Datasheet

Phase Shift
Phase Trigger = Phase Trigger Register value or Filter Duty
DPWM0 Start of Period
Period Counter
DPWM0 Start of Period
DPWM1 Start of Period
Period Counter
DPWM1 Start of Period
UCD3138
SLUSAP2F –MARCH 2012 –REVISED NOVEMBER 2013 www.ti.com
Blanking A-Begin and Blanking A-End can be used to blank out noise from the MOSFET turn on at the
beginning of the period (DPWMA rising edge). Blanking B could be used at the turn off time of DPWMB.
The other edges are dynamic, so blanking is more difficult.
Cycle Adjust B has no effect in Normal Mode.
4.6 Phase Shifting
In most modes, it is possible to synchronize multiple DPWM modules using the phase shift signal. The
phase shift signal has two possible sources. It can come from the Phase Shift Register. This provides a
fixed value, which is useful for an interleaved PFC, for example.
The phase shift value can also come from the filter output. In this case, the changes in the filter output
causes changes in the phase relationship of two DPWM modules. This is useful for phase shifted full
bridge topologies.
The following figure shows the mechanism of phase shift:
34 Functional Overview Copyright © 2012–2013, Texas Instruments Incorporated
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