Generation of triangular waveforms with an offset

Bhanu,

I would recommend taking a look at the SINGEN library in controlSUITE:
\controlSUITE\libs\dsp\SGEN\v101\

RampGen creates triangular waveforms and optionally with offset.

However, I will mention that what you're appearing to try to do is create a sinusoidal PWM output.  If this is the case, then you do not really need a ramp specifically, just a timer.  The ePWM peripheral is meant to help generate complex PWM outputs.


Thank you,
Brett 

Thanks for your suggestion Brett.

If possible can you show me a simple example for generation of a triangle using ePWM peripheral..Similar to the one shown in figure

Thank you

Bhanu,

If you've gotten a sinusoidal output, then you could follow the same steps to make a triangular waveform.

My methodology would be to:
Output a PWM (or HRPWM) through a low pass filter to decrease the effect of higher order harmonics.  Set the PWM to have a constant period, and in each PWM cycle update the PWM's CMPA value which will correspond to the PWM's duty cycle.   As the duty cycle goes up the voltage output will go up.  Increase the duty cycle each cycle until you get to a limit and the start decreasing it every cycle, etc, etc.


Thank you,
Brett

Are you looking for 3 level pwm generation for a (dual?) sinusoidal output? 

If you have control over sinusoidal, instead of giving offset to carrier, adjust reference as required. 

Reference1 and Reference1 - offset and use normal PWM method.

Cheers

Joy

How do you do that?

Let's say sinusoidal waveform is the reference1.

Let's say we create an offset to reference1

how can you compare reference 1 and reference 1-offset to get PWM..

Hey Brett,

I am not good in writing codes..I used sine table to generate sinusoidal output. I tried to write for triangular waveform but its not working..Please help me out here.. 

Hey Brett,

I think RampGen works for me..but the only thing is I want count up and down mode..How to change either positive ramp output or negative ramp output to count up and down mode??

and how can I use High frequency like 2kHz..It shows that the maximum frequency is 300Hz