Razavi Electronics 1, Lec 25, Biasing Techniques II

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  • Опубликовано: 30 окт 2024

Комментарии • 29

  • @andyfang4230
    @andyfang4230 6 месяцев назад +2

    eight hours before exam and im cramming through these Razavi vids
    Hopefully this will help a bit
    Thanks for Professor Razavi and the uploader of these vids!

  • @Peter_1986
    @Peter_1986 3 года назад +3

    I find it very satisfying how these circuits are frequently analysed with Ohm's Law, KCL *_and_* KVL.
    That's like one big refresher of the most important analysis techniques from Circuit Theory.

  • @VIGNESHBSBEC
    @VIGNESHBSBEC 2 года назад +17

    22:30 Current (I) = Power(P)/Voltage(V)

    • @mr.ANIMAT0N
      @mr.ANIMAT0N 2 года назад +4

      They still give the same result as in this example P=V
      It was just a slip of the tounge

    • @anupammathur17
      @anupammathur17 8 месяцев назад

      @@mr.ANIMAT0N not the same result, current would be of Kilo Amps magnitude in this case, Also P and V are not of same order

  • @hichhikr
    @hichhikr 6 лет назад +27

    22:30
    Icc = P / Vcc

  • @nirvanaandre
    @nirvanaandre 9 лет назад +9

    Hello, just wanted to point out, that I believe you ended up mixing R1 & R2 from your 1st example.
    If we see that R1 + R2 = 15k Ohms, then we see that:
    R2/(R1+R2) = 0.9/Vcc
    R2/(15k) = 0.6 therefore,
    R2 = 9k Ohms and R1 = 6k Ohms
    PS: Thank you very much for these extremely helpful lectures! Very good work!

    • @Upgradezz
      @Upgradezz 4 года назад +2

      Hope you are doing good buddy.

    • @RaviNagar16
      @RaviNagar16 Год назад

      @@Upgradezz Hope you both are doing good ?!

  • @mnada72
    @mnada72 4 года назад +1

    Thank you from the bottom of my heart ❤

  • @Upgradezz
    @Upgradezz 4 года назад +2

    Why wasn't vcc change modeled into the small signal model from the output side?

  • @prakhargoel1962
    @prakhargoel1962 Год назад +1

    20:37 shouldn't it be Vx- Ve in RHS? As base emitter voltage isn't Vx but the difference Vx-Ve

    • @Roronoa_Zoro.
      @Roronoa_Zoro. Год назад

      Vx is a voltage on base w.r.t ground and Vc is a voltage on collector w.r.t ground.... now to make base collector jxn RB VC >= Vx.
      And that is what razavi sir has written.....
      I think your doubt will be cleared by the following equation.
      (Vc - Ve) >= (Vx - Ve)

  • @vishalmishra7568
    @vishalmishra7568 4 года назад +5

    HEY WHAT HAPPENED TO INTRO MUSIC......EARLIER IT HAD "VIVALDI FOUR SEASONS".....IT WAS LIKE THEME SONG OF "GOT" I NEVER SKIPPED IT

    • @rodge4980
      @rodge4980 2 года назад +1

      It's in the outro.

  • @bitvision-lg9cl
    @bitvision-lg9cl Год назад

    "Idea evolves" by ‪Behzad Razavi‬

  • @alexandrosanastasiou1964
    @alexandrosanastasiou1964 5 лет назад

    I don't understand this : At 28:10 professor says that you need V_c > V_x which is V_x = 0.9Volt. BUT. For reverse biasing between the Collector and the Base, you want V_ce > V_be, so V_c has to be bigger than 0.8V which is chosen for V_be. I guess I'm wrong, but I don't know why. Anyone care to explain ?

    • @ajayrajan8882
      @ajayrajan8882 5 лет назад +2

      Vcc - IcRc is the voltage across Rc.
      That is the collector voltage Vc.
      Now Vx is essentially the Base-emitter voltage. Therefore, the Vc voltage must be equal or greater than Vx so as the transistor stays is the forward active region.
      Now here the Vcc is 1.5V, Rc came out to be 600ohm and Ic was 1mA. On putting these values in the equation Vc = Vcc- IcRc, we get a collector voltage of 0.9V which is same as the Vx,
      Please make note these values chosen by professor are just for understanding and not as accurate as they should be, because now the transistor in kinda on the verge of soft-saturation, as Vc has came out exactly equal to Vx.. Yet the model is good enough for understanding the underlying concept.
      hope this helps:)

    • @이상혁-b1w
      @이상혁-b1w 4 года назад +1

      @@ajayrajan8882 Hi. I'm sorry but i think your explanation is little bit wrong. Vx is not a Base-Emitter voltage, but rather the voltage between base and ground. To make transistor in forward active region, (suppose it's npn transistor), we need a reverse bias between collector and base. Therefore, Vc>Vx.
      The original question was why V_ce>V_be. At lecture 17, professor mentioned that (again, suppose npn transistor)
      1. collector and base junction is zero or reverse biased
      2. base and emitter junction is forward biased.
      when these two conditions are met, we call it Active Forward Bias.
      Therefore to precisely satisfy Active Forward Bias, we need V_c > V_x.

    • @이상혁-b1w
      @이상혁-b1w 4 года назад

      FYI, the term should be corrected to "Forward Active Bias".

  • @muhammadhayat6350
    @muhammadhayat6350 Год назад +1

    the circuit won't bite:(

  • @inquisitortr7930
    @inquisitortr7930 5 лет назад

    can someone write equation of Rout/Rin please.

  • @chang-seopyuk3785
    @chang-seopyuk3785 5 лет назад

    1:01:11 Is there anyone here to explain why Rf equals betaRc divided by 10?

  • @andyralphine3387
    @andyralphine3387 4 года назад +2

    32:12 I think he got the gain wrong. It is nearly 6 but he got 4.76.

  • @pratikdas1780
    @pratikdas1780 3 года назад

    37:07