4.2.5.2 Implementing a DAC Function Using an R+C Reconstruction Filter
In this example, the PWM requirements are:
• PWM frequency = 533 kHz (that is, TBPRD = 150)
• PWM mode = Asymmetrical, Up-count
• Resolution = 14 bits (MEP step size = 150 ps)
show the DAC function and the required PWM waveform. As explained previously,
configuration for the ePWM1 module is almost identical to the normal case except that the appropriate MEP
options need to be enabled/selected.
EPWM1A
V
OUT1
LPF
Figure 4-13. Simple Reconstruction Filter for a PWM Based DAC
EPWM1A
CA
T
PWM
= 2.5 µs
Z
CA
Z
Z
Figure 4-14. PWM Waveform Generated for the PWM DAC Function
The example code shown consists of two main parts:
• Initialization code (executed once)
• Run time code (typically executed within an ISR)
This example assumes a typical MEP_SP and does not use the SFO library.
High-Resolution Pulse Width Modulator (HRPWM)
SPRUH18I – JANUARY 2011 – REVISED JUNE 2022
TMS320x2806x Microcontrollers
395
Copyright © 2022 Texas Instruments Incorporated
Содержание TMS320 2806 Series
Страница 2: ......