Designing Power MOSFET Circuits - Circuit Tips and Tricks

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Күн бұрын

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Designing Power MOSFET Circuits - Circuit Tips and Tricks
MOSFET circuit design and selection is a commonly requested topic for me to cover. There are a lot of uses for MOSFETs, as a result, they have become more commonplace than standard BJT or NPN transistors, especially in high-power applications. I will cover information and equations needed to design useful circuits without getting "down in the weeds" with complicated derivations
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Пікірлер: 520

@Graham_Wideman 3 жыл бұрын

Problem! It's great that you're making videos like this, but I think the power calculation is a bit off. if you're going to deliberately slow the on-off and off-on transitions, then those transition times are durations when the MOSFET will have to conduct significant current while exhibiting significant resistance. This can easily dominate the heat output.

@MicroTypeEngineering 3 жыл бұрын

Yes, you're right. I had to limit what went in the video, and was focusing mainly on high-power low switching speeds drives. But yes, I wish I would have at least mentioned the losses during switching.

@Graham_Wideman 3 жыл бұрын

@@MicroTypeEngineering Thanks for replying. I'll just add that I think what happens during turn-on/turn-off is especially crucial to mention, because an unaware designer could be lulled into over-optimism by the astoundingly low on resistance that some of these devices have. That low resistance does indeed mean that your sample device can carry very high current, especially given suitable heatsink. But factor in frequent switching, and the numbers blow up, perhaps surprisingly for some.

@JGott0001 3 жыл бұрын

I'm glad you two brought this up. Thank you for the video, MTE!

@dwalden74 3 жыл бұрын

So should we reduce the gate resistance to speed up the on-off transitions?

@Graham_Wideman 3 жыл бұрын

@@dwalden74 Right, you would reduce the gate resistance according to the calculations that MTE did in the last 5 minutes of the video. That's assuming the gate driver chip can handle the current pulse and isn't the limiting factor. But first, you would first want to assess how much heat is dissipated during those transitions to see how fast you need the transitions to be. If you are switching infrequently, then slow transitions are not much of a concern. But if you're switching frequently, then they can easily dominate the heat output. To assess the heat output per transition, conceptually you would need the gate waveform (VGS vs t), then the corresponding RDS (drain-source resistance) vs VGS, so you arrive at an RDS vs t. That's pretty tedious, so instead model it in Spice (for example). The Spice sim can directly plot the power dissipated per transition (just VDS x IDS). And run a range of parameter values, as VGS vs RDS is not a tightly controlled parameter.

@Roody Жыл бұрын

Just the first 5 minutes, and I can totally say THIS is the way to explain things. Clear, simple, direct, practical examples. I've seen tons of videos about the same topic, and none of them were useful at all. Man, you deserve credit. Thank you for the vid.

@Blandified 3 жыл бұрын

This is incredible, thanks so much! I especially love how you explain WHY you do certain things. A lot of videos say "oh just do this, put this resistor here" then they move on. But you explain WHY certain things go there. I love it cause it helps me learn!

@MicroTypeEngineering 3 жыл бұрын

Glad it was helpful!

@jonathanm9436 3 жыл бұрын

Agreed - the "why" is so often missing. This has been a marvellous video.

@wouldntyouliketoknow9891 2 жыл бұрын

"Theres not a whole lot of in between" - I have observed this on many topics. It is the curse of the internet. So much information, so little relevant information.

@og.StudMuffin Ай бұрын

Wow.. you make things so much easier to understand. You dont assume we know anything at all and its great. Everything you say if it isnt obvious, you breifly explain what you meant in laymans terms. Thank you!

@KholyScript 3 жыл бұрын

I've never seen a video that holds all the information needed in less than half an hour! Right into the point like an arrow! Well done.

@MicroTypeEngineering 3 жыл бұрын

Thanks, glad you enjoyed!

@houtmann774 2 ай бұрын

A concise, to the point explanation in a language the 'mortal' being can understand without the 'gobbledygook' and 'dreaded' calculus. Great stuff, keep it up!

@damny0utoobe 3 жыл бұрын

Perfectly practical introduction into using a mosfet with MCUs.

@MicroTypeEngineering 3 жыл бұрын

Glad you liked it!

@bimmerboard 3 жыл бұрын

I have a degree in EE, but I never had such a clear explanation from any of my professors back in school. Well done!

@tonyonofrio1147 3 жыл бұрын

@@jamescollier3 The circuit in this video is using the mosfet at it's most simplest function, as switch. So normally you would wire your "load" (led, motor, etc) in series with the switch (mosfet). Mosfets are popular as switches since they dissipate very little power compared to transistor switches. The video you linked to is using the mosfet as an (analogue) amplifier. Without going into the many different amplifier configurations (some which have the speaker in series with the mosfet) the results, conditions, and calculations are different.

@truthorhappiness 3 жыл бұрын

This has been the most helpful video on MOSFET's I've seen yet. Thank you!

@MicroTypeEngineering 3 жыл бұрын

Wow, thanks!

@MadScientist267 3 жыл бұрын

I completely agree. Too many videos rely on music, obnoxious antics, weird visual effects, and the like. A simple factual presentation that covers the crucial aspects with explanations is an increasingly rare thing, and definitely appreciated.

@Taylor_5724 3 жыл бұрын

Yeah I agree this was extremely helpful

@jedfrank9597 2 жыл бұрын

Thank you for teaching that so well. This is the first bit of info I've come across that actually helps me make an informed decision on which mosfet to get. Thank you for taking the time to make this video.

@warrenmondon3375 11 ай бұрын

WOW. Great job...I learnt without frowning and scrunching up my face. The information just went straight in. I will be watching ALL of your videos. Thank you.

@mth32871 2 жыл бұрын

Now that was an excellent explanation! This is probably one of the clearest and and most thoroughly explained videos about any electronics topics that I have ever seen (and there are quite a few great ones out there). Very well done. Thank you!

@MicroTypeEngineering 2 жыл бұрын

Wow, thanks!

@richardandrews573 Жыл бұрын

So I needed to refresh myself with a single concise tut on MOSFET's and I found it. Bravo.

@stanspb763 3 жыл бұрын

This showed up in recommended channels....how did it know I was working on a large smps for a power amp with blown MOSFETS at that moment. It was a design I did and surely the KZfaq masterminds were trying to tell me something. Very well explained and the production values of your videos are welcome indeed. Thank you. Why only 6k subs? It is 6k +1 now.

@cs_fl5048 3 жыл бұрын

I know virtually nothing about any of this, but I watch a lot of tear down channels as I find it very interesting. This video made so many things that those gloss over so clear... such as why there are little circuits with resisters going around the "real" circuits, etc. THANKS!

@LOGICOMA 3 жыл бұрын

I've watched this multiple times, and it has helped so much! They explain components and pcb design tips really well! Thanks so much!

@MicroTypeEngineering 3 жыл бұрын

You're very welcome!

@Jonmal0ne 3 жыл бұрын

Clear, concise, pragmatic. Love it mate. I learned a lot thanks to you. :)

@a1nelson 4 жыл бұрын

Easily, by far, the best guide to real-world use of MOSFETs on KZfaq. Not a home run - a grand slam. It absolutely accomplished the goals stated at the start: genuinely useful, while steering clear of the weeds that others let their viewers/students get lost in. Definitely sets the new high-water mark for the MTE channel. Looking forward to whatever comes next! Thanks much.

@MicroTypeEngineering 4 жыл бұрын

Wow, I appreciate the comment :) Yeah, I don't know how I can follow this one up haha!

@wills3212 3 жыл бұрын

Perhaps the best instructional video for mosfets really clear thank you

@the-beneficiary1809 Жыл бұрын

I really appreciate you taking the time to thoroughly explain Mosfets and how they work in conjuction with the MOSFET Drivers. As a controls engineer I can say this was very well explained and simple to undertsand. Trying to research everything i need so I can design a BLDC controller for a special project I have jumped into to keep my self busy. Thanks Brother.

@barry7608 3 жыл бұрын

Extremely well explained thanks, I still have a long way to go but with tutorials like this half the battle is won

@eugenenault4935 Жыл бұрын

Most in-depth mosfet circuit explanation on KZfaq . Great job. Thanks

@MicroTypeEngineering Жыл бұрын

You are welcome!

@loadingUserID... 3 жыл бұрын

Very well explained. You keep it practical. Nice job!

@iot_enthusiast 3 жыл бұрын

Thoroughly enjoyed the crystal clear explanation!

@bryanst.martin7134 3 жыл бұрын

I've been doin this a while, but sir, this was clearly and concisely explained. Kudos. Subbed.

@user-dx8fv9ji6b 2 ай бұрын

This is an absolutely superb presentation. This mechanical engineer is now in with a fighting chance of building a simple dc switch which demands effectively zero gate current once energised. Thank you for improving my education with no pain.

@Ammothief41 3 жыл бұрын

Awesome. Wish I had watched this a few years ago, I'm sure it'll be useful to anyone getting into electronics.

@BusyElectrons 4 жыл бұрын

Excellent overview! Thank you for doing this.

@samk2630 3 жыл бұрын

The video I’ve been hunting for too long. Thank you, earned a sub!

@Frank_McIsaac 11 ай бұрын

Great video! Your explanation was so clear. Nice work!

@hollymedici2936 Жыл бұрын

you are the only one that had actual values for the resistors big help thank you

@pcbworks Жыл бұрын

I love the way you speak and explain things. Thank you

@SuperCookieGaming_ Жыл бұрын

this is a wonderful explanation! the simple videos you mentioned make it seem so easy to drive but the other videos make it so complicated. you managed to find whats important and relayed that info in a clear and concise way. I am designing a 9v battery to usb charger and i wanted to add undervolting protection. i found a very low power comparator that has an internal reference that makes it easy. the problem is my buck converter doesn’t have an enable pin. so i have to use something to turn the circuit on and off. i didn’t want to waste power driving a bjt but mosfets seem so complicated. now i understand what to do.

@thecriticalpoint 3 жыл бұрын

This is the last MOSFET video I'll ever search for. I just wish I'd have found it 6 months ago. I've been spinning my wheels. You're smart engineer and have a gift for demystifying the black magic that all too often bars people entry from realizing their applications. No BS, no stretching, no clickbait titles, no grandstanding or egocentric self promotion. You got yourself another subscriber.

@MicroTypeEngineering 3 жыл бұрын

Woah, thanks for the kind words! Though, I am working on a part 2 of sorts, so you might need to add another MOSFET video to your list! ;)

@simonndungu1196 4 жыл бұрын

I am a huge fan of your design tips

@garymucher9590 3 жыл бұрын

Amazing how many EE's don't know how to decode any component's specs. I worked with a lot of just-out-of-college EE's that would read a component's spec and think they could drive parts beyond their real specs using one or two maximum specs as their only guide while forgetting that everything has to be observed. Just because a part can handle 10 amps and 100 watts, doesn't mean you can drive it to that 10 amps at any voltage. And watching them burn up circuits (and their bench tops) was actually funny... Thumbs Up!

@marv4895 3 жыл бұрын

i would love to see more educational and practical videos like this from you

@shvideo1 3 жыл бұрын

Very useful video on MOSFET. Thank you for covering the datasheet parameters and their meaning. Thoroughly enjoyed it. Thank you.

@MicroTypeEngineering 3 жыл бұрын

Glad it was helpful!

@bowesterlund3719 3 жыл бұрын

Super happy I found this channel! Will binge every vid soon I think

@MicroTypeEngineering 3 жыл бұрын

Welcome aboard! Enjoy :)

@snehamoypatra9786 2 жыл бұрын

Your contribution to this field is really unmatched.

@MicroTypeEngineering 2 жыл бұрын

I appreciate the words 😊

@69MazdaR100 3 жыл бұрын

Great video with excellent explanation. Learnt more from this video than the 20 previous ones combined, subscribed!

@MicroTypeEngineering 3 жыл бұрын

Awesome, thank you!

@afonsomanuel1585 8 ай бұрын

This man is gold, great work.

@willbill808 2 жыл бұрын

I never thought about that gate inrush current before! And here I was with just a 10K pull down for my Arduino.

@scottneels2628 2 ай бұрын

Thanks for this, it's exactly the level of detail I needed, and from your explanation I can appreciate when and why there are cases where far more detailed selection/calculations would be required. i suspect that for my purposes I'll probably never need more than these basic selection considerations and quick safe limit proximity checks.

@dancoz5477 11 ай бұрын

Bravo monsieur. Keep the good work going. Your prononciation is clear and sufficiently slow so people like me (?) can understand and follow you. I taught at the university level in Canada and I would of liked to have your ease and pedagogic talent of communication during those years.

@midronome Жыл бұрын

Nice content, thank you! Love the format, simple and calm explanation - that really changes from those crazy super-fast videos out there on KZfaq ;) Cheers Simon

@ihtsarl9115 2 жыл бұрын

Thanks for this Tutorial I am grateful for taking your precious time to make this video.

@danlscan Жыл бұрын

Thanks! Just the right amount of detail.

@eugen995 3 жыл бұрын

Very beautiful explanation sustained by a clear and slow speed language! Thank you!

@MicroTypeEngineering 3 жыл бұрын

Glad you liked it

@killer2point057 5 ай бұрын

Great explanation. Thank you for your time.

@georgemarkuly8180 2 жыл бұрын

Excellent pragmatic presentation. Especially important discussion of gate resistors seldom addressed by many videos.

@iblesbosuok 3 жыл бұрын

Hats off for well structured and crystal clear explanation.

@ScienceShack 8 ай бұрын

Wow - this is fantastic. So well presented and really useful even for those of us who have been using mosfets for years. New sub for sure :)

@zonnig46 3 жыл бұрын

I learned so much about the mosfet. Thanks a lot for this video. Gtz from Amsterdam, The Netherlands.

@dianbasit9624 Жыл бұрын

Excellent explanation and especially you give the reason for using the resistors in gate of mos transistors. Thanks for great and concise explanation.

@sampathsubasinghe929 8 ай бұрын

Great explanation on driving MOSFETs. Thanks !

@raytry69 Ай бұрын

You're such a good teacher.

@lukasstieglitz2941 2 жыл бұрын

very well explained. thank you!

@marklowe7431 2 жыл бұрын

Super well explained. Thanks.

@nigelmurraysmith5498 5 ай бұрын

Clear and refreshing pertinent rational thinking process

@Brian-mf3ry 2 жыл бұрын

This is literally what I needed. Thank you!

@SimplySpace 2 жыл бұрын

Instant subscribe. Huge help, thank you!

@jatag100 2 жыл бұрын

Great video, thorough and clear! Thanks!!

@k9kj 2 жыл бұрын

This video was amazing! Just what i was looking for

@MethodMan- 9 ай бұрын

This was really helpful, thank you very much!

@virajytube 4 жыл бұрын

This video is enough for every MOSFET designer. I appreciate for your efforts. Please, make a video on intricate-accurate MOSFET calculations.

@gkdresden 5 ай бұрын

This is really a handy way to do rough calculations around a power MOSFET. I personally calculate with half of the gate current to get more realistic switching times. Under more critical timing conditions I also consider the internal gate resistance, which is typically in the order of 1 to 10 Ohm. So in some cases you don't need an additional gate resistor or you have to avoid it to fulfill your switching requirements.

@WayneMcNab 2 жыл бұрын

Excellent. You commented on increasing the gate resistor. The thing to watch is that by doing this, you increase the charge time and the amount of time the divine is in linear mode. During this time it is dissipating much more power. If the gate resistor is too high, it will increase the delta T.

@sivaapss0015 3 жыл бұрын

Finally and finally i got what I searched for a very Long time

@tewodrosgirma3019 2 жыл бұрын

I am glad I watch this video, it's amazing. For a complete explanation about the power losses, it would be better to include the switching losses. Thank you very much for such outstanding explanations.

@ArturoLopezPadilla Жыл бұрын

I am glad to meet you. Seriously. Excellent work. Very useful to me. Thank you very much.

@MicroTypeEngineering Жыл бұрын

Thanks for the kind words!

@michaelhawthorne8696 5 ай бұрын

Nice bit of theory Liked and subbed ! 👌

@WilliamHinojosa 3 жыл бұрын

Excellent video mate, keep them comming, very well explained. Subscribed!

@MicroTypeEngineering 3 жыл бұрын

Thanks for the sub!

@stuchump 2 жыл бұрын

wonderfully explained. you should have more subs

@J_Bazzle 3 жыл бұрын

I know this is an old video but you are the first ever educational channel I have subscribed too cause I feel like learning from this channel is actually interesting and informative.

@borisfilipovic5253 2 жыл бұрын

Excellent job, bro. Are there oscillators that work on about 150MHz? What is max frequency of your gate driver circuit?

@pylonpeet 10 сағат бұрын

Very good information, thank you for sharing!

@venkir1408 2 жыл бұрын

Thank you so much for such a great explanation, I never had this clear idea before. really useful. 💯

@CCDobrescu 3 жыл бұрын

Wow excellent explanation! Great job!

@ihtsarl9115 2 жыл бұрын

Thank you for this tutorial on Mosfets. Posting a further video on IGBTs would be helpful especially because according to my experience IGBTs are more difficult to work with.

@karlOFuchs 2 жыл бұрын

This was awesome. Thank you for creating this video.

@davidandrews8566 4 жыл бұрын

Greetings from the UK. This was a most interesting and informative video thank you. I will now be subscribing to your channel

@MicroTypeEngineering 3 жыл бұрын

Awesome, thank you!

@minazulkhan8287 2 жыл бұрын

I m working as electronic engineer . This video was very informative .Thanks .Expects more videos

@VeryMuchBlessed 3 жыл бұрын

Very good instructive video. Information I've been searching for in trying to improve my circuits. Thanks much for making this.

@MicroTypeEngineering 3 жыл бұрын

Great to hear!

@VeryMuchBlessed 3 жыл бұрын

Just saw the comment below on hooking Mosfets up in parallel. Circuit would consist of two,three, or more Mosfets with all Gates joined, all Drains joined, and all Sources joined, apparently for driving really HUGE loads that one Mosfet could not handle. One KZfaq video regarding this is called "Issues on Connecting MOSFETs in Parallel" and addresses some of the problems. It seems that the electric vehicles would have to have multiple banks of Mosfets just to propel the vehicles down the road. Would like to hear your thoughts on this. Thanks again. Great videos.

@MicroTypeEngineering 3 жыл бұрын

I don't have any direct experience with FETs in parallel, but typically the reason people shy away from parallel components is that they won't react the same way to the current across them. In some use-cases (fuses), parallel components are OK, since the resistances even out due to heat. But FETs can have their resistances decrease with heat, causing a runaway condition. (I know Vgs decreases with heat, not sure about Rds off the top of my head.)

@TheScissorunner Жыл бұрын

Lord, I’ve wasted so much time prior to finding this extremely-excellent-explanation.

@deltabravo2810 3 жыл бұрын

Thanks for the explanation, Now I understand working principal, the design parameters and calculations.

@ramirosuarez9537 Жыл бұрын

Amazing! Many thanks.

@10e999 4 жыл бұрын

As always; excellent.

@jasonpap7092 Жыл бұрын

with videos like these existing, i am convinced i didn't need to go school for this

@KF-bj3ce 3 жыл бұрын

Great explanation specially the parts where you refer to the tech data sheets.

@mitz8892 4 жыл бұрын

Great explanation !! Thanks a lot.

@alocin110 Жыл бұрын

I liked your video. Excellent explanation and calculation. I subscribed to your channel. Thak you for sharing.

@Estudio322 3 жыл бұрын

Im so thankfull to have found your channel

@abdelazizelbekkar6567 3 жыл бұрын

Thank you very much. very clear and instructive video!

@paulj2383 3 жыл бұрын

Thank you for this very clear, practical and helpful explanation.

@MicroTypeEngineering 3 жыл бұрын

Glad you enjoyed it!

@tinfever 3 жыл бұрын

Awesome! I feel like I actually understand basic MOSFETs now!

@johnmcclain3887 3 жыл бұрын

Me Too!!

@qaziqazi9727 2 жыл бұрын

Well explained. Thanks sir

@Olavotemrazaodenovo 4 жыл бұрын

Congratulations from Brazil..

@MadScientist267 3 жыл бұрын

Excellent information and presentation. Thank you.

@MicroTypeEngineering 3 жыл бұрын

Glad you enjoyed it!