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TMS320F28035: PSFB_VMC_PWM SETTING

ksma
Intellectual 290 points
Part Number: TMS320F28035
Other Parts Discussed in Thread: CONTROLSUITE, UCC28950, TIDM-02000

Hello.

Please tell me about the PWM setting of PSFB_VMC.

In the C28x digital power library, dead time is not described in the SR gate signal. 

On the other hand, in the controlSUITE assembly macro, 10 is added as "Extra safety cycles".

As a result, the rise of the SR gate signal will be delayed a little like the yellow-painted part.

What kind of effect does it have? Is it dangerous with "0" setting?

In addition, the ucc28950 datasheet has the ability to delay the fall of the SR gate signal.

If this delay is small, it is the conduction loss of the SR diode.

If there are many, the reset of Lr is completed and we recognize that it is dangerous.

Is this delay setting not available when using the C28x Digital Power Library?

In C28x and ucc28950, active / passive_leg is replaced, so is it like this?

Best regards!PSFB_VMC_PWM.pdf

  • 0
    TI__Genius 15935 points

    Hi,

    This is an old PCMC PSFB in controlSUITE, so I am not clear about all the details.  By looking at the scheme in digital power library. the turn on of pwm:p:B is decided by CBU. I am think if it is possible to change the CMPB to add the dead band. Same for CMPA.

    FYI, we have another PCMC PSFB design based on f28004x which is TIDM-02000

    Regards,

    Chen

  • 0 in reply to Chen Jiang ti
    Intellectual 290 points

    Thank you for reply.

    The control SUITE I referred to is from VMC, not PCMC.

    It is possible to insert a dead time at the rise to change CMPA or CMPB, but I think it is impossible because the fall is controlled by PRD or ZRO.

    In any case, do you mean that details such as design intent are unknown because the materials are old?

    Do you have the latest design documentation for VMC?

    Best regards.