MOSFETs and How to Use Them | AddOhms #11

MOSFETs are the most common transistors used today.
Support on Patreon: / baldengineer
They are switches that can be used an Arduino, BeagleBone, or Raspberry Pi. This is part 2 of a 2 part series, which covers MOSFETs. (Part 1 Covered BJTs).
When it comes down to it, MOSFETs are pretty complicated devices. This video will cover the basics of what you need to use them in your circuit, including calculating if you need a heat sink or not.
Learn what they are and how to use them.
Part 1 (BJTs):
• BJTs as Transistor Swi...
Show Notes:
www.addohms.com/ep11
Follow us on twitter: @addohms
#mosfet #transistor #

[@AddOhms]

When looking at a datasheet, do NOT use the value of Vgs in the section "Absolute Max." This section is for conditions that will damage the MOSFET. More information here: discuss.addohms.com/t/what-does-absolute-max-mean/72

[@hairyoldhippy]

Nikša No additional components are required for basic switching. For high speed one would likely need a higher drive current (because of the gate capacitance) than can be provided by a signal generator and physically adjacent rather than at the end of a cable. Just ensure that the generator swing goes close to zero to ensure 'off' and for fullest conduction the drive voltage should approach the maximum allowed on the spec sheet. But do you actually need a BIMOSFET? Plain MOSFETs are much more readily available and cheaper. Old PC motherboards are a good source. If you do need the enhanced high voltage capacity of a BIMOSFET it might not be particularly wise to embark upon such experiments until you have gained more experience because it can be dangerous and expensive. Have fun though. BTW, BIMOSFETs are just IGBTs, the additional name is just marketing. And IGBT is a silly name anyway 'GIT' (gate insulated transistor) would have been far better, that's what we call them in the lab.

[@DaniloAlves-vy2od]

Traslate to pt-BR, please..

[@brentparrish5453]

AddOhms a

[@alejandrajorge2338]

One question, we are working with a 2n7000 n channel transistor and in the drain caracteristics grafic states that the id max its reach at Vgs=10v with 1.5ma aprox. why its this, isnt it supose to be at Vgs=0v idss?

[@Paul-gz5dp]

I look at the Vgs and even the Vbe on BJT as what will kill it, and have put an LED on that location between base to emitter or gate to source to prevent the damage, as even a BJT can have too high of a voltage when there is not enough load on the collector when in darlington configuration. Best designs are ones that take into account what might happen to cause failure, then if something unusual happens it does not die on you.

[@PaganiTypeR]

finally... someone explained how to select the mosfet in practice... in university they are all about calculating amplification, working of a mosfet in molecular level, etc. but they won't tell simple things like these, which are super important when using and selecting the transistor in practice. Thank you, sir!

[@_valles3438]

I agree, I just knew they were voltage controlled -_- This guy taught me so much in 7 minutes, I really liked the datasheet part (at school they just throw questions and say to use the datasheet, but not explain what to look for or determine if a heat sink would be required)

[@philipvernejules9926]

........I remember those type of textbooks.. It's important to have a play with the components to get familiarized. I'm surprised how many people don't know a simple set up with a p and n channel jfet that results in a tunnel diode effect but when I first came across this simple circuit I just had to try it out and it produces excellent sine waves according to my hearing perception.

[@slathian1223]

@dylans voice Which is why some companies are moving away from schools. Had an interview taking 3 hours of an online quiz, had questions from basic programming to PCB design. They had open internet and said go for it. We will contact you if you are selected after it was completed. Overall, the best interview I could say that I had, I also believe they had 7-8 other candidates taking the test, we were all spaced like 15 minutes apart to have the 1 on 1 personal questions.

[@Trev9]

I failed Electronics as a subject and hated it for its Transfer Functions, but I could build any circuit I chose to. Damn lecturer was as boring as mud

[@eddd653]

@dylans voice yup cheaper too 💀

[@ericthered9655]

Excellent! Finally someone covered the stuff one actually needs to know for their projects. I'm trying to buy a MOSFET, not design one.

[@K1GBD]

I'm making t-shirts that say "I'm trying to buy a MOSFET, not design one." That expresses my - an many people's - frustrations perfectly, and why I also very much appreciate this video even 8 years later!

[@humbertobruniguitar]

Hi James. This Channel is one of the BEST anyone can find in KZbin. I really like your videos. My reasons: 1) Your diction is great, extremely clear, well articulated. 2) You have music ONLY in a few spots, which I consider that is perfect. I hate those tutorials when it’s almost impossible hear what the person is saying. 3) You visual and graphics material are of the super highest quality. 4) Once in a while a joke is perfect, as an “ice breaker”. 5) You have a great respect for your audience. A+++ 👍 I subscribed to your Channel & Turned On the notifications. Congratulations!

[@mikhoyan5997]

My uncle is an Electrical Engineer. I have asked him many times about mosfets as I have been watching him working on circuits since my childhood. But every time his lectures just flew over my head. Then I searched youtube and got my answer.

[@richardcowan2889]

Your MOSFET guide/worksheet is great. So are your videos. The guide/worksheet has helped me immensely with an IRF540.

[@pAirA_]

When you started talking about mosses I just rolled with it. really shows how easily zoned out I can be :P

[@ohmurr9403]

Thank you for making this video so much, good sir! I wish that my radio lab instructor could explain all the concepts as clearly as you did in less than 10 minutes. You got a real gift.

[@robotmad]

Great Vid with no annoying background music. Subscribed

[@DracosTube]

Hey man, thanks for the videos! They're not only clear, but the production is pretty good. Keep 'em coming, they're much appreciated.

[@VitoVeccia]

I love it how you broke down the complex systems into easy to understand simplicity. That, and the random humor helps keep things interesting.

[@tomsparks3259]

This is my favorite AddOhms video. The viewer KNOWS they need a MOSFET and you show them how to use the data sheet to select one. The review is a nice touch too.

[@johndoe-bq1xt]

Thank you for making these videos because you don't just throw equations at us but you explain how fets mechanically works and then use the V,R I's in equations but they're within the context of your tutorials.

[@jm5642]

this is a great video. really enjoyed how you not only explained the functionality of MOSFETs but how to actually use them in a real-world application. thats something i wasn't taught when i was in school (not sure why though).

[@mimiculmore]

Sorry I don't understand?

[@Noogleminus]

Audio, power supplies, motor controllers, and really anything that requires significant power. BJT's are generally lower power transistors. MOSFET are used when you need to power something. If you open up a power supply, you may see these guys regulating the output and/or gating the input. Often times, they replace the role of a relay. Relays are great, but they have their short comings when compared to transistors. This an area where MOSFET's shine. An example can be found in Arduinos. These are little micro-controller boards. They have an extremely limited power budget to work with. The Arduino can't even kick out enough power to close a relay. The Arduino has the brains, but not the brawn to make a lot happen. If you wanted to make your Christmas light flash on and off in time with music, you'd have a situation where you'd want relays to close reliably in time. These relays may need to be beefy enough to take several amps of current and require significant power to close. The MOSFET might be your interface between the Arduino and the relay. Another example would be in car audio amplifiers. You might need several amps at 30+v alternating at 30+hz in a sine wave. MOSFETs are used to make this happen. Consequently, they put off significant heat which creates the requirement of the large heat sink chassis. There are countless other reasons to use a MOSFET, but this is already a book.

[@starcitizenmodding4436]

School is the slow way to learn :/

[@gerardofire69]

youre absolutely right, the truly deal is out there, were's the real troubles are,

[@mal35m]

I took eet in college many years ago. This 7.45 minute video is worth 2 hours of class time as far as I am concerned. The classes I took were not bad, it is just that there was an extreme reluctance to get into anything practical.

[@GTA2SWcity]

Thank you. While I knew the basics in general, your video here showed me what I was getting wrong and what I was getting right. Now that I know how to interpret a datasheet *correctly* and what to look for, I can make better decisions for designs. That's all I am looking for is plain spoken direct explanations.

[@MatrixRage]

I've been trying to increase my limited Electrical knowledge, and your videos are some of the most informative and easily understood. The fact that you back them up with fact/cheat sheets on your website is really a nice touch. Look forward to some more videos from you in the future, they've done me a lot of good. Thanks

[@finnigan16]

Great video! Gets right into practical application to show you how to select the device that will work for your circuit. Love it! Please keep this kind of content up!

[@AlanMedina314]

My professor talked about this but with you assistance this now makes clear sense. I really do like your approach to teaching this concept. Very easy to understand and the anecdote at the beginning was a good way to diffuse any tension when learning new concepts.

[@kabkab8441]

I agree!!! Sometimes I wish there was a pause button to push to slow down professors, or a please make this clear button - no such luck!!

[@ronjones4069]

Great explanation about heat. Thanks, it is often overlooked because it is confusing, but your explanation was superb. Thanks!

[@jimstanley_49]

Just don't forget that the ambient temperature won't always be 25°C. If the installation is some cupboard next to a south-facing window, you can bet that it'll get up to 45 in there and let the smoke out.

[@stucorbishley]

I love that you make the connections between the datasheet and the behaviour! So great!

[@adrasx6999]

Just awesome, so short, so compact, and yet "all" you need to know. Thank you very much!

[@hvanmegen]

30 seconds in and I've seen an engineer with an efficient hairstyle, information on transistors and MOSFETs and seen an intro.. subbed!

[@pattykuvshin]

Great video, very well produced! :)

[@CSSIandAssociate]

I was so impressed I subscribed before the video ended. Keep up the good work.

[@MP-mx9nf]

dito. superb video

[@robbiecardew7538]

Same here, I agree.

[@HillsWorkbench]

Concise, a classic I have to re-watch every so often.

[@johnhamilton4449]

Great Video - after 40 years as an EE I now understand MOSFETs a whole lot better.

[@paparoysworkshop]

Good video, you have another subscriber. Keep up the good work.

[@Willam_J]

This is, BY FAR, the most comprehensive and accurate tutorial for MOSFETs on KZbin.

[@AddOhms]

"Most accurate..." except for the part where I draw a depletion mode symbol while explicitly stating it is an enhancement mode symbol. ;)

[@ShawnyDsMusic]

Absolutely wonderful video man. Would love to see this education approach on how to implement high and low side switches using MOSFETS

[@FutureInventions]

Wow, what a fantastic video. Great stuff, very helpful

[@IslandHermit]

MOSFETs were a godsend to me when I was transitioning from vacuum tube circuits to solid state. Because they are both voltage driven, it was fairly easy to adapt the designs from one to the other. That gave me some breathing space while I got my head wrapped around current driven BJTs.

[@dreece2000]

I feel a rudely impulse to ask what you were building

[@ecospider5]

Fantastic information thank you. I’m finally starting to understand MOSFETs. I will have to watch this a couple more times and I will be subscribing.

[@aaqilkhan]

Great video. You put in lot of effort into doing this and will greatly benefit lot of beginners. Kudos.

[@OttoCruz787]

Nice video. Love the 'autorouter' shirt. ^_^

[@BillAnt]

At 0:28 The other says "I'll get H2O" too ... the second guy might die, but at least he'll be disinfected by H peroxide. ;)

[@3deeguy]

Thanks so much for this tutorial. I see it's been here awhile but I plan to start using them so I can scale up my robots. Explaining the datasheet was great info.

[@sunshine7453]

In just a couple minutes, you have explained clearly the selection and the application of MosFET. Thank you!

[@toms4123]

Very well done tutorial, I am pleased it was suggested by youtube. subscribed.

[@alokcpradhan]

When you started explaining about moss i really thought there was a deeper connection between Mosfets and moss and started having all sorts of imagination about how it could be related....

[@WereCatf]

This was a really good video, even if it's several years old by now. I'm just learning about MOSFETs and I was unsure on how to calculate the heat-dissipation thing, but you made it pretty damn easy and clear. I also quite enjoy your style of presentation here. I suppose I should check out the rest of your videos for more good stuff!

[@richardsandwell2285]

Clear has glass description, excellent. Thank you so much.

[@Imstalcon]

We are waiting for a lesson about IGBT!

[@adolphjanssen6580]

Man I love this stuff. I should have become an electrical engineer, I find all this so interesting.

[@farawayskies]

What did you do instead?

[@gusmotorsports]

Same here , I choose IT instead.

[@vor946]

@@gusmotorsports i found the middleground in the domain of embedded design

[@ratbagley]

I love the way you present, to the point well done. Good sound quality too for us old guys. I took electronics for 3 years but still need a refresher now and then. Thanks.

[@AddOhms]

Thanks.

[@supersuperintendant]

You're a legend and I love everything about you. Keep educating us you awesome person!

[@svennism]

Brilliant! Very nicely illustrated. By the way, do you perhaps know how to dimension the external gate resistance to a mosfet driver? I'm having a really hard time finding anything about this.

[@AddOhms]

Sveinn Grétarsson why are you trying to determine that?

[@svennism]

It's fine, I finally found a decent article covering this. The reason is that I am currently working on a hydraulic solenoid valve driver circuit which used a 200V mosfet as a switch, and used a mosfet driver (LM5112MY) as gate driver. The applicaiton note of the driver stated that an external gate resistance should be used, but never mentioned any guidelines as to how it should be determined. It is ofcourse just an RC circuit, of which you determine the resistance to get a predefined time constant. Silly me. :)

[@ProtoG42]

Great video, subscribed!

[@MarkReisch]

same!

[@froedlmetallmann4643]

Me too.

[@JeremyCook]

Hello.

[@ProtoG42]

Hey!

[@SebVEVO]

Thx, finally a beginner oriented and well explained tutorial.

[@johnw1385]

Used a power depletion fet to drain the bank on my CD welder(through power resistors) either when switched off or wanting to weld with a Lower voltage. It was expensive relative to other parts but not having a relay on an otherwise solid state design was oh so satisfying. Nice video only thing I would have added is if you want to high side switch one can avoid a lot of headake using a floating supply on the gate and an opto isolate to signal it. Esp practical for one offs where a few bucks isn't multiplied by hundreds or thousands

[@m.s.3346]

Absolutely professional Video! Thank you!

[@Zanzubaa]

You know you are into electrics when you have a favorite type of transistor.

[@marf5303]

Great video! explaining the datasheet helps a lot in my understanding.

[@malcolmhodgson7540]

Now THIS is how an instructional video SHOULD be! Awesome work, have subscribed. You taught me more in a couple of minutes than all the so called forum experts and their arguing and sniping at each other! Just THANK YOU!!!

[@TCSC47]

Yeah, liked the H2O2 joke! The old ones are always the best ones!

[@pupper6044]

I think I found my "KZbin channel". Thanks, sir.

[@jdmxxx38]

Great video. Thanks. I learned a lot easily and quickly. Nice set of production values as well.

[@KelikakuCoutin]

Thanks James! Got here from Rossmann Repair Group. Thanks so very much and keep up the fantastic commentary! B'H.

[@jtveg]

Love the hydrgen peroxide joke in the intro. Here another one: *There are only 10 kinds of people, those that understand binary and those that don't.*

[@kingsman428]

Actually, it's 11, those that understand binary, those that don't and those that know tristate

[@gordo8189]

I still think those depletion mode mosfets each contain a tiny little vacuum tube

[@rickpontificates3406]

A really cool feature of FETs is that many of the enhancement mode type can be triggered and stay triggered with nothing connected to the gate! That’s also it’s downfall as a FET in an SMPS can stay triggered and pop if a suitable gate resister isn’t used to stabilize off time.

[@oddjobbob8742]

I have been watching various electronics KZbins for a year or so. Now I understand what a mosfet is used for.

[@AddOhms]

But I’m sure you’ve seen how N and P type materials are laid on top of each other, countless times. ;)

[@oddjobbob8742]

@@AddOhms hahah yes, like that really explains a lot to me when it comes to knowing what a transistor does in a circuit.

[@CigaretteTricks]

I thought there was a boba and jango FET too

[@_valles3438]

YESSSSSSSSSSSSSSSSSSSSSSSS

[@ozasl]

Great video. However, almost nobody talks about the necessity of using a resistor between the gate and the ground to sink the current trapped in the gate and for turning the mosfet off properly in any mosfet video on youtube...

[@AddOhms]

Excellent point. It's something I already planned to cover in the future. However, it is exactly why I at at least included in the schematic, to hopefully prompt the question "why is it there?"

[@ozasl]

This is not a hidden secret of electronics. However, I have learnt that the hard way after hours of google search and experimenting. And sometimes such small details can be really demotivating for an hobbyist or a beginner... It would be good, if you can cover this in the next mosfet video.

[@JeremyCook]

Wow, thanks so much! Was wondering what I was doing wrong. Any idea what type of resistor is needed to ground (I put in a 2k which seemed to work fine). Also, I assume there should also be a small resistor from the positive voltage to the gate as drawn.

[@eddiefoy3701]

Awesome simple explanation/app note. Quick, fast, cheat-sheet style. love it!

[@cpakditno4n95]

I have years watching electronic videos on youtube, and i can tell maybe 5 are the channels that are actually worth to watch, this is one of them..great job mate

[@voltixD]

Regarding the 2 guys in the bar ordering H2O, the second guy dies because he ordered Hydrogen Peroxide H2O2(too).

[@TheProCactus]

I had to read that 3 times to get it. is that bad ?

[@AhmedSalam]

kind of!!

[@raspbianu7817]

voltixD thanks!!

[@nejiniisan1265]

If he didn't, at least he got a nice diarrhea.

[@maxxsmaxx1901]

voltixD . Hahahahaha

[@ThalesPo]

0:28 I get it, the second man drank hydrogen peroxide.

[@joost199207]

This is very well explained. Thank you!

[@winamushala5280]

FCP 380n60 which one is the voltage?!?

[@stephenwgreen78]

Thank you for the great video. Love the format

[@terminsane]

dont forget the Boba FETs

[@michaelhawthorne8696]

Very nice and unusual presentation, clear script too. Liked the joke but I now need to find out what chemical H2O2 is. Your picture of the Enhancement MOSFET @2:17 is blured and looks more like a Depletion mode type. Could cause confusion..... Sub'd...........

[@michaelhawthorne8696]

+Michael Hawthorne Aahh the wonders of Google.... H2O2.... Hydrogen Peroxide.

[@AddOhms]

+Michael Hawthorne Yeah, I drew it wrong.

[@mrinalthakur3459]

H2O2 his hydrogen peroxide the chemical which caused the disaster resulting in the sinking of submarine Kursk

[@_cw_]

maybe consider putting a note in the description?

[@linmanicebird8670]

I doubt it! Western Media Story. My guess is that those rumors about an accident (collision) between Trident US Navy submarine and Kursk are more true than not. These collisions happen all the time, they are just not reported about. Often in Black Sea. Often between ships, less likely submarines. I am fine with these collisions being kept in semi-secret mode. There is one story for the public, another for inner circle. Sadly, this makes sense as most people are no longer capable of critical thinking. "Democracy is based upon the conviction that there are extraordinary possibilities in ordinary people." - Harry Emerson Fosdick

[@MephistoRolling]

thanks a lot, watched a bunch of videos on this to try find the info i needed, but they missed lots of the key info i was looking for, and yours had it!

[@guillermorobledo2842]

FINALLY A VIDEO THAT ACTUALLY TEACHES HOW TO SELECT A MOSFET! Anyways, great video👏.

[@samykamkar]

Moss...I lol'd!

[@bati5996]

LOL

[@L-udo]

._.

[@GeekMustHave]

Just ran across your channel and I am so glad. Love your training material and presentation. As an instructor, I may a little fussier about videos, yours are great. Never seen whiteboard style like this. I also learned more about what I didn't know about MOSFETs in less than 10 minutes. I am a new subscriber. Keep broadcasting!!

[@johnrobinson4445]

Late to the party, but I really like this presentation. Smooth and professional. Great!

[@tomohlsson9045]

Good job explaining, clear, concise and truly informative. Keep up the good work!

[@joeflosion]

Holy moly, great video my man! Very detailed and I appreciate that you have even more information linked to your own website! You've most definitely earned my subscription! Thank you!

[@alexwild4350]

Excellent teaching skills there James, a real credit to you. I've subscribed. Great video look forward to more of them - you've so much to contribute with your clear style. Many thanks from across in the UK.

[@brad1716]

Awesome T-Shirt!!!! Thanks for the tutorial, it was a nice refresher!

[@dylanbenn6361]

Nice video. Well thought out. Clear and practical. I like the introduction of the data sheet. Practice hands on learning

[@charlesrg]

Great video, showing the datasheets is awesome as it's the way we would need to look for them too. Great video.

[@kopaczp]

Greatest and easiest explanation so far. Thank you! Good job.

[@delightful-ish]

I really appreciate the moss joke. I'm interpreting it as a reference to how so many of these videos or articles go straight down into the weeds of stuff you really don't seem to need to know to get started learning how to use these things.

[@AddOhms]

Thanks, but you put more thought into it than I did. I just wanted to point out the videos are scripted. People are often ask: "how do I make videos like yours?!" I always say: "start by writing a script."

[@gabrielvarela5]

This video is great!! i was searching for something like this to know about mosfets and i really didn´t expect to find such a good video. Greetings from uruguay!!

[@portblock]

Thank you sir, I was actually using a mosfet driver from microchip to drive some mosfets then ran across your video about the FQP30N06L being logic level, you just reduced my parts count by 2

[@S2AnnyS2]

I just started it and already love it :D

[@EarlWallaceNYC]

Thanks for the video. I was very helpful, especially the part on when a heat sink is needed. (That was news to me)

[@torehanssen9602]

from northen norway. love your videos high quality end easy to understand. keep up the good work.

[@21thTek]

I really enjoy the video and learned a lot in little time. I wish most of the tutorials were like this one. I would say people empowering people !!! THANKS ⭐⭐⭐⭐⭐

[@stustjohn]

Absolutely excellent! Thank you for making this clear and understandable video 😀

[@benjaminschlageter266]

I wasted about 1h in googling some informations abour BJTs and/or MOSFETs. And now after more than the half of the time, I got what I need. Thanks man! :-)

[@mattgray666]

I had no access to videos like these nor invested teachers back when I took electronics in high school. Seeing it taught like this makes me realize how different my education could have been... how different I could have been. There should be a government subsidy to pay KZbinrs for producing educational content that can replace classroom lectures.

[@black4083]

Great presentation! Thank you! It's helped me a lot!!!

[@okaytokay]

A lot of videos on MOSFETs goes into too much details and ended up confusing. But this is perfect, just enough of what I need to know. Thanks!

[@FortniteMaster-vi6qt]

Fantastic video- first thing I found which actually helped me to put the MOSFET into practice myself. Thank you so much

[@vb6code]

Great video, thanks for the good work!

[@Leif_YT]

Thank you. That was very well explained and easy to follow.

[@marioalbertojimenezsanjurj3183]

Recently I have subscribed. Let me say thank you very much for both, your useful information and multimedia material. Saludos desde México!!!!!

[@farzadfaradjizadeh3916]

Wonderful instruction. Thank you James.

[@NancytheNippleNazi]

Enjoyable video! Love the high quality camera!