CTR = 0
CTR=CMPB
X
EN
SyncOut
Phase reg
EPWMxA
EPWMxB
SyncIn
Φ
=0
°
Application Examples
2055
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
Enhanced Pulse Width Modulator (ePWM) Module
35.3 Application Examples
An ePWM module has all the local resources necessary to operate completely as a standalone module or
to operate in synchronization with other identical ePWM modules.
35.3.1 Overview of Multiple Modules
Previously in this user's guide, all discussions have described the operation of a single module. To
facilitate the understanding of multiple modules working together in a system, the ePWM module
described in reference is represented by the more simplified block diagram shown in
. This
simplified ePWM block shows only the key resources needed to explain how a multiswitch power topology
is controlled with multiple ePWM modules working together.
Figure 35-51. Simplified ePWM Module
35.3.2 Key Configuration Capabilities
The key configuration choices available to each module are as follows:
•
Options for SyncIn
–
Load own counter with phase register on an incoming sync strobe—enable (EN) switch closed
–
Do nothing or ignore incoming sync strobe—enable switch open
–
Sync flow-through - SyncOut connected to SyncIn
–
Master mode, provides a sync at PWM boundaries—SyncOut connected to CTR = PRD
–
Master mode, provides a sync at any programmable point in time—SyncOut connected to CTR =
CMPB
–
Module is in standalone mode and provides No sync to other modules—SyncOut connected to X
(disabled)
•
Options for SyncOut
–
Sync flow-through - SyncOut connected to SyncIn
–
Master mode, provides a sync at PWM boundaries—SyncOut connected to CTR = PRD
–
Master mode, provides a sync at any programmable point in time—SyncOut connected to CTR =
CMPB
–
Module is in standalone mode and provides No sync to other modules—SyncOut connected to X
(disabled)
For each choice of SyncOut, a module may also choose to load its own counter with a new phase value
on a SyncIn strobe input or choose to ignore it, i.e., via the enable switch. Although various combinations
are possible, the two most common—master module and slave module modes—are shown in