CCS/TMS320F28379D: Question using the Ramp Generator for implementation of a Peak Current Mode Control

Sebastian Toro

Tool/software: Code Composer Studio

Hi!

I'm trying to implement a Peak Current Mode Control on a TMS320F28379D and i have a question about the use of the ramp generator of the CMPSS Module. I use the ADC interruption to update my PI values and i also want to update the max value of the ramp generator (RAMPMAXREFS) for every interruption. My question is: Is there a way to update RAMPSTS by software inside an interruption? Or i have to wait for the next EPWMSYNCPER signal to update this value?

Thank you very much!

over 5 years ago

0 tlee over 5 years ago

TI__Guru 62975 points

Sebastion,

The Ramp Generator block diagram in the TRM should be accurate:

You might be able to manipulate some signals from the ISR to update RAMPSTS. Practically speaking, the Ramp Generator state machine was designed so that direct RAMPSTS updates like this are not necessary for typical PCMC implementations.

-Tommy

0 Sebastian Toro over 5 years ago in reply to tlee

Prodigy 30 points

Thank you for your answer! I think i got my issue resolved, but i would like to corroborate, do you know if there is a guide or something for typical PCMC implementation?

0 tlee over 5 years ago in reply to Sebastian Toro

TI__Guru 62975 points

Sebastian,

There is this appnote that was written before the Ramp Generator was implemented. The theory is the same, but the CLA-based DAC update scheme is now replaced by the local Ramp Generator logic.

-Tommy

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CCS/TMS320F28379D: Question using the Ramp Generator for implementation of a Peak Current Mode Control