Razavi Electronics2 Lec1: Introduction, Cascode Current Sources

[@dongding7117]

im so addicted to the lectures that i was teaching my cat to bias a FET in saturation in my dream.

[@michaelcostello6991]

This chap should get a nobel prize for for sharing knowledge and making such a big impact on peoples lives. He is empowering people in the world of electronics in a way that very very few can. I have never come across a lecturer like him either online or in the real world. Thank you professor.

[@theminertom11551]

This is truly the active circuit information that I wish that I had before I started my career as an EE.

[@hemantj675]

This time don't leave us begging for more. We have waited for a long time for these lectures.
You are amazing. You make it look all easy and interesting unlike others.
Thanks for your affection towards us

[@coolwinder]

01:25 - Intro and review of Electronics I and II
10:28 - Examples of Circuits of Interest
14:45 - Current Source with MOSFETs
24:07 - Improving Current Sources with Degeneration
33:20 - We need a device that can degenerate but does not follow Ohm's Law - That offers same or higher incremental resistance - That will serve as an negative Current-Voltage feedback element
39:20 - Fundamental Property of Cascode
42:40 - Double-Cascode
45:00 - What happens when the widths of transistors in a cascode are doubled?

[@moshmo885]

These are by far an away some of the best lectures I've attended. Very rarely has a professor been able to keep me interested in the content while also being so thorough. Thanks!

[@tze-ven]

This is why we need true expert to teach this subject. I never knew the true reason till now. Everyone else gave unnecessarily complex and confusing reasons. Thanks Prof. Razavi!

[@Nutan.K]

# KING OF ELECTRONICS IS BACK..... very fortunate to have him again..

[@srikanthm7276]

Thanks a lot Prof. Razavi for hearing out our requests and taking out your time for making this video lectures for free.

[@francescosanna7240]

Thanks for being alive in this century!!!!!
Oh professor, my professor!!!

[@madhu_parimi]

Boss is back in action.....thank you sir for the lectures

[@eliabramov757]

Thank you dear Prof. Razavi for your valuable efforts!
Also big thanks to you Dr. Kong for uploading the videos.
These lectures are priceless!

[@dogdogdog2024]

He is back! Thanks prof. Razavi

[@sanjayd411]

Brilliant teaching. This is a refresher for me but I wish you were my professor while I was pursuing my MSEE degree and took a class on Analog IC design at a university in the Chicago area. I love Dr. Razavi’s RF Microelectronics textbook.

[@aerodynamico6427]

I read his book, fell asleep. I found his videos on TH-cam, now I can't sleep! Thank you , professor!

[@vishwapriyagautam8227]

same here

[@mohamedabdirahmanabdulle2285]

really i have never seen any teacher explaining like prof. razavi but what i like to say is thanks million times prof. razavi i wish long and health life and request to continue helping hungry the students for your knowledge.

[@ayushkumar1539]

I am in love from the first lecture itself, but I can not comment on every lecture because viewing ur lecture seems more important than my comment but I really feel very good to see people like u, who put there whole life efforts knowledge to share so effectively..
ur all-time student.
:)

[@sahhaf1234]

Thank you very much, Mr. Razavi, or should I say king of us all? I cannot sufficiently express how much I like your books and video lectures. You love electronics and it shows at every second of your programs..
Needless to say, we all hope for electronics-3..
Best regards from Turkey!!

[@mdwaliurrahmankhan4347]

Sir, you are an incredible Professor. I truly thank you from my heart.

[@n-hexane8271]

sir i beg you please cover the video lectures on all the topics mentioned in your book example, oscillators, efficiency of amplifiers, etc.....🤧🤧😭😭😭you have no idea how much a life saver these lectures are. The only reason that I passed my semester is because of you.. i have no words to express my gratitude believe me 🙏🙏🙏🙏🙏 Thankyou very much.

[@sahhaf1234]

Dear Prof. Razavi,
You are very different from many other lecturers on electronics, because you love what you teach..
And we are your devoted students, because we love what you teach.. We also love your style..
I beg on my knees: Please continue.. There are so much more in your mind to teach us..

[@mrpossible5696]

He's back😎
Love from India

[@prolawren6491]

easily the best electronics 2 class on youtube !!! Thank you soo much. these videos are very helpful !!

[@TuanMinh-tl4vm]

I always feel a pang of sadness every time Prof. Razavi says time's up. I just want more and more of his lectures.

[@prabhakardas4261]

God of electronics is back,i respected all the teachers but they should learn from sir how to teach and deal with the subject.. Thank you sir, it will helpful if you teach communications subjects in this manner.

[@abhinavsingh5873]

Thanks a lot sir for making Electronic- 2.

[@slayerxyz0]

Thank you so much for making these videos. These videos are the best resouce for building a good understanding of transistor circuits I've been able to find on the internet.

[@ozangozluklu1017]

Perfect expression. Thank you Mr. Razavi, you are the best.

[@lavague7648]

Amazing proffesor. He makes thinks so comprehensive and simple that anybody can follow. Congratulations for sharing this knowledge.

[@user-hj8pc8eg3e]

Professor you really save my day...
I can't wait to enjoy the journey of Electronics II with you.
Lots of LOVE from Taiwan.

[@ParminderKaur-zm4kw]

Can you please tell me why there is need to improve the current source (24:10)

[@user-hj8pc8eg3e]

@@ParminderKaur-zm4kw Because we want a better approach to "IDEAL" current source, which has wider operation region, open circuit in small signal analysis, and many other benefits.

[@pasamkiranteja6654]

Without Professor Razavi , understanding analog would have been impossible for some..Thank you sir

[@aryanroy7057]

this man is a legend i am watching these lectures for fun now

[@karanrawat19]

Aaaaaand He's Back Thank You Sir for your efforts

[@billy_tomas]

M1 is an amplifier (common gate) and therefore (for low frequency operations) it should be operating in moderate/weak inversion to maximise its gm for a given current. M2 is your main mirror device which should be in strong inversion to improve random offset (i.e. mismatch). Both devices must be in saturation.
To achieve the above, usually M1 has a large W/L ratio (and L can be very small). M2 has a large L since mismatch is inversly proportional to L (for a fixed current), so you can simply push M2 in strong inversion by setting the W to something small (technology dependent) and increasing the L to whatever size or speed limitations you may have.
I am not sure why many books assume that the devices should be the same or even identical.

[@mohammedabdulhakabdullaabd1121]

how is M1 a common gate if input signal is applied to the gate and sensed at the drain? to me it looks like a common source.

[@billy_tomas]

@@mohammedabdulhakabdullaabd1121 No it’s not; it’s a cascode device, by definition a common-gate configuration with input current at its source and fixed Vb at its gate.

[@mohammedabdulhakabdullaabd1121]

@@billy_tomas agreed. Thanks for clarifying.

[@ovitvchannel]

Sir you made my day. lots of love and prayers for you ❤️🌹

[@margewon3791]

Professor at my heart Thank U for coming back

[@adityab943]

Legend, the master of Education. Never before , ever after student experience

[@digitalsystemdesign3817]

Thank you Sir! You are amazing! And thank you Long Kong for posting these video lectures. We are miles away but i still find connections between us. I wish that Prof. Razavi give video lectures on Design of Analog CMOS ICs. It would be great! :)

[@user-nm1vz7te3h]

The amazing lecturers. Thanks for uploading!

[@bahouchemebrouk1698]

The best electronics lecture. Thank you very much for sharing your knowledge

[@choco_chanel5377]

Thank you very much for free but invaluable lecture!

[@ravexi6622]

Excellent Work Sir they really help out a lot in concept building

[@antoniodibartolomeo8152]

Great books and wonderful lectures. Thank you Prof. Razavi!

[@armanmanukyan1970]

Thank you for starting new series.You're great .

[@bp4422]

Thank you very much, Professor Razavi !!

[@mdismailsarkar8270]

mesmerizing, couldn't stop the video for sec

[@madarvalishaikdandu5026]

One of the best lecture i have heard. Love from india

[@videosdopedro]

i think you're the best teacher in the world

[@victrixmortalis7823]

Indeed he is

[@user-bt4cw8cd5n]

I love the way he is teaching

[@LinAhMaLe]

Thank you, the great master Razavi.

[@rahuldussa6927]

Thank you prof. Razavi for electronics-2 lecture series

[@poplilly80]

Yes

[@Ahura_Mazda111]

The best for ever, prof Razavi

[@Agntjpa]

Thanks a lot sir for your benevolence.

[@edkaran5346]

Grateful for the lessons Only reason I just passed my exams bless👍

[@swetha6555]

India is missing these type of legends !! ..oh god, pls in next birth make me classroom student of razavi sir ..plss god...

[@vinaychandra6003]

Awesome ! So excited .... Keep it up sir.

[@satishganta2310]

Thank uu so muchhh razavi sirr... Much waited video lectures👌🙌🙏

[@chenkelvin1130]

无敌👍 gooood book and gooooood professor

[@prashantsharma5618]

Excellent Contribution.

[@vivekkeviv9506]

Glad to see Electronics 2!!!

[@aydinseyedi825]

Awesome! Let the learning continue.

[@karamany9870]

Could you provide higher level courses covering Two and three stage op-amps, ADCs, DACs, PLLs..etc?

[@seinfan9]

Razavi is the man.

[@himanshuful]

Prof is back with same Outfit (same color shirts :p).

[@dantecpp]

You gave meaning to my live!

[@kelvin17549]

the music is better than before!

[@maximecholvy2813]

Thank you very much sir, great lectures !

[@srinivasan7790]

Thank you very much was waiting for this long time

[@amribnaas]

Phenomenal Lecture

[@alexandrosanastasiou1964]

This dude is straight awesome bruh

[@Gatos77]

Πάμε κάψιμο!!!

[@yashwanthn9697]

Your teaching is excellent sir. But please do take care of the Noise!!

[@vyshaknijagunastanika809]

Look who's back!

[@nashs.4206]

A beautiful presentation.

[@nagabhushanjoshi254]

Thankful and Grateful to "Mr. Kong" for the upload and to "Mr. Razavi" for the lectures.

[@aadityanaresh9847]

Excellent !! No word😊😊😊😊

[@georgepapoutsas5198]

why does he always put such bangers at the start

[@PawanKumar-ot2qs]

Thank you so much sir for making electronic 2 lectures these videos are really helpful for me making concept better

[@utkarshpant5297]

pawan singh Are you preparing for GATE ECE too?

[@PawanKumar-ot2qs]

Yes i am preparing for gate 2020

[@keshavsharma7396]

Finally, I like Analog.

[@aadityanaresh9847]

Thank You very much sir...for this wonderful lecture.

[@scatteringparameters.4167]

what a simple genius

[@zinhaboussi]

When doubling W, the ro will be reduced because ro=1/kn*W/L*(VGS-Vth)^2, so our Rout will be reduced

[@victrixmortalis7823]

LEGEND!!

[@musaibshaikh5075]

amazing

[@panl422]

Seems there is a logical fallacy around the 32-33th minute which is this: the saturation condition of the non-degenerate MOS is V_DS > = V_GS - V_th => V_DS > = VG - V_th (assuming the source S is grounded, so V_GS = VG - 0 = VG). However, with degeneration, the condition is still the same except that the source S is no more grounded, and therefore, the condition becomes V_DS > = V_GS - V_th = VG - VS - V_th = VG - ID*Rs - V_th ... so, the left (lower) limit of the saturation region from the value of VG - V_th then shifts to the value of VG - ID*Rs - V_th

[@stakor666]

very good lecture, thanks!

[@joydeepdebnath9741]

The god is back!

[@sanjaysingh9072]

Thank you very much sir for making this videos

[@dongding7117]

omg! i don't knowwhat to say but thank you!!!!!!!!!!!!for saving me

[@Nitishkumar1516713]

He is the real professor, not the money heist guy :-)

[@monkinght6980]

31:59 sir here i got confused and check the privious classes the Vgs here is (Vb1-RI) not there is (Vb1+RI)

[@aristotle8777]

same brother

[@santhoshchittimalla2097]

Excellent lectures

[@tag1343]

Electronic 3 please!

[@aerodynamico6427]

WTF!!!!

[@ahmedsalah-jb9ov]

digital ;)

[@Str8ightO]

Please correct me if I am wrong.
Here's my answer for the concluding question:
If the width of the transistors are increased while keeping their drain current constant, that would mean their overdrive voltage would have to decrease in order to accommodate the rest of the circuit and keep its current flowing.

[@sahhaf1234]

I guess in these calculations we assume that r_o=infinity, ie, no channel length modulation.

[@lalalastar2322]

you save my midterm！！！！！！

[@revatishaktivel496]

God of electronics

[@ahmedelashmawy8176]

Thank you Prof Razavi

[@harshitgupta2872]

execellent lecture

[@Hndm27]

thanks a lot sir

[@mohammedabdulhakabdullaabd1121]

in the Cascode version of the current source in the SS model we replaced M2 with its output impedance r02 as the equivalent degenerating resistor. I am not sure about the effect of r02 on the limit of collapsing into Triode if we try to increase r02 by selecting M2 with a lower Lambda for instance (knowing that r0=1/(lambda*Id)). Is it going to be the same effect as with degenerating using Rs (normal resistance). we went to M2 in place of Rs to avoid adhering to Ohms law but if we replace M2 with r02, are we not going to adhere to ohms law, hence reducing the saturation region which means restricting the voltage range variations this current source can handle before leaving Saturation.

[@zattiya]

The transistor would just blow up if you double the length, either that or gm would double making Rout twice as large.