LAUNCHXL-F28379D: PWM-DAC Implementation & Examples

Hatif Bin Abdul Majeed

Hello,

I hope you are doing well. I am using the Launchpad to implement an inverter and get the analogue signals out. I can't use the buffered DAC as they are already being used for another purpose and I only have PWM-DAC1/2/3/4 which are mapped to the Typhoon Device that I am working with. I can't use any other pins for getting these analogue signals out. But the problem is that I can't find any example anywhere which shows how to implement DAC using these pins.

I will appreciate it if you can provide any example code which utilizes these pins as DAC for me to work with. I know that these pins have an built-in RC filter too. If I can get an example code i'll be really grateful.

Thanks

Hatif

over 2 years ago

0 Santosh Jha over 2 years ago

TI__Guru 50611 points

Hi,

We have assigned to subject matter expert. He will get back to you later today.

Regards, Santosh

0 Hadi Moradisizkoohi over 2 years ago

TI__Expert 7100 points

Hello Hatif,

Thanks for your patience.

There isn't an example for using PWM as digital to analog converter in this device. However, there is an application report presents a method for utilizing the on-chip PWM signal generators on the TMS320F280x family of digital signal controllers as a DAC. You can find it here:

https://www.ti.com/lit/an/spraa88a/spraa88a.pdf?ts=1674770293889

Regards,

Hadi

0 Hatif Bin Abdul Majeed over 2 years ago in reply to Hadi Moradisizkoohi

Prodigy 30 points

Hello Hadi,

I understand and I have already read this application note, but the problem is that I need to use PWM-DAC pins, because they are the only ones mapped to my Hardware-in-the-loop device. I can't use the simple PWM signal generators. And because there is no example, I don't even know how to access those pins (syntax, initializations etc). I couldn't find anything regarding these pins in the Technical Reference Manual too. I will be much appreciated if you can help me regarding this.

Thanks.

Hatif

0 Hadi Moradisizkoohi over 2 years ago in reply to Hatif Bin Abdul Majeed

TI__Expert 7100 points

Hi Hanif,

As I know we don't have any example for using PWM as a DAC.

Please let me talk to other experts to see if there is any other documents to find out how you can set up PWM for generating DAC.

Regards,

Hadi

0 Hadi Moradisizkoohi over 2 years ago in reply to Hadi Moradisizkoohi

TI__Expert 7100 points

Hi Hanif,

As you mentioned before, there isn't any example for the device you are using; however, you can use the example provided for other devices to gain an understanding of generating DAC from PWM module.

Here is the link for technical reference manual of F2838x device:

https://www.ti.com/lit/ug/spruii0d/spruii0d.pdf?ts=1675200791172&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTMS320F28388D

You can find the example in section 26.15.1.8.2 Implementing a DAC Function Using an R+C Reconstruction Filter.

Regards,

Hadi

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LAUNCHXL-F28379D: PWM-DAC Implementation & Examples