3.3.3 Controlling Multiple Buck Converters With Independent Frequencies
One of the simplest power converter topologies is the buck. A single ePWM module configured as a master can
control two buck stages with the same PWM frequency. If independent frequency control is required for each
buck converter, then one ePWM module must be allocated for each converter stage.
buck stages, each running at independent frequencies. In this case, all four ePWM modules are configured as
masters and no synchronization is used.
shows the waveforms generated by the setup shown in
; note that only three waveforms are shown, although there are four stages.
CTR=zero
CTR=CMPB
X
En
SyncOut
Phase reg
Ext SyncIn
(optional)
EPWM1A
EPWM1B
SyncOut
Phase reg
CTR=CMPB
CTR=zero
X
En
EPWM2B
EPWM2A
Master2
Master1
SyncIn
CTR=zero
CTR=CMPB
SyncOut
X
EPWM3B
Phase reg
Master3
En
EPWM3A
1
2
3
Φ
=X
Φ
=X
Φ
=X
CTR=zero
CTR=CMPB
SyncOut
X
EPWM4B
Phase reg
Master4
En
EPWM4A
3
Φ
=X
Buck #1
Vout1
Vin1
EPWM1A
Buck #2
Vin2
EPWM2A
Vout2
Buck #4
Buck #3
Vin3
EPWM4A
Vin4
EPWM3A
Vout3
Vout4
SyncIn
SyncIn
SyncIn
A.
Θ = X indicates value in phase register is a "don't care"
Figure 3-54. Control of Four Buck Stages. Here F
PWM1
≠ F
PWM2
≠ F
PWM3
≠ F
PWM4
Enhanced Pulse Width Modulator (ePWM) Module
304
TMS320x2806x Microcontrollers
SPRUH18I – JANUARY 2011 – REVISED JUNE 2022
Copyright © 2022 Texas Instruments Incorporated
Содержание TMS320 2806 Series
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