I love how this is formatted with common beginner mistakes, and then mehdi explains his mistake in detail as though hes trying to teach himself the logic behind it.
way back, or at least in the 80's I worked at a company selling mosfet based amplification modules. It was interesting to read the specs, as these small and pretty cheap modules produced up to 150W and the data was very clean and impressive. So at least on paper they had better data than what the huge audio amplifier manufacturers were selling. Thing was, I was told by the man designing them, that audiophiles didn't like perfectly clear amplification. They wanted and payed for "soft" sounding amplifiers that cut the high end making the sound more pleasurable to hear rather than clinically perfect amplifiers that retained all the fragments of the recorded sound. As an example he pointed to the tube based amplifiers and the way they colored the sound significantly. And yet audiophiles were claiming they sounded much better than any other magnifier. Later I found that at least some of the big names in the business had separate lines of magnifiers for the US, Europe and some other parts of the world. These had a sound characteristics that matched the markets and what most Europeans liked differed from what was best selling in the US. So "perfect" amplifiers, if they were actually possible, would not have the sound most people would want. But it goes further because the amplifiers, microphones and recoding techniques are not perfect on the recording side either. So the signal that you stereos amplifiers have to work with is already far from perfect. Add to that the speakers that also are far less than perfect. All in all use whatever amplifier and speakers you find you like. Perfection in signal amplification isn't really all that important. That you like what you hear is.
I remember learning this when I was around 8 years old. My dad was an electrical engineer and I asked him if there was a way to power a car stereo from an AC source. Instead of going to the store to buy a prebuilt AC-DC converter, we went to the store and bought all the parts to build one. He then took me through a week-long crash course on what each component does and how to read electrical schematics, then told me to go ahead and build it and he’d check in on me every once in a while. Ultimately I built a converter that provided 12.5VDC @ 1.5A (max). It was the size of a loaf of bread (this was in the early 1980s) but it did what it was designed to do.
good for you, one night my dad said go out to buy a pack of cigarette , since then i never see him again, yup 40 years , i guess cigarette grown from tree right??so he probably plant a cigarette tree .
This was the most entertaining explanation of MOSFETs I've ever seen. You almost made me spit take coffee on my keyboard. Thanks for another fun video!
Hi Electroboom, I believe that you have the width and length of a MOSFET backwards when you discuss its R_DSon value. Channel length is defined as the distance between the drain and source terminals of the MOSFET so in your diagram at 8:00 length should be horizontal. Channel width on the other hand is the vertical dimension. Increasing the width decreases R_DSon because you are effectively adding more channel in parallel for charge carriers to flow. Increasing channel length actually has the opposite effect and will increase R_DSon.
Agree. I was instantly triggered by that explanation of increasing the length of the channel to reduce the resistance. Seems also to be somehow mixed-up with "channel thickness" which , btw., is not constant between D and S (but that info is not required on this level of detail). So, usually the width is increased to reduce R_DSon as the length is already at its design minimum.
He is just defining the channel measurements differently. I’ve found both definitions in both literature before, so I’m not sure there’s a universal convention here (though one might be more popular in certain fields).
Came here to say this. At least he increased the correct dimension to reduce the on-resistance, even though the name was "wrong" (according to how I learned it in school at least) :)
in two minutes Mehdi has taught me more about the structure of a FET than my mosfet amplifier course ever did. I finally understand how the hell they work.
for as funny as it was, it was also dead-on right down to how electrons both engorging and draining are the main factors changing the amount of p-ness there is in the junction.
The best form of lecture content is to give a super simple explanation of how it works (aka like Mehdi's videos), then explain each component in detail. Most professors/teachers seem to forget the first half
@@AshrZ Absolutely correct. Whenever I try to learn about something technical, they immediately bury me with formulas and highly specific info. My brain just overloads and turns off. I need to see context to understand why and where math is needed.
I'm a student in electronics and communications engineering, my whole semester so far Ive been studying mosfets as a weird circuit symbol that I have to calculate many parameters for without knowing what its for. Thank you so much for making it so interesting to know about it while in my university class all I can do is dread learning about this in Analog electronics. Now I finally understand what channel length and width actually mean with your examples and other terms too❤
There will never be too many intro videos on fundamental concepts. Everyone learns in different ways, so having many teachers doing it differently can make a world of difference to the student.
If you're using a microcontroller, you can use an opto coupler to protect it from the pness of the mosfet. Always use protection on your microcontrollers.
5:50 The arrows on the FET symbols (actually on BJTs also) show the direction of the p-n junction. For the NMOS, substrate is P and channel is N. So the arrow points to the gate, since that's where the channel forms. For PMOS, substrate is N, so arrow points to the substrate.
When I was in electronic technician course(2002) the teacher didn't explain it at all, just mentioned it, although I had used them a lot, I never fully understand how they work. Thank you very much.
6:07 I have been summoned by a fellow persian electrical engineer. The arrows on the new symbols show the diode that is formed between the bulk and channel/source. NMOS has heavily n-type regions on a slightly p-type wafer, and PMOS has heavily p-type regions on a slightly n-type wafer. This is not important for discrete transistors on PCB's, but critical in semiconductor manufacturing where both types of devices are on the same wafer and has the possibility to interfere with each other without some clever workarounds
Oh my thoughts were correct then! As an IC designer, I never experienced using MOSFETS with the updated symbol. It's always either the 3-terminal symbol or the 4-terminal symbol where the bulk/substrate can be tied anywhere else other than the source. But maybe because I was only in the industry for 2 years as of now (and ~4 years from academe)
It is technically true that the schematic arrows correspond to the orientation of one of the diode junctions, but I'm pretty sure that's not actually what they're representing (nor do they actually have anything to do with the physical construction of the device). The arrows represent the *direction of electron flow* required to form the channel (and turn on the MOSFET). Since electrons have negative charge, this of course, counterintuitively, means the arrow goes in the opposite direction to what we normally think of as "current flow" (from positive to negative). Basically, if the tip of the arrow is positive relative to the other end, the MOSFET will be on (so you can think of it as "the arrow points to positive", as a convenient mnemonic).
@@nobody7817 Please try to actually read what you're responding to before making dumb comments. They said that *the type of wafer it is made from* does not matter for discrete components (and they are right, you can make either type of transistor from either type of wafer and it will function the same, if you are just making a discrete transistor). They said nothing at all about "hooking up" the wrong type of transistor for a particular application.
Excellent video. I think this is the first time I've come across a detailed explanation that gets me all warmed up about learning about mosfets. I think the main disaster with learning about mosfets, as far as I am concerned, are the symbols they use for them. In bjts, the symbol provides some indication about current direction but with mosfets (all their varieties) it is always counter-intuitive. The video certainly helps with that aspect but the more important achievement in my opinion is that it packs quite a lot of detail but it manages to circumvent all the technical, mathematical elements by presenting everything using pictures and animations that build a very badly needed intuition when it comes to learning the fundamentals of mosfet operation. For a beginner, mosfets may appear easier to understand using the traditional semi-mathematical approach but for someone like me who can never remember which way the arrows go and which orientation the symbols have (with regards to source vs. drain) a good, solid grasp of the basic behaviour trumps everything else.
Hey man thanks for the content. Currently at dominion in the nuclear control room operations training program and your hilarious content has actually been very helpful in my electrical science training. The areas my instructing doesnt quite make super clear you have a very humerous and engaging way of clearing those gaps for me. Thank you
"It can't imagine a Middle Eastern guy with no beard" had me rolling 😂 That totally sums up AI at this stage. It also can't imagine blond women without a pair of HUGE...erm....nose 😅
A *_pair_* of *_noses?!_* 🤨😋 The logical, and meta, thing to have said would've been EYES! Because not only do they (typically!) also come in a pair, but the common comment one might hear is: _"Hey... my eyes are up here! ✌️"_
Part of the issue is that AI doesn't understand conditionals, so saying "no beard" means its seeing "beard" in the prompt and adding a beard because its in the prompt so you want it obviously. The real thing to do would be say something like "clean shaven".
@@realastropulse Nailed it. The lack of the ability to utilize logic is the biggest shortcoming of current AI. I don't even like calling it AI as, to me, Intelligent would include the ability to reason. We have what I like to call Artificial Statistically Significant Production Entity Networks or ASSPEN for short.
you can, but power dissipation would go through the roof, better to stick with BJTs for low power analog, Hfe and current base to emitter is definitely easier to control than Gate to Drain voltage alone.
There's nothing wrong with using MOSFETs for low-power analog applications. They can actually be really convenient in some situations, because they can change very quickly (allowing for very high frequencies), can have almost zero DS threshold (so do not require heavy biasing), and basically act like variable resistors in a circuit (which can be useful in some types of analog circuits)... For a lot of analog stuff, JFETs are actually more common, though (they behave similarly to MOSFETs, but are constructed somewhat differently, and are normally on, so you need to apply a voltage to turn them off instead).
As a former microelectronic engineer intern working on a SMASH sigma-delta ADC, i feel like analog design is much more fun than designing a numerical filter. Designing a full differential OTA and seeing it working is like having a baby making the first steps
I used a MOSFET on my dimmer circuit controlled by the PWM pins on an Arduino board. I then used buttons for lowering and raising the PWM signal to the MOSFET. It works really well. I use it every day for the LEDs under my monitors on my work desk so I can lower the brightness after I am done working and I want to watch something. MOSFETs are really awesome! This is an amazing video! Thanks for the in depth explanation Mehdi! When I did it, I just crawled through a bunch of forums and fiddled with it until I got it how I wanted. I didn't really know much about how it works.
Your explanations are perfect for my brain. I also got an electronics kit as a kid and have been the family electronics guy since i was six. I took a different study and career path but I am still absolutely a hobbiest for life.
My High School (1974) electronics/physics teacher (not enough students in either course, so we combined!) had a real talent for explaining stuff. His lecture on PN junctions and the depletion zone sticks with me to this day! When I consider a diode, I 'see' a tiny capacitor in there.
Veritasium released a video on this principle in his minidocumentary about the development of the blue LED. It really is a fascinating watch, and probably one of Veritasium's best videos to date. Also the way P type and N type is explained by him is extremely intuitive. I really recommend watching it.
The horrible truth that nobody ever speaks aloud: There are actually tiny capacitors in _everything._ They're inside of diode junctions, and amplifiers, they're inside of inductors, and wires, and even the circuit board itself. They're behind your eyelids when you try to sleep... You can't escape them. _You will never escape them..._
Those arrows indicate the direction of the conventional current flow in relation to the type of mosfet. On a N-Channel Mosfet the arrow points inwards (toward the transistor) indicating the conventional current flows into the source when in conduction mode. On a P-Channel Mosfet the arrow points outwards (away from the transistor) showing that the conventional current flows out of the source when the mosfet conducts. Basically they represent the polarity of the source terminal relative to the rest of the device.
In my second year of apprenticeship schooling we have to build a slow draining MOSFET circuit. It's honestly really cool, doesn't seem like there's a lot of great uses until you consider that basically every handicap door uses them, hit the button and the door opens and holds itself and then slowly drains after time and then the gate releases and the door closes on its own!
I really appreciate this. I have a passing interest in electronics, but some of the concepts have been too dense for me to parse out. This was good, at a basic level, I finally understood what was actually moving and doing the work.
This is legitimately a very good tutorial on MOSFETs! Funny and step-by-step informative! I am going to think of the arrows as pointing to where the positive voltage should be to turn on the gate, whether they are or not. The p-channel MOSFET's body diode at 9:21 makes it look like the transistor's existence is unnecessary because of the diode's existence. As long as Vds>0, current will flow on the right through the diode. I guess that's why some people go even 1 more step further and put a circle around the entire transistor & body diode.
My favorite part is how your explanations show that you know how to NOT do the boom. Reminds me of a teacher I had that would demonstrate component failure for the same reason. It helps to teach the component's operations and parameters, while teaching how to diagnose said component's failure.
Fellow electrical engineer here! @electroboom I think at 7:52 the channel width and length are switched up, since current flows between source and drain so the conductive channel is actualy horizontal on the drawing. That means the length is the distance from source to drain and the width is the other one!
Awesome explanation!! Just a quick question Mehdi at 8:09 you said that increasing the length of channel will decrease the resistance but in high school we studied resistance is directly proportional to the length of the conducting path...
I use transistors all the time. I always have to look up the details on if I need PNP or NPN and if that's P-channel or N-channel etc. You just taught that to me effortlessly in a couple of minutes. Better than my university! thank you Mehdi!
Medi, "it can't imagine a middle eastern man without a beard!" 😂 I feel for you. As a Japanese American I can't get AI to draw me without crazy anime hair.
You explained the material science / device theory (with humor I might add) better than what was presented to me in my past EE college courses! We need more professors to be like you!!!
For sure you know what source or arrow means. It’s source of electrons or flow direction or electrons! But yes it’s reverse(stupid convention) of the current direction!
That's because we are positive-biased. We say electric current flows from + to - because the electrons leave holes in the lattice that act as positive charges. Those holes move in the opposite direction of the electrons due to how electrons jump into the wake of the previous electrons moving out of holes (which themselves are jumping into the wake of their predecessor). It also perfectly demonstrates the quantum nature of electrons and electric current. Also, the fact that the holes determine the characteristics of the current, is very good because the holes can move at a good fraction of light speed while electrons themselves can only move a few millimeters per second through a conductor. P.S. It really are the electrons doing the work, but in doing so they create a quasi-particle (the electron holes)
@@paulmichaelfreedman8334 It has another meaning underneath too. Think about it, if you have two bottles of liquid in different pressure, for sure the(molecules of) high one will flow to the low one. In EM field this is not the case. Electrons will flow from lower potential to higher potential. This is because charges repel each other in EM field, unlike gravity, mass attract each other(although gravity may not be called a “field”). This imply the strength of electric field(potential) is the opposite of magnetic field(charge). And it’s unintuitive to say current flows from low to high potential, so somebody just flipped the convention. Technically, current is not refer to electrons flowing but the effect of electrons moving causing potential flowing.
@@flyviawall4053 Uhm...no. Charge never flows from lower to higher potential. That requires input of energy. And even then the extra energy creates a potential greater than the one it needs to flow to -> still from high to low. Maybe you're confused with high and low entropy. You should learn the laws of thermodynamics (especially the 2nd one) and the law of conservation of energy. They are tried and true. Your arguments are complete BS. And the electric field is not opposite the magnetic field, it's phase shifted 90 degrees, if you know what that means.
New ElectroBOOM subscriber here. I thought he was just the guy who kept shocking himself, but now I see practical explanations, critical thinking, and rage-fixing. Keep it coming, brother!
This was really awesome work Mehdi! Love the way you explained it! I like to add from my point of view as an engineer who is more towards the application of engineering concepts in products for real life, I love to see more about the applications of the MOSFETs in a cool project! Very nice work again, I always watch your videos within the first hour of release.
06:08 I think the arrow symbolizes the flow of electrons either into the P type to make it behave like N type forming the N channel or away from N type to make it behave like P type to make the P channel
I might be a dumb person but I think for me it is a bit of a confusing simplification calling them switches. It's kinda like saying "it's the current that kills you not the voltage", if you think about a logic circuit that for example switches on and off due to the voltage on a capacitor you might find out that for some part of the cicle the transistor does not act like a switch (but as a voltage controlled current generator) which will not make the circuit behave like you want to or you might get problems with the 0.7V voltage drop being imposed. In short: when I was just curious about electronics and did not yet study it but just used really basic stuff to connect my pre-made boards I did not in fact fully understand how they behaved and often failed at designing logic circuits with mosfets as switches (using them like relays) and that's because everyone says they are a switch.
The thing is, MSOFETs do not have a 0.7V forward voltage drop like bipolar junction transistors do. In fact, the voltage across a MOSFET’s source and drain terminals is basically zero for low currents, rising by a small amount more or less linearly as the current increases, just like a resistor. The only time that the on-voltage across a MOSFET jumps upwards is once the transistor is saturated and cannot handle more current. This saturation current gets pushed up the more you increase the gate voltage. So in many case you can consider a MOSFET like a voltage-controlled switch with a current limiter. Of course, you don’t want to run the transistor in saturation for too long or it will overheat.
You need a significant overvoltage on the gate compared to the normal supply voltage on the drain(or source, dependant on P or N type) to really open up a MOSFET down to Rds on.. I use a 24V step up module that can supply a little current to supply the (pulled-down) switching voltage to the gates (8 MOSFETs, 200A each, on a big fat heatsink). only a couple of square cm area on a PCB and works perfectly on my 12V car battery powered battery spotwelder which I built myself. Best welds are with a pulse width of 30 milliseconds. Often stronger than factory-welded batteries
Alright, I hate the comments that say something like "I learned more in this video than I did in my entire college course," you're either lying or weren't paying attention. But I will say that the field effect part really did help me understand it better. I always knew that it just worked, but I never really had a good intuitive understanding of it, and I think this explanation really helped
6:54 Incorrect, the breakdown doesn't occur at that low voltage, Gate-Source oxide layer in power transistors breaks down at around 80V. At this voltage the transistors will be irreversibly damaged. Gate voltages above ~20V only shorten the lifespan of the transistors, but won't necessarily destroy it.
Great vid, the arrows point to the "p- Ness". So an n channel MOSFET has a p-type substrate, and so has an arrow pointing at the middle substrate part. In a BJT device the arrow shows the p-n junction direction so a npn transistor points to the n or the emmiter, as conventional current flows from base to emitter via that arrow. In a PNP the arrow points up to the base as conventional current flows from emitter to base to turn it on.
About the arrows in the mosfet symbols: basically they represent diode symbols - n channel mosfets have an arrow pointing inwards, because the tip is negative, and for a p channel mosfet the arrow points away from the positive channel.
Years ago, I read about a guitar effects pedal that used cmos inverters to make a nice "tube like" distortion. The inverter outputs were tied to the inputs using 1Mohm resistors to midpoint bias them I using feedback. Just for the hell of it, I did the same thing using a pair of complementary power mosfets - and IRF510 and IRF640 iirc. I used a pot instead of a single resistors with the wiper tied to the gates. I put a 2n5000 mosfet source follower stage in front of it. It's a very low power amp, a very naive design, but actually does overdrive quite nicely. It's house in an ATX power supply housing.
in five minutes, you have successfully explained how a MOSFET works better than my 2yrs in electronics classes have done. This is one of those things that i never really "understood" and just knew the expected outcome if i did X or Y.
I'm currently writing a thesis on the physics of matter, semiconductors and uses of it. P-ness is DEFINITELY something I'll be using from now on and the presentation will for SURE be fun.
Okay, when I was in the Navy, I was trained as an Electronics Technician. We had multiple days dedicated to transistors and how they function. And yet somehow, a 12-minute UA-cam video explained it better than my instructor did in four days.
You can switch AC with MOSFETs by connecting two, source to source. When the current flows in one direction, it flows through the body diode of one and the channel channel of the other. When the current reverses, the body diode and channel roles reverse as well. If you Google "international rectifier mosfet switch ac" the first link takes you to a design note. It's how many solid state relays are built.
You can switch AC with MOSFETs by connecting a pair in a common source configuration. If you control the gates independently, you can chop the voltage in both directions too.
Why is my favorite vacation channel talking about this electrical stuff?
I agree. I have no need for this knowledge I'm learning but I watch every video.
It's the eyebrow. Damn hypnotic face worm.
he makes alot of electrical videos 💀
Tbh I can't tell if this is sarcasm 😅
@@m0ment219 how lol
I love how this is formatted with common beginner mistakes, and then mehdi explains his mistake in detail as though hes trying to teach himself the logic behind it.
Teaching by example! Best kind!
The return of the fuuull bridge rectifier!
You mean FULL BRIDGE RECTIFIER!!! ?
FULL BRIDGE RECTIFIA
FOOOLLL BREEEDGEEE RECTIFIERRR
It's not rectifiah?
Full bridge Rectumfryer😂😂
way back, or at least in the 80's I worked at a company selling mosfet based amplification modules. It was interesting to read the specs, as these small and pretty cheap modules produced up to 150W and the data was very clean and impressive. So at least on paper they had better data than what the huge audio amplifier manufacturers were selling. Thing was, I was told by the man designing them, that audiophiles didn't like perfectly clear amplification. They wanted and payed for "soft" sounding amplifiers that cut the high end making the sound more pleasurable to hear rather than clinically perfect amplifiers that retained all the fragments of the recorded sound. As an example he pointed to the tube based amplifiers and the way they colored the sound significantly. And yet audiophiles were claiming they sounded much better than any other magnifier.
Later I found that at least some of the big names in the business had separate lines of magnifiers for the US, Europe and some other parts of the world. These had a sound characteristics that matched the markets and what most Europeans liked differed from what was best selling in the US. So "perfect" amplifiers, if they were actually possible, would not have the sound most people would want.
But it goes further because the amplifiers, microphones and recoding techniques are not perfect on the recording side either. So the signal that you stereos amplifiers have to work with is already far from perfect. Add to that the speakers that also are far less than perfect. All in all use whatever amplifier and speakers you find you like. Perfection in signal amplification isn't really all that important. That you like what you hear is.
I remember learning this when I was around 8 years old. My dad was an electrical engineer and I asked him if there was a way to power a car stereo from an AC source. Instead of going to the store to buy a prebuilt AC-DC converter, we went to the store and bought all the parts to build one. He then took me through a week-long crash course on what each component does and how to read electrical schematics, then told me to go ahead and build it and he’d check in on me every once in a while. Ultimately I built a converter that provided 12.5VDC @ 1.5A (max). It was the size of a loaf of bread (this was in the early 1980s) but it did what it was designed to do.
You are fortunate to have a parent who saw potential in their child and gave you a headstart in your later year's
good for you, one night my dad said go out to buy a pack of cigarette , since then i never see him again, yup 40 years , i guess cigarette grown from tree right??so he probably plant a cigarette tree .
Show off
And then everyone applauded
That's awesome.
This is a way better explanation of how transistors and fets work than any other I've seen. Glad I can finally understand these things.
This was the most entertaining explanation of MOSFETs I've ever seen. You almost made me spit take coffee on my keyboard. Thanks for another fun video!
I knew exactly now mosfets worked and this was still wildly entertaining (and taught me a thing I hadn't thought about)
Also one of the best I have seen. It even explains the symbol of a mosfet
Hi Electroboom,
I believe that you have the width and length of a MOSFET backwards when you discuss its R_DSon value. Channel length is defined as the distance between the drain and source terminals of the MOSFET so in your diagram at 8:00 length should be horizontal. Channel width on the other hand is the vertical dimension. Increasing the width decreases R_DSon because you are effectively adding more channel in parallel for charge carriers to flow. Increasing channel length actually has the opposite effect and will increase R_DSon.
Agree.
I was instantly triggered by that explanation of increasing the length of the channel to reduce the resistance. Seems also to be somehow mixed-up with "channel thickness" which , btw., is not constant between D and S (but that info is not required on this level of detail).
So, usually the width is increased to reduce R_DSon as the length is already at its design minimum.
He is just defining the channel measurements differently.
I’ve found both definitions in both literature before, so I’m not sure there’s a universal convention here (though one might be more popular in certain fields).
Came here to say this. At least he increased the correct dimension to reduce the on-resistance, even though the name was "wrong" (according to how I learned it in school at least) :)
in two minutes Mehdi has taught me more about the structure of a FET than my mosfet amplifier course ever did. I finally understand how the hell they work.
Yep, my thoughts exactly
for as funny as it was, it was also dead-on right down to how electrons both engorging and draining are the main factors changing the amount of p-ness there is in the junction.
The best form of lecture content is to give a super simple explanation of how it works (aka like Mehdi's videos), then explain each component in detail. Most professors/teachers seem to forget the first half
@@AshrZ Absolutely correct. Whenever I try to learn about something technical, they immediately bury me with formulas and highly specific info. My brain just overloads and turns off. I need to see context to understand why and where math is needed.
Exactly! Same here.
I’m an experienced electronic engineer, but this educational video taught me two new things about MOSFETs that I didn’t previously know
P-ness had me losing it, I couldn't stop laughing! 🤣🤣
npc
Lol true
He even beeped it
Bot
Are you 13?
I'm a student in electronics and communications engineering, my whole semester so far Ive been studying mosfets as a weird circuit symbol that I have to calculate many parameters for without knowing what its for. Thank you so much for making it so interesting to know about it while in my university class all I can do is dread learning about this in Analog electronics. Now I finally understand what channel length and width actually mean with your examples and other terms too❤
I AM SOOOOO HAPPY THAT THE 101 SERIES IS BACK!!! This and Rectifier are the best of Electroboom! Keep it up, dude! ♥
Love them too
There will never be too many intro videos on fundamental concepts. Everyone learns in different ways, so having many teachers doing it differently can make a world of difference to the student.
If you're using a microcontroller, you can use an opto coupler to protect it from the pness of the mosfet. Always use protection on your microcontrollers.
lol
0:34 the speed switch cracked me up! 😂
5:50 The arrows on the FET symbols (actually on BJTs also) show the direction of the p-n junction. For the NMOS, substrate is P and channel is N. So the arrow points to the gate, since that's where the channel forms. For PMOS, substrate is N, so arrow points to the substrate.
When I was in electronic technician course(2002) the teacher didn't explain it at all, just mentioned it, although I had used them a lot, I never fully understand how they work. Thank you very much.
This was super easy to understand. And very entertaining as well. You would be an awesome professor
6:07 I have been summoned by a fellow persian electrical engineer. The arrows on the new symbols show the diode that is formed between the bulk and channel/source. NMOS has heavily n-type regions on a slightly p-type wafer, and PMOS has heavily p-type regions on a slightly n-type wafer. This is not important for discrete transistors on PCB's, but critical in semiconductor manufacturing where both types of devices are on the same wafer and has the possibility to interfere with each other without some clever workarounds
Oh my thoughts were correct then!
As an IC designer, I never experienced using MOSFETS with the updated symbol. It's always either the 3-terminal symbol or the 4-terminal symbol where the bulk/substrate can be tied anywhere else other than the source. But maybe because I was only in the industry for 2 years as of now (and ~4 years from academe)
I was thinking, because electrons travel from negative to positive, but I've been drinking 😂
It is technically true that the schematic arrows correspond to the orientation of one of the diode junctions, but I'm pretty sure that's not actually what they're representing (nor do they actually have anything to do with the physical construction of the device).
The arrows represent the *direction of electron flow* required to form the channel (and turn on the MOSFET). Since electrons have negative charge, this of course, counterintuitively, means the arrow goes in the opposite direction to what we normally think of as "current flow" (from positive to negative). Basically, if the tip of the arrow is positive relative to the other end, the MOSFET will be on (so you can think of it as "the arrow points to positive", as a convenient mnemonic).
The HECK It is NOT important on Discreet transistors on PCBs. Hook the wrong one up and see how fast YOU become BOOM BOOM PERSIAN BOOM!
@@nobody7817 Please try to actually read what you're responding to before making dumb comments.
They said that *the type of wafer it is made from* does not matter for discrete components (and they are right, you can make either type of transistor from either type of wafer and it will function the same, if you are just making a discrete transistor). They said nothing at all about "hooking up" the wrong type of transistor for a particular application.
Perfect! I studied electronics at high school for two years and never got a hold on mosfets. This, however, was both fun and helpful! :)
I have my Electronics Circuits Exam Tomorrow and 12 Marks comes from MOSFET.
Thank you very much. Love from Nepal.
Excellent video. I think this is the first time I've come across a detailed explanation that gets me all warmed up about learning about mosfets. I think the main disaster with learning about mosfets, as far as I am concerned, are the symbols they use for them. In bjts, the symbol provides some indication about current direction but with mosfets (all their varieties) it is always counter-intuitive.
The video certainly helps with that aspect but the more important achievement in my opinion is that it packs quite a lot of detail but it manages to circumvent all the technical, mathematical elements by presenting everything using pictures and animations that build a very badly needed intuition when it comes to learning the fundamentals of mosfet operation. For a beginner, mosfets may appear easier to understand using the traditional semi-mathematical approach but for someone like me who can never remember which way the arrows go and which orientation the symbols have (with regards to source vs. drain) a good, solid grasp of the basic behaviour trumps everything else.
0:18 bro casually dissed Nelson Pass's whole career
Yep lol.
i have been desperately waiting for this vid. Mehdi told me he was working on it months ago. it was as informative as i could have wished.
0:02 that may be a new ElectroBOOM record for fastest messup
Hey man thanks for the content. Currently at dominion in the nuclear control room operations training program and your hilarious content has actually been very helpful in my electrical science training. The areas my instructing doesnt quite make super clear you have a very humerous and engaging way of clearing those gaps for me. Thank you
"It can't imagine a Middle Eastern guy with no beard" had me rolling 😂 That totally sums up AI at this stage. It also can't imagine blond women without a pair of HUGE...erm....nose 😅
A *_pair_* of *_noses?!_* 🤨😋
The logical, and meta, thing to have said would've been EYES! Because not only do they (typically!) also come in a pair, but the common comment one might hear is:
_"Hey... my eyes are up here! ✌️"_
To be fair, I have the same problem. I'm willing to keep trying though.
Part of the issue is that AI doesn't understand conditionals, so saying "no beard" means its seeing "beard" in the prompt and adding a beard because its in the prompt so you want it obviously. The real thing to do would be say something like "clean shaven".
@@realastropulse Nailed it. The lack of the ability to utilize logic is the biggest shortcoming of current AI. I don't even like calling it AI as, to me, Intelligent would include the ability to reason. We have what I like to call Artificial Statistically Significant Production Entity Networks or ASSPEN for short.
@@realastropulseI think you mean "negation" that's what they don't understand. Or rather, a negator is a weak signal.
"Who uses it as an amplifier?"
Right here, as well as LDMOS. 🤣🤣
He just said fill all my holes.... Stop it I'm done. I laughed too hard😂
So one type has holes but also p-ness. Semiconductors be wildin'.
dude, don't be gross, he's pretending to be a mosfet and explaining how he gets turned... never mind.
Hahahaha
For 10 years I've been watching your videos Mehdi. TEN YEARS.... and you still manage to make me jump in the first couple of seconds.
@3:47 P is like fill all my holes with Electrons 🤣😂.
Great educational content as always.
6:20 the arrows show the direction of electron flow atleast it looks like it
derpy slugcat spotted
3:17 LMAO 😭😭
This was the most unexpected sht ever
cant believe I laughed so hard at this
0:02 Bro made a lightbulb launcher 😂
Best intro
I’m a PhD student in analog IC design, sounds like avoiding analog uses of MOSFETs was probably the right idea 😂
Hey if you are doing analog IC design, there is no avoiding analog MOSFET design! You do so we don't have to make it out of discrete components!!
you can, but power dissipation would go through the roof, better to stick with BJTs for low power analog, Hfe and current base to emitter is definitely easier to control than Gate to Drain voltage alone.
There's nothing wrong with using MOSFETs for low-power analog applications. They can actually be really convenient in some situations, because they can change very quickly (allowing for very high frequencies), can have almost zero DS threshold (so do not require heavy biasing), and basically act like variable resistors in a circuit (which can be useful in some types of analog circuits)...
For a lot of analog stuff, JFETs are actually more common, though (they behave similarly to MOSFETs, but are constructed somewhat differently, and are normally on, so you need to apply a voltage to turn them off instead).
As a former microelectronic engineer intern working on a SMASH sigma-delta ADC, i feel like analog design is much more fun than designing a numerical filter. Designing a full differential OTA and seeing it working is like having a baby making the first steps
Fun fact: you don't need to say you are an engineer/PhD/researcher/God before saying something.
I used a MOSFET on my dimmer circuit controlled by the PWM pins on an Arduino board. I then used buttons for lowering and raising the PWM signal to the MOSFET. It works really well. I use it every day for the LEDs under my monitors on my work desk so I can lower the brightness after I am done working and I want to watch something. MOSFETs are really awesome! This is an amazing video! Thanks for the in depth explanation Mehdi! When I did it, I just crawled through a bunch of forums and fiddled with it until I got it how I wanted. I didn't really know much about how it works.
ELECTROBOOM 101 IS BACK???? YEAAHHH BAYBEEEE
Your explanations are perfect for my brain. I also got an electronics kit as a kid and have been the family electronics guy since i was six. I took a different study and career path but I am still absolutely a hobbiest for life.
"p-ness" got me falling on the floor 💀
followed by the filling of holes
Back in the good days of internet, we use to say "ROFLMAO"
@@paavangoyalThat's what she said
with a pee channel
"Fill all my holes with electrons" --Electro boom 2024
My High School (1974) electronics/physics teacher (not enough students in either course, so we combined!) had a real talent for explaining stuff.
His lecture on PN junctions and the depletion zone sticks with me to this day!
When I consider a diode, I 'see' a tiny capacitor in there.
Veritasium released a video on this principle in his minidocumentary about the development of the blue LED. It really is a fascinating watch, and probably one of Veritasium's best videos to date. Also the way P type and N type is explained by him is extremely intuitive. I really recommend watching it.
The horrible truth that nobody ever speaks aloud: There are actually tiny capacitors in _everything._
They're inside of diode junctions, and amplifiers, they're inside of inductors, and wires, and even the circuit board itself. They're behind your eyelids when you try to sleep... You can't escape them. _You will never escape them..._
@@foogod4237 Nice! 😂 I like'em 😊
Those arrows indicate the direction of the conventional current flow in relation to the type of mosfet.
On a N-Channel Mosfet the arrow points inwards (toward the transistor) indicating the conventional current flows into the source when in conduction mode.
On a P-Channel Mosfet the arrow points outwards (away from the transistor) showing that the conventional current flows out of the source when the mosfet conducts.
Basically they represent the polarity of the source terminal relative to the rest of the device.
His cringe when he goes to plug it in at 8:33 hoping to not get jolted reminds me of the movie Down Periscope 🤣
(Matt Berry voice) Up periscope! Down periscope!
In my second year of apprenticeship schooling we have to build a slow draining MOSFET circuit. It's honestly really cool, doesn't seem like there's a lot of great uses until you consider that basically every handicap door uses them,
hit the button and the door opens and holds itself and then slowly drains after time and then the gate releases and the door closes on its own!
8:45 you really honour that transistor :-D
Wow a member
Wait wut
She offered her honour / He honoured her offer / And all through the night / He was on her and off her
oh there a member i was actually questioning my eyes *7 hours?! nah it says 7 Minutes*
I really appreciate this. I have a passing interest in electronics, but some of the concepts have been too dense for me to parse out. This was good, at a basic level, I finally understood what was actually moving and doing the work.
3:44 I can't stop laughing 😂😂😂😂
This is legitimately a very good tutorial on MOSFETs! Funny and step-by-step informative!
I am going to think of the arrows as pointing to where the positive voltage should be to turn on the gate, whether they are or not.
The p-channel MOSFET's body diode at 9:21 makes it look like the transistor's existence is unnecessary because of the diode's existence. As long as Vds>0, current will flow on the right through the diode. I guess that's why some people go even 1 more step further and put a circle around the entire transistor & body diode.
0:02 we cant have a Electroboom without a 'boom'
My favorite part is how your explanations show that you know how to NOT do the boom. Reminds me of a teacher I had that would demonstrate component failure for the same reason. It helps to teach the component's operations and parameters, while teaching how to diagnose said component's failure.
Tubes and mosfets sound great!
Tubes and mosfets go brrr
Fellow electrical engineer here! @electroboom I think at 7:52 the channel width and length are switched up, since current flows between source and drain so the conductive channel is actualy horizontal on the drawing. That means the length is the distance from source to drain and the width is the other one!
"Oh yeah, fill all my holes with electrons" - Moaning Mehdi Sadagdar (aka Electroboom) - Oct 2024
0:09 MOSFET's linear region have left the chat.
Awesome explanation!!
Just a quick question Mehdi at 8:09 you said that increasing the length of channel will decrease the resistance but in high school we studied resistance is directly proportional to the length of the conducting path...
@@BromideBride Can you please elaborate.
@@azhankhan9218 The extra "length" is in parallel with the initial channel. Does this help? Maybe the channel becomes wider rather than longer.
I use transistors all the time. I always have to look up the details on if I need PNP or NPN and if that's P-channel or N-channel etc. You just taught that to me effortlessly in a couple of minutes. Better than my university! thank you Mehdi!
Medi, "it can't imagine a middle eastern man without a beard!" 😂
I feel for you. As a Japanese American I can't get AI to draw me without crazy anime hair.
😂
Yup they made amplifiers sound like vacuum tube amps. Nice.
Adjusts the voltage but lets the current draw happen naturally.
Nice ZAPs. I wonder...what would be another fun component to explain in a future 101?
Op-amps. They are simply awesome and not so simple.
@@squidcaps4308yep, I need Mehdi to explain those for me
I hope videos like this could become an Electroboom Master Class. Very informing!
3:40 P-region 😂😅🤣
You explained the material science / device theory (with humor I might add) better than what was presented to me in my past EE college courses! We need more professors to be like you!!!
1:31 good video
I always wondered how as mosfet transistor was made. calling it a double diode makes SO MUCH SENSE thank you for the diagram
2:19 "Some electrons move from N to pee."
😂
This Electroboom101 series basically cover all of basic of electronic lecture (but not in detail), from circuit analysis to microelectronic
For sure you know what source or arrow means. It’s source of electrons or flow direction or electrons!
But yes it’s reverse(stupid convention) of the current direction!
That's because we are positive-biased. We say electric current flows from + to - because the electrons leave holes in the lattice that act as positive charges. Those holes move in the opposite direction of the electrons due to how electrons jump into the wake of the previous electrons moving out of holes (which themselves are jumping into the wake of their predecessor). It also perfectly demonstrates the quantum nature of electrons and electric current.
Also, the fact that the holes determine the characteristics of the current, is very good because the holes can move at a good fraction of light speed while electrons themselves can only move a few millimeters per second through a conductor.
P.S. It really are the electrons doing the work, but in doing so they create a quasi-particle (the electron holes)
@@paulmichaelfreedman8334 It has another meaning underneath too. Think about it, if you have two bottles of liquid in different pressure, for sure the(molecules of) high one will flow to the low one. In EM field this is not the case. Electrons will flow from lower potential to higher potential. This is because charges repel each other in EM field, unlike gravity, mass attract each other(although gravity may not be called a “field”). This imply the strength of electric field(potential) is the opposite of magnetic field(charge). And it’s unintuitive to say current flows from low to high potential, so somebody just flipped the convention.
Technically, current is not refer to electrons flowing but the effect of electrons moving causing potential flowing.
@@flyviawall4053 Uhm...no. Charge never flows from lower to higher potential. That requires input of energy. And even then the extra energy creates a potential greater than the one it needs to flow to -> still from high to low. Maybe you're confused with high and low entropy. You should learn the laws of thermodynamics (especially the 2nd one) and the law of conservation of energy. They are tried and true.
Your arguments are complete BS. And the electric field is not opposite the magnetic field, it's phase shifted 90 degrees, if you know what that means.
A mosfet masterclass made in a fun and simple way.
Congratulations.
Instructions unclear, p_ness stuck on drain
New ElectroBOOM subscriber here. I thought he was just the guy who kept shocking himself, but now I see practical explanations, critical thinking, and rage-fixing. Keep it coming, brother!
3:25
*The* _Rizz_
That's the clearest explanation I've seen, and now it makes much more sense. Thanks!
I'm laughing like a moron at the P-Ness LOL.
People in the office wondering what's wrong with me. 😆
Hey, all circuits now and then need a little P-Ness in them!
This was the very best explanation of ANYTHING electro I’ve ever heard!! 😮
1:53 Cute "fetus" transistor 😂
This was really awesome work Mehdi! Love the way you explained it! I like to add from my point of view as an engineer who is more towards the application of engineering concepts in products for real life, I love to see more about the applications of the MOSFETs in a cool project! Very nice work again, I always watch your videos within the first hour of release.
1:02 Where is your beard ?😂
I almost cried when you mentioned the full bridge rectifier !!! Absolute cinema
06:08 I think the arrow symbolizes the flow of electrons either into the P type to make it behave like N type forming the N channel or away from N type to make it behave like P type to make the P channel
That's how I've always interpreted it yep.
Guitar pedal manufacturer here, we DO use them as an amplifier sometimes! :)
I might be a dumb person but I think for me it is a bit of a confusing simplification calling them switches. It's kinda like saying "it's the current that kills you not the voltage", if you think about a logic circuit that for example switches on and off due to the voltage on a capacitor you might find out that for some part of the cicle the transistor does not act like a switch (but as a voltage controlled current generator) which will not make the circuit behave like you want to or you might get problems with the 0.7V voltage drop being imposed. In short: when I was just curious about electronics and did not yet study it but just used really basic stuff to connect my pre-made boards I did not in fact fully understand how they behaved and often failed at designing logic circuits with mosfets as switches (using them like relays) and that's because everyone says they are a switch.
The thing is, MSOFETs do not have a 0.7V forward voltage drop like bipolar junction transistors do. In fact, the voltage across a MOSFET’s source and drain terminals is basically zero for low currents, rising by a small amount more or less linearly as the current increases, just like a resistor. The only time that the on-voltage across a MOSFET jumps upwards is once the transistor is saturated and cannot handle more current. This saturation current gets pushed up the more you increase the gate voltage. So in many case you can consider a MOSFET like a voltage-controlled switch with a current limiter. Of course, you don’t want to run the transistor in saturation for too long or it will overheat.
You need a significant overvoltage on the gate compared to the normal supply voltage on the drain(or source, dependant on P or N type) to really open up a MOSFET down to Rds on.. I use a 24V step up module that can supply a little current to supply the (pulled-down) switching voltage to the gates (8 MOSFETs, 200A each, on a big fat heatsink). only a couple of square cm area on a PCB and works perfectly on my 12V car battery powered battery spotwelder which I built myself. Best welds are with a pulse width of 30 milliseconds. Often stronger than factory-welded batteries
@@beanapprentice1687saturated fets gets use in an electronic loads. It really behave like a heavy duty resistance with a good linearity
Alright, I hate the comments that say something like "I learned more in this video than I did in my entire college course," you're either lying or weren't paying attention. But I will say that the field effect part really did help me understand it better. I always knew that it just worked, but I never really had a good intuitive understanding of it, and I think this explanation really helped
6:54 Incorrect, the breakdown doesn't occur at that low voltage, Gate-Source oxide layer in power transistors breaks down at around 80V. At this voltage the transistors will be irreversibly damaged. Gate voltages above ~20V only shorten the lifespan of the transistors, but won't necessarily destroy it.
Great vid, the arrows point to the "p- Ness". So an n channel MOSFET has a p-type substrate, and so has an arrow pointing at the middle substrate part. In a BJT device the arrow shows the p-n junction direction so a npn transistor points to the n or the emmiter, as conventional current flows from base to emitter via that arrow. In a PNP the arrow points up to the base as conventional current flows from emitter to base to turn it on.
Manipulating P-Ness with voltage! thats brilliant!
I’m sure somewhere someone is into that.
@@jimsvideos7201 Bzzzzzt
This video sneered questions I’ve had about MOSFETs for years. Thank you.
4:13 the automatic caption gone wild 💀
Ayooo
About the arrows in the mosfet symbols: basically they represent diode symbols - n channel mosfets have an arrow pointing inwards, because the tip is negative, and for a p channel mosfet the arrow points away from the positive channel.
Lovely
Years ago, I read about a guitar effects pedal that used cmos inverters to make a nice "tube like" distortion. The inverter outputs were tied to the inputs using 1Mohm resistors to midpoint bias them I using feedback.
Just for the hell of it, I did the same thing using a pair of complementary power mosfets - and IRF510 and IRF640 iirc. I used a pot instead of a single resistors with the wiper tied to the gates. I put a 2n5000 mosfet source follower stage in front of it.
It's a very low power amp, a very naive design, but actually does overdrive quite nicely. It's house in an ATX power supply housing.
Guys, at 4:00 mehdi shows a transistor cheme with 4 contacts, but they only have 3, where did extra contact came from?
Substrate and one n-channel are united as a source electrode
The extra contact is called the bulk terminal (also called substrate, also called body). Typically it is internally connected to the source terminal.
4:41 he explains this
Slow down Mehdy😂
That's the power of lingam
in five minutes, you have successfully explained how a MOSFET works better than my 2yrs in electronics classes have done.
This is one of those things that i never really "understood" and just knew the expected outcome if i did X or Y.
I'm currently writing a thesis on the physics of matter, semiconductors and uses of it. P-ness is DEFINITELY something I'll be using from now on and the presentation will for SURE be fun.
Okay, when I was in the Navy, I was trained as an Electronics Technician. We had multiple days dedicated to transistors and how they function. And yet somehow, a 12-minute UA-cam video explained it better than my instructor did in four days.
You can switch AC with MOSFETs by connecting two, source to source. When the current flows in one direction, it flows through the body diode of one and the channel channel of the other. When the current reverses, the body diode and channel roles reverse as well. If you Google "international rectifier mosfet switch ac" the first link takes you to a design note. It's how many solid state relays are built.
Bro u are an absolute genius 🙌🏼🙇♂️
Excellent video on mosfets! Best explanation I've ever seen on UA-cam
Timestamps:
0:02 🤣
6:33 🤣
7:25 🤣
8:51 🤣
And the best part: 10:16 🤣
Enjoy!
Tomorrow I have a final exam about BJT and MOSFET this guy helped me out once again.
You can switch AC with MOSFETs by connecting a pair in a common source configuration. If you control the gates independently, you can chop the voltage in both directions too.