see Using SDK with Makefiles)
  • Establish connections as mentioned in External Connections section
  • Launch a CCS debug session and run the executable, see CCS Launch, Load and Run

See Also

EPWM

Sample Output

Shown below is a sample output when the application is run,

EPWM Chopper Test Started ...
EPWM Chopper Example runs for 5 Secs
EPWM Chopper Test Passed!!
All tests have passed!!

EPWM Chopper Example Sample Capture