Razavi Electronics 1, Lec 34, MOS Small-Signal Model, PMOS Device

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Behzad Razavi (Long Kong)

Күн бұрын

Small-Signal Model; PMOS Device (for next series, search for Razavi Electronics 2 or longkong)

Пікірлер: 43

@CoalCandyX 4 жыл бұрын

I LOVE so much how this serier doesn't make me feel stupid. I'm taking an integrated electronics course atm, and I don't understand anything of the lectures that my professor is giving. THis series is so helpful!

@fidelcertuche8002 Жыл бұрын

Same with me!!!

@theminertom11551 Жыл бұрын

Don't feel so badly about not understanding what your professor says about active circuits. I took those courses 40 years ago as an undergrad E.E. and I think that my professor could not tell the difference between an active circuit and a hole in the ground. And that is putting it politely.

@d4rcym 2 жыл бұрын

Love that he knew that I would be confused about the current direction in the PMOS small signal model

@ligipham5137 5 жыл бұрын

yêu thầy Razavi ghê gớm!! cảm ơn thầy nhiều :))

@mrinalmahato_art 5 жыл бұрын

razavi razavi razavi, razavi mera guruuuuu, thank u ra re thank u ra

@nikosgouv8466 4 жыл бұрын

Unbelievably good explained!!!

@Sourav_Soumyajit Жыл бұрын

Wonderful examples.

@hakankara8216 Ай бұрын

A LEGEND

@letsgame514 11 ай бұрын

Dr. Razavi is the best.

@ashwanisingh3291 Жыл бұрын

Sir ,you know about MOSFETs more than any scientists or engineers who invented it 😀😀

@Peter_1986 3 жыл бұрын

Here are a few analogies that I like to use for circuit quantities: *current flow* = water current *resistance* = obstacles such as rocks and water gates *voltage* = pressure against obstacles

@stockfish3379 3 жыл бұрын

Noice

@h0liravi0li96 3 жыл бұрын

Those re fine until the water starts hiting capacitors and inductors

@spiros6804 Жыл бұрын

@@h0liravi0li96 corny

@ayushuniyal7035 2 жыл бұрын

very good lecture sir

@zedlepplin9450 7 жыл бұрын

around 50:10, prof razavi wrote plus minus, instead of minus plus

@Skall-ex 4 ай бұрын

Incredible

@vyshnavikonka9440 Жыл бұрын

at 40:00 why we didn't use channel length modulation for gm and why use that for r0

@gopalkrishna9130 4 жыл бұрын

1:02:29 should not the gate have - minus and source should have + sign , since gate is more negative

@sajidjoy85 4 жыл бұрын

I also think that...

@methakongpoon329 3 жыл бұрын

No, that is correct. It's a small signal model not a large signal model. When VG increases the drain current decreases or the small signal current is negative. So the small signal current will go from drain to source.

@e1490807aa Жыл бұрын

That is correct. The varying voltage(signal) is still attached at Gate. Remember that there's only time-dependent voltage/current source existing as source in small-signal model. Value of constant voltage/current sources doesn't vary by time, so that we set to 0 in small-signal model.

@girijahegde-cb3mb 14 күн бұрын

54:19 -> it should be mu (p) not mu(n) for the current equation used for PMOS devide

@daikavinhbao Жыл бұрын

At 54:00, in the equation of Id in saturation region, mu_n must be mu_p since the charge carriers in the channel now are holes.

@anupammathur17 4 ай бұрын

yes, Up should come in place of Un

@yatishpachigolla7914 Жыл бұрын

at 33:52, in the small signal model representation, the voltage change (delta V) across the drain and source terminal is missing... isn't it?

@RohanLautre 3 ай бұрын

same doubt

@prasheen11man95 Жыл бұрын

In small single model why source of pmos is given - be sign ?

@user-vh5nt1ts3h 3 жыл бұрын

A constant current source also doesn't change in time, so why we drow the model in small signals?

@shyavakbhuyan5743 3 жыл бұрын

The current source is dependent on vin (Small signal input) which is dependent on time, so it isn't removed from the model. Your statement is true for independent current sources.

@jagadeeshimmadi103 4 жыл бұрын

something happened at 45:45. Part of the board was erased :D

@srikanthpanasa9648 3 жыл бұрын

Can anyone explain me at 29:44 I got. Confusion at that time

@prakhargupta1409 3 жыл бұрын

What specifically you didn't understand ?

@N.AJAYKUMAR 7 жыл бұрын

In PMOS The gate to source polarities + and - how can it be we apply negative voltage gate. so gate terminal - and source terminal + I have a doubt please clarify 1:10:20

@govindbajpai9447 6 жыл бұрын

Dear Ajay, In PMOS -ve and +ve potentials are applied at Gate and Source respectively during biasing. When biasing is done and PMOS is in saturation, add small signal to it. After short circuiting all the DC sources it becomes similar to NMOS small signal model. Remember in small signal model only alternating signals are taken in to consideration. Don't get confused in biasing and adding small signal.

@manhalrahman5785 4 жыл бұрын

In small signal model of PMOS he drew current from drain to source but in the actual MOSFET figure in which source is at the top and drain is at the bottom the current flows from top to bottom ie source to drain... confused.

@sakethamargani8846 3 жыл бұрын

it 's just convention we used that id will flow from drain to source. IN nmos take it as it is,but when considering pmos take id direction same but with negative sign. I.e -id . Don't worry about actual mosfet symbol. Its standard symbol , to distinguish between pmos and nmos , so there we reverse direction,not using negative sign for Id. Imp point is while doing analysis for pmos , take Id same direction as in Nmos but with negative sign.

@electronics_enthusiast 5 күн бұрын

@@sakethamargani8846 very important detail,thnx for clarifying