Texas Instruments TMS320C6745 DSP - Simple PWM-Chopper Submodule Waveforms Showing Chopping Action Only; PWM-Chopper Submodule Waveforms Showing the First Pulse and Subsequent Sustaining Pulses

PSCLK
OSHT
EPWMxA in
EPWMxA out
Prog. pulse width
(OSHTWTH)
Start OSHT pulse
Sustaining pulses
PSCLK
EPWMxA
EPWMxB
EPWMxA
EPWMxB
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SPRUH91D–March 2013–Revised September 2016
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Enhanced High-Resolution Pulse-Width Modulator (eHRPWM)
14.2.7.4 Waveforms
Figure 14-33 shows simplified waveforms of the chopping action only; one-shot and duty-cycle control are
not shown. Details of the one-shot and duty-cycle control are discussed in the following sections.
Figure 14-33. Simple PWM-Chopper Submodule Waveforms Showing Chopping Action Only
14.2.7.4.1 One-Shot Pulse
The width of the first pulse can be programmed to any of 16 possible pulse width values. The width or
period of the first pulse is given by:
T
1stpulse
= T
SYSCLKOUT
× 8 × OSHTWTH
Where T
SYSCLKOUT
is the period of the system clock (SYSCLKOUT) and OSHTWTH is the four control bits
(value from 1 to 16)
Figure 14-34 shows the first and subsequent sustaining pulses.
Figure 14-34. PWM-Chopper Submodule Waveforms Showing the First Pulse and
Subsequent Sustaining Pulses