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CCS/TM4C123GH6PGE: CCS/TM4C123GH6PGE

SHIKHAR GUPTA
Prodigy 220 points
Part Number: TM4C123GH6PGE

Tool/software: Code Composer Studio

Hi all,

Solar Water Pump Controller(Variable Frequency Drive) using your TIVA C Series  (TM4C123GH6PGE) to run 3 ph Induction Motor.In this project, we use all possible technique that we got through your portal.The concept is based on SVPWM to generated Pulses and V/F method for Speed Control and Freuency of PWM working is 4kHz.

Now the requirement is two generate separate pwm i.e complementary to each other with 50 kHz frequency.

So,my question is -is it possible to generate pwm with different frequency in same program.

If it possible please tell me possible method.

Please help us and we are always  depends on your Technology and Products.

Thank you

  • 0
    TI__Guru**** 159445 points

    Hi,

      Unfortunately, this is not possible. As described in the datasheet, the PWM module can select either the system clock or a predivided system clock as the timebase that will be shared by all the PWM generators. 

  • 0 in reply to Charles Tsai
    Guru 117850 points

    Greetings - friend Charles,

    As my small group has (some) background & success in such PWM Control (especially re: Motor Control - and focused upon BLDC Motors in particular) may I add 'my take' to client's request?

    He noted, "is it possible to generate pwm with different frequency in same program."

    Now I agree (in general) w/your response.   That said - poster MAY Vary the PWM Frequency (and Duty Cycle, of course) w/in the SAME PROGRAM!   (and my firm does that - almost ALWAYS.)    The key/critical point - Not upon MULTIPLE Different Channels - and at the Same Time!    (Yet - thinking about that - even (that) just may - be possible.)     I'm envisioning two separate PWM Modules - while each is driven from the identical System Clock - the set-up and/or configuration of EACH MODULE UNIQUELY - just may - MEET this Client's Needs!    Maybe!    (Pardon - but staff/I KNOW such can be met - by (other) ARM MCUs - so perhaps 'yours too' can achieve poster's desire.)     And that is my justification for arriving here - and offering 'my take.'

    Poster asked about 'Complementary PWM' and that IS SUPPORTED by your devices.    (at least by the '123' which is the only device we employ from your assortment.)    When employing such complementary PWM - the proper design & implementation of the Power Stage - especially the (likely) Power FET Gate Drivers - and their location & routing to the Power FETs - must be 'Implemented wHigh Precision!'

    And - while NOT supporting such 'complementary PWM' - the MCU's (many) Timers - may conspire to produce PWM - and at VASTLY Different Frequencies!    Such proves true - don't you agree?

    Poster's question provides (some) necessary info - yet (far from) sufficient info - forcing added burden - upon all 'hapless responders'  (even YOU!)

  • 0 in reply to cb1_mobile
    TI__Guru**** 159445 points

    Hi cb1,

      Thank you. I think I misinterpreted poster's question. Certainly each PWM generator has it own LOAD and CMPA/B registers to configure the PWM period and  the duty cycle.  

  • 0 in reply to Charles Tsai
    Guru 117850 points

    Hi and Thank You, Charles.

    Might you 'give a 2nd glance' to my earlier writing?   I dictated - gurlz typed - and our flow was 'sporadic.'   (not entirely 'unexpected' around here - where inmates far outnumber - (may I say) guards!

    By 'Relaxing' and/or Enabling 'Dead-Band Time' variable - poster can achieve 'Complementary PWM' - which (also) was among his issues/requests.   I've not used '123 in quite awhile (since kicked off here) - so memory clouds.    Note that (some) Dead-Band Time must be employed - or it proves (almost) certain - that the Power Stage will assume (room temperature!)     Which in the case of a Power Semi - is not (always) a bad thing...)