CCS/TMS570LS3137: Generating PWM signals with phase shift

user6247440

Part Number: TMS570LS3137
Other Parts Discussed in Thread: HALCOGEN

Tool/software: Code Composer Studio

Hello everyone:
I want to use TMS570LS3137 to generate a PWM signal with phase shift to control a phase-shifted full-bridge converter.
I have read some examples of PWM generation using HALCOGEN HET, but I didn't find a method for PWM phase shift.
Can someone provide setting of HALCOGEN and program of CCS to achieve the function of PWM phase shift,please.

Thanks so much.

Best regards,

over 5 years ago

0 Sunil Oak over 5 years ago

TI__Mastermind 49120 points

Hello,

Please refer to the information on this post: https://e2e.ti.com/support/microcontrollers/hercules/f/312/t/833353

Regards, Sunil

0 user6247440 over 5 years ago in reply to Sunil Oak

Prodigy 40 points

Thank you for your reply. I have seen that Mr._MM_ has a phase shift function in the URL you provided. Can you provide me with his method?

0 Sunil Oak over 5 years ago in reply to user6247440

TI__Mastermind 49120 points

I cannot provide his code directly. Below is from his post on the thread that I referenced:

I implemented the 120° shift as period for the 6 PWM directly in Halcogen (the channels have different frequencies/periods);

Afterwards, I set the correct value of frequency by code. The result is that when the frequencies are set up to the common value, the phase relationship is kept.

This solution works fine. As I also mentioned on that other post, the method shown in this post is a more generic / flexible solution (https://e2e.ti.com/support/microcontrollers/hercules/f/312/p/834645/3087160#3087160).

0 user6247440 over 5 years ago in reply to Sunil Oak

Prodigy 40 points

I think adding a delay function before the PWM input should be able to achieve the phase shift effect, but I type delay (us) in CCS and it shows no effect.Can you share method of delay function by CCS program and setting HALCOGEN?Thanks so much.

0 Sunil Oak over 5 years ago in reply to user6247440

TI__Mastermind 49120 points

Check the PWM configuration in HALCoGen in the post that I referenced. The High-End Timer (N2HET) is a coprocessor dedicated for timing tasks, and any delays implemented in main CPU software do not affect N2HET operation.

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CCS/TMS570LS3137: Generating PWM signals with phase shift