Texas Instruments TMS320x28xx Manuel D’Utilisation
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3.4
Controlling Multiple Buck Converters With Same Frequencies
CTR=zero
CTR=CMPB
X
En
Φ
=0
°
SyncOut
Phase reg
Ext SyncIn
(optional)
EPWM1A
EPWM1B
SyncOut
Phase reg
CTR=CMPB
CTR=zero
X
Φ
=X
En
EPWM2B
EPWM2A
Slave
Master
Buck #1
Vout1
Vin1
EPWM1A
Buck #2
Vin2
EPWM1B
Vout2
Buck #4
Buck #3
Vin3
EPWM2B
Vin4
EPWM2A
Vout3
Vout4
SyncIn
SyncIn
Controlling Multiple Buck Converters With Same Frequencies
If synchronization is a requirement, ePWM module 2 can be configured as a slave and can operate at
integer multiple (N) frequencies of module 1. The sync signal from master to slave ensures these modules
remain locked.
integer multiple (N) frequencies of module 1. The sync signal from master to slave ensures these modules
remain locked.
shows such a configuration;
shows the waveforms generated by the
configuration.
Figure 3-5. Control of Four Buck Stages. (Note: F
PWM2
= N x F
PWM1
)
SPRU791D – November 2004 – Revised October 2007
Applications to Power Topologies
75