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LMG2640: Powerloss calculations of the LMG2640, LMG2652 & LMG2650

Jan Hummel
Prodigy 50 points
Part Number: LMG2640


Tool/software:

Hello,

 i want to calculate the power losses of this devices with different currents and Voltages and Switching frequencies.

here you can find a calculation tool. LMG2652 data sheet, product information and support | TI.com 

which is leading to  LMGXX-GAN-LLC-CALC Calculation tool | TI.com 

When i try to use it i get the following error:

>> LMGXX_GAN_LLC_CALC_VER_1
Error defining property 'RdsonPN' of class 'LMGXX_GAN_LLC_CALC_VER_1'. Class named 'symfun' is undefined or does not
support property validation. Classes that do not support property validation include Java, COM classes, and MATLAB
classes that do not use the classdef keyword.

how can i execute the calculator?

is there a paper or reference guide on  how to calculate powerloss calculation for GAN Fets? 

Best regards

Jan 

  • 0
    TI__Expert 4520 points

    Hello Jan,

    For the Matlab calculator, there is a text file titled "how to run" which lists a few different methods for running the calculator.
    If you are having trouble running still, you can use the free online version of Matlab which has not shown any issues: https://www.mathworks.com/products/matlab-online.html 

    We have other Excel based calculators on ti.com such as a totem pole PFC calculator: Link

    The method for calculating GaN power losses is very similar to other FETs like Silicon and Sic, and many general papers can help provide detail here.
    We have some high level guidance in some of our newer device datasheets such as LMG2100R044 in section 8.2.2.4 Power Dissipation

    The conduction and switching losses here can apply to high voltage GaN FETs as well.
    One note is related to gate drive losses. TI GaN FETs include integrated gate drivers, protection features, and advanced features, meaning gate drive losses must include more than just the GaN FET gate charge.
    The Device should be thought of as an IC, where the VDD supply power includes all gate drive losses and other features. Each datasheet will have a figure for VDD supply current vs switching frequency, so you can calculate the VDD power at whatever operating frequency your system is running 

    Thanks,
    Zach S

  • 0 in reply to Zachary Soviero
    Prodigy 50 points

    Hello Zach,

    Thanks for the quick response.

    I get the same error using the suggested online version of matlab I tried all three approaches of the "how to run" text file.

    I can not look into the code because it is protected p-file:

    Thanks for the other answers.

    Best regards

    Jan

  • 0 in reply to Jan Hummel
    TI__Expert 4520 points

    Hi Jan,

    I have validated the script on my installed Matlab, but let me take a look at the online tool and see if I have any issues there.

    Thanks,
    Zach Soviero

  • 0 in reply to Zachary Soviero
    Prodigy 50 points

    is there an update to the error message?

  • 0 in reply to Jan Hummel
    TI__Expert 4520 points

    Hi Jan,

    Below is a screenshot from my machine running the online Matlab tool. I copied the LLC calculator files into the Matlab page (click and dragged), right clicked on the .p file, and clicked "run"
    I notice that your files are in a folder, maybe try copying the files outside of a folder and run that way

    Thanks,
    Zach S