 Hi! Today I'm going to talk about MOSFETs. This is my favorite component, the MOSFET. So you've probably seen maybe a symbol that looks something like, I don't know, like this maybe? Or, you know, maybe it goes the other way around. Maybe you've got like an arrow going this way and something like this. Or maybe you've seen something like that. Or, you know, with an arrow going that way. Or possibly with an arrow going the other way. Well, we can talk about that, but what I'd like to do is just do some experiments with some MOSFETs and see what happens. And then we can talk about why it happened using some theory. So let's do that. Now I have some MOSFETs here that I have left over from various projects. Let's see. So here is a MOSFET. This is an IRL B8743. Let's take a look at it. So it looks just like a power transistor. In fact, it is a power transistor. So it's got three terminals and a little tab. And we can look at the, we can look at this. It says that it's 30 volts and 78 amps. Wow, that's pretty huge. I guess that's why there is this huge tab on it to dissipate all that heat. 30 volts basically means the amount of voltage that the MOSFET can take between its two main electrode terminals. So this is the gate and these are the electrode terminals. And typically it is oriented. So you would have maybe here's the gate, here is the drain, and here is the source. Likewise, here is the gate, the drain, and the source. And for some of the other MOSFETs, it's actually reversed, where there's the source up here and the drain up here, whatever. If you've ever seen on a chip, the labels VDD and VSS, well that refers to the voltage that goes to the drain, i.e. power, and the voltage that goes to the source, i.e. ground. So anyway, yeah. So when it says 30 volts on here, that means the maximum amount of voltage that can go across here, typically from drain to source. And the current is the maximum amount of current that can flow through the thing. Okay, so that's that. I've got a bunch of others. Let's see, what have I got here? Here's one. This is a 2N70002K-7. This one is 60 volts, so that is twice as much as the big power one. But look, it can only do 300 mA, so it's kind of small. In fact, I'll show you how small it is. Yeah, that's a whole bunch of them right there. They're really small. Teeny tiny little things. Look at that. They're so small. Here, let's see if I can focus on that. Yeah, see how small they are? They're pretty small. Okay. So, yeah, those are small. Obviously, they're not meant for breadboards, which is kind of unfortunate, but it's a surface mount world. Get used to it. So, that's nice. Let's see what else I have. Okay, here's another one. This one is 60 volts and also 300 mA. It's 0.3 amps. In fact, it's the same thing. It's the 2N70002, except it's DW. This is a neat package. I like this one because, actually, here, let me show you it mounted on a little board. So, I've got three of them mounted on this little board. And they are a six pin package because there are actually two MOSFETs in each package, which is pretty cool. The other reason that I like this is that each package, it doesn't have a pin one. You can actually flip it around and because it's symmetrical on the inside, it doesn't matter which way you orient it, which is kind of neat. And you get two for one. Two for one. So, that's an interesting one. I have another one here that we can play with. Focus. Let's see. This is a BSD223PH. It is 20 volts and 390 mA. Now, you'll notice that this one says P channel, P, and this one says N channel. And all of these other ones that I pulled out are also N channel. So, we will talk about that in a moment. This guy, the BSD223, is also a dual MOSFET. So, that's why I like these two. So, let's take a look at the datasheet. Let's first just talk about this one. This is the big guy. Where did I put him? Here. Come on, big dude. Get out. You don't want to come out. There we go. Got some bonuses. All right. So, this is this. So, you can see that we have three pins. There's gate, drain, and source. And you can see that the tab is also electrically connected to drain. So, let's look at some of the parameters here. So, here's one. The drain to source voltage is 30 volts. So, that's VDSS. VDS means the voltage from drain to source, and the extra S at the end usually means that this is an absolute limit. VGS, this is the gate to source. So, gate to source is plus or minus 20 volts. So, if you look at this, what that means is that from here to here, you can have at most 30 volts. But from here to here, you can have anything from plus 20 to minus 20. So, the gate can go below the source by 20 volts, or it can go above the source by 20 volts. So, that's what that means. And then we have ID. And it says here, continuous drain current with VGS at 10 volts. And it says 150 amps. Wow. That's incredible. There's a little note next to it. This one also says ID. This is at a temperature of 100 degrees. So, you can see that they have derated it 110 amps. And then here's another ID which says package limited 78 amps. So, I guess silicon limited means that, well, this thing, if it were maybe in another package, you could do 150 amps. But inside this package with this heat tab here, you can only do 78 amps. So, I'm not really sure why they bothered to say silicon limited when, you know, this is the package right here. That's what you're limited to. Okay. So, and then they talk about, this is interesting, pulse drain current. This means not continuous of course, but just a brief spike. You can briefly go up to 620 amps. Wow. And then you've got some power dissipation and some thermal things that you can calculate what sort of heat sink you might need. In its simplest form, a MOSFET is basically a switch. So, here's the gate. Here is this thing. So, here's the gate. Here's the drain. And here's the source. So, perhaps we could, I don't know, put the source down here and ground it and maybe put a resistor up here to some, you know, I don't know, plus, let's say 20 volts. And here's your output. And then, out. And then basically what this does is if you set the gate to ground, that turns the MOSFET off. And then you've got 20 volts flowing through a resist, with a resistor connected to the output. But if you turn the MOSFET on, simply by putting the gate above a certain threshold above the source voltage, that effectively turns this on. And you could treat it as maybe zero resistance. So, this out would be completely connected to ground. And of course, you would have current flowing from the power supply through the resistor down to ground. But basically it's like a switch. And that's why sometimes when we're just dealing with MOSFETs in logic circuits, we draw them like this. And this is a nice symbol, because first of all, the arrow sort of tells you that this is the way that the voltage has to be oriented in order to turn the MOSFET on. So, for example, if this were ground, then the voltage here would have to be positive to not really, but sort of let current flow through here, even though there's very, very, very little current actually flowing into the gate. But nevertheless, that's a kind of convenient symbol. It looks kind of like a transistor. And the mnemonic here is that that's the base emitter junction. And that's the way the current flows. So, you know, similarly, that's what it would look like. This is an n-channel MOSFET. And a p-channel MOSFET would be the opposite symbol. It looks like this, just like a p-n-p transistor kind of looks like that. And with this, the opposite is true. So, here is the gate, here is the source, and here is the drain. And now, in order for this thing to be turned on, the voltage has to look like this so that the arrow is in line with the polarity of the voltage. In this case, the voltage from gate to source is actually negative. So, you'll sometimes see the threshold voltage in terms of a negative voltage. Sometimes you'll see it in the data sheet as a positive voltage, even though it's a p-channel. And what that simply means, usually, is that, well, they just left the negative out because they sort of assume that you know what you're doing. And the current flows this way, just like the arrow. So, this is kind of a neat little way of sort of getting rid of all of this crazy stuff over here. Sometimes you'll also see a little bubble over here. This is kind of like the logical not symbol because the threshold is reversed. Basically, to turn it on is the opposite of turning an n-channel MOSFET on. Let's see what else we have on page two. We have the breakdown voltage from drain to source. So, this is what we've seen before, minimum 30 volts. That means that, if you put 30 volts across the drain and the source, or if you exceed 30 volts, then this thing is probably just going to turn on. It's going to break down. So, it doesn't matter if you've turned the transistor off using the gate, you're still going to get current flowing, and that's no good. So, don't exceed that. Don't do that. Here's another nice parameter. This is RDS on. So, it says static drain to source on resistance. Now, if you look at the front page, they have in huge bold letters, RDS on max, 3.2 milliohms. This is actually a marketing thing. The transistor, where the transistor is actually on, is measured in any way you basically want. Maybe you say, well, if I connect the gate to the drain, that makes the transistor on, or maybe if I have the gate 10 volts above the source, that turns the transistor on. So, they could basically choose any point and say effectively, what's the resistance across this. Now, this is a power MOSFET. So, of course, you're going to be sending a lot of power through this, you know, 78 amps. So, of course, you want low resistance, extremely low resistance when you turn the transistor on. So, what do they say here? Well, okay, so typically 2.5 milliamps, where VGS is 10 volts, and you're sending 40 amps through it. Here's another one. It's 3.5 milliohms when VGS is 4.5 volts, and you're sending 32 amps through it. So, you know, typically what you would do is you would just use this as a sort of rough estimate as to, you know, how much like a switch the thing is. So, here's the gate threshold voltage. Again, this is, again, threshold is kind of sort of, you know, again, a kind of a marketing thing. It's very vague. You know, what does it mean to, what does it mean to turn the transistor from off to on? It's actually a continuous function. So, they basically choose some reasonable point. And they're saying that it's between 1.35 and 2.35 volts. And, of course, they've got conditions attached to it. Well, this is only when the drain to source is the same as the gate to source, and also you're only sending 100 microamps through it. So, you know, that that's probably not your application. But anyway, then they talk about drain to source leakage current. So, this is basically when the transistor is off, how much current is actually going to leak through it. And here they're saying, well, you know, if you slap 24 volts across it and you basically connect the gate to the source effectively turning it off, you know, you can go to negative 20 on this MOSFET. But if you turn it off with zero volts, then you're going to get only one microamp through the thing. And they've got a whole bunch of other things, which we can talk about later. One of the interesting things that I want to show is this symbol over here. So, you're going to see this a lot, a diode connected from source to drain. And this basically indicates that even though you may have looked at a MOSFET diagram and seen something like, I don't know, this is the substrate and this is a doped thing. And this is an insulator and this is your gate contact. So, there's the gate, there's the drain, there's the source. Well, it's symmetrical. So, you know, why is the diode pointing in one way? Well, I don't know. I guess it has to do with the way it's fabricated. But anyway, it basically means that the current can only flow one way. Well, okay, the transistor will only prevent current from flowing one way. If you swap the terminals, current will just flow right through the diode. And this is called a body diode. It's intrinsic to the device. It's not something that they add to the package for you for protection. It's actually there as part of the fundamental physics of the device. So, that's an important thing to recognize that when you've got your MOSFETs connected up the right way. I mean, you can obviously connect it up, quote the wrong way, and utilize that. And in fact, they've got other parameters in here about the body diode. So, for example, here is continuous source current through the body diode is 150 amps with another little circle around that that probably means no, not really. But in any case, there's the diode forward voltage. It basically says one volt. So, if you do pass current from source to drain, in other words, in the wrong direction, you'll get a voltage drop of one volt. So, anyway, that's kind of neat. Let's play with this. Let's play with this MOSFET. Let's breadboard something and see what happens. So, let's play with our MOSFETs. So, here's my little breadboard, and let's draw out a circuit. So, let's do the thing that I was talking about before, where we're just going to have our n-channel MOSFET, because this guy is an n-channel MOSFET, and we're going to connect a resistor up to VDD, which we'll just say is five volts, and this is our output, and I'm going to connect an LED to it through some sort of a resistor. Actually, no. We don't even have to, right? Because the rule of thumb for five volts and an LED is 330 ohms, maybe lower, maybe greater, but in any case. So, when the transistor is off, this will be grounded, and the LED will be off. When, I'm sorry, when the transistor is on. When the transistor is off, of course, we will just have five volts going through a 330 ohm resistor going through the LED and lighting it up. So, that's it. And here's our gate, and we will connect it, you know, alternately between ground and five volts. So, let's do that and see what happens. Okay, so I've gathered up a few wires, and I've got my resistor over here, and I've got an LED here. This is a green one. Let's see. So, it says maximum current, 20 milliamps. That's fine, because when you've got, oh, and there's a forward voltage here, three to 3.2 volts. Well, let us calculate. If we have five volts and we drop three volts, that would be two volts. Two volts across a 330 ohm resistor is certainly more than 10 milliamps, but less, well, no, actually it's less than 10 milliamps. So, let's whack it in and see what happens. So, I've got my power supply on. You can hear the fan go. So, here's the LED. Let's just test this to make sure it works. Make sure the LED works. The positive terminal is the longer terminal, typically on these things. So, I'm just going to whack that in, and then I'm going to, actually, let me connect the bottom leg to ground, and then this top guy goes over to plus. You've got to watch out a little bit for these breadboards, because that little gap here means that there's a break between this rail and this rail, and between this rail and this rail. So, be careful. Okay, let's go grab a plus wire. It's red, and a minus wire. This one's blue. Great. And let's see. For some reason, my negative cord is green, and my positive cord, for some incredibly strange reason, is blue. Well, you can't have everything. Yay, okay, it lights up. Well, that's pretty good. Okay, so, we've got our little signal thing. So, let's go ahead and whack this circuit in here. So, I've got my device here. Now, one thing that they caution you, all the time is that MOSFETs are static sensitive. Why? Well, because remember, if you remember this little diagram over here on how a MOSFET is built, this insulator is very, very, very thin. So, if you shock the thing with a huge amount of voltage between gate and any of these terminals, well, you're going to blow a hole right through that insulator. And it may work, kind of, sort of, but it'll be leaky, and it won't work exactly the way the data sheet says, so you really can't rely on it. Now, I did something really stupid, and I'm going to share it with you, because when I do something stupid, I go all the way. Well, I bought this thing. It's an SMD container. It's got, like, all these neat little components, and you can put, here, I've put some capacitors in here. I've got another one with resistors. It's really neat. Well, anyway, I got a bunch of those nice six-terminal dual MOSFETs, and I stuck it in here. I just dumped them in. Well, I'm an idiot. This is not a static protective device. Once you shake it, there's static all over this thing, and I just ruined, literally, a hundred of each MOSFET. Luckily, they're cheap. Luckily, they're really cheap. Anyway, so don't do that. I've got a nice blue grounded mat on my thing. I really should be wearing a wrist strap, but I can't be bothered, and I don't really care about this, whether it, you know, doesn't work to spec or whatever. So, okay, so what are we going to do? Well, we know that the gate is going to be our little switch. We know that the, let's see, this is the drain here, and this is the source. The way that I always remember it is that, is that there's conventional current, which always flows from positive to negative, and then there's actual physical current, which flows from negative to positive, because the charge carriers in here, not in semiconductor devices, there are two charge carriers, but through wires and things, they're basically electrons. Electrons come from the negative end, so physically current actually goes backwards, but we don't like to think of it that way. We like to think of electricity as flowing from positive to negative, and that's why it's called conventional current. But I always remember that, and I always think of, oh, well, you know, the negative terminal, that's kind of the source of all the electrons, but that's just me. So, okay, so gate drain and source. So we know that gate is our switch, and source has to be connected to ground, so let's do that. So I'm just going to stick it in there. Boy, that was horrible. Okay, let's not do that. It's hard to do this with just one hand here. I'll do it with both hands. Wow. This really doesn't want to go in. It's the other problem with these new breadboards is that they kind of tend to be quite tight here. Let me just do this. Maybe open up these. There we go. All right. So now that I've totally and thoroughly put my hands all over this thing. Okay, so what did we want to do? We wanted to connect source to ground. So let's do that. Source is now connected to ground, and the drain is going to be connected to this LED over here. So I'm just going to stick. I've got a white wire over here. Oh, yeah. This also has to go down there. Okay, so the idea is that when the transistor is on, that means that all the current is going to be flowing through this wire and out to ground and not through the LED. But when the transistor is off, then this wire is effectively not even there, and then the current will flow through the resistor and through the LED and turn it on. And here is the gate. So I am just going to connect it to ground, and that will turn it off. And now I'm going to connect up the power and see what happens. Boom. Oh, yes. So the transistor is off, which means that the LED is on because this wire is effectively not there. Now if I turn it on, first of all, I'm going to pull the wire and see what happens. Okay, it's still on. And if I connect it to plus five, there we go. It's off. Now I'm going to pull the wire again and look at that. It's still off. What happened? Well, if you look at this, it's almost inherent in the symbol. There's a little gap here, and that's really a capacitor. There's charge stored in there, so you can actually store temporarily some charge in that gate. And that's why that transistor is still on. Now sometimes if you touch the gate, you can do something. Here I'm going to ground it, and then I'm going to release the wire and maybe touch it. Sometimes you can get it to go. Yeah, touching it is not a great idea. Oh, look, there it went. Look at that. So I'm adding charge to it. I'm taking charge away. It's not a touch sensor. Don't use it as a touch sensor. Okay, so that's our basic circuit, which is kind of neat. Now, can we actually build some logic elements out of this? Well, sure. I mean, this is basically an inverter. If we turn the transistor on, that turns this off. So this is an inverter. Let's put another inverter in front of it. So how are we going to put another inverter in front of it? Well, instead of maybe this thing, what we're going to do is connect this up to the gate of the next transistor. And we have our circuit here, VDD, oops, VDD, and there. So now when we connect, let's see, so when we turn this transistor off, that means that this gate is going to see five volts, which means that this transistor is on, which means that this LED is off, right? Off, off, two inverters. If we connect the gate to VDD, then this transistor is on, which means that this terminal is grounded, which means that this gate will see ground, which means that this transistor is off, which means that this LED is going to be on, on, two inverters. So let's do that. See, here's my second thing. And we turn off the power, we just connect the power and put some opening force in there. There, see, went a lot better. So let's make sure that the drains don't touch because there's that drain over there and that's drain, that drain over there. Okay, so let's pull this wire, and now I have a little jumper here. So I'm going to connect, first of all, the source down to ground, and we move that over, source to ground. Excellent. I'm going to connect the gate of the first transistor down here to ground so that it's going to be off. And then I'm going to use another little jumper to connect, let's see. Oh, I need another resistor, don't I? Let's go grab another resistor. Okay, so I've chosen another 330 ohm resistor. We need the 330 ohm resistor here, definitely, for the LED. For here, though, what is the current flowing through the gate from here when this transistor is off over to here? Actually, practically nothing. I mean, there is something because there is effectively a capacitor in here, so it does have to charge up, but after it's charged up, there's pretty much no current flowing through it. And that's why MOSFETs are really great because they use no power when they're on or off, only in the transition when you're pushing charge into the capacitor or pulling charge out of the capacitor. So let's see, what was I going to do? Right, I was going to take this resistor and connect it to the drain, which is in the middle, and that has to get connected to VDD. Don't let it touch the other lead. Why did I do that? Why don't I just use a jumper? Don't have to go all the way. There we go. And now a jumper. Okay, that's nice. And now we just need to connect the two. So we go from drain to gate. So drain to gate. So something like, here I'll just use another wire. Here's a gray wire. So drain to gate. And we also need to connect the drain of the second transistor to the LED thing. Excellent. Okay, now remember that when we grounded the first, when we only had one transistor, in other words, one inverter, we grounded the input and the LED went on. That was the inversion. So now with this connected to ground, in other words, the first transistor is off. The second transistor should be on, which means that the LED should now be off. Well, let's see if that is true. And it is. And let's connect it up to plus. And there we go. So you can see, oops, somehow ground got away. There we go. Ground is off. It's on. It's off. It's on. And again, we're seeing that charge effect. So there we go. Now, here's a question. Can we make another gate? Well, yes. In fact, we can. So what if we do this? We have one transistor, and we feed it directly into another transistor. Connect that to ground plus VDD, LED. Well, what's going to happen? So here is gate one, and here is gate one, here's gate two. Here is the drain, and here is the source, and here is the drain, and here is the source. Well, we definitely know that when we ground G2, that's definitely going to turn this transistor off, which means that no matter whether this transistor is on or off, this path is blocked. So the LED is going to be on. So G2, ground, LED, on. Great. Now, the same reasoning should apply for G1. So we can connect that to ground, and since there's nothing in the system that's lower than ground, the source is never going to get lower than ground, that's going to turn this transistor definitely off. So if G1 is ground, again, the LED is on. So if and only if both G1 and G2 are connected up to plus, turning both transistors on, will we get a path through these? So G2 and G1 have to be plus, and then the LED is going to be off. Well, if we say ground is zero, and the LED on is one, and we say ground is zero, the LED on is one, one, one, and zero, the only case where the LED or the output is going to be zero is if both inputs are one. Well, that's a NAND gate. So let's hook that up and see what happens, see if that actually works. So oops, let me take the power off. So here we've got our two transistors. Let's see. We only need the one resistor, and we only need the one LED connected to the output, actually. Okay, if this is this top transistor, yeah, okay, so this one is the top transistor because it's closest to the LED. So I need to remove the ground from the source. So here, we will connect the drain, which is the middle thing, to the LED. Great. We've got our one connection, one input. Let's use, let's get, see what do I have? I've got a yellow wire for the gate of the other transistor. So we're going to connect both of them to ground to make sure that they're off. Let's see. The source of the, of this transistor is connected to ground. Now I need to connect the drain of this transistor to the source of this transistor, which I'll do using this wire. So the drain of this transistor goes to the source of this transistor. And now we should have an NAND gate. Well, let's hook up power and see. So we have both of these are, both of these transistors are off and the LED is on. Okay. If I take one connection and hook it up to plus, well, as you can see the LED is still on. So one and zero is a one. Can do the same thing for the other connection. And again, zero and one. But if I connect both of them up, there we go. The LED is off. That's a NAND gate. And you can actually make another kind of gate. What happens if we have our two transistors like this and we connect them up in parallel? There is gate one. There is gate two. There is our connection to VDD through a resistor. And there is our LED telling us the state of the output. Well, it should be fairly straightforward that if any one of these is connected to ground, then of course the LED is going to be off. Both of them, if both of them are on, sorry. Okay. What I meant was, okay, so if this transistor is off and this transistor is off, in other words, off, off, that's the only way that the LED can light, right? If either one of these is on, then that will give a path to ground. And then the LED will be off. So let's see what that means in terms of the table. So we have ground, ground, ground, plus, plus, ground, plus, plus. Okay. So if both of these are off, then the LED is going to be on. But if any of these are on, in other words, if their gate is connected to plus, then the LED is going to be off. Well, what's this? It's a NOR gate. Let's make a NOR gate. So I'm going to turn power off, pull these wires again. We still have our two inputs. I'm going to ground them both. So those are our two inputs. And let me get my circuit back. Okay. So we see that the sources are both connected to ground. So let's do that. Easy enough. Sources are both connected to ground. This wire is being a pain. Okay. So we've got both sources connected to ground. We need both drains connected together and to the LED. So let's do that with a little wire between the drains. And of course, it's being a bit of a pain because I haven't yet opened up the leaves. Let's go grab another wire and connect the two drains together. Wow. This is really being a pain. Well, all right then, I'll just use this wire. Okay. So our drains are connected and now I need to connect both of the drains to the LED. Okay. So again, the idea is that when both gates are off, in other words grounded, then the LED should be on. But if any one of these goes to plus, then the LED should turn off. So I'm going to connect power and I expect to see the LED on. Great. But if I connect any one of them to plus, the LED turns off. And of course, when both of them are plus, the LED is off. So those are two basic gates. And from there, because both a nor and a nand are universal gates, you have everything you need to create a computer with the exception of memory. And you saw that you could actually make a little memory using one of these guys because it stores its charge. Now, of course, that charge isn't going to be there forever, but you could perhaps refresh it and make it, for example, a dynamic RAM. So you have to actually read the data out and then write the data back in on a regular schedule. So anyway, those are MOSFETs. MOSFETs are used in logical circuits. Now, there are other ways that you can use MOSFETs, of course. You can use them in analog conditions. These particular ones are pretty good for switching large amounts of power or high voltages. I, in fact, built a tiny little board, which you can actually see over here, this purple thing. I connected two MOSFETs in order to switch 150 volts or 170 volts on and off using just a 3.3 volt logical signal. And you can kind of sort of see how that might work. So I would have my, for example, my low voltage MOSFET over here and my high voltage MOSFET over here. And there you go, you're done. On, on. So that's one possibility. Now, being a power MOSFET, these are actually a bit pricey. So on Digikey, at least, this is $1.16 US for one and it's 80 cents for 100. So if you want to buy a whole bunch of these, you would get a little bit of a discount, but not fantastic. I mean, that's $80 right over there. But if you take a look at these smaller guys, so here is the single MOSFET. This is 21 cents a piece. But if you buy 100, it goes down to 9 cents a piece. $9 for 100 FETs for 100 MOSFETs. Just $9. That's really good. So if you wanted to, you know, build a replica computer just out of MOSFETs like some projects that I've heard of, you could because it's pretty cheap. These are the double ones. So, and here's another reason why I like the double ones. So the double ones are 26 cents a piece, but you get two. So of course, that's really 13 cents a piece. How does that compare with this? Well, it's a lot cheaper. And at quantity 100, it goes down to 11 cents a piece, which is actually five and a half cents or $5.50 US for 100. That's pretty cheap. And let's see. This other guy is the P1, the dual P-channel. P-channels tend to be a little more expensive. So this is 35 cents for one or 15 bucks for 100 of them. So that's why I like to play with those. So I have this little board here, and I've mounted three of these guys in here. And this is now breadboard friendly, and I can play with them and, you know, do all sorts of interesting experiments. So prices, they're cheap. And I know what you're saying. You want to see me reverse the current on this. You want to see current flow through that body diode. Well, all right then. So let's take a look at what that circuit would look like. So here's a gate, here's my source, and here's my drain. Now instead, I'm going to hook up ground to here, and I'm going to put my diode, my LED this way, and my resistor up here. And I'm going to connect this to plus, and there's my gate. Now it shouldn't matter what the gate does, because there's an intrinsic diode here. And the forward voltage on that diode was over here. Forward voltage, one volt. So we're going to actually have a one-volt difference over here. So it's like, instead of connecting the LED up to five volts, I would be connecting it up effectively to four volts. So the LED should be a little more dim, but still it should light up. Let's try it. So I'll remove that, I'll remove everything. So what are we going to do? We're going to take our drain. Let me label these again. Drain and source. So we're going to take our drain and connect it to ground. Okay. So the center terminal is drain. That's now connected to ground. The gate doesn't matter. I'm just going to take the gate and connect it to ground. And here's the LED. So the LED is now going to be connected. Let's see. The negative terminal is going to be connected to the source. So I'm just going to connect that to the source, and then I need a resistor to plus. Great. So here's my LED, and I connect power. And of course, the LED is on. And no matter what I do to the gate, the LED is on. That's because the current is flowing in the other direction. Okay. So one thing that we didn't do was play with the PMOS, and I think I will leave that for the next video. So until the next video, I will see you. Bye-bye. So let's play with our MOSFETs.