TMS320F28335: f28335

Yedida Rudrasimha

Part Number: TMS320F28335

Hi,

I want to generate rising edge pulse of fixed width like monostable multivibrator using 28335. From Epwm output I want to generate rising edge pulse as well as delayed pulse as shown in the below figure. Epwm output is the generated pulse. I want to generate rising edge pulse of fixed duration say 100uS and modified Epwm output which is delayed by original pulse by 100uS. Please let me know can I do mentioned problem with Epwm event trigger or Ecap or by any software coding.

Thanks,

over 7 years ago

0 Cody Watkins over 7 years ago

TI__Mastermind 42195 points

Yedida,

Yes, I think you should be able to do this. Do you actually need the Rising edge pulse?

Try configuring PWM1 in Up-down-count mode and configure TBPRD for the correct period. Then use CAU and CAD to produce the correct duty cycle for the ePWMA's output. It should then be very simple to offset CBU and CBD by the width of "D" to produce the "modified ePWM output" on EPWMB channel.

If you would like to have the "rising edge pulse of fixed width" then use the sync chain to synchronize PWM2 and configure the CMPA event to the fixed width of "D".

Regards,
Cody

0 Yedida Rudrasimha over 7 years ago in reply to Cody Watkins

Prodigy 130 points

Hi Cody,

If we do add offset to to duty CMPA then problem is will get offset at both rising edge (lagging delay) and falling edge (Leading delay). But I want only pulse to be shifted by some fixed time delay at rising edge and waveform should remain constant.

Thanks,

0 Cody Watkins over 7 years ago in reply to Yedida Rudrasimha

TI__Mastermind 42195 points

Yedida,

I have drawn a PWM diagram, please let me know if this makes more sense. Both CBU and CBD will be shifted by the same value preserving the waveform's duty.

Regards,
Cody

0 Yedida Rudrasimha over 7 years ago in reply to Cody Watkins

Prodigy 130 points

Hi Cody,

Thanks...!

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TMS320F28335: f28335