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.
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
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!
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?
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!
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..
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.
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. :)
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!!
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.
@@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.
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.
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.
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.
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! :)
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 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.
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
I am lost. Assume M1 is the cascode device and M2 is the degenerating device, I can understand the output resistance is boosted to gm1 * r01 * r02. So far so good. But how could M2 help the narrower DS1 voltage range issue? To avoid M1 getting into the triode region, DS1 voltage needs to be narrower just like using a simple Rs resistance at M1 source... Correct? What's the advantage of M2 over Rs in this perspective?
I thought about this again.. if degenerating device is a NPN, the CE voltage can be selected at a low value,,, say, put it at the edge of saturation so CE voltage is small to minimize its impact on cascode device DS voltage. But if degenerating device is a NMOS, its DS cannot be too small. Its impact on cascode device DS voltage is unavoidable... What do I miss here?
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.
Forgive a basic question. In what sense are these transistor based "current sources" really sources? Aren't they really current limiters? The only current "sources" are the power supply rails.
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.
im so addicted to the lectures that i was teaching my cat to bias a FET in saturation in my dream.
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.
This is truly the active circuit information that I wish that I had before I started my career as an EE.
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
Thank you dear Prof. Razavi for your valuable efforts!
Also big thanks to you Dr. Kong for uploading the videos.
These lectures are priceless!
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!
Thanks for being alive in this century!!!!!
Oh professor, my professor!!!
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?
# KING OF ELECTRONICS IS BACK..... very fortunate to have him again..
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!
Boss is back in action.....thank you sir for the lectures
Thanks a lot Prof. Razavi for hearing out our requests and taking out your time for making this video lectures for free.
I read his book, fell asleep. I found his videos on RUclips, now I can't sleep! Thank you , professor!
same here
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..
He is back! Thanks prof. Razavi
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.
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.
:)
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!!
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.
Professor you really save my day...
I can't wait to enjoy the journey of Electronics II with you.
Lots of LOVE from Taiwan.
Can you please tell me why there is need to improve the current source (24:10)
@@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.
Sir, you are an incredible Professor. I truly thank you from my heart.
easily the best electronics 2 class on youtube !!! Thank you soo much. these videos are very helpful !!
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.
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.
He's back😎
Love from India
I always feel a pang of sadness every time Prof. Razavi says time's up. I just want more and more of his lectures.
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.
Without Professor Razavi , understanding analog would have been impossible for some..Thank you sir
Amazing proffesor. He makes thinks so comprehensive and simple that anybody can follow. Congratulations for sharing this knowledge.
this man is a legend i am watching these lectures for fun now
Aaaaaand He's Back Thank You Sir for your efforts
Perfect expression. Thank you Mr. Razavi, you are the best.
Sir you made my day. lots of love and prayers for you ❤️🌹
Thanks a lot sir for making Electronic- 2.
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! :)
Legend, the master of Education. Never before , ever after student experience
Professor at my heart Thank U for coming back
One of the best lecture i have heard. Love from india
i think you're the best teacher in the world
Indeed he is
Excellent Work Sir they really help out a lot in concept building
The amazing lecturers. Thanks for uploading!
The best electronics lecture. Thank you very much for sharing your knowledge
Thank you for starting new series.You're great .
Great books and wonderful lectures. Thank you Prof. Razavi!
Thank you very much for free but invaluable lecture!
The best for ever, prof Razavi
Awesome ! So excited .... Keep it up sir.
mesmerizing, couldn't stop the video for sec
Thank you very much, Professor Razavi !!
Grateful for the lessons Only reason I just passed my exams bless👍
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.
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.
@@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.
@@billy_tomas agreed. Thanks for clarifying.
I love the way he is teaching
Thank you very much was waiting for this long time
Thank you prof. Razavi for electronics-2 lecture series
Yes
Thank uu so muchhh razavi sirr... Much waited video lectures👌🙌🙏
Thank you, the great master Razavi.
Excellent Contribution.
无敌👍 gooood book and gooooood professor
Thank you so much sir for making electronic 2 lectures these videos are really helpful for me making concept better
pawan singh Are you preparing for GATE ECE too?
Yes i am preparing for gate 2020
Glad to see Electronics 2!!!
You gave meaning to my live!
India is missing these type of legends !! ..oh god, pls in next birth make me classroom student of razavi sir ..plss god...
Awesome! Let the learning continue.
31:59 sir here i got confused and check the privious classes the Vgs here is (Vb1-RI) not there is (Vb1+RI)
same brother
Samee
This dude is straight awesome bruh
Πάμε κάψιμο!!!
Your teaching is excellent sir. But please do take care of the Noise!!
Thanks a lot sir for your benevolence.
Could you provide higher level courses covering Two and three stage op-amps, ADCs, DACs, PLLs..etc?
Excellent !! No word😊😊😊😊
the music is better than before!
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
Did you get any answer for this?
Even I'm facing the same doubt.
Phenomenal Lecture
Razavi is the man.
I am lost. Assume M1 is the cascode device and M2 is the degenerating device, I can understand the output resistance is boosted to gm1 * r01 * r02. So far so good. But how could M2 help the narrower DS1 voltage range issue? To avoid M1 getting into the triode region, DS1 voltage needs to be narrower just like using a simple Rs resistance at M1 source... Correct? What's the advantage of M2 over Rs in this perspective?
I thought about this again.. if degenerating device is a NPN, the CE voltage can be selected at a low value,,, say, put it at the edge of saturation so CE voltage is small to minimize its impact on cascode device DS voltage. But if degenerating device is a NMOS, its DS cannot be too small. Its impact on cascode device DS voltage is unavoidable... What do I miss here?
Prof is back with same Outfit (same color shirts :p).
Thank you very much sir, great lectures !
what a simple genius
Look who's back!
A beautiful presentation.
why does he always put such bangers at the start
Thank You very much sir...for this wonderful lecture.
Finally, I like Analog.
omg! i don't knowwhat to say but thank you!!!!!!!!!!!!for saving me
LEGEND!!
amazing
The god is back!
very good lecture, thanks!
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.
When doubling W, the ro will be reduced because ro=1/kn*W/L*(VGS-Vth)^2, so our Rout will be reduced
Thank you very much sir for making this videos
you save my midterm！！！！！！
I guess in these calculations we assume that r_o=infinity, ie, no channel length modulation.
Afarin Ostad
Forgive a basic question. In what sense are these transistor based "current sources" really sources? Aren't they really current limiters? The only current "sources"
are the power supply rails.
execellent lecture
God of electronics
Excellent lectures
Thankful and Grateful to "Mr. Kong" for the upload and to "Mr. Razavi" for the lectures.
I love him too
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.
Thank you Prof Razavi