MOSFET Transconductance and MOSFET Small Signal Model Explained

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  • เผยแพร่เมื่อ 24 พ.ย. 2024

ความคิดเห็น • 64

  • @ALLABOUTELECTRONICS
    @ALLABOUTELECTRONICS  4 ปีที่แล้ว +25

    Timestamps:
    0:00 Introduction
    0:37 What is Transconductance?
    2:06 Different MOSFET transconductance equations
    5:47 MOSFET Small-Signal Model

  • @anoopcc2361
    @anoopcc2361 4 ปีที่แล้ว +69

    Sir I wanted to thank you for your videos I got placed in my core job at MaxLinear for higher package, especially your practical explanation of circuits was helpful for me in interviews ❤️

  • @honeypaaturi9979
    @honeypaaturi9979 10 หลายเดือนก่อน +2

    Thank you so much, just can't show enough gratitude through words. You're the real teacher.....☺️🤗 Understanding a concept thoroughly gives such satisfaction to student that we just can't express it enough. 🙏🏻🙏🏻🙏🏻

  • @iamavolk
    @iamavolk 2 ปีที่แล้ว +6

    Immense respect for you, sir, and many thanks! One of the best educators on TH-cam.

  • @michaelpogrebitskiy6122
    @michaelpogrebitskiy6122 2 ปีที่แล้ว +2

    I have my microelectronics final exam in 4 and a half hours, and the small signal model always confused me. Thank you for this very understandable explanation!

  • @neilharris478
    @neilharris478 2 ปีที่แล้ว

    At the very end of the video, the polarity of Vo being positive on upper rail and negative on lower rail is as many textbooks show it. But current flows UPWARD through the resistor from the lower rail, making the resistor more positive in its lower half. HOWEVER, you explained that vo = -gmViRd (the minus sign helps clear this up!) Thank you!

  • @薇季芬
    @薇季芬 ปีที่แล้ว +5

    0:39-0:46 to use the mosfet as a amplifier, it should be operated in the saturation region 如果要用mosfet當作放大器,那麼應該要保持在飽和區
    0:46-0:54 because the drain current iD is a function of voltage VGS 因為電流iD是一個電壓的函數
    0:54-1:00
    but if you see the relationship between drain current and the voltage VGS,you will find the relationship is not linear.但如果你觀察drain current iD和電壓VGS的關係,你會發現這個關係不是線性的
    1:40-1:55
    it is defined that the transcinductance of the mosfet. ths transconductance is equal to the change in the drain current divided by the change in the voltage VGS
    定義一個東西叫做conductance=drain current iD的變化量 除於 電壓VGS的變化量
    2:01-2:06 從圖形上來看consductance就是operating point的斜率
    2:26-3:02
    微積分內容
    3:11-3:22 from this expression,you can see.The transconductance is proportional to VGS minus Vt.從這條式子可以發現,當使用同一個mosfet時(意即mosfet參數不變),transconductance 和 (VGS - Vt) 成正比
    4:38-5:41 最精簡的方式表示gm

  • @passion_is_
    @passion_is_ 4 ปีที่แล้ว +3

    Sir we are waiting for your next video plz post the next topic as soon as possible

  • @camilotello3296
    @camilotello3296 3 ปีที่แล้ว +1

    Sir, I'm extremely happy I came across your video, this explained a lot and was really insightful. Thank you so much!!!

  • @sanderbank2058
    @sanderbank2058 4 ปีที่แล้ว +3

    Thnx you are really good at explaining these things

  • @heregulmithal7063
    @heregulmithal7063 4 ปีที่แล้ว +3

    Wonderful presentation.

  • @Lwyte17
    @Lwyte17 2 ปีที่แล้ว +1

    Dude, awesome! Thanks for making these great videos.

  • @guhbnu
    @guhbnu ปีที่แล้ว +1

    excelent explanation!!!!!!

  • @theminertom11551
    @theminertom11551 ปีที่แล้ว

    Very clear explanation!

  • @venkateshwaran292
    @venkateshwaran292 2 ปีที่แล้ว

    Very helpful video. Clear and to the point explanation.

  • @raeafreund9242
    @raeafreund9242 3 ปีที่แล้ว +1

    This is so clear thank you!!!

  • @lakshmipriyanka4490
    @lakshmipriyanka4490 3 ปีที่แล้ว +1

    Thank you so much sir

  • @supoyu6893
    @supoyu6893 2 ปีที่แล้ว +1

    Really help!

  • @dr.vandanakhanna8813
    @dr.vandanakhanna8813 3 ปีที่แล้ว

    Very nicely explained. Great!

  • @प्रणव_गुप्ता
    @प्रणव_गुप्ता ปีที่แล้ว +1

    Sir what is general value of the small signal Vi in practical experiments??

  • @akshatsharma7639
    @akshatsharma7639 3 ปีที่แล้ว

    wow amazing explanation.

  • @kommsk
    @kommsk 3 ปีที่แล้ว

    Very good job bro

  • @teresafaasolo144
    @teresafaasolo144 3 ปีที่แล้ว +1

    Is this process the same for when we calculate for the transconductance for a Mosfet in a triode region?

  • @ececse
    @ececse 6 หลายเดือนก่อน

    thankyou sir.

  • @finalinvention
    @finalinvention 2 ปีที่แล้ว

    Thank you for valuable lecture. One question. Why VDD is grounded? Shouldn't mosfet be saturation mode which requires large Vds?

    • @ALLABOUTELECTRONICS
      @ALLABOUTELECTRONICS  2 ปีที่แล้ว +1

      This is small signal analysis. So, for that, all the DC voltage sources in the circuit has been assumed as zero. That's why VDD is grounded.

  • @user23xx76
    @user23xx76 3 ปีที่แล้ว +1

    thank you ^^

  • @vinaykumarkv5830
    @vinaykumarkv5830 3 ปีที่แล้ว

    Thanks a lot ❤

  • @bipulkumarsingh554
    @bipulkumarsingh554 2 ปีที่แล้ว

    can u make video on switch capacitor pls

  • @anveshreddy1245
    @anveshreddy1245 3 ปีที่แล้ว

    Can you explain large signal model of mosfet

  • @hasibuddin2437
    @hasibuddin2437 3 ปีที่แล้ว

    Thnks

  • @killermitians7640
    @killermitians7640 3 ปีที่แล้ว +1

    At 11.20 is the current flows in clockwise direction?

    • @ALLABOUTELECTRONICS
      @ALLABOUTELECTRONICS  3 ปีที่แล้ว +1

      No, its flowing in the anti-clockwise direction.

    • @killermitians7640
      @killermitians7640 3 ปีที่แล้ว

      @@ALLABOUTELECTRONICS but i can't understand it sir ....can u explain it for me ?

    • @ALLABOUTELECTRONICS
      @ALLABOUTELECTRONICS  3 ปีที่แล้ว +2

      @@killermitians7640 The dependent current source is connected between drain and source. (Downward direction) On the left, gate to source terminal acts as an open circuit. So, there is only one way that current can flow. Through drain resistor. And to satisfy KCL, it will flow from bottom to top through drain resistor. Or in other words, in the loop, it is flowing in the anti-clockwise direction.
      I hope it will clear your doubt.

    • @killermitians7640
      @killermitians7640 3 ปีที่แล้ว

      @@ALLABOUTELECTRONICS Thank you so much sir ....sir a humble request do make videos on MOSFET biasing as soon as possible as we are having our exams on January.....btw thank you once again sir

    • @ALLABOUTELECTRONICS
      @ALLABOUTELECTRONICS  3 ปีที่แล้ว +1

      @@killermitians7640 I have already made videos on it.
      Please check the JFET and MOSFET playlist.
      You will get it.
      Here is the link: th-cam.com/play/PLwjK_iyK4LLC-tRT_Uml3T-ifdcmuykjV.html

  • @user-ge8hj9br6w
    @user-ge8hj9br6w 3 ปีที่แล้ว

    can you teach to find net transconductance and output resistance of mosfet combo circuits

    • @ALLABOUTELECTRONICS
      @ALLABOUTELECTRONICS  3 ปีที่แล้ว

      It has been already covered in the cascode amplifier video.

    • @user-ge8hj9br6w
      @user-ge8hj9br6w 3 ปีที่แล้ว

      @@ALLABOUTELECTRONICS oh yes, thank you

  • @bestofbest8213
    @bestofbest8213 3 ปีที่แล้ว +1

    kinly make play list , it is very hard find specific vedios

    • @ALLABOUTELECTRONICS
      @ALLABOUTELECTRONICS  3 ปีที่แล้ว +1

      Please check JFET and MOSFET playlist on the playlist page. You will find all related videos there.

  • @rohitnaidu2432
    @rohitnaidu2432 2 ปีที่แล้ว

    does the current direction change based on p-type or n-type classification?

    • @ALLABOUTELECTRONICS
      @ALLABOUTELECTRONICS  2 ปีที่แล้ว

      For p-type, the current is flowing from source to drain.

  • @MuntahaRahman-m9d
    @MuntahaRahman-m9d ปีที่แล้ว

    why do we only do small signal analysis in saturation region?

    • @ALLABOUTELECTRONICS
      @ALLABOUTELECTRONICS  ปีที่แล้ว

      Because in the saturation region, MOSFET acts as a voltage controlled current source. And in that region, it can be used as an amplifier. Using the small signal analysis, it possible to find the relevant characteristics of the amplifier. (Gain, input and output impedance etc)

  • @exaltant2464
    @exaltant2464 3 ปีที่แล้ว +2

    why am i giving fee to college?

  • @suryakanth5370
    @suryakanth5370 3 ปีที่แล้ว

    Sir if vi

    • @ALLABOUTELECTRONICS
      @ALLABOUTELECTRONICS  3 ปีที่แล้ว

      2 Vi (Vdc - Vt) will be small but Vi^2 will be even smaller. And hence Vi^2 term can be neglected.
      For example, let's say Vi = 10^-4 V and Vdc - Vt is 1 V. So, 2 Vi (Vdc - Vt) is 2 x 10^-4, while Vi^2 = 10^-8. So, if you compare both terms then Vi^2 is much much smaller and hence in comparision to other two terms it can be negleted.
      I hope, it will clear your doubt.

  • @harshbardhanon4901
    @harshbardhanon4901 3 ปีที่แล้ว

    sir why Vgs=Vdc+vi

    • @ALLABOUTELECTRONICS
      @ALLABOUTELECTRONICS  3 ปีที่แล้ว

      The voltage Vgs is the superposition of the DC voltage (which is appearing between the gate and source terminal) and the AC input signal (which is also applied between the gate and source terminal).
      The Vdc is the required biasing voltage, while Vi is the AC input signal which we want to amplify.
      I hope, it will clear your doubt.

  • @opposites-369
    @opposites-369 4 ปีที่แล้ว +1

    Finnaly at least Hindi with English pronounce & English subtitle, thx bro 🙏🏻👍🏻, I really learn from you, uh.. I hate Hindi, urdu, bangla, tamil with no translation or English subtitle 😠😡🤬

    • @hrkalita159
      @hrkalita159 3 ปีที่แล้ว

      Did anyone ask you?

  • @rahulkurup3351
    @rahulkurup3351 2 ปีที่แล้ว

    sir please share these notes

    • @ALLABOUTELECTRONICS
      @ALLABOUTELECTRONICS  2 ปีที่แล้ว +1

      The notes are available on the website.
      Please check www.allaboutelectronics.org

  • @zulfiqarali2563
    @zulfiqarali2563 3 ปีที่แล้ว

    اردو یا ہندی یا براہوٸ میں لیکچر دو سر جی
    سرجی انگریزی میں کیا بتا رہے ہو

  • @pavansai6338
    @pavansai6338 2 ปีที่แล้ว

    🤯

  • @jivey5123
    @jivey5123 2 ปีที่แล้ว

    Hard to listen to.

  • @piyush-hp9pz
    @piyush-hp9pz 2 หลายเดือนก่อน

    thanky you sir