Digital Compare
Signals
Counter Compare
Signals
Time Base
Signals
Dead
Band
(DB)
Counter
Compare
(CC)
Action
Qualifier
(AQ)
ePWMxA
ePWMxB
CTR = 0
EPWMxINT
EPWMxSOCA
EPWMxSOCB
Time-Base
(TB)
CTR = PRD
CTR = 0
CTR_Dir
EPWMxSYNCI
EPWMxSYNCO
EPWMxTZINT
Event
Trigger
and
Interrupt
(ET)
Trip
Zone
(TZ)
ADC
PIE
PIE
Digital Compare
Signals
Digital Compare
Signals
CTR = CMPB
CTR = CMPA
CTR = CMPC
CTR = CMPD
CTR = PRD
PWM-
chopper
(PC)
ePWMxA
ePWMxB
TZ1 to TZ3
GPIO
MUX
Digital
Compare
(DC)
EMUSTOP
CLOCKFAIL
EQEPxERR
GPTRIP
CPU
SYSCTRL
EQEPx
COMPxOUT
GPTRIP
PIEERR
ECCDBLERR
TZ1
TZ3
to
GPIO
MUX
28x RAM/
Flash ECC
ePWM Submodules
720
SPRUHE8E – October 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
C28 Enhanced Pulse Width Modulator (ePWM) Module
7.2.6 PWM-Chopper (PC) Submodule
illustrates the PWM-chopper (PC) submodule within the ePWM module.
Figure 7-33. PWM-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 you need
pulse transformer-based gate drivers to control the power switching elements.
7.2.6.1
Purpose of the PWM-Chopper Submodule
The key functions of the PWM-chopper submodule are:
•
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
7.2.6.2
Controlling the PWM-Chopper Submodule
The PWM-chopper submodule operation is controlled via the registers in
Table 7-18. PWM-Chopper Submodule Registers
Register Name
Address Offset
Shadowed
Description
PCCTL
0x1E
No
PWM-Chopper Control Register
7.2.6.3
Operational Highlights for the PWM-Chopper Submodule
shows the operational details of the PWM-chopper submodule. The carrier clock is derived
from SYSCLKOUT. Its frequency and duty cycle are controlled via the CHPFREQ and CHPDUTY bits in
the PCCTL register. The one-shot block is a feature that provides a high energy first pulse to ensure hard
and fast power switch turn on, while the subsequent pulses sustain pulses, ensuring the power switch
remains on. The one-shot width is programmed via the OSHTWTH bits. The PWM-chopper submodule
can be fully disabled (bypassed) via the CHPEN bit.