Datasheet
Digital Compare
Signals
Counter Compare
Signals
T ime Base
Signals
Dead
Band
(DB)
Counter
Compare
(CC)
Action
Qualifier
(AQ)
EPWMxA
EPWMxB
CTR = CMPB
CTR = 0
EPWMxINT
EPWMxSOCA
EPWMxSOCB
EPWMxA
EPWMxB
nTZ1 to nTZ3
CTR = CMPA
T ime-Base
(TB)
CTR = PRD
CTR = 0
CTR_Dir
EPWMxSYNCI
EPWMxSYNCO
EPWMxTZINT
PWM-
chopper
(PC)
Event
Trigger
and
Interrupt
(ET)
Trip
Zone
(TZ)
GPIO
MUX
ADC
VIM
Digital
Compare
(DC)
CPU Debug Mode
OSCFAIL or PLL SLip
Combination of EQEP1ERR
and EQEP2ERR
Digital Compare
Signals
Digital Compare
Signals
VIM
ePWM Submodules
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34.2.6 PWM-Chopper (PC) Submodule
Figure 34-30 illustrates the PWM-chopper (PC) submodule within the ePWM module.
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.
Figure 34-30. PWM-Chopper Submodule
34.2.6.1 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
34.2.6.2 Controlling the PWM-Chopper Submodule
The PWM-chopper submodule operation is controlled via the registers in Table 34-16.
Table 34-16. PWM-Chopper Submodule Registers
Register Name Address Offset Shadowed Description
PCCTL 3Ch No PWM-chopper Control Register
34.2.6.3 Operational Highlights for the PWM-Chopper Submodule
Figure 34-31 shows the operational details of the PWM-chopper submodule. The carrier clock is derived
from VCLK3. 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.
1750
Enhanced Pulse Width Modulator (ePWM) Module SPNU562–May 2014
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