How to eliminate the One-Shot pulse from the MCPWM modul with carrier modulation

rob_bits
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Joined: Wed Jun 13, 2018 5:15 am

How to eliminate the One-Shot pulse from the MCPWM modul with carrier modulation

Postby rob_bits » Tue May 17, 2022 5:14 am

Hello,

I would like to implement the example waveform from the technical reference manual in the MCPWM section, PWM Carrier Submodule, where the generated signal does not have One-Shot pulse in the beginning (Figure 120: Example of Waveforms Showing PWM Carrier Action).

I was able to generate the signal which has a different first pulse as the subsequent pulses (Figure 121: Example of the First Pulse and the Subsequent Sustaining Pulses of the PWM Carrier Submodule) however I cannot disable the first pulse.

The documentation says:
The width of the first pulse is configurable. It may assume one of 16 possible values and is described by the
formula below:
T1stpulse = TPWM_clk ×8×(PWM_CARRIERx_PRESCALE +1)×(PWM_CARRIERx_OSHTW T H +1)

So if I set PWM_CARRIERx_OSHTWTH to 0, still the pulse width will be equal to the period of the subsequent pulses.

Do I need to implement a dead time configuration, or how can I eliminate the unnecessary one pulse signal?

Regards,

Robert
Attachments
mcpwm_carrier_modulation.png
PWM_CARRIERx_OSHTWTH is set to 0
mcpwm_carrier_modulation.png (8.12 KiB) Viewed 771 times

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