2 Replies Latest reply on Jun 30, 2015 5:09 AM by user_14586677

    PWM Duty Cycle

    aditya.karn

      I am trying to change the duty cycle of signal. if I set higher period for PWM component, i can acheive the duty cycle whereas I am not geeting the exact frequency. 

         

      I am using Timer(tc) to input the PWM. 

         

      How can I acheive the duty as well as correct frequency?

        • 1. Re: PWM Duty Cycle
          user_1377889

          Use a PWM component and a clock. Set the period value so, that Clock / Period = desired frequency.

             

          Now you may set in your program the compare-value with the appropiate API between 0 (0%) and the period value (100%).

             

          This will keep the frequency of the PWM stable and only changes the duty-cycle.

             

           

             

          Bob

          • 2. Re: PWM Duty Cycle
            user_14586677

            Note the update of the compare register is async, so you can short cycle

               

            the current period duty cycle being output by PWM. To avoid this use an ISR on

               

            the Tc output to do the update of compare register. Note this is not true for the

               

            period register, it is updated at end of period with an internal reload of period register.

               

             

               

               

             

               

             

               

             

               

             

               

            Regards, Dana.