TMS320F280025C-Q1: Measure mean current on PCMC

Hi Marcus,

Can you provide on which topology you are using this? 

For PCMC why do you need the mean current, detecting the peak in each cycle should be enough right?

We have few reference designs showcasing PCMC implementation, please refer these TIDM-DC-DC-BUCK, PSFB-DC_DC 

Also, app notes: https://www.ti.com/lit/ug/tidueo1b/tidueo1b.pdf?ts=1717790533357&ref_url=https%253A%252F%252Fdev.ti.com%252F,

https://www.ti.com/lit/an/sprabu2/sprabu2.pdf?ts=1717790544597&ref_url=https%253A%252F%252Fdev.ti.com%252F

I will check with EPWM expert and get back to you.

Best Regards,

Uttam

Hi Uttam,

I'm using PCMC to control the current inside a solenoid. Therefore, I'm interested in the mean current as it relates to the mean force of the solenoid.

Besides the problem noted in the initial post, everything is working well. Hopefully, the experts will find a good approach for this.

Best regards,

Markus

Hi Markus,

Could you provide more information on your configuration and what events are getting missed? I am not familiar with PCMC but if you describe the problem strictly in EPWM terms I can help come up with a solution.

You may be able to use CLB to implement a modified approach.

Thank you,

Luke

Hi Luke,

my EPWM is configured upcounting with a CMPA of 98% of the full period for bootstrap reasons. Furthermore, the output is configured to get high on TBCTR=0 and low on TBCTR=CMPA. The DCxEVT will set the output low to enable PCMC, too.

The problem is, that I use DCxEVT to trigger the ADC (measure Imax). This DCxEVT does not trigger in PWM-Cycles with max. duty (TBCTR reaches CMPA). Is there a way to get a ADCTriggerSourc for a falling edge of the PWM output? Using the GPIO input of the ADC is no option because I need more than one channel...

Best regards,

Markus