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Original question:

LM5023: LM5023 OVP

LM5023: LM5023-CCM MODE

Max
Intellectual 820 points
Part Number: LM5023
Other Parts Discussed in Thread: LM5021

Hi 

We are using LM5023 in our design.

I need  to build a 19V,3.3A continuous mode Medical Grade power supply.

For continuous mode of operation what are things to be considered while designing SMPS.

In EVM it is given as discontinuous mode of operation Schematics.

Kindly Help us to proceed further.

  • 0
    TI__Mastermind 31360 points

    Hello Max, 

    Thank you for your interest in the LM5023 quasi-resonant (QR) flyback controller. 

    The LM5023 is specifically designed to operate only in QR and DCM modes.  It is not possible to configure this controller into CCM operation. 

    I suggest that you consider the LM5021 or UCC28C5x family of controllers capable of CCM.  
    Further information can be found here:
    https://www.ti.com/product/LM5021#tech-docs
    https://www.ti.com/product/UCC28C54#tech-docs

    Regards,
    Ulrich

  • 0 in reply to Ulrich Goerke
    Intellectual 820 points

    Hi Ulrich

    Thanks for the reply

    I have a 400uH with turns ratio of 12:1:2 19V 3.3A transformer, Whether shall i use this transformer with LM5021 for 19V 3.3A adapter or anything to changed/considered while designing.

  • 0 in reply to Max
    TI__Mastermind 31360 points

    Hello Max, 

    I recommend that you follow the design procedure given in the Applications Section of the LM5021 datasheet, using values appropriate for your specific application (rather than those of the example application).  

    This procedure should transformer design parameters that are close to optimal for application.  Then you can compare the parameters of the 400uH transformer that you have on hand to those of the "paper design" and decide if it is close enough to be useable with a few minor adjustments to your application targets.  
    If your application targets need to be modified too much in order to use the existing transformer, then I recommend designing a new custom transformer that is fully suited to your original design targets. 

    The LM5021 datasheet will also provide information on the considerations for designing with this controller.  
    Additional information available here https://www.ti.com/product/LM5021#design-development may also be of some use.  

    Since this thread no longer involves the LM5023, I will close it out.
    If you have any future issues involving the LM5021, please open a new post for that controller. 

    Regards,
    Ulrich