Multiple Step-Down Voltage Rails from a single DC Power Supply












1














I have one working PCB which has three different Voltage Rails: 3.3V, 4V and 1.8V. They are generated using three separate step-down buck converters. The input voltage to all the converters is a single DC Power Supply (12V).




  • Buck Converter Generating 4V powers 4G LTE Module (Load 2.5A)

  • Buck Converter generating 1.8V powers LoRa IC SX1231 (Load 1A)

  • Buck Converter generating 3.3V powers iMX6ULL System-on-module (Load: 3A)


enter image description here



These three different buck converters are occupying alot of PCB space and increasing the BOM. I am thinking to implement single IC solution for my system. A quick google search landed me on two solutions.




  • A Triple Step-Down Converter from TI (TPS6526x)

  • Using a single Buck Converter to generate multiple voltages. (The link is over here).


What should I consider? Is there any different solution other than listed above?










share|improve this question






















  • Can’t you use the same 3.3V supply for at least the SX1231 and iMX6ULL? (maybe also the unnamed LTE modem)
    – Michael
    2 hours ago


















1














I have one working PCB which has three different Voltage Rails: 3.3V, 4V and 1.8V. They are generated using three separate step-down buck converters. The input voltage to all the converters is a single DC Power Supply (12V).




  • Buck Converter Generating 4V powers 4G LTE Module (Load 2.5A)

  • Buck Converter generating 1.8V powers LoRa IC SX1231 (Load 1A)

  • Buck Converter generating 3.3V powers iMX6ULL System-on-module (Load: 3A)


enter image description here



These three different buck converters are occupying alot of PCB space and increasing the BOM. I am thinking to implement single IC solution for my system. A quick google search landed me on two solutions.




  • A Triple Step-Down Converter from TI (TPS6526x)

  • Using a single Buck Converter to generate multiple voltages. (The link is over here).


What should I consider? Is there any different solution other than listed above?










share|improve this question






















  • Can’t you use the same 3.3V supply for at least the SX1231 and iMX6ULL? (maybe also the unnamed LTE modem)
    – Michael
    2 hours ago
















1












1








1







I have one working PCB which has three different Voltage Rails: 3.3V, 4V and 1.8V. They are generated using three separate step-down buck converters. The input voltage to all the converters is a single DC Power Supply (12V).




  • Buck Converter Generating 4V powers 4G LTE Module (Load 2.5A)

  • Buck Converter generating 1.8V powers LoRa IC SX1231 (Load 1A)

  • Buck Converter generating 3.3V powers iMX6ULL System-on-module (Load: 3A)


enter image description here



These three different buck converters are occupying alot of PCB space and increasing the BOM. I am thinking to implement single IC solution for my system. A quick google search landed me on two solutions.




  • A Triple Step-Down Converter from TI (TPS6526x)

  • Using a single Buck Converter to generate multiple voltages. (The link is over here).


What should I consider? Is there any different solution other than listed above?










share|improve this question













I have one working PCB which has three different Voltage Rails: 3.3V, 4V and 1.8V. They are generated using three separate step-down buck converters. The input voltage to all the converters is a single DC Power Supply (12V).




  • Buck Converter Generating 4V powers 4G LTE Module (Load 2.5A)

  • Buck Converter generating 1.8V powers LoRa IC SX1231 (Load 1A)

  • Buck Converter generating 3.3V powers iMX6ULL System-on-module (Load: 3A)


enter image description here



These three different buck converters are occupying alot of PCB space and increasing the BOM. I am thinking to implement single IC solution for my system. A quick google search landed me on two solutions.




  • A Triple Step-Down Converter from TI (TPS6526x)

  • Using a single Buck Converter to generate multiple voltages. (The link is over here).


What should I consider? Is there any different solution other than listed above?







power-supply voltage-regulator circuit-design switch-mode-power-supply buck






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked 4 hours ago









abhiarora

438416




438416












  • Can’t you use the same 3.3V supply for at least the SX1231 and iMX6ULL? (maybe also the unnamed LTE modem)
    – Michael
    2 hours ago




















  • Can’t you use the same 3.3V supply for at least the SX1231 and iMX6ULL? (maybe also the unnamed LTE modem)
    – Michael
    2 hours ago


















Can’t you use the same 3.3V supply for at least the SX1231 and iMX6ULL? (maybe also the unnamed LTE modem)
– Michael
2 hours ago






Can’t you use the same 3.3V supply for at least the SX1231 and iMX6ULL? (maybe also the unnamed LTE modem)
– Michael
2 hours ago












2 Answers
2






active

oldest

votes


















1














The triple converter gets you some space savings while maintaining the basic simplicity of buck regulators. However, the chip now is a single point of failure. Multiple outputs from one switching stage will save more space. However, the magnetics no longer are simple inductors so the added design and development time might eat up or exceed the BOM savings. Unless you're talking about high volume, I'd go with a triple controller. I prefer Linear Tech, but TI should be fine.






share|improve this answer





















  • Where to start for magnetics of single switching stage?
    – abhiarora
    4 hours ago






  • 2




    Triple converters also often have startup/shutdown features that make it easier to keep power sequencing constraints like "the 5V rail may not drop more than 0.3V below the 3.3V rail at any time".
    – Simon Richter
    4 hours ago



















1














There are many triple output SMPS on the market and in Design Reference sites like Analog, LTI, TI but they tend not to be give out the larger power designs that are worth more and may have OEM IT property tricks or custom magnetics.



You need to assess your cost, performance, skills, time and qty tradeoffs then consider everything including AC to DC, EMI, performance, cost and reliability.



If you have the skills then you will have at least a 1 page list of all specs.



If you do then expand it to at least 5 pages and do some due diligence cost analysis and see if you can achieve $5 in volume for 22W from AC to triple output DC like this possibility.
enter image description here






share|improve this answer





















    Your Answer





    StackExchange.ifUsing("editor", function () {
    return StackExchange.using("mathjaxEditing", function () {
    StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
    StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["\$", "\$"]]);
    });
    });
    }, "mathjax-editing");

    StackExchange.ifUsing("editor", function () {
    return StackExchange.using("schematics", function () {
    StackExchange.schematics.init();
    });
    }, "cicuitlab");

    StackExchange.ready(function() {
    var channelOptions = {
    tags: "".split(" "),
    id: "135"
    };
    initTagRenderer("".split(" "), "".split(" "), channelOptions);

    StackExchange.using("externalEditor", function() {
    // Have to fire editor after snippets, if snippets enabled
    if (StackExchange.settings.snippets.snippetsEnabled) {
    StackExchange.using("snippets", function() {
    createEditor();
    });
    }
    else {
    createEditor();
    }
    });

    function createEditor() {
    StackExchange.prepareEditor({
    heartbeatType: 'answer',
    autoActivateHeartbeat: false,
    convertImagesToLinks: false,
    noModals: true,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: null,
    bindNavPrevention: true,
    postfix: "",
    imageUploader: {
    brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
    contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
    allowUrls: true
    },
    onDemand: true,
    discardSelector: ".discard-answer"
    ,immediatelyShowMarkdownHelp:true
    });


    }
    });














    draft saved

    draft discarded


















    StackExchange.ready(
    function () {
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2felectronics.stackexchange.com%2fquestions%2f414326%2fmultiple-step-down-voltage-rails-from-a-single-dc-power-supply%23new-answer', 'question_page');
    }
    );

    Post as a guest















    Required, but never shown

























    2 Answers
    2






    active

    oldest

    votes








    2 Answers
    2






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    1














    The triple converter gets you some space savings while maintaining the basic simplicity of buck regulators. However, the chip now is a single point of failure. Multiple outputs from one switching stage will save more space. However, the magnetics no longer are simple inductors so the added design and development time might eat up or exceed the BOM savings. Unless you're talking about high volume, I'd go with a triple controller. I prefer Linear Tech, but TI should be fine.






    share|improve this answer





















    • Where to start for magnetics of single switching stage?
      – abhiarora
      4 hours ago






    • 2




      Triple converters also often have startup/shutdown features that make it easier to keep power sequencing constraints like "the 5V rail may not drop more than 0.3V below the 3.3V rail at any time".
      – Simon Richter
      4 hours ago
















    1














    The triple converter gets you some space savings while maintaining the basic simplicity of buck regulators. However, the chip now is a single point of failure. Multiple outputs from one switching stage will save more space. However, the magnetics no longer are simple inductors so the added design and development time might eat up or exceed the BOM savings. Unless you're talking about high volume, I'd go with a triple controller. I prefer Linear Tech, but TI should be fine.






    share|improve this answer





















    • Where to start for magnetics of single switching stage?
      – abhiarora
      4 hours ago






    • 2




      Triple converters also often have startup/shutdown features that make it easier to keep power sequencing constraints like "the 5V rail may not drop more than 0.3V below the 3.3V rail at any time".
      – Simon Richter
      4 hours ago














    1












    1








    1






    The triple converter gets you some space savings while maintaining the basic simplicity of buck regulators. However, the chip now is a single point of failure. Multiple outputs from one switching stage will save more space. However, the magnetics no longer are simple inductors so the added design and development time might eat up or exceed the BOM savings. Unless you're talking about high volume, I'd go with a triple controller. I prefer Linear Tech, but TI should be fine.






    share|improve this answer












    The triple converter gets you some space savings while maintaining the basic simplicity of buck regulators. However, the chip now is a single point of failure. Multiple outputs from one switching stage will save more space. However, the magnetics no longer are simple inductors so the added design and development time might eat up or exceed the BOM savings. Unless you're talking about high volume, I'd go with a triple controller. I prefer Linear Tech, but TI should be fine.







    share|improve this answer












    share|improve this answer



    share|improve this answer










    answered 4 hours ago









    AnalogKid

    1,47525




    1,47525












    • Where to start for magnetics of single switching stage?
      – abhiarora
      4 hours ago






    • 2




      Triple converters also often have startup/shutdown features that make it easier to keep power sequencing constraints like "the 5V rail may not drop more than 0.3V below the 3.3V rail at any time".
      – Simon Richter
      4 hours ago


















    • Where to start for magnetics of single switching stage?
      – abhiarora
      4 hours ago






    • 2




      Triple converters also often have startup/shutdown features that make it easier to keep power sequencing constraints like "the 5V rail may not drop more than 0.3V below the 3.3V rail at any time".
      – Simon Richter
      4 hours ago
















    Where to start for magnetics of single switching stage?
    – abhiarora
    4 hours ago




    Where to start for magnetics of single switching stage?
    – abhiarora
    4 hours ago




    2




    2




    Triple converters also often have startup/shutdown features that make it easier to keep power sequencing constraints like "the 5V rail may not drop more than 0.3V below the 3.3V rail at any time".
    – Simon Richter
    4 hours ago




    Triple converters also often have startup/shutdown features that make it easier to keep power sequencing constraints like "the 5V rail may not drop more than 0.3V below the 3.3V rail at any time".
    – Simon Richter
    4 hours ago













    1














    There are many triple output SMPS on the market and in Design Reference sites like Analog, LTI, TI but they tend not to be give out the larger power designs that are worth more and may have OEM IT property tricks or custom magnetics.



    You need to assess your cost, performance, skills, time and qty tradeoffs then consider everything including AC to DC, EMI, performance, cost and reliability.



    If you have the skills then you will have at least a 1 page list of all specs.



    If you do then expand it to at least 5 pages and do some due diligence cost analysis and see if you can achieve $5 in volume for 22W from AC to triple output DC like this possibility.
    enter image description here






    share|improve this answer


























      1














      There are many triple output SMPS on the market and in Design Reference sites like Analog, LTI, TI but they tend not to be give out the larger power designs that are worth more and may have OEM IT property tricks or custom magnetics.



      You need to assess your cost, performance, skills, time and qty tradeoffs then consider everything including AC to DC, EMI, performance, cost and reliability.



      If you have the skills then you will have at least a 1 page list of all specs.



      If you do then expand it to at least 5 pages and do some due diligence cost analysis and see if you can achieve $5 in volume for 22W from AC to triple output DC like this possibility.
      enter image description here






      share|improve this answer
























        1












        1








        1






        There are many triple output SMPS on the market and in Design Reference sites like Analog, LTI, TI but they tend not to be give out the larger power designs that are worth more and may have OEM IT property tricks or custom magnetics.



        You need to assess your cost, performance, skills, time and qty tradeoffs then consider everything including AC to DC, EMI, performance, cost and reliability.



        If you have the skills then you will have at least a 1 page list of all specs.



        If you do then expand it to at least 5 pages and do some due diligence cost analysis and see if you can achieve $5 in volume for 22W from AC to triple output DC like this possibility.
        enter image description here






        share|improve this answer












        There are many triple output SMPS on the market and in Design Reference sites like Analog, LTI, TI but they tend not to be give out the larger power designs that are worth more and may have OEM IT property tricks or custom magnetics.



        You need to assess your cost, performance, skills, time and qty tradeoffs then consider everything including AC to DC, EMI, performance, cost and reliability.



        If you have the skills then you will have at least a 1 page list of all specs.



        If you do then expand it to at least 5 pages and do some due diligence cost analysis and see if you can achieve $5 in volume for 22W from AC to triple output DC like this possibility.
        enter image description here







        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered 3 hours ago









        Tony EE rocketscientist

        61.8k22193




        61.8k22193






























            draft saved

            draft discarded




















































            Thanks for contributing an answer to Electrical Engineering Stack Exchange!


            • Please be sure to answer the question. Provide details and share your research!

            But avoid



            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.


            Use MathJax to format equations. MathJax reference.


            To learn more, see our tips on writing great answers.





            Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


            Please pay close attention to the following guidance:


            • Please be sure to answer the question. Provide details and share your research!

            But avoid



            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.


            To learn more, see our tips on writing great answers.




            draft saved


            draft discarded














            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2felectronics.stackexchange.com%2fquestions%2f414326%2fmultiple-step-down-voltage-rails-from-a-single-dc-power-supply%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown





















































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown

































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown







            Popular posts from this blog

            Morgemoulin

            Scott Moir

            Souastre