This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TMS320F28075: Strange small pulse when using HR

Part Number: TMS320F28075
Other Parts Discussed in Thread: TMS320F28035

Hello,

I use a PWM module to control the high-side and low-side signals of my buck converter. In order to obtain the best performance, I use the HR module. The high-side signal is controlled by the CMPA register. The signal low-side is generated from the high-side signal by the submodule deadband.

I configure the PWM registers so that CMPA is copied from shadow to active when the counter passes by TBPRD because the high-side signal is centered at 0. Theoretical CMPAHR should be copied from shadow to active when the counter passes by TBPRD as CMPA. However, there is a small pulse appearing in the middle of the low level of the high-side signal (yellow signal).

To avoid this problem, I must change the loading mode of CMPAHR: it must be copied from shadow to active when the counter passes by 0. Therefore the small pulse would be generated when the high-side signal is at high level.

Could you tell me if the problem I explained above is a bug in the TMS320F28075 microcontroller ?

Thank you ver much.

Best regards,