Don't understand MOSFET as amplifierHow is possible that with same Ibase there is more than one Vce?My amplifier produced a negative gain when it should be positive. Why?Designing a BJT Amplifier given some constraintsAoE3: Grounded Emitter Amplifier DistortionGain and output impedance of an amplifierHow does the voltage difference develop when MOSFET is biased with Current Source?Common source amplifier using mosfet: Why is my Id dependent on my Rd?Difficulties in biasing MOSFET push-pull amplifierHow to identify which transistor is in active region and which one is in saturation?About the output resistance of a voltage amplifier

Are illustrations in novels frowned upon?

How to organize ideas to start writing a novel?

!I!n!s!e!r!t! !n!b!e!t!w!e!e!n!

Can you grapple/shove with the Hunter Ranger's Whirlwind Attack?

In an emergency, how do I find and share my position?

Running script line by line automatically yet being asked before each line from second line onwards

How to setup a teletype to a unix shell

Can my boyfriend, who lives in the UK and has a Polish passport, visit me in the USA?

Is "stainless" a bulk or a surface property of stainless steel?

Do I have to learn /o/ or /ɔ/ separately?

Sleeping solo in a double sleeping bag

Shouldn't the "credit score" prevent Americans from going deeper and deeper into personal debt?

Thread-safe, Convenient and Performant Random Number Generator

What is the evidence on the danger of feeding whole blueberries and grapes to infants and toddlers?

Are there any plans for handling people floating away during an EVA?

Most practical knots for hitching a line to an object while keeping the bitter end as tight as possible, without sag?

Metal that glows when near pieces of itself

What professions would a medieval village with a population of 100 need?

Can a group have a cyclical derived series?

What is "Wayfinder's Guide to Eberron"?

Church Booleans

Why were movies shot on film shot at 24 frames per second?

Is there a SubImageApply?

How do you call it when two celestial bodies come as close to each other as they will in their current orbits?



Don't understand MOSFET as amplifier


How is possible that with same Ibase there is more than one Vce?My amplifier produced a negative gain when it should be positive. Why?Designing a BJT Amplifier given some constraintsAoE3: Grounded Emitter Amplifier DistortionGain and output impedance of an amplifierHow does the voltage difference develop when MOSFET is biased with Current Source?Common source amplifier using mosfet: Why is my Id dependent on my Rd?Difficulties in biasing MOSFET push-pull amplifierHow to identify which transistor is in active region and which one is in saturation?About the output resistance of a voltage amplifier






.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty margin-bottom:0;








1












$begingroup$


When a MOSFET is working in its saturation region, it might be used as an amplifier. But, as far as I understand, the more you increase vGS (voltage between the MOSFET's gate and ground) the less output voltage you get, which is the opposite of amplifying. Let me explain:



Having this (supposed) amplifier:



enter image description here



when it is in saturation region, it behaves as a VCCS, which, apparently, leads to an amplifiers' behaviour:



enter image description here



In the above picture, vO will be VS - eL, if eL is the voltage drop in RL. Following the iD equation, the more vIN incrases, the more voltage drop you will have in RL, right? That means that the more vIN increases, the more vO decreases. That isn't amplifying, but the opposite.



What am I missing?










share|improve this question









$endgroup$









  • 3




    $begingroup$
    This is an inverting amplifier, so the AC gain has a negative sign.
    $endgroup$
    – glen_geek
    8 hours ago











  • $begingroup$
    If |ΔVo/ΔVin| >1 then it is amplifying.
    $endgroup$
    – Phil G
    8 hours ago










  • $begingroup$
    electronics.stackexchange.com/questions/355899/…
    $endgroup$
    – G36
    8 hours ago

















1












$begingroup$


When a MOSFET is working in its saturation region, it might be used as an amplifier. But, as far as I understand, the more you increase vGS (voltage between the MOSFET's gate and ground) the less output voltage you get, which is the opposite of amplifying. Let me explain:



Having this (supposed) amplifier:



enter image description here



when it is in saturation region, it behaves as a VCCS, which, apparently, leads to an amplifiers' behaviour:



enter image description here



In the above picture, vO will be VS - eL, if eL is the voltage drop in RL. Following the iD equation, the more vIN incrases, the more voltage drop you will have in RL, right? That means that the more vIN increases, the more vO decreases. That isn't amplifying, but the opposite.



What am I missing?










share|improve this question









$endgroup$









  • 3




    $begingroup$
    This is an inverting amplifier, so the AC gain has a negative sign.
    $endgroup$
    – glen_geek
    8 hours ago











  • $begingroup$
    If |ΔVo/ΔVin| >1 then it is amplifying.
    $endgroup$
    – Phil G
    8 hours ago










  • $begingroup$
    electronics.stackexchange.com/questions/355899/…
    $endgroup$
    – G36
    8 hours ago













1












1








1





$begingroup$


When a MOSFET is working in its saturation region, it might be used as an amplifier. But, as far as I understand, the more you increase vGS (voltage between the MOSFET's gate and ground) the less output voltage you get, which is the opposite of amplifying. Let me explain:



Having this (supposed) amplifier:



enter image description here



when it is in saturation region, it behaves as a VCCS, which, apparently, leads to an amplifiers' behaviour:



enter image description here



In the above picture, vO will be VS - eL, if eL is the voltage drop in RL. Following the iD equation, the more vIN incrases, the more voltage drop you will have in RL, right? That means that the more vIN increases, the more vO decreases. That isn't amplifying, but the opposite.



What am I missing?










share|improve this question









$endgroup$




When a MOSFET is working in its saturation region, it might be used as an amplifier. But, as far as I understand, the more you increase vGS (voltage between the MOSFET's gate and ground) the less output voltage you get, which is the opposite of amplifying. Let me explain:



Having this (supposed) amplifier:



enter image description here



when it is in saturation region, it behaves as a VCCS, which, apparently, leads to an amplifiers' behaviour:



enter image description here



In the above picture, vO will be VS - eL, if eL is the voltage drop in RL. Following the iD equation, the more vIN incrases, the more voltage drop you will have in RL, right? That means that the more vIN increases, the more vO decreases. That isn't amplifying, but the opposite.



What am I missing?







mosfet amplifier






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked 8 hours ago









MartelMartel

155 bronze badges




155 bronze badges










  • 3




    $begingroup$
    This is an inverting amplifier, so the AC gain has a negative sign.
    $endgroup$
    – glen_geek
    8 hours ago











  • $begingroup$
    If |ΔVo/ΔVin| >1 then it is amplifying.
    $endgroup$
    – Phil G
    8 hours ago










  • $begingroup$
    electronics.stackexchange.com/questions/355899/…
    $endgroup$
    – G36
    8 hours ago












  • 3




    $begingroup$
    This is an inverting amplifier, so the AC gain has a negative sign.
    $endgroup$
    – glen_geek
    8 hours ago











  • $begingroup$
    If |ΔVo/ΔVin| >1 then it is amplifying.
    $endgroup$
    – Phil G
    8 hours ago










  • $begingroup$
    electronics.stackexchange.com/questions/355899/…
    $endgroup$
    – G36
    8 hours ago







3




3




$begingroup$
This is an inverting amplifier, so the AC gain has a negative sign.
$endgroup$
– glen_geek
8 hours ago





$begingroup$
This is an inverting amplifier, so the AC gain has a negative sign.
$endgroup$
– glen_geek
8 hours ago













$begingroup$
If |ΔVo/ΔVin| >1 then it is amplifying.
$endgroup$
– Phil G
8 hours ago




$begingroup$
If |ΔVo/ΔVin| >1 then it is amplifying.
$endgroup$
– Phil G
8 hours ago












$begingroup$
electronics.stackexchange.com/questions/355899/…
$endgroup$
– G36
8 hours ago




$begingroup$
electronics.stackexchange.com/questions/355899/…
$endgroup$
– G36
8 hours ago










1 Answer
1






active

oldest

votes


















6












$begingroup$

It is an amplifier because you put a wiggly signal in, and you get a bigger wiggly signal out. The fact that the output wiggles down when the input wiggles up is a trivial detail, that -- if it's a problem at all -- can be solved in any number of ways (not least of which is following one stage by another, because two negative gains, when multiplied, result in a positive gain).






share|improve this answer









$endgroup$

















    Your Answer






    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%2f453815%2fdont-understand-mosfet-as-amplifier%23new-answer', 'question_page');

    );

    Post as a guest















    Required, but never shown

























    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    6












    $begingroup$

    It is an amplifier because you put a wiggly signal in, and you get a bigger wiggly signal out. The fact that the output wiggles down when the input wiggles up is a trivial detail, that -- if it's a problem at all -- can be solved in any number of ways (not least of which is following one stage by another, because two negative gains, when multiplied, result in a positive gain).






    share|improve this answer









    $endgroup$



















      6












      $begingroup$

      It is an amplifier because you put a wiggly signal in, and you get a bigger wiggly signal out. The fact that the output wiggles down when the input wiggles up is a trivial detail, that -- if it's a problem at all -- can be solved in any number of ways (not least of which is following one stage by another, because two negative gains, when multiplied, result in a positive gain).






      share|improve this answer









      $endgroup$

















        6












        6








        6





        $begingroup$

        It is an amplifier because you put a wiggly signal in, and you get a bigger wiggly signal out. The fact that the output wiggles down when the input wiggles up is a trivial detail, that -- if it's a problem at all -- can be solved in any number of ways (not least of which is following one stage by another, because two negative gains, when multiplied, result in a positive gain).






        share|improve this answer









        $endgroup$



        It is an amplifier because you put a wiggly signal in, and you get a bigger wiggly signal out. The fact that the output wiggles down when the input wiggles up is a trivial detail, that -- if it's a problem at all -- can be solved in any number of ways (not least of which is following one stage by another, because two negative gains, when multiplied, result in a positive gain).







        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered 8 hours ago









        TimWescottTimWescott

        12.3k1 gold badge9 silver badges24 bronze badges




        12.3k1 gold badge9 silver badges24 bronze badges






























            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.




            draft saved


            draft discarded














            StackExchange.ready(
            function ()
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2felectronics.stackexchange.com%2fquestions%2f453815%2fdont-understand-mosfet-as-amplifier%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

            Canceling a color specificationRandomly assigning color to Graphics3D objects?Default color for Filling in Mathematica 9Coloring specific elements of sets with a prime modified order in an array plotHow to pick a color differing significantly from the colors already in a given color list?Detection of the text colorColor numbers based on their valueCan color schemes for use with ColorData include opacity specification?My dynamic color schemes

            Invision Community Contents History See also References External links Navigation menuProprietaryinvisioncommunity.comIPS Community ForumsIPS Community Forumsthis blog entry"License Changes, IP.Board 3.4, and the Future""Interview -- Matt Mecham of Ibforums""CEO Invision Power Board, Matt Mecham Is a Liar, Thief!"IPB License Explanation 1.3, 1.3.1, 2.0, and 2.1ArchivedSecurity Fixes, Updates And Enhancements For IPB 1.3.1Archived"New Demo Accounts - Invision Power Services"the original"New Default Skin"the original"Invision Power Board 3.0.0 and Applications Released"the original"Archived copy"the original"Perpetual licenses being done away with""Release Notes - Invision Power Services""Introducing: IPS Community Suite 4!"Invision Community Release Notes

            199年 目錄 大件事 到箇年出世嗰人 到箇年死嗰人 節慶、風俗習慣 導覽選單