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TMS320F280039C: Launch

Don Williams
Prodigy 140 points

Part Number: TMS320F280039C

We are just commencing a development to create an HFAC MicroGrid.

The first pass is a 32.768KHz sinewave running ePWM onto a Half Bridge under 400Vdc. Later a full bridge under 600Vdc

There are lots of attractive ideas about how to start. Also some dumb questions regarding processor resources needed.

Using and analog dead band creation or internal ePWM deadband creation processor resources is one sort of question. rather get someone's experience on this rather than build & test !

I anticipate UP/DOWN counter ePWM operation but need negative feedback modulation of the signal feed from NVM for an amplitude created by rectified output of resonant LC-LC filtered drive. The resonant filter should allow a less demanding sample rate multiple of the Nyquist frequency, which we use to get less heat loss in the filter magnetics.

The principal question I have for a start is - why doesn't the application suggest the use of the CLA would be perfect for the sinewave memory feed? Is there enough capacity in the CLA to adjust the UP/DOWN counters of ePWM stream ?

Why couldnt the Sigma-Delta converter be used on the feedback bitstream to reduce switching frequency ?

I hope this forum can answer these strategy questions .... I would be VERY grateful.

Finding out by trialing is very time consuming ....

  • 0
    TI__Mastermind 28580 points

    Hi Don,

    Do you mean "HVAC"? I am not familiar with HFAC.

    When you say "why doesn't the application suggest...", are you referring to a specific reference design provided by TI?

    We have software examples demonstrating control of PWM with CLA. What do you mean by "capacity" when referring to CLA?

    I do not have much experience with the Sigma-Delta Filter module, my expertise is in assisting with implementing and debugging EPWM solutions. However I can loop in our HVAC reference design expert if you have more general questions about what is possible with a C2000 device. If you have more specific questions about implementing a solution within a specific module such as CLA, I can refer you to the expert for that module.

    Apologies for not being able to provide a direct answer to your questions. If you can answer my above questions then I can hopefully refer you to the appropriate expert as soon as possible.