Complementary PWM query

Hi Team,

1) I am using RX24T family CPU for inverter application. I would like to use complementary PWM to drive H-bridge inverter in below pattern.

Let me know, how to generate PWM's of two frequencies using complementary PWM mode?

2) When I tried to make duty cycle 0% for PWM1, its complementary PWM2 duty cycle is 98% or 99%. Whereas PWM1 is coming with 0% duty cycle perfectly. It should be 100% (without dead time). Let me know, How to achieve PWM of 0% & 100%. 

  • Hi vaibhav,

    You can provide more information like the IDE and compiler you're using. If it's just okay, you can post your code here too so that others can help you identify what's wrong. You can also tell what external input are you using to change the duty cycle of the PWM signal.

    JB
    RenesasRulz Forum Moderator

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  • In reply to JB:

    Hi JB,

    My question is related to the complementary PWM generation using MTU with carrier frequency of 20KHz & Modulator frequency of 50Hz, so I feel this one is not depend on the IDE or Compiler. But for your question, at present I am using CS+ version 6. Please check the attached screenshot for your ref.

    You can consider the modulation index of 0.8. 

    I hope you have some background of sinusoidal PWM, which is carrier wave of 20Khz generated using sin values. The carrier wave of 20Khz for left half bridge arm will looks like - 

    The expected bridge output is - 

  • In reply to vaibhav:

    Any update on above query?
  • In reply to vaibhav:

    vaibhav,

    Have you found the answer you were looking for?

    Mike Clements
    RenesasRulz Moderator