Razavi Electronics 1, Lec 33, Large-Signal & Small-Signal Operation

Рет қаралды 118,691

Behzad Razavi (Long Kong)

9 жыл бұрын

Large-Signal & Small-Signal Operation
(for next series, search for Razavi Electronics 2 or longkong)

Пікірлер: 87

@himadridebnath9177 4 жыл бұрын

I study Mtech in IIT and trust me there are some teachers who are shame to this society. I wish we had Teacher like you sir...

@jeventures8044 2 жыл бұрын

which iit ??

@himadridebnath9177 2 жыл бұрын

@@jeventures8044 kgp

@prashik4810 Жыл бұрын

@sakibtouhidul 5 ай бұрын

its worse in BD.

@ArloAude Жыл бұрын

We train every new designer with these courses. Thank you Dr. Razavi. - Arlo Aude

@San-ix7ki 3 жыл бұрын

I can't resist myself from liking these lectures...thankyou professor❣️❣️

@sonlinesonline 4 жыл бұрын

Thanks a lot for this great lecture, I hoped we had such skilled teaching professor at the university instead of the selfish ones we had

@phuha-van2504 7 жыл бұрын

A good methodology of teaching. Thank Professor.

@shankysays 6 жыл бұрын

You're way of teaching is phenomenal... And you got a sense of humor too.. so overall you got a package...

@gwav1a 8 ай бұрын

Sense of humour? Where was it demonstrated?

@chinthalaadireddy2165 Жыл бұрын

Just Marvelous and awesome.. You are literally the GOD of Analog electronics to many people in the world.. each detail u teach and the style u have in teaching are just unparalleled and we are so much grateful for you Sir for making seemingly difficult subject so interesting.. Much Love from India !

@buvlywahba1854 3 жыл бұрын

i will write u r the greatest in every video i watch too much love

@mariafernandacarranza3088 3 жыл бұрын

Sir you have saved me for my Electronic Circuits course

@20tejas 3 ай бұрын

I hope professor uploads more lectures if he can. He is doing gods work.

@user-fg9io1cv7m Жыл бұрын

It's awesome Professor, thanks a lot

@himanshuvyas7485 8 жыл бұрын

god of Electronics :)

@Sourav_Soumyajit Жыл бұрын

I learnt a whole new approach to small signal analysis thanks to this phenomenal explanation!! Thank you, Sir.

@ANKITKUMAR-hp4fp Жыл бұрын

Love his forearms!

@dogdogdog2024 7 жыл бұрын

Professor! Thank you!

@vamsiakula653 4 жыл бұрын

that's true

@zjwang573 3 жыл бұрын

59:00 my goodness, i screammed out. It's gm!

@ayushmeena5708 3 жыл бұрын

Circuit is Messi but you're Ronaldo (GOAT)

@amirdavatgar6563 8 жыл бұрын

A Real Teacher

@jananethaadda 3 жыл бұрын

Love from jananetha adda channel

@user-di1oh2tq8m 7 жыл бұрын

thanks. how do i watch the lecture 'Electronic circuit II' ?? I really want it.

@stefano.a 11 ай бұрын

at 21:00 if we use the last equation for gm we obtain the same result (new gm = 2 x old gm) because W/L doubles but doubles also Id, because the new Id to be considered is the sum of Id1 and Id2 (that have the same value)

@ayushkumar1539 4 жыл бұрын

why don't other professors are like u and the worst part is Why I am paying them

@PunitJain8695 5 жыл бұрын

@58:00 and after, shouldn't it be (V0-Vth) instead of (Vgs-Vth) in the denominator?

@ishangupta7387 5 жыл бұрын

wondering same

@zamp7927 4 жыл бұрын

this is what exactly i wanted to say; it is a mistake i guess

@MixalisXaxalios 4 жыл бұрын

i am thinking that because Vgs=Vo+Vm , and Vm

@rithanipriyanka2393 3 жыл бұрын

He made a correcction later :)

@jos4552 3 жыл бұрын

He teaches, Calculus, electronics, mathematical reasoning etc. all in one lesson. Who is this teacher?

@MDKHALIDELB Жыл бұрын

Behzad Razavi sahab

@amoghnelavigi 7 ай бұрын

@@MDKHALIDELB😂

@mnada72 3 жыл бұрын

1:07:00 Does anybody know where is the rest of the series specially circuit theory I & II

@gokuson5261 5 жыл бұрын

anyone has razavi coursebook solution? where can I find one?

@reemalshanbari 3 жыл бұрын

in the small-signal model, I think it should be (Vo+Vmike -Vth)^2. Am I right?

@himadrishekharbhattacharyy3774 3 жыл бұрын

That is my question also and thats why I am in the comment section to check if anyone noticed this or not.

@leftfist3085 Жыл бұрын

He eventually corrects himself

@Peter_1986 4 жыл бұрын

What is the exact definition of "much smaller"? Does it mean that the signal is 1/10 as big than the DC voltage, or 1/100 as big, or something like that?

@Peter_1986 3 жыл бұрын

@Yihan Du That sounds like a reasonable definition. I guess another way to think of it in some cases is that "much smaller" simply refers to anything that can be neglected compared to something else without making a significant difference.

@sbnprajwalreddy3981 5 жыл бұрын

My Demi GOD!!!!!

@vamsiakula653 4 жыл бұрын

hi ra prajwal

@kavouras5 Жыл бұрын

In 47.00 he says it's sort of open. Does that mean that we analyze it mathematically as an open circuit?

@stefano.a 11 ай бұрын

He forgot to short circuit V1

@chinku689 4 жыл бұрын

45:00 Small and Large signal difference!!

@chaitanyabalaga9830 2 жыл бұрын

Can anyone tell me is it good to terminate the small signal model with short circuit at end ? I think as we finally keep both the circuits in parallel, this connection may short circuit the V1 in bias model. pls anybody?

@agentdoodo299 Ай бұрын

Terminating it makes sense because it's consistent with superposition theorem. You are actually short circuiting V0 as well if you think about it.

@mokkarallasivaramakrishna1645 5 жыл бұрын

send me the reason if someone knows of the below question:( why we removed the Rs in the small signal model when we consider it in large signal?

@manojmedigeshiraghu3256 4 жыл бұрын

Rs is the load ,it is used to measure the output voltage ,since he is combining both the large signal and small signal by superposition eventually,you dont need another RS,i might be wrong though .

@serden8804 4 жыл бұрын

@@manojmedigeshiraghu3256 no its wrong, he removed Rs in order to simplify things, he considered most simple case

@mahmudulhasandip6308 4 жыл бұрын

Yo razavi mamu

@pawansharma6226 Жыл бұрын

33:56 Sir, what if signal comes in , then value of Vgs will increase. And due to that Ids will increase , resulting Vds to decrese, in that casr mos device will no longer in saturation????

@adityatripathi02 Жыл бұрын

Yes, you are right. That is why we must have swing limits on the incoming input signal. For max amplitude of the incoming signal sinusoid, we need to maintain the boundary condition (for bias + signal) VDS = VGS - VTH to maintain the transistor in saturation. Assuming the signal is small such that the small signal model can be applied, the total VDS = V1 - RL*ID - gm*RL. Total VGS = Vo + vmsinwt. If we substitute these values in the boundary condition equation required to maintain operation in the saturation region, I believe we should be able to calculate the maximum limit on vm which is the amplitude of the input signal sinusoid.

@manavarora1130 4 жыл бұрын

Why do we need a MOS to be in saturation for it to be used in amplifier 22:50

@gamar1226 3 жыл бұрын

Lets say you apply a sinusoidal signal very close to Vth , (Vgs is close to Vth). If the Vgs is less than Vth ( on the negative portion of the period it could become ) , Id will be zero. In this case the output signal will be clipped. Some part of it will be 0 and some other part ( positive portion of the period) will be amplified. When we go into the saturation region we eliminate cliping of the signal for exemple. Also as the professor pointed out, for a certain amplification you`d need an exspensive resistor

@harshitgupta2872 10 ай бұрын

@@gamar1226why we are not use MOS in linear region for amplification , in linear region Id=f(Vgs,Vds) also gm is const for particular Vds but in saturation region gm is varying with Vgs it would be better to use in linear region

@srinivasan7790 6 жыл бұрын

@51 mins VGs must be equal to V0 i dont know why he still puts VGs

@pupuzdrik 6 жыл бұрын

i think when Vm is very small then Vgs is almost V0. not sure though...

@pupuzdrik 6 жыл бұрын

he made a correction later )

@MeatCreater 4 жыл бұрын

53:27 Correction

@shailendragurjar9690 6 жыл бұрын

sir as you discussed when two transistor connected in parallel their w/l increases but what happend in series can you explain it to me and how?

@ajayrajan8882 5 жыл бұрын

A cmos is what you get when you connect a pmos and nmos in series. Read how to analyse a cmos and you'll get a a fair share of idea about it.

@bibekanandabora 5 жыл бұрын

it will be same as two capacitors are in series. If both r having same W/L then effective W/L is W/2L

@NaaJeevitham500 5 жыл бұрын

It could be a multi-stage amplifier

@gamar1226 3 жыл бұрын

If both transistor are open, and are the same Id should be the same for both so w/l should remain the same.

@nagireddymallikarjunareddy9624 4 жыл бұрын

I have one doubt ,,if VDS Inc ,CL will decreases ,, finally the electron needs to reach the drain terminal through channel & drift of depletion region ,,but total distance traveled by the electron is same ,even the CL will decreases also ,then how current Inc..let me know ,,if anyone understand ..pls let me know..

@krishnareddykrishnareddy3076 3 жыл бұрын

Once see the drain current equation....if u see the equation then current is inversely proportional to effecive channel length....as channel lenght decreases then the current increases but the incerment is very low ...once check previous video....prof.razavi explained very clearly....

@madakagnaneswari4973 3 жыл бұрын

If channel length decreases electron density increases and hence the current increases

@xong485 8 жыл бұрын

RAZAVI, my god

@harshitgupta2872 10 ай бұрын

why we are not use MOS in linear region for amplification , in linear region Id=f(Vgs,Vds) also gm is const for particular Vds but in saturation region gm is varying with Vgs it would be better to use in linear region anyone can explain?

@khaledelsayed3507 7 ай бұрын

Because in saturation current is approximately constant thus the gain will be higher but in triode the triode gian is so small

@sakshisingh4197 4 күн бұрын

Draw the graph between Id and vds. Then take small change in Id for linear region and do the same for saturation region then see the change in voltage corresponding to both linear and saturation. You will see for small change in current large change in voltage is present for saturation region. Hence amplification better in saturation.

@satirthapaulshyam7769 Жыл бұрын

45:40

@linzhang2328 Жыл бұрын

48:04 small-signal operation

@29758143 6 жыл бұрын

Can someone explain why there is a Rs in large signal model but not in small signal?

@sunilrathore6490 6 жыл бұрын

i think to make calculation small.or sir want to relate the full model with two different model like small and large signal model.

@sarthakbaral5308 5 жыл бұрын

sir forgot to include it

@NaaJeevitham500 5 жыл бұрын

Why did he keep resistor Rs for large signal circuit and not for the small signal circuit?

@andel0792 3 жыл бұрын

Vmike

@vamsiakula653 4 жыл бұрын

it is surprising to see 5 dislikes to this video!!!

@rohithbhaskar8465 3 жыл бұрын

I know right, what is wrong with these poeple

@shadigamal9726 3 жыл бұрын

Dear sir, in minute (41) you forgot to add the resistance (Rs) between the source and the ground when you modified the circuit to add a signal to the input voltage.