EPWM Chopper

Table of Contents

• Chopper Submodule
• Example Description
  • External Connections
    • On AM263x CC/ AM263Px CC with HSEC Dock,
    • On AM263x LP/ AM263Px LP,
    • On AM261x LP
• Supported Combinations
• Steps to Run the Example
• See Also
• Sample Output

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) (EPWM2 in case of AM261x-LP)
   • No Chopper enabled (Chopper bypassed)
   • 50% duty Cycle with Period 100 uS
2. EPWM 1 (EPWM_CHOPPER_1_8TH) (EPWM3 in case of AM261x-LP)
   • 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) (EPWM4 in case of AM261x-LP)
   • 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) (EPWM6 in case of AM261x-LP)
   • 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 (EPWM 2A in case of AM261x-LP) for Reference waveform
2. Probe EPWM 1A,2A,3A,3B (EPWM 3A,4A,6A,6B in case of AM261x-LP) 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

On AM261x LP

Probe J2 40, J2 38, J2 36, J6 78, J6 77 respectively for EPWM 2A, 3A, 4A, 6A and 6B

Supported Combinations

Parameter	Value
CPU + OS	r5fss0-0 nortos
Toolchain	ti-arm-clang
Board	am263px-cc, am263px-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