PSCLK
OSHT
EPWMxA in
EPWMxA out
Prog. pulse width
(OSHTWTH)
Start OSHT pulse
Sustaining pulses
PSCLK
EPWMxA
EPWMxB
EPWMxA
EPWMxB
Architecture
330
SPRUH91D – March 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Enhanced High-Resolution Pulse-Width Modulator (eHRPWM)
14.2.7.4 Waveforms
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)
shows the first and subsequent sustaining pulses.
Figure 14-34. PWM-Chopper Submodule Waveforms Showing the First Pulse and
Subsequent Sustaining Pulses