All concepts, explainded lucidally & in logical sequence, i have no words to thank you for your generosity to take this up on mission mode!! people like you are bringing real change.
since in C.B configuration , collector is reverse biased , so it would be replaced by dependent source and the emitter in FB will be replaced by the re
There is a mistake while finding re. You selected the current flow through diode as reversed biased and actually the current is flowing in forward bias, I mean current from base to emitter. @Neso Academy
And again tnx for making videos in english we foreigners are also watching you.go ahead.and plzz if u guys have any good playlist of power amplifies then plz lemme know in the reply
All ur lectures are awesome, i am scoring high marks in my internals, semester because of your splendid work . No words to thank but thank you so much 🙏🙏🙏🤩🤩🤩♥️♥️♥️
At 4:01, how can the slope of the characteristics be approximated to zero, which is actually a high value. If the slope is zero, the collector current will be constant and this is possible only in saturation region and not in active region.
Hello, Can anyone tell me why in the switch From 3:03 tp 3:05, did the dependent source's direction arrow in collector branch was pointing downwards ? (while the direction of the diode was upwards)
It is because the current flowing from collector to emitter is due to the minority carriers of the reverse bias section. In other words, the reverse bias section injects its minorities carrier to the forward bias section. Those minorities carriers are seen as majority carriers in the forward section, therefore allowing high conductivity.
Sure, I apologize before hand for my English and my delay. So, when we are introduced in electronics usually the first four things we study about are "P" and "N" materials, minor and major carriers. It seems very bore but in fact it is very important to understand better what happen in diodes and later on in transistors. The diode is the simplest of the electronics components and it is form when a "P" and N material are joined together. A Bipolar Junction Transistor (BJT) in the other hand is form when you sandwich a "N" material between two "P" materials forming a NPN transistor, or when you sandwich a "P" material between two "N" forming PNP transistor. Therefore, is not too crazy to think about a transistor or modeling it as two diodes with common cathode or anode as the video suggest. Moreover, also when we study diodes we learn about what happened internally when a diode is reverse biased or forward biased. When in forward bias condition the diode act almost as a short circuit or a conductor (a wire for example). We must say almost because we need a minimum voltage across the diode for the current start to flow through it, that is about 0.7 volts for Si (Silicon) and 0.3 for Ge (Germanium) less than that will act as a open circuit, Also only the majority carriers flow trough the diode when in forward bias condition. In the other hand when reverse biased the diode act almost as an open circuit. once again we must say almost because that not quiet true. there is current flowing through it due to the minority carriers but it is so little that (micro and nano amperes) that can be consider Zero for a diode. Going back to the transistor, part of the transistor is forward biased (Base emitter; the voltage difference of the base with respect of the emitter is positive ) and the other is reverse biased ( Base -collector, the voltage of the base with respect of the collector is negative) for the transistor to be in the active zone. However that also means that Base emitter (P-N) junction is forward biased and majorities carriers are flowing through it from base to emitter. At the same time, because base collector is reverse biased, here we may think that it should be consider open and no current should be flowing, so why he said it is a current source? But we never said it was open, what we said was that there was minority carriers flowing through it, and it was very small when we were talking about diodes. but in the transistor that's not the case. Why? We need to take into consideration that the amount of minorities carriers depends of the operation temperature, impurities (how pure the semiconductor material is; minorities carriers are proportional to impurities) and amount of doping (elements that are added to make P and N material out a semiconductor material) , and manufacturer can easy control these factors and therefore how much current does a P-N junction conduct when reverse biased (a lot or very little), for diodes manufactures want very small minorities carriers when reverse biased because you want to simulate a open circuit, and that means the least the better. but that's not the case for transistor we really what a lot of minorities carriers in the reversed bias junction. Now comes the tricky part. minority and majority carriers are relative to the type of semiconductor material we are talking about. For instance, in P material minority carriers are electrons and majority carriers are holes and in N material minorities are holes and majority carriers are electrons. Taking that into consideration, therefore, the minority carries that flows from the collector to base are seen as majority carriers from base to emitter junction, think about it. this is why we model it with a current source. Finally, I think is good to know also that the thickness of the semiconductor material used in a transistor on the base is very small in comparison with the collector and emitter, to increase resistivity of the base in relationship with collector and emitter. usually 1000:1. this is to control the leak current from collector to base, and to make sure that a very small amount of current flow to the base form the collector, since current prefer to flow through the less resistance path. Hope this help. Regards, Luis
what do u mean by dc eq.circuit at 10.11 in the video.i mean we r doing ac analysis here so from where did the term'dc eq. circuit' come from all of a sudden?
Shiva Reddy in order to find emitter current we need to use dc equivalent circuit...watch the dc equivalent lecture that sir has taught earlier...u will get to know how to calculate emitter current
Diodes convert ac to dc and therefore we need to do dc analysis to get emitter current because diode out is dc. I havent phrased it properly but I hope you get the idea
The reverse diode is replaced with a high resistance, which was actually (here) open circuited. The current source is not the exact replacement of the reverse biased diode. It actually comes from the forward biased diode.
HW Solution
1-a (its in f.b., so replaced by Re)
2-b (as Ic=alpha . Ie, its dependent source)
All concepts, explainded lucidally & in logical sequence, i have no words to thank you for your generosity to take this up on mission mode!! people like you are bringing real change.
you have no idea how much you're helping me in all my subjects sir. God bless you
This video series is really the best explanation on the topic I have seen. Well done!!
sir, all the lectures are very clear .please upload the lectures of " transistor at high frequency"
since in C.B configuration , collector is reverse biased , so it would be replaced by dependent source and the emitter in FB will be replaced by the re
Sir please make videos on operational amplifiers also.
Solassyste
Mmmodel
There is a mistake while finding re. You selected the current flow through diode as reversed biased and actually the current is flowing in forward bias, I mean current from base to emitter. @Neso Academy
Raja G kya baat hai
answer 1 (a)
2(b)
pkka??
@@MohdAqib-un3rk Haan
Thank u very much sir i am getting everything outstandingly that's why i am best in electronics because of u😍😍
So useful and well-explained. Thanks a lot. Much better than at Uni.
And again tnx for making videos in english we foreigners are also watching you.go ahead.and plzz if u guys have any good playlist of power amplifies then plz lemme know in the reply
seriously the best explanation sir!!! well done :)
Subscribe thoko
P1=re
P2=(alpha)(ie)
All ur lectures are awesome, i am scoring high marks in my internals, semester because of your splendid work . No words to thank but thank you so much 🙏🙏🙏🤩🤩🤩♥️♥️♥️
Sir we need your videos on opamps
Sir, please complete the full playlist with videos of chapter 9,10,11,12
Thank you sir ❤
Thank you sir , this is extremely helpful
p1 (1)
p2 (2)
1. Re ----> p1
2. Ic -----> p2
3:14 *why the reverse bias diode becomes dependent current source* ?? Please anyone clarify ??
Very useful sir
Where is the cut off frequency for Re and H models and what frequency ranges should you use Hybrid Pi?
awesome lectures
very helpful
Nice explanation
How will we get to know what element goes where(in the common base configuration)? nice video anyway
Thank you sir
amazing lecture Sir...
tq..
Thanks a lot 🤝
re - P1
ic - P2
thank you very much sir
At 4:01, how can the slope of the characteristics be approximated to zero, which is actually a high value. If the slope is zero, the collector current will be constant and this is possible only in saturation region and not in active region.
Sir why you consider dependent source in place of reverse bias collector -base junction
In CE transistor the current Ie flows through diode but when we write the equation for Rd we take Ib not Ie
thank u for this video
Sir why dont we take 0.7V voltage drop during forward bias of base-emitter.
Vo dc analysis me lete the
Ac analysis me f.b.diode is replaced by rd
6:33 the arrow of I d would be opposite ... Or not ?
That direction is of reverse saturation right?
could u pls explain about FETs,biasing and amplifiers
Hello,
Can anyone tell me why in the switch From 3:03 tp 3:05, did the dependent source's direction arrow in collector branch was pointing downwards ? (while the direction of the diode was upwards)
This is because the diode is in reverse bias and in reverse bias current flows in the opposite direction.
opposite direction of what?
opposite to the direction pointed by the diode or in other words from N-side to the P-side
Now I get it! thanks man!
pleasure to help u ;) !
thanks sir
P1 re, p2 current
why reverse biased diode is replaced by current source?
It is because the current flowing from collector to emitter is due to the minority carriers of the reverse bias section. In other words, the reverse bias section injects its minorities carrier to the forward bias section. Those minorities carriers are seen as majority carriers in the forward section, therefore allowing high conductivity.
Luis Pena Mateo can you explain more please and why he replaced the transistor with 2 diode !
bas aise he...
Sure, I apologize before hand for my English and my delay. So, when we are introduced in electronics usually the first four things we study about are "P" and "N" materials, minor and major carriers. It seems very bore but in fact it is very important to understand better what happen in diodes and later on in transistors. The diode is the simplest of the electronics components and it is form when a "P" and N material are joined together. A Bipolar Junction Transistor (BJT) in the other hand is form when you sandwich a "N" material between two "P" materials forming a NPN transistor, or when you sandwich a "P" material between two "N" forming PNP transistor. Therefore, is not too crazy to think about a transistor or modeling it as two diodes with common cathode or anode as the video suggest.
Moreover, also when we study diodes we learn about what happened internally when a diode is reverse biased or forward biased. When in forward bias condition the diode act almost as a short circuit or a conductor (a wire for example). We must say almost because we need a minimum voltage across the diode for the current start to flow through it, that is about 0.7 volts for Si (Silicon) and 0.3 for Ge (Germanium) less than that will act as a open circuit, Also only the majority carriers flow trough the diode when in forward bias condition.
In the other hand when reverse biased the diode act almost as an open circuit. once again we must say almost because that not quiet true. there is current flowing through it due to the minority carriers but it is so little that (micro and nano amperes) that can be consider Zero for a diode.
Going back to the transistor, part of the transistor is forward biased (Base emitter; the voltage difference of the base with respect of the emitter is positive ) and the other is reverse biased ( Base -collector, the voltage of the base with respect of the collector is negative) for the transistor to be in the active zone. However that also means that Base emitter (P-N) junction is forward biased and majorities carriers are flowing through it from base to emitter. At the same time, because base collector is reverse biased, here we may think that it should be consider open and no current should be flowing, so why he said it is a current source? But we never said it was open, what we said was that there was minority carriers flowing through it, and it was very small when we were talking about diodes. but in the transistor that's not the case. Why?
We need to take into consideration that the amount of minorities carriers depends of the operation temperature, impurities (how pure the semiconductor material is; minorities carriers are proportional to impurities) and amount of doping (elements that are added to make P and N material out a semiconductor material) , and manufacturer can easy control these factors and therefore how much current does a P-N junction conduct when reverse biased (a lot or very little), for diodes manufactures want very small minorities carriers when reverse biased because you want to simulate a open circuit, and that means the least the better. but that's not the case for transistor we really what a lot of minorities carriers in the reversed bias junction.
Now comes the tricky part. minority and majority carriers are relative to the type of semiconductor material we are talking about. For instance, in P material minority carriers are electrons and majority carriers are holes and in N material minorities are holes and majority carriers are electrons.
Taking that into consideration, therefore, the minority carries that flows from the collector to base are seen as majority carriers from base to emitter junction, think about it. this is why we model it with a current source.
Finally, I think is good to know also that the thickness of the semiconductor material used in a transistor on the base is very small in comparison with the collector and emitter, to increase resistivity of the base in relationship with collector and emitter. usually 1000:1. this is to control the leak current from collector to base, and to make sure that a very small amount of current flow to the base form the collector, since current prefer to flow through the less resistance path.
Hope this help.
Regards,
Luis
Luis Pena thankyou. This was very helpful.
Thank u bro..
why did you reverse the polarity of Vbe in homework problem @ 12:01
Sir I have the same doubt ..
Why did you reverse the polarity (vbe) for the hw question
Is this model only called as T model of BJT??
Could you please upload videos on Microprocessor 8085
Sir, rd = Vd/Id and also = Vbe/Ib or wt? That means Vbe=Vd? And Ib=Id?
Sir pls can u suggest the best book to solve the problems from basics to advance for analog ...
Pls pls pls pls pls
1-a
1-b
Can we have a sheet with all the formulas in the r model and h model?
1-a
2-b
Sir plz make videos on power amplifier
Hey,do you have videos on power amplifier?
Sir in previous lecture slope zero said
Sir differentiate karte time Vd kahan gaya jo exponential mein hai
the music at the start is very loud compared to your voice during the video and very off-putting. Balance the audio in the next video?
Id is forward bias current or reverse bias current ?
Sir, while editing the videos please increase speed by 1.5x
The lecture is much better at that speed
P1- 1
P2- 2
In this lecture you r saying not zero why this controversy not understanding can you explain sir
load current should be delivered to load but you have taken from the load so I didn't understand that please explain me
p1-a p2-b
re goes at position 1.
Why don't we take the 0.7V VBE?
Why do we need to place ro parallal when there vl b no current passing through it??? N what is Vt? Why it is taken 26mV??
VT is thermal voltage and the value at room temperature is 26mV
operational amplifier upload kro yrr
what do u mean by dc eq.circuit at 10.11 in the video.i mean we r doing ac analysis here so from where did the term'dc eq. circuit' come from all of a sudden?
Shiva Reddy in order to find emitter current we need to use dc equivalent circuit...watch the dc equivalent lecture that sir has taught earlier...u will get to know how to calculate emitter current
Diodes convert ac to dc and therefore we need to do dc analysis to get emitter current because diode out is dc. I havent phrased it properly but I hope you get the idea
diodes only convert ac to dc in a rectifier, there is no rectifier here.
its a transistor.
Shiva Reddy to find emitter current we have to use the dc analysis bro....That's the one he said....about
Why reverse bias diode is replaced by current source?
The reverse diode is replaced with a high resistance, which was actually (here) open circuited. The current source is not the exact replacement of the reverse biased diode. It actually comes from the forward biased diode.
what do u mean by ro(output resistance at 3.40 in the video.is it a part of the output circuit ?
I don't get we do you have put Id+Is in the derivation ??? -_-
helpful
when will the new videos coming ???
pos 1..... 1
pos 2..... 2
whuch prog u type on it
p1=re
p2 =alpha.ie
1 a
2 b
Babaaaa boynuma dola babaaa
Sir please pin the correct answer
👌
is re = rpi ?
R pi = Beta *re
You need to calculate this for
Not ammeter that's emitter speak Wrightly
Hi
please try to speak in loud.I couldn't here your videos..
Sir please make videos on operational amplifiers also.