AM261x MCU+ SDK: EPWM Chopper

| AM261x MCU+ SDK 26.00.00 |

EPWM Chopper

# 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/ AM261x SOM 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 | am261x-som, am261x-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