[User] Please transcribe this text

[Assistant] Okay, now that current is divided between these two resistors. So there's a current divider here. So this is Vx over Ro, with a good approximation.


[User] Please transcribe this text

[Assistant] And then I need to calculate IE in terms of that. So how do I divide this current? It's a current divider, right? What's a current divider ratio? It's this resistor divided by the sum of those two resistors. So it's gonna be, so this current IE is going to be negative Vx over Ro times Re divided by Re plus alpha Rm.


[User] Please transcribe this text

[Assistant] So that's IE. So that's this, that's this IE. So that tells me what this current is. So this current is alpha times that. So what is this total current? That's what I'm trying to find out. This is IX. So IX, do you agree that it's this current plus this current?


[User] Please transcribe this text

[Assistant] And this current is alpha times this thing, which basically becomes negative, uhm, vx over ro, alpha re divided by re plus alpha rm.


[User] Please transcribe this text

[Assistant] Now this is one of the places that I will not make that approximation because of, you will see why. I would not drop alphas to be 1, for example here. Because we are calculating the difference of RE and alpha RE. Right? So because you get an R,


[User] Please transcribe this text

[Assistant] Okay, and from this, if I did, now I have vx to ix ratio, right? That's what our, our o is, our out prime. So our out prime,


[User] Please transcribe this text

[Assistant] Which you can also write if you multiply both numerator and denominator by gm.


[User] Please transcribe this text

[Assistant] Let's see what it means. So, and this is the, remember, this is the intrinsic part. So the total part, R out, was Rc parallel to this intrinsic part.


[User] Please transcribe this text

[Assistant] Right? Which we had dropped already. It was an RC looking up. Okay. So what does it mean? Let's see how it behaves.


[User] Please transcribe this text

[Assistant] How small? Let's say RE is much smaller than RM.


[User] Please transcribe this text

[Assistant] If Re is much smaller than Rm, what is this value going to reduce to?


[User] Please transcribe this text

[Assistant] Well, if RE is much smaller than RM, then RE divided by beta is also going to be much smaller than RM.


[User] Please transcribe this text

[Assistant] So this becomes basically Rm over Rm times Ro, so it becomes R out is Ro.


[User] Please transcribe this text

[Assistant] This divided by that, or you can, so basically becomes RM plus RE over RM, which you can write as 1 plus GMRE. So this is something that you see commonly.


[User] Please transcribe this text

[Assistant] In a lot of scenarios, a lot of situations, 1 plus GMRE.


[User] Please transcribe this text

[Assistant] The output resistance is increasing by a factor that's determined by RE and GM. So now your output resistance, as you increase your RE, as you're increasing your emitter resistance, your output resistance is increasing. And this is important, we'll see why. Now, there's another scenario when RE is even greater than beta RM, or r pi.


[User] Please transcribe this text

[Assistant] If r is greater than that, then what happens? Then these two terms dominate, right?


[User] Please transcribe this text

[Assistant] Roughly, it's beta over alpha, right? Because these two terms don't matter. We've got beta arrow, right? It's beta over alpha arrow, but roughly beta.


[User] Please transcribe this text

[Assistant] There's a limit it reaches, the output resistance reaches a limit. And you will see, the output resistance is important. Why do we get so hung up on the output resistance and how high it can be?


[User] Please transcribe this text

[Assistant] A drive and a load resistance. And the only way to increase the gain, really, is to increase one of these two. Either the drive capability or the output resistance.


[User] Please transcribe this text

[Assistant] Because increasing the drive capability usually requires other things like power consumption and things like that.


[User] Please transcribe this text

[Assistant] So if you have a certain amount of current, you want to get, in several situations,


[User] Please transcribe this text

[Assistant] So that's the maximum output resistance this can have, this stage. And you will see this is actually different when you go to a MOSFET. Yes.


[User] Please transcribe this text

[Assistant] And it usually is, right? Let's say at 1 milliamp, this is 25 ohm, this is, and, and it's like, VA is like 100 volt, like 100 kilo ohms to 25 ohms. So it's hundreds of kilo ohms to tens of ohms.


[User] Please transcribe this text

[Assistant] If alpha is one and beta is infinity, this term disappears. So you will end up here. Right? So there is no limits like this.


[User] Please transcribe this text

[Assistant] Fundamentally, for the output resistance, how much it can be increased. So you increase the RE and


[User] Please transcribe this text

[Assistant] You increase output, you see it has topological implications.


[User] Please transcribe this text

[Assistant] I mean, I'll tell you what example of it. We haven't seen why, but we will see it. The topological implication is that you see double cascodes.


[User] Please transcribe this text

[Assistant] And you don't see, you see triple cascades in mosfets, but you don't see them in bipolar.


[User] Please transcribe this text

[Assistant] Well, how do we know that they're not two 222s with nine 2s in the middle?


[User] Please transcribe this text

[Assistant] Master, you almost got eaten just this morning.


[User] Please transcribe this text

[Assistant] We'll eat the Tang Monk, and we'll all live forever.


[User] Please transcribe this text

[Assistant] Watch this episode, it'll help you be patient. Christmas is coming.


[User] Please transcribe this text

[Assistant] But it says, do not open until Christmas.


[User] Please transcribe this text

[Assistant] But it said, do not open until Christmas. You should have waited, Snoopy.


[User] Please transcribe this text

[Assistant] Yes ma'am, I'd like to buy a Christmas present for a girl I know.


[User] Please transcribe this text

[Assistant] I was thinking maybe a pair of gloves. Twenty five dollars for a pair of gloves?


[User] Please transcribe this text

[Assistant] I'm sorry ma'am, that's more than I can afford.


[User] Please transcribe this text

[Assistant] Could I maybe buy just a thumb?


[User] Please transcribe this text

[Assistant] Yes ma'am, I sold my whole collection of comic books, see?


[User] Please transcribe this text

[Assistant] Every time I go outside with my heavy coat on, I fall down on the ice.


[User] Please transcribe this text

[Assistant] It's so heavy I can't even move my arms. Then I can't get up and I have to lie there until I freeze to death. Boy that's disgusting.


[User] Please transcribe this text

[Assistant] I'm worried about Snoopy. He took his Beagle Scouts backpacking on a Christmas hike and I'm afraid he may be lost in this snowstorm.


[User] Please transcribe this text

[Assistant] I dunno, I sort of had the idea he was an expert at getting around in the woods.


[User] Please transcribe this text

[Assistant] Journey to the West, Chapter 77, The Magic Fan.


[User] Please transcribe this text

[Assistant] For over a day, the wind from the fan carried Wukong.


[User] Please transcribe this text

[Assistant] When he finally landed, he was far from the Iron Immortals mountain.


[User] Please transcribe this text

[Assistant] Wukong looked around and saw a mountain nearby. It looked familiar.


[User] Please transcribe this text

[Assistant] The monkey told the bodhisattva everything that had happened with the iron immortal.


[User] Please transcribe this text

[Assistant] The Bodhisattva handed a small stone to Wukong.


[User] Please transcribe this text

[Assistant] Before she could shut the door Wukong turned into a cricket. He quickly leaped into the cave.


[User] Please transcribe this text

[Assistant] Silently, he followed the iron immortal along a tunnel.


[User] Please transcribe this text

[Assistant] Wukong found his companions in the village with the old man.


[User] Please transcribe this text

[Assistant] Suddenly there was a roar as the flames grew bigger, filling the sky.


[User] Please transcribe this text

[Assistant] It wasn't that I was attached to the robot so much as the robot was attached to me. The robot became part of me. It became my leg pretty quickly.


[User] Please transcribe this text

[Assistant] That fan's wind magic is powerful. How did the monkey steal it?


[User] Please transcribe this text

[Assistant] Alright, so what we've done so far is that we've actually understood and reviewed the single stage amplifiers, right? And we've looked at, well, single transistor stages, really. And we've looked at a couple of them with more transistors, and we'll talk about it. But what we did first was that we understood these three basic configurations, right?


[User] Please transcribe this text

[Assistant] That where in the case of a MOSFET would be common source, common drain or also known as source follower and the common gate.


[User] Please transcribe this text

[Assistant] And we saw that each one of them has certain properties. These are the most basic building blocks. And then what we did, for example, we saw in the case of a common source, you have a reasonably high input impedance.


[User] Please transcribe this text

[Assistant] You have, rel- depending on what kind of the, uh, load you use, you can have a high impedance, uh, output, a high impedance output, because essentially the output impedance what you see is the look what you see looking into the drain, or in the case of a common, uh, emitter, you're looking into the collector. So that's where the termin- the terminal with the highest resistance.


[User] Please transcribe this text

[Assistant] And in two out of these three configurations, the output is taken out of the collector.


[User] Please transcribe this text

[Assistant] So those are the ones that give you the high output impedance in principle.


[User] Please transcribe this text

[Assistant] Of course the overall impedance is going to be low, but so when we talk about the output impedance, we're talking about the intrinsic, what you see looking in the transistor. So remember, this transistor roughly, looking into the source, you see RM, or looking into the emitter, you see RM. Looking into the


[User] Please transcribe this text

[Assistant] Gate, now, or base, this is where it's gonna be different. So in bipolar, because you have the current, you have the r-pi.


[User] Please transcribe this text

[Assistant] Which is about, it's just beta times Rm. In the MOSFET, you have basically infinity.


[User] Please transcribe this text

[Assistant] For classic MOSFET because there's no DC current flowing. But that also means that that terminal cannot carry current. So you really can't take an output out of that. You can't make the gate your output because there's no current handling capability, right? And if you think about it then there's the drain or the collector which has the RO.


[User] Please transcribe this text

[Assistant] Due to the early effect or channel length modulation or things of that sort. In general, an arbitrary combination. So, the common source and common base, common source and common gate, or the common emitter and common base, they are, both of them take the output from the collector.


[User] Please transcribe this text

[Assistant] Or the drain, right? Now the difference is that really the polarity of the input that's applied, but that implies that you're applying your input to a terminal that's low impedance in principle, RM.


[User] Please transcribe this text

[Assistant] Where basically your input was applied to your gate or base, which had relatively high impedance. Now what your output this time is taken from the source or the emitter. Now the output is now taken from the terminal that has low impedance.


[User] Please transcribe this text

[Assistant] So the output has to be taken out of those two, out of the terminal one or terminal two, in case of any arbitrary three terminal device. Those are the ones that can carry current. Generally you don't take output out of base or gate. Because there is no current generation or current handling capability in there.


[User] Please transcribe this text

[Assistant] And that basically leaves these three combinations. So these were the basic three combinations. And then what we saw is that we looked at essentially what were some of the two stages.


[User] Please transcribe this text

[Assistant] So what, what we did, for example, we looked at cascode as an example of a way of increasing the output resistance. We did the analysis, we saw that in the case of a bipolar transistor, the maximum output resistance that you can achieve with something like that was beta RO.


[User] Please transcribe this text

[Assistant] And of course next day we'll talk about three transistors stages, four transistors stages, but no, just, uh, so two transistors stages have interesting properties and they will become more actual, actually become more of building blocks for us too.


[User] Please transcribe this text

[Assistant] So we talked about CAS code first, right? I mean CAS code was one of the things we talked about and what was, so let's review CAS code for a second, right? I mean we, so, so go back to CAS code as another example of a two transistor stage.


[User] Please transcribe this text

[Assistant] Now, what do we mean by two transistor stage? The cascode, if you remember, was a stage where you can have, for example, if you do it in a MOSFET implementation, and by the way, we'll switch back and forth between MOSFET and bipolar constantly. So, you should be able to be comfortable with those or even ATDs, arbitrary three terminal devices. So, the concept is


[User] Please transcribe this text

[Assistant] There's a lot of similarities in the content. So you have something like this. You have an RD here. You had two transistors, W over L, let's say one.


[User] Please transcribe this text

[Assistant] W2 over L2 in general. We can keep them the same for now.


[User] Please transcribe this text

[Assistant] For the time being, for many of these stages, we will shoot for the next...


[User] Please transcribe this text

[Assistant] Lecture two. Well, this lecture and maybe next. We may see, you may see a lot of these. And afterwards you may see a lot of these, like, re-bias.


[User] Please transcribe this text

[Assistant] Right, at this point it means that somehow we are maintaining a constant voltage here, or mostly constant voltage, which essentially means that you can think about it as a voltage source.


[User] Please transcribe this text

[Assistant] We'll have extensive discussions about how these things are generated.


[User] Please transcribe this text

[Assistant] And we'll make it more sophisticated as we go through. So, but for now, let's just not worry about that.


[User] Please transcribe this text

[Assistant] And we'll come back to it later. So in the cascode, we had two stages, and the input was applied here and the output was applied there, so if you wanted to analyze it, what you could say, again, we will try to kind of think about these as


[User] Please transcribe this text

[Assistant] Doing the small signal model on this thing. So what we really mean is that this VIN has two parts. It has a DC part that keeps the transistor biased, and it has an AC part.


[User] Please transcribe this text

[Assistant] Which will show at lowercase v in. And that would, so we know if the transistor is in the pinch-off region, which is a condition that needs to be satisfied in general, so that's the first thing we check.


[User] Please transcribe this text

[Assistant] So if you are in pinch-off, we know that this is going to generate a current, a small signal perturbation current of gmvin. Right?


[User] Please transcribe this text

[Assistant] Now, we know that this current is going to be reflected here at low frequencies, right? Because we know that the drain and source currents of a MOSFET are essentially the same. Because the gate current is, in the classical model, zero.


[User] Please transcribe this text

[Assistant] So, this current directly appears here, this fluctuations.


[User] Please transcribe this text

[Assistant] So this current is being pulled out of this node. Another way to think about it is that you can say I have no source here. So this is another way to think about it.


[User] Please transcribe this text

[Assistant] You can say, I've nulled this, so from an AC perspective, or from DC perspective, this is just a fixed voltage. And from an AC perspective, it's ground. And then there's a current source here, of the value.


[User] Please transcribe this text

[Assistant] I'm basically doing essentially a Norton equivalent, if you think about it. With this terminal being the output terminal in ground.


[User] Please transcribe this text

[Assistant] So I'm going to erase this now, but you can think about it that way if it bothers you. That's what I'm doing. So this red stuff means that there's a current source being pulled out of it and you can ignore the effect of this guy then because that would replace this. Now, if I want to know what's the voltage on that node, how do we do that?


[User] Please transcribe this text

[Assistant] Well, if I want to know what's the voltage on a given node, if I know that there's a current being injected into it or being pulled out of it, what do I need to know? What else do I need to know?


[User] Please transcribe this text

[Assistant] The resistance, right, to apply Ohm's law. So I need to know what's the total resistance on this node, because that current source was being pulled out of it. Right?


[User] Please transcribe this text

[Assistant] So what is the total resistance on that node? It is a parallel combination of what you see looking up and what you see looking down. What you see looking up, basically when I say looking up, it means that looking up to the ground, to the AC ground. All of this stuff is a small signal. So this is RD. Right? From a small signal perspective, this terminal is what? It's a ground.


[User] Please transcribe this text

[Assistant] So this is an RD2 ground. Now, what is the resistance looking down here? Again, to understand, to evaluate that, I should null my independent source. Right? I'm doing a Norton equivalent.


[User] Please transcribe this text

[Assistant] If you want to think about it that way. Now, I'm shorting this, and I'm looking into here, and I want to see what the resistance is. And we've calculated this resistance before, right? We know, so let's call this M2 and M1. This is basically R01.


[User] Please transcribe this text

[Assistant] It's better to, I mean I actually prefer to write it like, unless this number is very small, I would just write it as, uhm,


[User] Please transcribe this text

[Assistant] Unless this number is really like 2 or 3, this 1 doesn't matter.


[User] Please transcribe this text

[Assistant] What is GM2RO2? What is this thing? This thing or that thing?


[User] Please transcribe this text

[Assistant] Right? So, you can see that the output resistance of this guy, which is what you would have seen looking down here,


[User] Please transcribe this text

[Assistant] Is multiplied by the maximum intrinsic gain of this guy because of this common gate operation. So that was the essence of cascode, right? We've seen this before.


[User] Please transcribe this text

[Assistant] And we exploited this last time to make stages with higher gain. So if you needed higher gain, you need to, the only way, so your drive is fixed. Let's say you have a given drive, right, which is this GM. Now for a given amount of drive, you want to maximize the gain, what do you need to do? You need to maximize that resistance on that node. This total resistance, which is the parallel combination of that and that.


[User] Please transcribe this text

[Assistant] Right? As the load, which pres- they present a similar kind of load. So, the idea was that if you wanted to really maximize the gain, you- we went to something that looked like this.


[User] Please transcribe this text

[Assistant] And we did this last time, so I'm just reviewing this for you, quickly.


[User] Please transcribe this text

[Assistant] Or if you were doing bipolar, you would use PNPs, or use P-type devices.


[User] Please transcribe this text

[Assistant] Uh, in the case of an arbitrary transistor or arbitrary three terminal device.


[User] Please transcribe this text

[Assistant] And then you have something like, so this is VB1, VB2, VB3, these are bias voltages, they're fixed voltages. This is your V in. And again, your output is taken from here, V out.


[User] Please transcribe this text

[Assistant] And if all these devices remain in pen shop, which is the requirement for this model, the small signal model that we use to hold. If you are in triode region, then you basically have a resistor model for the channel which we have also derived.


[User] Please transcribe this text

[Assistant] So, if you are in a pinch-off, what we see here, so let's call this, uh, M1.


[User] Please transcribe this text

[Assistant] So this is gonna be gmvin, this fluctuations here, small signal variations, which will be directly appear here because the current gain from the source to drain is one for a MOSFET. And if it were bipolar, what would this be? For example, if this was a BJT, what would, what would this number be? Alpha times that, right? So if you had a BJT, it would get multiplied by alpha. Now, and then,


[User] Please transcribe this text

[Assistant] So, and then this is again same deal. The only difference really between these two is that the output resistance looking down is still the same thing. So we can write it roughly as RO1, GM2, RO2.


[User] Please transcribe this text

[Assistant] R01, GM1, R02. And then the question is what is the resistance looking up? Now it's not RD, because I've replaced RD with something else. Right? What is it? Well,


[User] Please transcribe this text

[Assistant] It's a similar thing, right? It's a similar cast school, it's just upside down.


[User] Please transcribe this text

[Assistant] It's like the cascode except for the fact that it's input is not changing.


[User] Please transcribe this text

[Assistant] But it's the same deal. So what do you see looking into here? You see RO4.


[User] Please transcribe this text

[Assistant] And looking into here, you see basically RO.


[User] Please transcribe this text

[Assistant] 4 times gm3 ro3. It gets multiplied at the maximum intrinsic gain of this stage as then the same thing as this stage. I'm missing an arrow here. Okay.


[User] Please transcribe this text

[Assistant] Okay, so so that, so you're saying that is this GM different from that GM? Is that? And, and this one?


[User] Please transcribe this text

[Assistant] So this is, well, this would be gm1, right? Because this is the guy that's converting this from. Yea, it's a good question. So, it's converting this v into a g, to a current here. So this m1 is the one that's doing that one.


[User] Please transcribe this text

[Assistant] Is this, are these GMs the same or different? Well, it depends. But the currents are, right? So in the case of a bipolar transistor, let's say, for the sake of, if this was done with bipolars, so if these were NPNs and these were PNPs, and if they were sharing the same current, more or less,


[User] Please transcribe this text

[Assistant] And if you ignore the alpha, assume alpha is 1, or beta is infinity, then all of them share the same current. In the case of a bipolar, the


[User] Please transcribe this text

[Assistant] Sure, but in a MOSFET that's not necessarily the case because they can have different W over L's.


[User] Please transcribe this text

[Assistant] And you can see that there are newer knobs in MOSFET design. Because W and L's are parameters of the design.


[User] Please transcribe this text

[Assistant] And you know that in both expressions that we had for the GM of the MOSFET, both in terms of current, which was that square root of two mu and Cox W over L ID, or in the voltage format, which is basically mu and Cox W over L VGS minus VT, both of them had W over L in them.


[User] Please transcribe this text

[Assistant] So this GM can be different from the GM of the other one, so this is still GM1. Uh, right, so these GMs can be different in a MOSFET.


[User] Please transcribe this text

[Assistant] I mean bipolar, they are also different a little bit because of the alpha, but yeaah.


[User] Please transcribe this text

[Assistant] What's an alpha between friends, right? So, here, here's uhm,


[User] Please transcribe this text

[Assistant] What you have as a basic transistor. Now, it seems that it's actually helping, because now what is my gain? If I ask you what is your gain, I want you to be able to have intuition about this gain. You need to be able to give me not super precise expression, but you can say, it's roughly this. So what is it roughly? In terms of expressions that they have. Anyone who wants to go for it. What is the gain? The voltage gain from here to there.


[User] Please transcribe this text

[Assistant] The output voltage is going to be this current times the total resistance you see on this node, right? So what is the total resistance you see on this node? It's this.


[User] Please transcribe this text

[Assistant] Resistance in parallel with this resistance, right? Resistance looking up in parallel with the resistance looking down.


[User] Please transcribe this text

[Assistant] And what is the drive? It's gm. So if, it should not be surprising if you say av defined as vo over vin is going to be negative and that's because the current is being pulled out of the snow. Negative gm.


[User] Please transcribe this text

[Assistant] Uh, because I made a mistake. This should be GM2. Thank you.


[User] Please transcribe this text

[Assistant] You can get to ridiculously large numbers, you can even think about doing quad cascades, and at some point we saw that the numbers, if the numbers become too large, it means that essentially your model is starting to fail you.


[User] Please transcribe this text

[Assistant] Cause there are other things you're not modeling. There are other resistances you're not modeling. The leakage currents of the diodes and things of that sort. So don't get carried away with this.


[User] Please transcribe this text

[Assistant] But you will see sometimes triple cascades in mosfets.


[User] Please transcribe this text

[Assistant] I don't think I've seen many practical circuits with quad cascodes, but just triple cascodes I've seen. And there may be cases where people use quad cascodes. If you think about it, you'll probably remember something. But anyway, that doesn't matter. The key thing is that it matters that we built this cascode, we did this last time too. But now the question is what is the problem if you wanted to cascode more and more of these things?


[User] Please transcribe this text

[Assistant] Let's say we wanted to do a triple cascode to get a lot of gain. What would be a practical problem?


[User] Please transcribe this text

[Assistant] Well, think about it. What's happening to the process technologies? How are we making them faster? The scaling, which is one of the bases of the Moore's law, right? You're in the Moore's lab. Same Moore.


[User] Please transcribe this text

[Assistant] So, what's with Moore's Law? What's... what's...


[User] Please transcribe this text

[Assistant] What is happening when you scale the transistors? You're trying to make it smaller, right? We talked about this when we were talking about device physics. And when we make the transistors smaller, what happens to the voltages? We are shrinking the depletion region, but you have to shrink the voltages to make sure that you don't exceed the critical voltages. So what happens is that the supply voltages are shrinking.


[User] Please transcribe this text

[Assistant] And as a result, you remember, we said all bits are off as far as this model is concerned if these transistors are not in the pinch-off region.


[User] Please transcribe this text

[Assistant] And to be in the pinch-off region, you need to maintain a minimum VGS, right? Which has to be greater than VGS minus VT on every single one of them.


[User] Please transcribe this text

[Assistant] For the sake of argument, let's call this voltage, this DC drop you need to maintain is V1. And then DC drop, you need to maintain here V2. I drew it in the wrong place. Should be very crowded here, but it's okay. Let's call V1.


[User] Please transcribe this text

[Assistant] 0.3 volts, and this is 0.3 volts, and your supply voltage is 1 volt. What, what's the problem?


[User] Please transcribe this text

[Assistant] What's the problem? Can you think of a problem?


[User] Please transcribe this text

[Assistant] That I can operate, this can fluctuate up and down, it can move up and down in 0.4 volts before it, one of these things goes into triode region.


[User] Please transcribe this text

[Assistant] So your active range is reduced. This is basically called headroom, right? Because if these are the rails, it feels like the room, just like you're lowering the ceiling, so you're more crunched in between. Now, what happens here is that


[User] Please transcribe this text

[Assistant] Okay, so that's a problem. How do we solve this problem? Can we think of a solution to this problem?


[User] Please transcribe this text

[Assistant] So how can we, if, how can this evolve into something that solves this problem?


[User] Please transcribe this text

[Assistant] Folded cascode, right? So what it means, what do we mean by folded cascode?


[User] Please transcribe this text

[Assistant] The problem, the challenge is that these, the reason you're going up in voltage is that you need to maintain a positive voltage between drain source and drain source of this guy. Why do we need to maintain a positive voltage? Because these are n-type devices. Now, but for p-type,


[User] Please transcribe this text

[Assistant] You maintain a negative voltage between the drain and the source, right? If you think about it. So this is the drain and this is the source, so the drain source is negative.


[User] Please transcribe this text

[Assistant] And what's the definition of cascode? The cascode is not defined by the way you draw these things.


[User] Please transcribe this text

[Assistant] It's connected, it's defined by what terminal is connected, but to what terminal.


[User] Please transcribe this text

[Assistant] The cascode really is a common source followed by a common gate. That's the definition of a cascode. Or a common emitter followed by a common base.


[User] Please transcribe this text

[Assistant] Or in our ATD, common terminal 1, and act followed by common terminal 3.


[User] Please transcribe this text

[Assistant] So, regardless of that, we need to do that. But now, if we get this guy into, as a PFET,


[User] Please transcribe this text

[Assistant] Can I, if I draw something, I say, well, no problem, I'll make this a PFET.


[User] Please transcribe this text

[Assistant] What's the problem with this picture? Or is there a problem with this picture?


[User] Please transcribe this text

[Assistant] PFET, so, so PFET transistors, is this, is this, well, not this way, sorry. This way. Uh.


[User] Please transcribe this text

[Assistant] Because it had to be a common source followed by a common gate, right? And common gate gets its input from the source. Does this work?


[User] Please transcribe this text

[Assistant] What happens is that the current needs to be flowing in this direction, the DC current. And for this guy, the DC current needs to flow in this direction.


[User] Please transcribe this text

[Assistant] Talk about DC currents, maybe I should use a different color.


[User] Please transcribe this text

[Assistant] So the DC current is flowing this way and the DC current is flowing this way. So obviously you have a problem, right? You have


[User] Please transcribe this text

[Assistant] Two devices that are trying to pull current out of the same terminal. Right?


[User] Please transcribe this text

[Assistant] And then, this is also a problem, because now you're trying to push something into this guy, so this is gonna try to go above VDD, which it can't, cause then, what, what happens if, so, so you can say, well, what do you mean you can't do this? I can do whatever I want, I can take two transistors and put them, connect them anyway I want.


[User] Please transcribe this text

[Assistant] Nothing's gonna, it's not gonna be a black hole or something like that formed by doing that.


[User] Please transcribe this text

[Assistant] Something's gonna happen. Yes, that's true. Something's gonna happen. What's gonna happen if you connect them this way? What's gonna happen is that the source and drain are gonna switch.


[User] Please transcribe this text

[Assistant] Because this is going to be at a higher termin- voltage than this terminal. So, since nMOS is, it, or P, MOS transistors are essentially symmetrical, so what the correct drawing for this block diagram would be is, becomes this.


[User] Please transcribe this text

[Assistant] And then when that happens, you look at it, it looks like this basically from here to there is not going to be much gain because from here to there you had some gain because you had the basic active load with some resistance here. But then it basically becomes a stage that doesn't carry that much gain.


[User] Please transcribe this text

[Assistant] So, we wanted to have that, so it's clear, and this is not cascode anymore, because cascode by definition was a stage, a common source, so the drain of the first transistor should go into the source of the next transistor.


[User] Please transcribe this text

[Assistant] So what do we do? We have a problem. The problem is that they're trying to both draw currents this way. So what do you need to do? You need to provide a source of current. Right? What is that source of current? Well, you can put a current source.


[User] Please transcribe this text

[Assistant] So now you have a DC supply of current that provides current to this thing, and if this were really an ideal current source,


[User] Please transcribe this text

[Assistant] From an AC perspective, what you see looking here, looking down here. It's an open circuit, so it's not gonna do anything. So if you indeed had an open, had an ideal current source,


[User] Please transcribe this text

[Assistant] You would see that. Now, what if you ha- well, say, well, we don't have an ideal current source. True. So, what is it? Non-ideal current source. The non-ideal current source has some resistance here.


[User] Please transcribe this text

[Assistant] And for it to be a reasonable current, so this resistance has to be reasonably large.


[User] Please transcribe this text

[Assistant] How do we make current sources? We haven't really formally talked about it, but we make it out of transistors too, right? Now, what's the defining characteristic of a current source?


[User] Please transcribe this text

[Assistant] So, if I wanted to make it out of a transistor then, if I wanted to make it out of a single transistor, which terminal of the transistor would be the output of the current source? In your mind.


[User] Please transcribe this text

[Assistant] The drain, or the collector, right? The one with the highest impedance. So this is gonna be the impedance, so it's going back to your question, which is a good question, so how high is this resistor? It's an RO.


[User] Please transcribe this text

[Assistant] RO-ish, or maybe higher. If you can make better current sources, which we will make.


[User] Please transcribe this text

[Assistant] So this is an RO. Now if this were an RO, would this be a problem? Would this be a problem for this node?


[User] Please transcribe this text

[Assistant] So what, to understand if it's a problem or not, we have to understand what the other resistances are first, right? What is the resistance you see here? This is another RO, so this could be significant, right? This is an RO-ish thing. This is an RO. Now what do you see looking up? Looking into the source. What do you see? RM.


[User] Please transcribe this text

[Assistant] So you have, on that node, you have three resistors in parallel, an RM, and an RO, and an RO. Would adding a second RO to this combination matter? If you have an RM parallel with an RO already?


[User] Please transcribe this text

[Assistant] So let's say if this were bipolar, like, so you're talking about 25 ohms versus 100 kilo ohms, so you-


[User] Please transcribe this text

[Assistant] So if you have 25 ohms parallel to 100 kilo ohms, you add another 100 kilo ohms in parallel with it. It's still 25 ohms.


[User] Please transcribe this text

[Assistant] Well, remember, this is important to recognize. That small signal model is valid.


[User] Please transcribe this text

[Assistant] Because it's a perturbation. It's valid for NMOS and PMOS. Actually, it's the same for NMOS and PMOS. It looks the same. Because it's a perturbation model. It's the derivatives.


[User] Please transcribe this text

[Assistant] Right? So it's a fluctuation of this current anyway.


[User] Please transcribe this text

[Assistant] The basic resistance cannot become negative. So anyway, so this doesn't matter. So we take this and we redraw it in a more common fashion. And again, this is one of those things, a lot of things in circuit depends on how you draw it. If you draw it poorly,


[User] Please transcribe this text

[Assistant] You can make it become unpleasantly difficult.


[User] Please transcribe this text

[Assistant] Now here's the same thing, right? The only difference here is that I also had to make another change to my R. Because if this resistor goes to VDD, then it can't sync current, because remember, this is gonna be, current is going, wants to go upward.


[User] Please transcribe this text

[Assistant] And if this is VDD, it means that this voltage has to go above VDD.


[User] Please transcribe this text

[Assistant] Which in this kind of operation cannot. I mean there are some circuits that you can design that push it up. But at this point it can't. So it has to be a reference to ground.


[User] Please transcribe this text

[Assistant] But from an AC perspective, it's not going to make any difference. So this is going to still be RD. So this is what we call folded cascode.


[User] Please transcribe this text

[Assistant] Right? And the idea of folded cascode is that now let's see what the voltages look like. So even if we could make it double-folded cascode, so let's say if we were talking about singles for a second, if you were thinking about singles, the DC voltage across here was V1, and let's say here we had V2, right? Or the entire thing, let's say. This is V2.


[User] Please transcribe this text

[Assistant] Was basically V1 plus V2. So V1 plus V2 was VDD.


[User] Please transcribe this text

[Assistant] Had to cover the entire video. Here though, you have a V1 here, and a V2 here.


[User] Please transcribe this text

[Assistant] So this voltage, so what you have is that according to this V1 is equal to V2.


[User] Please transcribe this text

[Assistant] But it can be smaller than what you get from the VDD. So you have more headroom this way. Now,


[User] Please transcribe this text

[Assistant] This concept of the complementary devices, you see that we are using these complementary devices. We will see them more and more. It's very powerful if you have them at your disposal.


[User] Please transcribe this text

[Assistant] In other words, when you have NMOS and PMOS, or NPN and PMP, it's quite useful, especially if they're somewhat symmetrical. But what I mean by somewhat symmetrical is that one of them is not significantly worse than the other one. And some of, sometimes this is the case, and sometimes it isn't.


[User] Please transcribe this text

[Assistant] Now, whenever you have NMOS and PMOS, every stage has an inverted dual.


[User] Please transcribe this text

[Assistant] Right? You can flip it upside down. So if you start, for example, with a common source,


[User] Please transcribe this text

[Assistant] Let's say, uhm, rd, so this is a basic stage, right? We've talked about this, common source like that. I can always flip it upside down and use an n, a p-fit. So what we can do, the dual of this thing would be, or in, if inverted, how would it look like?


[User] Please transcribe this text

[Assistant] P type device. So, I'm gonna use a P type device.


[User] Please transcribe this text

[Assistant] And now remember, for a p-type device, the source has to be at the highest potential. So we have a VDD here.


[User] Please transcribe this text

[Assistant] Now, this would be my input, v in, and the load now needs to be referenced to ground.


[User] Please transcribe this text

[Assistant] I mean, if it's much worse you can still do that, but that stage will not perform well.


[User] Please transcribe this text

[Assistant] And sometimes you don't have the complementary device in certain processes.


[User] Please transcribe this text

[Assistant] So what, what you can do though, is that you can go from here to there. And this basically would be the same stage in terms of operation. This is still a common source. Right? Because the common terminal from an AC perspective is what?


[User] Please transcribe this text

[Assistant] This terminal, which was the same as this terminal. Because from an AC perspective, this is the same as that. This is, these are all ground. And if you draw a small signal for them,


[User] Please transcribe this text

[Assistant] You will get the same thing. Actually, let me just draw the small signal model for this. So the small signal model for this, you can do the t or pi. Let's do the t. It's like this. So I have Rm here.


[User] Please transcribe this text

[Assistant] They're just drawn differently. One is the upside down version of the other one. These are the same stage. Topologically.


[User] Please transcribe this text

[Assistant] So every n-type stage you can take it and make it into a p-type stage. And every p-type stage you can convert to an n-type stage. As long as you have the complementary device. Now sometimes, you may not have... Is there a question? Yea.


[User] Please transcribe this text

[Assistant] Not necessarily. So the question is that do we always assume that there's an RO in parallel with the current source? Not necessarily, but if you want to know what kind of resistance you're looking at if you're making that before you


[User] Please transcribe this text

[Assistant] Start making your circuit completely with transistors, you need to know that this is an RO type of thing.


[User] Please transcribe this text

[Assistant] So that tells you whether or not you have to worry about it. And if it tells you, yes, no, this is a source of worry, you're still not done.


[User] Please transcribe this text

[Assistant] We will see if we can make actually better current sources whose output resistance are higher than RO. Right?


[User] Please transcribe this text

[Assistant] We even have that topology essentially even on this whiteboard if you want to think about it.


[User] Please transcribe this text

[Assistant] If I want to get something higher than RO, where do you see something higher than RO? In the stuff that's behind me.


[User] Please transcribe this text

[Assistant] A cascode, right? Exactly. So this, these resistances are


[User] Please transcribe this text

[Assistant] Higher than RO. So you can actually, if you really want to make something that's


[User] Please transcribe this text

[Assistant] Of course, there's a trade-off there. What's the trade-off? What are you losing when you use a cascode as a current source, for example, versus a single transistor? And we are going to talk about this in detail, but just think about them as we go.


[User] Please transcribe this text

[Assistant] Well, the current is going to be the same, right? Because you can just basically just be passing the same current through the same thing. It's a headroom issue again.


[User] Please transcribe this text

[Assistant] It can't go to a lower, it starts, stops being a current source, basically it leaves the pinch off region earlier. So the range of actual operation, usefulness of it, is reduced.


[User] Please transcribe this text

[Assistant] So, but you can't. So going back to your question, which is a good question, is that, not necessarily.


[User] Please transcribe this text

[Assistant] Sometimes it makes sense to think about it, okay, this is an ideal current source, I can just think about it, make it simple. The design process works that way. You don't want to start from the most complicated thing in the beginning.


[User] Please transcribe this text

[Assistant] You want to start with the simplest essential element and you want to add to it and build around it.


[User] Please transcribe this text

[Assistant] Because essentially you're designing the connection of your brains. Right? You don't want to start from the most complex thing. You want to see a simple example


[User] Please transcribe this text

[Assistant] Add a little bit more to it, add a little bit more to it, add a little bit more to it, expand on that.


[User] Please transcribe this text

[Assistant] We don't learn by just seeing the most com- most general case in the beginning, from the beginning. I don't think people learn that way. Yeah. Sorry.


[User] Please transcribe this text

[Assistant] Yeah, you can start with that, but in the back of your head you know that, okay, if the impedances that this is connected to are all large, then I have to worry about it. And if I have an RM, I don't have to worry about it. I don't even want to think about it.


[User] Please transcribe this text

[Assistant] Right? Let's talk about it. So this is the question. What if the current source is in the current path? If you have a current source in series with anything, what is that?


[User] Please transcribe this text

[Assistant] An ideal current source. In parallel, in series, did I say parallel?


[User] Please transcribe this text

[Assistant] Sorry, in series, in series with another element.


[User] Please transcribe this text

[Assistant] Right? As long as this is not another ideal current source, it's exactly equivalent to the current source itself.


[User] Please transcribe this text

[Assistant] The same way that an ideal voltage source in parallel with anything that's not an ideal voltage source is the same as that ideal voltage source.


[User] Please transcribe this text

[Assistant] And therefore, so it's an open circuit in series with some finite impedance. What is the series combination of finite and infinity? What is finite plus infinity? Infinity. So it's open circuit.


[User] Please transcribe this text

[Assistant] If you, if you, no, if your transistor is, no, no, so, see, this is the question, the question you ask, which was a good question, both of them are good questions, I'm just saying that, you need to differentiate. The question you ask is, what if I have a current source in series? I say that if you have an ideal current source, it's an op, it's,


[User] Please transcribe this text

[Assistant] It's just a current source. Now, if your ideal, if, if this is not an ideal current source, it has some R.


[User] Please transcribe this text

[Assistant] One, then of course, then this is, this is not equivalent to that. There's a Norton equivalent for this which you can calculate. And it will have some finite resistance.


[User] Please transcribe this text

[Assistant] No, these are good questions. You should keep asking them. Because it should make sense. This process should make sense. If it doesn't make sense, you cannot design. You're just shooting in the dark.


[User] Please transcribe this text

[Assistant] So, here's the thing. This is the folded casco. This is an example of a twist stage.


[User] Please transcribe this text

[Assistant] Uhm, two transistor stage, another transistor stage. So, so that's one example. Now, there are other stages that are of interest potentially for, as two transistor stages. And we're gonna talk about some, I'm gonna briefly talk about them so that you mention to them, mention them to you. And then we'll, we'll talk about perhaps the greatest of them all, uh, after the break. But before the break, let's cover some of the contenders, or some of the runner-ups.


[User] Please transcribe this text

[Assistant] Talked about, of course, is the active load. We've talked about this. You can have two drains, for example. So this is, again, we talked about this extensively. I'm just kind of like putting it there for completion. So let's say you have


[User] Please transcribe this text

[Assistant] Which basically is V in, and this is going to be GMV in. So if I ask you what's the gain, it's clear that it's GM times RON parallel ROP with a minus sign because the current is being pulled out of that node. So that's the voltage gain. In the absence of any additional load.


[User] Please transcribe this text

[Assistant] We talked about this and then we saw that we can cascode it, we just did that for MOSFET and that's fine. Now, the other thing, now the other interesting thing is that this works if you have the complementary device as we discussed right now, right?


[User] Please transcribe this text

[Assistant] Now, there are some cases where you don't have a really good complementary device.


[User] Please transcribe this text

[Assistant] Uh, for example, there are, we have talked about the bipolar process and the CMOS process and we've talked about there are two different worlds, right? I mean the way we deal with them right now is that we go to the bi-polar world, we deal with bipolar, we go to CMOS world, we deal with CMOS. But there are actually processes very commonly used that are called bi-CMOS processes. Which basically allows you to have both bipolar and CMOS.


[User] Please transcribe this text

[Assistant] On the same process. Now, some of the bipolars that are in there, actually they're HPTs. They're silicon germanium, for example, a very common form of this thing, are silicon germanium by CMOS processes, where you get a very good, incredibly high frequency bipolar, NPN, whose base is essentially made out of silicon germanium alloy,


[User] Please transcribe this text

[Assistant] And we talked about how it enhances the performance of the system by improving the emitter injection efficiency and the base resistance and all those things when we were talking about the device. And you also have a complementary CMOS process. But you do not have a really good PMP. Actually, your PMP is really crummy.


[User] Please transcribe this text

[Assistant] It's a lateral PMP and all those things, but just, uhm, so, are we, we said, oh, we have this great NPN, but we don't have a PMP, good PMP at all.


[User] Please transcribe this text

[Assistant] Our PMP's early voltage is horrible, its beta is horrible, its frequency response is horrible, all of it, everything about it is horrible. So uhm, what do we do? Are we done? Let's say we are in a BiCMOS process. Can you think of a solution, so if you could mix bipolar and CMOS transistors, can you think of something, a stage that could give you something reasonable, in terms of gain?


[User] Please transcribe this text

[Assistant] Why do we have this PMP instead of a resistor? We are really using it as something. As what? As a current source, right?


[User] Please transcribe this text

[Assistant] Basically we are using it as a high output impedance thing that can carry current.


[User] Please transcribe this text

[Assistant] So you can make a stage that will look like this. So your drive.


[User] Please transcribe this text

[Assistant] Your gm is coming from this, because the gm of bi-polars is ic over vt. And vt is a small number, this is their threshold voltage. Now this is where it gets really messy, because we have two different vts that are there. So, v thermal. Okay.


[User] Please transcribe this text

[Assistant] Uhm, right? That's a 25 millivolts of room temperature, 25.8 millivolts. So that you get for 1 milliamp you get 40 millisiemens.


[User] Please transcribe this text

[Assistant] Now, but I need high output resistance for something that can source current, right?


[User] Please transcribe this text

[Assistant] P-type devices can source current and N-type devices can sync current.


[User] Please transcribe this text

[Assistant] I'm using terminology, it's a common terminology. I throw them in because I want you to get familiar with this terminology. So they can source current and this is, they can sink current. I want a high impedance thing that can source current.


[User] Please transcribe this text

[Assistant] P-type, right? So, a P-type MOSFET, here, at some V-bias, can do that. So let's say you have a V in, and this is your V out.


[User] Please transcribe this text

[Assistant] So here you have the R-O-N of the bipolar.


[User] Please transcribe this text

[Assistant] Which is basically an early voltage divider. Let's say this is running at 1 milliamp, right? This is gonna be about 100 kilo ohm. Then you have ROP of the MOSFET.


[User] Please transcribe this text

[Assistant] Or, if you don't want to do that, you say, oh that gives me too much capacitance here, et cetera, for some reason I don't want to deal with that, then I can cascode it.


[User] Please transcribe this text

[Assistant] B, did we say B? Yes, bipolar. And then V in times the parallel combination of these resistors.


[User] Please transcribe this text

[Assistant] And then we get to higher frequency, we'll see it also becomes a question of time constants. And transfer constants.


[User] Please transcribe this text

[Assistant] Right? You can distill it to some essence of this thing. But so, anyway, so those kind of things are possible. You can actually have combination of these things. Now another stage, any questions on this?


[User] Please transcribe this text

[Assistant] Circuit design is kind of like drawing, or painting.


[User] Please transcribe this text

[Assistant] You will see. If you look at, you know, people who have been designing circuits, I mean, sometimes I look at some circuits and say, well, this must have been designed by such and such.


[User] Please transcribe this text

[Assistant] People even develop their style after a while. This must be the work of such and such.


[User] Please transcribe this text

[Assistant] It's, it is kind of like that because there are infinite possibilities. There are many different ways to do the same thing. Which is actually the beauty of it. There's not one single solution.


[User] Please transcribe this text

[Assistant] Another combination of two transistors is the so called Darlington.


[User] Please transcribe this text

[Assistant] And this is used almost exclusively in bipolar and you will see why. The Darlington combination is basically having a transistor


[User] Please transcribe this text

[Assistant] The emitter of one transistor driving the base of the second transistor and they share the same collector current. So it's a compound transistor, if you will.


[User] Please transcribe this text

[Assistant] Something like that. You can like this, call this Q1 and Q2. Now, what does this compound transistor do? What is the purpose of this thing?


[User] Please transcribe this text

[Assistant] Current gain, right? Why? Because if this current is IB, let's call it IB1,


[User] Please transcribe this text

[Assistant] This current, which is basically IE1, is gonna be beta plus 1, well, practically beta, but which is the same thing as beta plus 1 as far as I'm concerned. But just let's write it precisely and uselessly as this. Well, should write it the other way around. Anyway, so let's keep it that way. And then,


[User] Please transcribe this text

[Assistant] This current is gonna get multiplied by another beta. So this current is gonna be beta times beta plus one, IB one. And this current was beta IB one.


[User] Please transcribe this text

[Assistant] Assuming that the beta for both transistors is the same,


[User] Please transcribe this text

[Assistant] Which may not be the case, even if there are similar transistors. And I'll ask you why in a few seconds. Just think about it.


[User] Please transcribe this text

[Assistant] I personally think that some of the beta plus twos and beta plus ones are a little bit ridiculous.


[User] Please transcribe this text

[Assistant] But you see them everywhere, so you need to understand. Sometimes it matters because if you subtract two of them, then that one matters.


[User] Please transcribe this text

[Assistant] Here, so it's basically a transistor, so if you think about this, if I put this inside a black box,


[User] Please transcribe this text

[Assistant] Right? And sell it to you. Say, this is the base, this is the collector, this is the emitter.


[User] Please transcribe this text

[Assistant] Beta score, so this is a very high beta transistor, like you get a value of 10,000, 5,000. So wow, this is a really high beta transistor. So what's great, we can increase our current gain, we can increase our beta significantly. What's the drawback of this thing? Can you point out drawback, a drawback or drawbacks?


[User] Please transcribe this text

[Assistant] Uh, you have to have a really high input impedance. You mean for the driver?


[User] Please transcribe this text

[Assistant] What is, what do you see? I mean, we know the trick for this. We know that, you remember the reflection rule? We said if you have something in the emitter, you can bring it to the base, look from the base, look at it from the base, is beta plus times whatever it is in the emitter, which is beta essentially times the emitter, and if you take something from the base and move it to the emitter, you divide it by beta plus one. Or beta. Okay? So, here, what do I see looking, if, if this was ground, for the sake of argument,


[User] Please transcribe this text

[Assistant] Well, it looks like this, but let's think about it a little bit more carefully. Because, what is r pi? r pi, isn't r pi? Beta rm, or beta over gm.


[User] Please transcribe this text

[Assistant] No, this IC is beta times roughly larger than this IC.


[User] Please transcribe this text

[Assistant] So this r-pi is beta times smaller than this r-pi. I'm saying, uh, yeaah, beta times smaller than this r-pi. So what do you roughly get? So, let's say if this r-pi, let's say this, let's call this rm, so let's call this r-pi.


[User] Please transcribe this text

[Assistant] So this is RM, which is the GM of this big transistor. So R pi 2 is this, but R pi 1 related to R pi 2 is going to be beta times larger.


[User] Please transcribe this text

[Assistant] Which is roughly saying it's 2 beta r pi 2, which basically is saying it's 2 beta squared r m 2.


[User] Please transcribe this text

[Assistant] Voltmeter. It's a good thing. You're making a better voltmeter. Because your input impedance is going up. That's actually one of the reasons that this state will be used.


[User] Please transcribe this text

[Assistant] Fine, you reduce this base current, but there's a price to be paid because this guy is not operating at the same current and that's why sometimes you add a current source here.


[User] Please transcribe this text

[Assistant] In between to adjust for that. We can talk about that. But the other question I have for you is that now, what is the overall GM of this device? Or, or, let's let me ask you this question. Uh, from a practical perspective, is it as easy to use as a single transistor?


[User] Please transcribe this text

[Assistant] Exactly, you need more voltage. Very good.


[User] Please transcribe this text

[Assistant] You need a lot, you need, if, if, you need a .7 volt to turn one on roughly, now you need 1.4 volts.


[User] Please transcribe this text

[Assistant] So you need a lot more voltage. So if you're operating in low voltage operations, this is not your cup of tea. This is not what you want.


[User] Please transcribe this text

[Assistant] And that's why nowadays you only see these kind of things in power devices, power electronic things, that work with relatively high voltages and things of that sort.


[User] Please transcribe this text

[Assistant] So, this stage has some benefits and advantages and disadvantages, but it's overall


[User] Please transcribe this text

[Assistant] That's essentially for that. There's another two transistor stage that again we will talk about more extensively later, but


[User] Please transcribe this text

[Assistant] I want us to be familiar with it at least at some level. And that's the so-called current mirror.


[User] Please transcribe this text

[Assistant] The idea of a current mirror is that if you think about a transistor to the first order, like a BJT or MOSFET, what determines its collector current or its drain current? What is the prime number one variable that determines the collector or drain current?


[User] Please transcribe this text

[Assistant] So, if two transistors have the same base emitter voltage or gate source voltage, you would expect them to have more or less the same current.


[User] Please transcribe this text

[Assistant] If they're both in the same region of operation, right, if they're both in pinch-off.


[User] Please transcribe this text

[Assistant] Things that have the same, share the same card. Basically, these are connected, right? I mean, don't show this connection often, but they have the same VGS.


[User] Please transcribe this text

[Assistant] So the VGS of this one and VGS of that one are the same. So if this current is ID,


[User] Please transcribe this text

[Assistant] If they have the same VGS, they should carry the same current, because the current


[User] Please transcribe this text

[Assistant] In the pinch-off region, as long as they're in the pinch-off region, mu n C ox over 2, W over L, Vgs minus Vt squared, right?


[User] Please transcribe this text

[Assistant] So ID1 and ID2 are going to be the same because they have the same


[User] Please transcribe this text

[Assistant] And force a current source I1, and I have a way of maintaining this in saturation, which means that I have to connect it to some voltage. Uh, this current would be I1, right? Is that correct?


[User] Please transcribe this text

[Assistant] So it seems that you can force, you can reflect this current from here to there. Does this stage work the way I've drawn it? Or is there something, a problem with it? Do you see a problem?


[User] Please transcribe this text

[Assistant] Let me ask you a question. What determines the potential of this node? The DC potential of this node?


[User] Please transcribe this text

[Assistant] The amount of charge on the gate, right? So, but that's not exactly the amount of charge on the gate. So this is like a floating note.


[User] Please transcribe this text

[Assistant] Two capacitors, so this is basically a capacitor here connected to another capacitor here to ground, to whatever, some voltage, right? To ground. It's like asking what's the voltage on this node? Could be anything, right?


[User] Please transcribe this text

[Assistant] So there's a problem. This gate is floating. The same way that this is floating. Called the floating gate. It's not.


[User] Please transcribe this text

[Assistant] Forced to have, so if you have some store charge in there, it can have some any arbitrary value, so you can get some unpredictable behavior. You need to make sure that this gate has some fixed


[User] Please transcribe this text

[Assistant] So there needs to be some connection to this gate. Now we do it by doing this.


[User] Please transcribe this text

[Assistant] We connect it to this side, which is the reference side, and that way we keep the drain of this guy separated from its gate, so we maintain a high impedance here.


[User] Please transcribe this text

[Assistant] But by doing so, you create a pathway for charge, for charging and discharging of this node, so you keep these two on the same level.


[User] Please transcribe this text

[Assistant] By the way, this also guarantees that if your threshold is positive, the transistor will never enter triode region. It will either be in pinch-off or off.


[User] Please transcribe this text

[Assistant] So when you feed this current, now in the case of a MOSFET, there will be no current flowing through here. No DC current. In the classic MOSFET sets.


[User] Please transcribe this text

[Assistant] And if there is a bipolar, some of that current is actually supplied through here. Some of that base current. So this is what we call a current mirror.


[User] Please transcribe this text

[Assistant] You can, if I take this node and connect it to another transistor,


[User] Please transcribe this text

[Assistant] Which is W over L. I can make another copy of this current. I can make multiple copies of this thing.


[User] Please transcribe this text

[Assistant] So if I have one good reference, which we'll talk about later, much later, about how we generate these really good references, you can copy it as many times as you want.


[User] Please transcribe this text

[Assistant] It would be twice as large, right? It's basically like saying, oh, I make two of them with W over L.


[User] Please transcribe this text

[Assistant] For reasons that we'll discuss later for matching and all those things. That current would be too ideal.


[User] Please transcribe this text

[Assistant] And we'll use it extensively, again. And again, of course, like any other stage, it can be flipped upside down. Right? It can be inverted.


[User] Please transcribe this text

[Assistant] So what's the inverted version of this thing look like? The inverted version of this thing looks like this.


[User] Please transcribe this text

[Assistant] Now, there's a difference between these, right? This is a current source that does what? Source or sink current? It can sink current, right? So an n-type current source can sink current.


[User] Please transcribe this text

[Assistant] And a p-type current source can source current.


[User] Please transcribe this text

[Assistant] So if you needed to source current, you can use a p-type current source. If you needed to sync current, you can use an n-type current source.


[User] Please transcribe this text

[Assistant] Now, let's say, if you say, well wait a second, but this way, you really need two of these good references. Right? Do I? Or can I make this out of this too?


[User] Please transcribe this text

[Assistant] Can you suggest a solution? There are more than one solution.


[User] Please transcribe this text

[Assistant] I just want to use that good current source that I've worked really hard to make a good reference current source and I want to reuse it somewhere else. How do I do that?


[User] Please transcribe this text

[Assistant] Right, you already have this, you can make another copy of that current source and put it here.


[User] Please transcribe this text

[Assistant] Cause now this is playing the role of that current source that was there.


[User] Please transcribe this text

[Assistant] This is used so extensively that sometimes you actually have a shorthand notation for this. So you may see something like this.


[User] Please transcribe this text

[Assistant] Right? So that's the shorthand notation for this. Does it make sense to you?


[User] Please transcribe this text

[Assistant] But remember, whatever you do, you need to have the gates that are connected to each other biased somehow. Or the base is connected somehow. Anyway. So, that was some of the review of some of the basic two, uh, transistor stages. Uhm, sorry?


[User] Please transcribe this text

[Assistant] Yeah, there are lots of ways to do that. We'll talk about it. We'll have more detailed discussions of this later. But yeah, there are lots of ways to play this game. This is the most common, this is the most standard way of doing it. Any other questions?


[User] Please transcribe this text

[Assistant] Alright, so after the break, we'll talk about the greatest of the two transistor stages.


[User] Please transcribe this text

[Assistant] Yellow Brows is powerful. He captured everyone with a magic cloth. He trapped me in a pair of symbols.


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[Assistant] You're not powerful, said the monkey. You just think you are because you have that cloth. I bet you're too scared to fight me without it.


[User] Please transcribe this text

[Assistant] Wukong laughed. Maybe you'll believe me one of these days, master.


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[Assistant] We won't harm you if you're truly sorry for being evil. But right now you're stopping the Tang Monk from continuing his journey. Sun Wukong needs your fan.


[User] Please transcribe this text

[Assistant] You two may return to your cave, but you must stay out of trouble from now on.


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[Assistant] It's good that you'll be the one to put out the mountain of flames, Wukong.


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[Assistant] You leaped out of the pot, disturbing the fire in his workroom.


[User] Please transcribe this text

[Assistant] A burning ember fell to earth that day. It started the fire on the mountain.


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[Assistant] Feel guilty and sort of ease up on our grading.


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[Assistant] She will be glad if you go to see her in person.


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[Assistant] He returned home for the first time in ten years.


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[Assistant] I have been living in Canada for almost five years.


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[Assistant] I'd gladly pay more for something if it's of high quality.


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[Assistant] You continue making the same mistakes time after time.


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[Assistant] A bookstore in that location wouldn't make enough money to survive.


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[Assistant] The bus stopped suddenly in the middle of the street.


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[Assistant] Florence is the most beautiful city in Italy.


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[Assistant] Tsunamis swept through rice fields and flooded the towns.


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[Assistant] Every time I read the Bible, I am deeply moved.


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[Assistant] The child had no overcoat on, although it was very cold.


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[Assistant] The bus is full. You'll have to wait for the next one.


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[Assistant] You have to study hard to catch up with your class.


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[Assistant] As more paper money came into use, the value fell.


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[Assistant] I had never seen a windmill until I visited the Netherlands.


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[Assistant] English is a very important language in today's world.


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[Assistant] Is it right for a doctor to decide when someone should die?


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[Assistant] The ice on the lake is too thin to bear your weight.


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[Assistant] I have too many things on my mind these days.


[User] Please transcribe this text

[Assistant] I want to get a haircut before I go on the trip.


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[Assistant] The Senator was censured by the Congressional Ethics Committee.


[User] Please transcribe this text

[Assistant] He wishes he had gone to the theater last night.


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[Assistant] A slip of the tongue is sometimes fatal to a politician.


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[Assistant] My uncle comes to see me from time to time.


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[Assistant] He had his sister help him paint the wall of his room.


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[Assistant] Scientists haven't found a cure for cancer yet.


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[Assistant] I think it's better for us to adopt his plan.


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[Assistant] He devoted the last years of his life to writing his autobiography


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[Assistant] You speak so softly that I cannot quite hear what you say.


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[Assistant] I'll always love you, no matter what happens.


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[Assistant] A good many people have told me to take a holiday.


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[Assistant] I don't see any reason why I have to apologize.


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[Assistant] I have to go shopping. I'll be back in an hour.


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[Assistant] They awarded her first prize at the Flower Show.


[User] Please transcribe this text

[Assistant] The end does not always justify the means.


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[Assistant] Judging from the look of the sky, it may rain this afternoon.


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[Assistant] After a couple of drinks, the guy was feeling no pain.


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[Assistant] He should apologize for being rude to the guests.


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[Assistant] I have to take my medicine every six hours.


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[Assistant] how long does it take to walk to the station


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[Assistant] You're the one who decided to do this job, right?


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[Assistant] You've both been very impressive today. I'm proud of you.


[User] Please transcribe this text

[Assistant] I'm not a university student, but I'm brighter than them.


[User] Please transcribe this text

[Assistant] Having lived in Tokyo, I know this city well.


[User] Please transcribe this text

[Assistant] I have two dogs. One is white and the other, black.


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[Assistant] My cell phone has a built-in digital camera.


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[Assistant] My husband reads the newspaper while eating breakfast.


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[Assistant] I live near the sea, so I often go to the beach.


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[Assistant] My wife's part-time job brings in a little extra money.


[User] Please transcribe this text

[Assistant] The train for Birmingham leaves from platform 3.


[User] Please transcribe this text

[Assistant] As soon as she wakes up, we'll turn on the music.


[User] Please transcribe this text

[Assistant] If I'd known the truth, I'd have told you.


[User] Please transcribe this text

[Assistant] Were you able to do everything you wanted to get done?


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[Assistant] I couldn't prevent Tom from eating all the cookies.


[User] Please transcribe this text

[Assistant] She spends a lot of time practicing the piano.


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[Assistant] I told you not to talk about the matter and her presence.


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[Assistant] My grandfather sometimes talks to himself when he is alone.


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[Assistant] Water is liquid. When it freezes, it becomes solid.


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[Assistant] You have changed so much that I can hardly recognize you.


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[Assistant] Hey, I may have no money, but I still have my pride.


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[Assistant] It is necessary for you to go there immediately.


[User] Please transcribe this text

[Assistant] The accident seemed to have something to do with the heavy snow.


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[Assistant] I hate when other people make me wait a long time.


[User] Please transcribe this text

[Assistant] The assignment took me longer than I had expected.


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[Assistant] I would like to have a look at your collection of stamps.


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[Assistant] We have less than five minutes to evacuate the whole building.


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[Assistant] About how much will I have to pay for all the treatments?


[User] Please transcribe this text

[Assistant] She did not visit me on Sunday, but on Monday.


[User] Please transcribe this text

[Assistant] A group of young men are playing handball in the playground.


[User] Please transcribe this text

[Assistant] I thought you'd be full after eating that big steak.


[User] Please transcribe this text

[Assistant] My father will often read the newspaper during meals.


[User] Please transcribe this text

[Assistant] We're out of tissue paper, so I need to go buy some.


[User] Please transcribe this text

[Assistant] I find it difficult to express my meaning in words.


[User] Please transcribe this text

[Assistant] This car was so cheap that he could afford it.


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[Assistant] Our eyes take time to adjust to the darkness.


[User] Please transcribe this text

[Assistant] I ran as fast as possible to catch up with him.


[User] Please transcribe this text

[Assistant] After reading his books, I feel I can construct a house.


[User] Please transcribe this text

[Assistant] The students were for the most part from the west coast.


[User] Please transcribe this text

[Assistant] The old houses were torn down to make room for a supermarket


[User] Please transcribe this text

[Assistant] With your approval, I would like to offer him the job.


[User] Please transcribe this text

[Assistant] This book is for students whose native language is not Japanese.


[User] Please transcribe this text

[Assistant] She bought six yards of cloth for a dress.


[User] Please transcribe this text

[Assistant] I don't want to hear any more of your complaining.


[User] Please transcribe this text

[Assistant] The air is thin at the top of a high mountain.


[User] Please transcribe this text

[Assistant] This problem is too difficult for primary school children to solve.


[User] Please transcribe this text

[Assistant] He makes it a rule to take a walk every morning.


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[Assistant] You've worked hard for months and have certainly earned a holiday.


[User] Please transcribe this text

[Assistant] The potato was so hot that it burned my mouth.


[User] Please transcribe this text

[Assistant] Quite by chance, I met my old friend in the airport.


[User] Please transcribe this text

[Assistant] Ebola spreads from person to person through bodily fluids.


[User] Please transcribe this text

[Assistant] Women eat lighter meals when they're eating with a guy.


[User] Please transcribe this text

[Assistant] This airplane is capable of carrying 40 passengers at a time.


[User] Please transcribe this text

[Assistant] I will provide you all the necessary information.


[User] Please transcribe this text

[Assistant] I hope he'll be able to come. I'd like to see him.


[User] Please transcribe this text

[Assistant] Could you please talk a bit louder? I can't hear very well.


[User] Please transcribe this text

[Assistant] If you can't come, you should let me know ahead of time.


[User] Please transcribe this text

[Assistant] Can you wake me up at 7 o'clock tomorrow morning?


[User] Please transcribe this text

[Assistant] Many schools are closed today because of the storm.


[User] Please transcribe this text

[Assistant] The first thing you have to take into consideration is time.


[User] Please transcribe this text

[Assistant] Judging from the look of the sky, it is likely to rain.


[User] Please transcribe this text

[Assistant] I felt so sleepy that I could hardly keep my eyes open.


[User] Please transcribe this text

[Assistant] They came up with a plan after a long discussion.


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[Assistant] She stayed in that area for a short while.


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[Assistant] He does nothing but complain from morning till night.


[User] Please transcribe this text

[Assistant] Books are for people who wish they were somewhere else.


[User] Please transcribe this text

[Assistant] Since my mother was sick I stayed home from school.


[User] Please transcribe this text

[Assistant] Our music teacher advised me to visit Vienna.


[User] Please transcribe this text

[Assistant] Fluency in English is a very marketable skill today.


[User] Please transcribe this text

[Assistant] My father has been in good shape since his operation.


[User] Please transcribe this text

[Assistant] Honesty is the primary reason for his success.


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[Assistant] I was a high school student at that time.


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[Assistant] She doesn't have as much patience as you do.


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[Assistant] I always have to wear a tie because of my job.


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[Assistant] The job looked quite simple, but it took me a week.


[User] Please transcribe this text

[Assistant] You can't drink seawater because it is too salty.


[User] Please transcribe this text

[Assistant] English is a universal language and is used all over the world.


[User] Please transcribe this text

[Assistant] The red flag indicated the presence of danger.


[User] Please transcribe this text

[Assistant] Let's divide this money between you and me.


[User] Please transcribe this text

[Assistant] Leaving something unfinished is the worst thing you can do.


[User] Please transcribe this text

[Assistant] People are more educated now than they used to be.


[User] Please transcribe this text

[Assistant] She can sing better than anybody else in her class.


[User] Please transcribe this text

[Assistant] He studied hard in order to get into college.


[User] Please transcribe this text

[Assistant] I can speak Chinese, but I can't read it.


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[Assistant] She wrote him a long letter, but he didn't read it.


[User] Please transcribe this text

[Assistant] I hope everything will be fine in the end.


[User] Please transcribe this text

[Assistant] There are a lot of new buildings here now.


[User] Please transcribe this text

[Assistant] I didn't expect to see you at a place like this.


[User] Please transcribe this text

[Assistant] I can't believe your parents let you come here by yourself.


[User] Please transcribe this text

[Assistant] Plastics have taken the place of many conventional materials.


[User] Please transcribe this text

[Assistant] What time does the train for New York depart?


[User] Please transcribe this text

[Assistant] You should try to form the habit of using your dictionaries.


[User] Please transcribe this text

[Assistant] She was at a loss for words to express her feeling.


[User] Please transcribe this text

[Assistant] I wouldn't be too surprised if this song became a hit.


[User] Please transcribe this text

[Assistant] You should not have lent the money to such a person.


[User] Please transcribe this text

[Assistant] I've done bad things that I should be punished for.


[User] Please transcribe this text

[Assistant] How come you know so much about Japanese history?


[User] Please transcribe this text

[Assistant] The coral reef is the region's prime attraction.


[User] Please transcribe this text

[Assistant] Their contract is to run out at the end of this month.


[User] Please transcribe this text

[Assistant] Some people like red wine, and some people like white wine.


[User] Please transcribe this text

[Assistant] There is no point in pretending to be sick.


[User] Please transcribe this text

[Assistant] Don't translate English into Japanese word for word.


[User] Please transcribe this text

[Assistant] The date of the festival coincides with that of the exam.


[User] Please transcribe this text

[Assistant] I like swimming, but I don't like to swim here.


[User] Please transcribe this text

[Assistant] We all consider your idea to be impractical.


[User] Please transcribe this text

[Assistant] The town was destroyed by the flood after the storm.


[User] Please transcribe this text

[Assistant] She came to Japan for the purpose of studying Japanese.


[User] Please transcribe this text

[Assistant] I am going to stay here for a couple of days.


[User] Please transcribe this text

[Assistant] Make sure to turn off all the lights before going out.


[User] Please transcribe this text

[Assistant] If I had taken that plane, I would be dead now.


[User] Please transcribe this text

[Assistant] A fire broke out in my neighborhood last night.


[User] Please transcribe this text

[Assistant] I had to abstain from smoking while I was in the hospital.


[User] Please transcribe this text

[Assistant] Marriage is the main cause of all divorces.


[User] Please transcribe this text

[Assistant] A trip to America was equivalent to a two-year salary for her.


[User] Please transcribe this text

[Assistant] He has just published an interesting series of articles.


[User] Please transcribe this text

[Assistant] It makes sense to pay off your credit card balance every month.


[User] Please transcribe this text

[Assistant] Lake Bakal in Russia is the deepest lake in the world.


[User] Please transcribe this text

[Assistant] What is the total amount of money you spent?


[User] Please transcribe this text

[Assistant] He always plans a thing out carefully before he does it.


[User] Please transcribe this text

[Assistant] The crane, unlike the dog, has never dreamed of flying.


[User] Please transcribe this text

[Assistant] The Tigers lost the game, which was a surprise to us.


[User] Please transcribe this text

[Assistant] He amazed everyone by passing his driving test.


[User] Please transcribe this text

[Assistant] All of a sudden, three dogs appeared in front of us.


[User] Please transcribe this text

[Assistant] She told me that she would go to Paris in August.


[User] Please transcribe this text

[Assistant] My father always speaks in a very loud voice.


[User] Please transcribe this text

[Assistant] China is about 25 times as large as Japan.


[User] Please transcribe this text

[Assistant] I love her so much that I can't leave her.


[User] Please transcribe this text

[Assistant] What is the distance between New York and London?


[User] Please transcribe this text

[Assistant] There are a lot of things you don't know about my personality.


[User] Please transcribe this text

[Assistant] You shouldn't share too much private information on the social networks.


[User] Please transcribe this text

[Assistant] She waved her hand until the train was out of sight.


[User] Please transcribe this text

[Assistant] In a way, you are right, but I still have doubts.


[User] Please transcribe this text

[Assistant] That's the computer on which he writes his articles.


[User] Please transcribe this text

[Assistant] He said he did not know the man, which was a lie.


[User] Please transcribe this text

[Assistant] English is not easy, but it is interesting.


[User] Please transcribe this text

[Assistant] You can get from Washington to New York by train.


[User] Please transcribe this text

[Assistant] Thanks very much for having me to dinner the other night.


[User] Please transcribe this text

[Assistant] Is this ladder strong enough to bear my weight?


[User] Please transcribe this text

[Assistant] The doctor told her that she should take a rest.


[User] Please transcribe this text

[Assistant] If you buy me an ice cream, I'll give you a kiss.


[User] Please transcribe this text

[Assistant] A doctor told me that eating eggs was bad for me.


[User] Please transcribe this text

[Assistant] Sir, that CD is available only by special order.


[User] Please transcribe this text

[Assistant] I do not like tea, so I generally drink coffee for breakfast.


[User] Please transcribe this text

[Assistant] He has not written to us since last February.


[User] Please transcribe this text

[Assistant] That was the first time that a man walked on the moon.


[User] Please transcribe this text

[Assistant] Islam first reached China about the middle of the 7th century.


[User] Please transcribe this text

[Assistant] If he is innocent, it follows that his wife is guilty.


[User] Please transcribe this text

[Assistant] Scientists can easily compute the distance between planets.


[User] Please transcribe this text

[Assistant] A foreign language cannot be mastered in a year or so.


[User] Please transcribe this text

[Assistant] I'm going off to Vancouver next week to see my sister.


[User] Please transcribe this text

[Assistant] The truth is that nothing is totally true or false.


[User] Please transcribe this text

[Assistant] More money for education growth.


[User] Please transcribe this text

[Assistant] 150 people entered the marathon race.


[User] Please transcribe this text

[Assistant] She was ashamed of herself for her carelessness.


[User] Please transcribe this text

[Assistant] The teacher has a great influence on his pupils.


[User] Please transcribe this text

[Assistant] It is true that she is pretty, but she is selfish.


[User] Please transcribe this text

[Assistant] Do I have to take off my shoes here?


[User] Please transcribe this text

[Assistant] Mary is not poor. On the contrary, she is quite rich.


[User] Please transcribe this text

[Assistant] As long as you keep quiet, you can stay here.


[User] Please transcribe this text

[Assistant] Apart from on rainy days, I always ride my bike to work.


[User] Please transcribe this text

[Assistant] There is no denying that she is very efficient.


[User] Please transcribe this text

[Assistant] We met in a coffee shop near the campus.


[User] Please transcribe this text

[Assistant] It is sometimes difficult to make yourself understood in public.


[User] Please transcribe this text

[Assistant] There is a certain amount of truth in what he's saying.


[User] Please transcribe this text

[Assistant] London, the capital of England, is on the Thames.


[User] Please transcribe this text

[Assistant] There is nothing worse than doing something in a half-hearted manner.


[User] Please transcribe this text

[Assistant] I went to the hospital to have my eyes tested.


[User] Please transcribe this text

[Assistant] You are old enough to know better than to act like that.


[User] Please transcribe this text

[Assistant] What is the difference between this and that?


[User] Please transcribe this text

[Assistant] A bicycle will rust if you leave it in the rain.


[User] Please transcribe this text

[Assistant] There are 50 states in the United States.


[User] Please transcribe this text

[Assistant] In a crisis, you must get in touch with your teacher.


[User] Please transcribe this text

[Assistant] To the best of my knowledge, the rumor is not true.


[User] Please transcribe this text

[Assistant] He crashed his car because someone tampered with the brakes.


[User] Please transcribe this text

[Assistant] If you can't have children, you could always adopt.


[User] Please transcribe this text

[Assistant] His absence gave birth to all sorts of rumors.


[User] Please transcribe this text

[Assistant] I go to the office by bicycle, except on rainy days.


[User] Please transcribe this text

[Assistant] We promised to stand by him in case of trouble.


[User] Please transcribe this text

[Assistant] The average height of the girls in class is over 155 centimeters.


[User] Please transcribe this text

[Assistant] We take it for granted that he will succeed in his business.


[User] Please transcribe this text

[Assistant] I don't care what color ink, just bring me a pen.


[User] Please transcribe this text

[Assistant] The internet is an invaluable source of information.


[User] Please transcribe this text

[Assistant] The show was very interesting. You should have seen it.


[User] Please transcribe this text

[Assistant] I'm going to run a couple of errands. Wanna tag along?


[User] Please transcribe this text

[Assistant] I'd like to try this on. Where are the fitting rooms?


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[Assistant] The old church on the hill dates back to the 12th century.


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[Assistant] I can't get at the exact meaning of the sentence.


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[Assistant] A caged cricket eats just as much as a free cricket.


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[Assistant] I found the secret compartment quite by accident.


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[Assistant] He amassed a fortune in stock trading during the last boom.


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[Assistant] Everyone is anxious to know what has become of the former champion.


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[Assistant] Sorry, but can you show me the way to the next village?


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[Assistant] Will you please explain the meaning of this sentence to me?


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[Assistant] What does he want? He said we must return the queen.


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[Assistant] Well, hello and welcome to this English lesson about pet peeves. If you don't know the term pet peeves, a pet peeve is something that bothers you. Uhm, there might be things in life that you really enjoy, but there's also things in life that bother you. They bug you. They make you annoyed.


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[Assistant] In this particular lesson, I'm going to be talking about pet peeves that I have.


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[Assistant] You'll be, uh, some of these will be familiar to you. Not all of these are things that annoy me. But, uh, in this English lesson, I'll talk about some very common pet peeves that other people have. And, uh, and I'll mention which ones are ones that also bother me. Most of these bother me as well.


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[Assistant] Please pay attention during the lesson to the phrases I use when I talk about each pet peeve. I'm going to say things like, that bothers me, that drives me nuts, that drives me crazy, that really, uhm,


[User] Please transcribe this text

[Assistant] Is something that, yeaah, just bothers me. Sorry, I'm forgetting the phrases that I had memorized for this lesson. But anyways, I think you know the point. Welcome to this English lesson about pet peeves.


[User] Please transcribe this text

[Assistant] So here's the first one, telemarketers. So lately at my house, one of the things that has really been bothering me, one of the things that annoys me is when the phone rings and it's someone trying to sell me something. A telemarketer is someone who works in a call center.


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[Assistant] And they just phone people randomly and try to sell them something.


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[Assistant] The last phone call I got from a telemarketer I think was actually a scam.


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[Assistant] A scam is when they try to trick you into giving them money.


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[Assistant] But telemarketers are annoying. Telemarketers really bother me. Uhm, this particular scam, they wanted me to verify that I had gotten a payment from the government and they wanted me to give them all my banking information so they could verify it too. And at which point I said


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[Assistant] You are trying to scam me. So some telemarketers are just trying to sell you something, but some telemarketers I think are trying to scam you. I guess technically that's not a telemarketer, that's just a scammer. Anyways, I don't like it when the phone rings and it's someone trying to sell me something.


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[Assistant] People who chew loudly. Oh, a little bit too big there. People who chew loudly or chew with their mouth open. So Brent mentioned this in the chat earlier. In North America in particular, and I don't know what the tradition is in your country or what is considered polite, but in North America, we usually chew with our mouths closed. If I take a bite, I usually chew with my mouth closed. It's considered polite.


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[Assistant] But chewing with your mouth open is not polite, and chewing loudly is not considered polite in North America, and it can really, really bother people. I know that for me, when my kids chew with their mouths open, uh, I usually say, hey, please chew with your mouth closed, because that is the polite thing to do.


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[Assistant] Uhm, people who text and drive or use a phone while driving. This one is a particularly annoying thing for me. I like to go for a walk every morning along my road and I've noticed a couple of things. One is people drive too fast. That bothers me.


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[Assistant] But I also notice a lot of people driving with their head down. So they're driving like this. So I'm assuming they're on their phone. They're probably texting and driving. Very, very dangerous. Uhm, I'm always worried that one of them will lose control of their car and get into an accident.


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[Assistant] But, uh, definitely people who text and drive or use a phone while driving this kind of, uh,


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[Assistant] It's something that I wish would just stop. There's a big fine, by the way, in Canada for doing that. I think it's a $400 fine if you get caught.


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[Assistant] People who are always late, this is another one that bothers me. I am generally on time. I would say 95% of the time, if I need to go somewhere, I arrive on time. If I need to be somewhere at 9, I get there at 5 to 9. If I need to be at work at 8.30, I get there at 8.25. I like to be on time.