• State Resolved
  • Locked Locked
  • Replies 8 replies
  • Answers 2 answers
  • Subscribers 65 subscribers
  • Views 777 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

WEBENCH® Tools/TPS43061: operating value is limited to 243 khz

Vern Bunch
Intellectual 520 points
Part Number: TPS43061
Other Parts Discussed in Thread: TPS43060, TPS40210, CSD18543Q3A

Tool/software: WEBENCH® Design Tools

hi, webench will not allow > 240 khz on New design using tps43061.  tried everything.

I want 444khz, maybe higher.

using Advanced options, I can set userfsw = 500khz   can see this in Current Design window.

but operating value is limited to 243 khz.  doing Advanced options shows limit is 243 khz.

popup window says instabilty.  how can 24v in 40v out 4.2a be unstable?

clicking redesign does not fix this.  help.

  • 0
    TI__Mastermind 21720 points

    Hi Vern,

    I was able to get WEBENCH to make a design at 430kHz. I'm not sure what problem you might be running into.

    What is the minimum input voltage that this application requires? 

    Thanks,

    Garrett

  • 0 in reply to Garrett Roecker
    Intellectual 520 points

    thanks, for WEBENCH® Tools/TPS43061, I have previously played with 36 different webenches.  20v in. 24v in, and 32v out 4.2A.

    but this one, can't remove the webbench locked in 243khz (could have been lower, but I wanted higher), will not allow > 243 khz.  doesn't seem to like 40v out.

    my next step is 48v out.

    I reported in another blog that changing frequency is limited or none.  so I started over completely new. I started fresh to get this far.  my userfsw is 500 khz.

    side note, webench requires going through entire IC selection, but I already have decided to use tps43061.  is there a way?

    of course, the main purpose of simulation is iterating to find optimum frequency.


  • 0 in reply to Vern Bunch
    Intellectual 520 points
    hi, wanted to add, that my 20v 24v in, 48v out 4.2A will not even allow tps43061--says design fsw outside range. but tps43061 fsw spec is higher.
    tried 46, 44v out 44v allows tps43060, but not tps43061. not even 34v out allows tps43061.
    the only diff. between 43060 and 43061 is gate drive.

    I want the 43061 5.5v gate drive, and sync rectifier mosfet, for top top top efficiency.

    so tried 20v 24v in, 46v out 4.0A (instead of 4.2A), 444khz. surprisingly, 7 previous 8 IC choices are gone! only diff. is 4.0A instead of 4.2A, only tps43060 and tps40210 are allowed. isn't that odd?

    selected tps40210, and freq = 434khz!

    started new with 24v min and max, now the 8 choices are back, but not 43061.

    please tell me what to do, so I can use tps43061 in webench.
  • 0 in reply to Vern Bunch
    TI__Mastermind 21720 points
    Hey Vern,

    I have contact the internal team that support this WEBENCH device. They are looking into the issue. It should be resolved shortly.

    Thanks,

    Garret
  • 0 in reply to Garrett Roecker
    TI__Intellectual 1625 points
    Hi Vern,

    We looked into the issue and found that for your input,output conditions, Mosfets are not available due to which the frequency is getting reduced. After reducing the frequency, again the mosfet availability is checked and is being selected.
    We are now able to create designs for VIN = 20V to 24V, VOUT = 48V & IOUT = 4.2A and also for VIN = 18V to 36V, VOUT = 48V & IOUT = 4.2A.
    You will see the latest updates on ti.com in our next release.

    Thanks,
    Kiran Kumar
  • 0 in reply to Kiran Kumar10
    TI__Genius 14455 points
    Hi Vern,
    To give you some more details.
    In WEBENCH, designs will not get created if a suitable FET is not found for the operating design condition.

    1. 20V-24Vin, 48Vout, 4.2A, will not allow TPS43060 or TPS43061 at 444KHz – says fsw is out of range
    This is because when the design is forced to operate at 444KHz, there are not enough FETs in the database that handle the high current and the large switching frequency. We are working on improvements to this algorithm – such as paralleling of FETs and providing idealFETs to help generate the design.

    2. 20V-24V, 46V, 4.2A, no designs using TPS43060 or TPS43061
    This is again FET not being found issue.

    3. 20V-24V, 44V, 4.2A, no designs using TPS43061 but TPS43060 appears
    This is because as the TPS43061 is optimized for Low Qg NexFETs, WEBENCH design recommends only TI NexFETs. The TPS43060 is able to select 3rd party FETs and hence able to create design.

    4. 20V-24V, 46, 4.0A, only TPS43060 and TPS40210 are allowed- why?
    We are not seeing TPS43060/1 which is consistent with what we saw at 4.2A. This is again due to FETs.

    5. When I increase the Vmin to 24V, I see more choices
    This is correct because as the Vmin increases the current required to boost would be less. This causes less power dissipated and FETs to be selected causing more designs to be created

    Please let us know if you have more questions.

    Regards,
    Gerold
  • 0 in reply to Gerold Dhanabalan - Online Design Tools
    Intellectual 520 points
    thanks. seems you reduced freq, not fair, but I want high freq.
    I differ with your answer, there are many mosfets, my choice is TI CSD18543Q3A. only 8nc and 8.5mohms at my operating values.
    I design my boost circuit around the graphs of CSD18543Q3A, that is optimum design, right?
    seems webench is for dummies, and I am one. but once beyond dummy stage, please give more control. I have no valid useful results from webench, that's a fact. all my webench pcb outputs use a huge inductor, lower frequency, parts are far apart. oh well.
    I can only wait for updates, but these issues have been in existence for how many years? 10?
  • 0 in reply to Vern Bunch
    TI__Genius 14455 points

    Hi Vern, Your points are noted. We are improving our algorithm and will have a solution for you really soon.

    Regards,

    Gerold