Designing Power MOSFET Circuits - Circuit Tips and Tricks

[@Graham_Wideman]

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]

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]

@@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]

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

[@dwalden74]

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

[@Graham_Wideman]

@@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.

[@wouldntyouliketoknow9891]

"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.

[@Roody]

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]

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]

Glad it was helpful!

[@jonathanm9436]

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

[@cs_fl5048]

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!

[@the-beneficiary1809]

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.

[@shvideo1]

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

[@MicroTypeEngineering]

Glad it was helpful!

[@snehamoypatra9786]

Your contribution to this field is really unmatched.

[@MicroTypeEngineering]

I appreciate the words 😊

[@dancoz5477]

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.

[@SuperCookieGaming_]

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.

[@TheScissorunner]

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

[@dianbasit9624]

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

[@tarunarya1780]

I have watched lots of videos on mosfets and yours is the most succinct and easily understandable with just about everything you need on one page that you can see during the explanation. You crystalized quite a few things for me. The only thing that was not mentioned was about use of zener diodes to pull up voltages but you may cover these in another video, and possible use of a transistor to be triggered to charge up the gate capacitor.. The gate driver IC I guess is most useful for driving higher frequency as it allows higher currents for charging it. I was not sure why the gate driver is better than use of these. Is it because it simplifies the pcb layout, as you still need other components? I was trying to get to grips with them for making an h bridges for an initially rc controlled (pre automated) lawnmower with brushless motor 40v/(?100a from an existing possibly failed esc) and dc brushed wheelchair motors.24v 250-340w. Your video will helped look to do this rather than buying expensive driver escs such as the sabretooth 2x60 as well as make a lawnmower esc to fix the lawnmower which uses 60v 100a mosfets inside he box.

[@sampathsubasinghe929]

Great explanation on driving MOSFETs. Thanks !

[@69MazdaR100]

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

[@MicroTypeEngineering]

Awesome, thank you!

[@Kholy.Himself]

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]

Thanks, glad you enjoyed!

[@AlessioSangalli]

Hot damn the "algorithm" works! KZbin suggested this out of the blue and now after your explanation, I'm ready to go ahead with a project I put on the back burner because I was hesitant to commit on the power mosfet section. Damn your style is good...

[@MicroTypeEngineering]

Hah! Praise the algorithm! Thanks for the words :)

[@AlessioSangalli]

@@MicroTypeEngineering I'm going through your videos ,😀 However do you remember if you have one that explains a good LED PWM circuit? Lots of people online have very different views on how it should be done.

[@SimplySpace]

Instant subscribe. Huge help, thank you!

[@aum55533]

Awesome!!! great explanation, please make a vide for advanced calculations also.

[@prashantk241]

I finally understand why gate resistors are used in uC circuits.

[@damny0utoobe]

Perfectly practical introduction into using a mosfet with MCUs.

[@MicroTypeEngineering]

Glad you liked it!

[@deltabravo2810]

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

[@AdamGtr86]

I just ran into a circuit where I run 2.5A coil with my mosfet and all is good. If I disconnect and install a 12A coil, my mosfet will not turn off. I have gate resistor, resistor to ground to drain it, but it must be picking up EM interference from my power cord because once I pull the coils power supply off, the mosfet turns off. And the power supply is still green despite being off, so it had capacitance to supply the coil, the coil just never took it because the EMI was gone the split micro second I uplugged the power. After playing around with all my power cords and making sure they have no wraps in them, this seemed to mostly fix the issue. It occurred less frequently and appears to be solved by directly grounding the gate so that it immediately drains the gate and it can't hold any charge in the gate line.

[@paugasolina5048]

holy fuck dude. i give this presentation an A*. you re pretty damn good at explaining.

[@abegafouda9136]

Thanks for this excellent video. My question : how can we replace the relay in a battery charger by one or two MOSFETs? I imagine a P MOSFET mounted as a polarity protection and directly charging the battery through a schottky, and the voltage of the battery sensed by a BJT thru a voltage divider that will block the MOSFET as the battery reaches 14 volts or so. What would be the values of the components : transistor (N? P?), voltage divider... Can you make a video on that? Thanks once again. You are great.

[@truthorhappiness]

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

[@MicroTypeEngineering]

Wow, thanks!

[@MadScientist267]

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]

Yeah I agree this was extremely helpful

[@joshuamazurek6746]

This is a very helpful video. Exactly what I was looking for. One quick question though how does 25 amp squared * 1.4 ohms equal 0.8 watts? Is there a reason why you divided by 1000 ?

[@seriousfacts838]

Answer pls Assuming a linear fall of voltage in a transistor at turn on, falling from V to zero in actime t2 , derive an expression for the snubber inductance L which will delay the rise of current to its on state value of I in a time of t1. Derive expressions for the switching energy loss and the inductor energy , in terms of V,I,t1 and t2 and show that the overall loss will be a minimum when t1=(2/3)t2

[@jatag100]

Great video, thorough and clear! Thanks!!

[@Olavotemrazaodenovo]

Congratulations from Brazil..

[@bimmerboard]

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]

@@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.

[@loadingUserID...]

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

[@willbill808]

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

[@mmoci81]

Very very useful video! Thnx! Looking forward for more "in between" practical circuit calculations and examples. One question. Even if I do all those calculations, I would still have to look at bunch of MOSFET datasheets to find matching MOSFET. Than could take a lot of time if you randomly opening MOSFET datasheets and don't know how to look, like I don't. There are naming conventions that could guide you to look for certain type of MOSFET based on your circuit requirements which could narrow down number of datasheets you have to look at. Can you help with that? How to match MOSFET without looking bunch of datasheets and spend hours on that? Not sure is it something that you want to cover on your channel, but would be interesting to understand for example practical calculations of inductor and capacitance for buck or boost convertor. Or for example example, simple design for power amplifier with bjt transistor. Just some ideas...

[@MicroTypeEngineering]

Yep, I am planning on a selection video/blog coming up, seems to be a common request. One of the next videos is going to be on a review of a buck converter, so I'll cover some of that :)

[@walterblanc9708]

Very good Vid, nice explanations, I wish I could have watched this 30 years ago. I think some power Mosfets like the IRF3205 and irlb8721 will happily switch at 5v and low RDSon, not as low as 1m Ohm but maybe 10 to 20 m Ohm and source certainly a few amps? My only criticism of this video was the audio, its clear but fades in and out quite a bit. I never paid much attention to switching speeds as mine are always so low its never been a problem but now you have provided me with a good explanation I shall work them out ! Thankyou for your good work.

[@MicroTypeEngineering]

Totally agree. Logic level FETs have come a long way. By far I use them more often than standard 10v FETs. But when you need the lowest Rds or gate charge, you don't have much of an option! Thanks for the words, and yeah, still trying to get audio dialed in!

[@mth32871]

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]

Wow, thanks!

[@dawnminilla9299]

You most certainly can use the 7530 at a continuous 240A, with an adequate heatsink, preferably a soldered copper spreader to aluminum but its only 60 watts of dissipation. While I agree, you would never design a circuit to run a fet at it's package or any limit, the dpak will transfer enough to good thermal solution to get rid of 60 or so watts, everything else being best case. Good video

[@MicroTypeEngineering]

Oof! I'd love to see your source or calculations saying that a DPAK can dissipate 60 watts continuously! That's not happening due to their thermal resistances. Especially since you can't directly affix a heatsink to the metal portion like the THT FETs. I'm sure for short peak's it is possible, but certainty not sustained. See here for a good appnote on real-world max power dissipations: www.infineon.com/dgdl/ThermalPackageConsideration-DPAK-SO-8.pdf?folderId=db3a304412b407950112b408e8c90004&fileId=db3a304412b407950112b40b5e9a07a8

[@dawnminilla9299]

@@MicroTypeEngineering Sure you can. Don't pay attention to all that tj temp blah blah. Get a 4x25x50mm copper plate, solder that bad boy right to it and bolt the copper plate to adequality sized heatsink and she'll be right. Ok maybe it won't maintain 240 but you can get up there, that is until your rdsOn climbs to high due to heating and you're no longer dissipating 50 or 60 watts. Copper has twice the thermal conductivity of aluminum, or very near it and has surprised me in the past.

[@analoghardwaretops3976]

Please Search & read up on Amperage/Current limitations of different switching device packages... i.e. their internal wafer/die to external leads/pins.. Back in 2003-2005 we were using a TO220 160A device..but later found out its D/S leads could handle a safe max.of 75A , above which any typical related failure mode could kick in... Leaving aside adequate heatsinking/ heatspreaders etc.

[@barry7608]

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

[@1381REZA]

Thank you for the practical video. one question: to calculate the power why is 25A considered?

[@davidandrews8566]

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

[@MicroTypeEngineering]

Awesome, thank you!

[@Ammothief41]

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

[@Sekhar_Home]

Very well explained. Ist time getting to know what a datasheet mean..

[@stanspb763]

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 KZbin 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.

[@Roy_Tellason]

One other consideration with regard to the gate resistor is the situation where the MOSFET fails, typically shorted. In that scenario you have a pretty good chance of applying Vdd to the microcontroller pin that's driving the circuit, with usually unpleasant results.

[@HillsWorkbench]

Are you using Kicad here? How did you get IEEE resistors instead of the euro rectangles? I couldn't find any back when I tried Kicad.

[@MicroTypeEngineering]

Yep, I am. Well I make all our symbols, but it's based off of the R_US symbol

[@Jonmal0ne]

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

[@Thecando]

Do you have any advice for a low noise one for audio circuits? Think of a Fetzer Valve application or something for microphones or amps.

[@anondusery1271]

Hello, does this data sheet specification "Vgs - Gate-Source Voltage: - 10 V, + 10 V" mean what I think it does? As in, do not supply more than plus or minus 10V to the gate from the driver? Gate-Source is confusing due to the MOSFET having a "source" pin. Does it really mean Driver-Gate Voltage?

[@tewodrosgirma3019]

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.

[@saidufarouk7260]

@microtype engineering Does adding a 10k pull down resistor on each mosfet protects from blowing up?

[@naimfuad5913]

great video! explaining whats matters in the datasheet really a life saver. keep it up! p/s: any consideration on making videos on SMPS maybe?

[@MicroTypeEngineering]

Thank you :) I have thought of it, but honestly, they're not a specialty of mine, and I fear I don't have enough knowledge of the intricacies of them to do the video properly.

[@iNowHateAtSigns]

Hope you're still monitoring comments, check this out: kzbin.info/www/bejne/pJOuqIiJfZ6Bn7s

[@MrEdwardhartmann]

Thanks - great job

[@prashantk241]

Can we use that NCP IC (MOSFET Driver) to drive Solid State Relays ?

[@d3stinYwOw]

As always great video! I missed you :)

[@MicroTypeEngineering]

Thank you! Hadn't seen you comment for a bit, wondered if you were still around! You still want that circuit reviewed, or any other? Go ahead and shoot it over if so.

[@d3stinYwOw]

@@MicroTypeEngineering mine? Why not, but I will send you other one, my OpenTacho project. Say if you're interested in! Why I wasn't commenting around? Work, work and work lately, so... But I'm still here!

[@MicroTypeEngineering]

Hah I hear you, yeah I'll take a look at it!

[@JohnDoe-eh4vd]

fuck yeah! thanks bro! so thankful for this information that im several orders of magnitude beyond thanks

[@og.StudMuffin]

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!

[@Witsenburg]

Thanks for the lesson! I have a question. Is it a problem to use such a Mosfet driver for non-switching applications? I want to run several high power mosfets from an STM32 chip (3,3V). Some will run PWM signals, some will just turn on at a certain point, but might only shut down after several hours. All info is welcome!

[@MicroTypeEngineering]

Not at all, it's just sometimes overkill to use one for that use case

[@houtmann774]

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!

[@simonndungu1196]

I am a huge fan of your design tips

[@jedfrank9597]

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.

[@VeryMuchBlessed]

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 KZbin 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]

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.)

[@uni-byte]

I have to disagree about the "two kinds of MOSFETs" You can certainly have high power logic level MOSFETs. An example that is not particularly new is the FDP8880. What makes a MOSFET logic level is a low threshold voltage. Particularly a MOSFET that will be essentially turned full on at or blow a Vgs of 5V. The FDP8880 has rds of only 14.5 mohm at 4.5V Vgs and can pass up to 54A, deal with 30V and dissipate 55W.

[@erikwallebom]

Great video! Also the max power and thermal resistance is related. 375 Watts * 0.4c/W gives junction temp rise of 150A. If case is held at 25c then junction would be at 175c which is max junction temp found in datasheet. Also at 375W and 338A then voltage would be 1,109V and that gives RDS(on) at 3,28mOhm which probably is the RDS(on) at 175c junction temp although I cannot find it in the datasheet.

[@kryptocat4240]

Great job

[@warrenmondon3375]

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.

[@notmuch_23]

This is nice to know if I want to use the high-current MOSFETs I have for modding flywheel dart blasters with a microcontroller for, say, a select-fire system.

[@gkdresden]

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.

[@erikvincent5846]

This is really good stuff! I have a couple of questions, though. If using that MOSFET driver, do I still need that gate pull down resistor, or is that included internally in that driver (I noticed the IN+ pin contains a 200K pull down, but wasn't sure if that translated to the gate pin). Second question is, if I use that setup, with the micro going to the MOSFET driver and then to the MOSFET, can I just hook that MOSFET drain straight to the brushed 10A DC motor's "negative" lead with the 12V going to the brushed 10A DC motor's "positive" lead? Assuming I use a fly back diode, like a MBR40100CT?

[@MicroTypeEngineering]

Great Questions! "If using that MOSFET driver, do I still need that gate pull down resistor" Typically no, because it is included like you say. But, an external resistor costs pennies, so I normally always include it, then there's never any surprises, and you can adjust the strength of it. "if I use that setup, with the micro going to the MOSFET driver and then to the MOSFET, can I just hook that MOSFET drain straight to the brushed 10A DC motor's "negative" lead" This one isn't as straight-forward. For the most part yes, what you described works. It depends on the motor in question though. Some don't like having their ground pin not at true ground. This is especially true if there's anything else on the motor (sensors, tach, encoder, etc.) that also uses ground. But for the most part, that is how I would control a brushed DC motor that I don't need directional control.

[@erikvincent5846]

@@MicroTypeEngineering Actually, I think I figured it out. If it's like a half-bridge MOSFET driver, then it appears to be "no pull down required" because the MOSFET driver takes care of that. On a different note, but similar. Is this why cheap Chinese PWM motor controllers, which don't use MOSFET drivers at all, and just use 555 Timers, or op-amps to create a PWM, require large heatsinks on their MOSFETs to keep them cool? I've traced a PCB from one, if you need one for reference.

[@a1nelson]

Easily, by far, the best guide to real-world use of MOSFETs on KZbin. 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]

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

[@DungNguyen-vu3ri]

Great video, thank you ! Also, can you please make a video comparing bjt gate-driver and optocoupler gate-driver. Thanks in advanced.

[@sidyajv]

Great video.

[@LOGICOMA]

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]

You're very welcome!

[@krzysztofadc2363]

Thank you for this usefull tutorial. Could you tell something about switching-losses? You described losses usung RdsON but if I understand correctly during switching, channel resistance varies from RdsOFF to RdsON and ofcourse power dissipation should be much higher.

[@JeremyCook]

Very informative. Thanks so much. Another video talked about average voltage to the gate via an Arduino analog output. That doesn't seem correct to me, as in an ideal situation you're simply passing a PWM signal from a microcontroller on to the MOSFET (possibly via a gate driver), which then replicates this same PWM signal as closely as possible. This would effectively be an average only on the final output. Or at least that is my understanding. Does that seem correct?

[@thusharapriyakalum3834]

What is the software you are using to demonstrate circuit in this video?

[@xiadu3539]

Could you make more video about the gate driver circuit design please? like DPT, active gate driver and so on. your video is really good. clear and easy to understand. Thank you so much.

[@Cutycats9]

Thanks a lot friend keep up we are with you forever

[@cncpreferred848]

Good video. I have to relearn a bunch of stuff. I had a bad heart attack causing hypoxia (lack of blood flow to the brain). My memory is like Swiss cheese. One thing I remember is that I used MosFETs to power 36 V motors at 36 A. I used a Flyback/Free Wheel diode across the motors but was burning holes in the MosFETs. I was operating at about 20,000 to 22,000 cycles per second adjusting the duty cycle for speed control. What I had to do is use Shottky fast acting diodes. Would a capacitor paralleled with the motor help prevent holes being burned in the MosFETs? I also have MosFETs rated at 120 A. I can't find the video again, but someone said I can push 120 A continuous through the MosFET in a TO-220 package. I have difficulty wrapping my brain around 120 A through a TO-220 package. Is 12 to 15 A more realistic, using 3 MosFETs paralleled for each motor. Or with 4 motors, can I just parallel 12 MosFETs to drive all four motors?? I am using a PWM to drive the gates.

[@craigpierce7996]

The depth of the theory dive is predicated upon the MOSFET's application. Speed AND power takes some theoretical application. This discussion is basically N-Channel grounded-source applications.

[@drsaif343]

Fantastic practical review. And I red the article in your blog. Its fantastic to. Thankvyou for the effort to simplify that important matter.

[@clems6989]

You reference 1.2A from the driver to the gate, But there's no way the gate will ever conduct 1.2A Right ?

[@seriousfacts838]

Tomorrow my exam pls help Sir A power mosfet with a breakdown rating BVDSS =800V MUST COnduct 10 A when on with a maximum on state voltage VDs =4v if the current density in the mosfet limit to 200A/cm2, estimate the conducting area which is required

[@EnergySeeker]

nice video i have a question for you if am connecting the mosfet to an optocopler and VDD is 15 volts on the optocoupler , when i connect the gate to the mosfet the signal on the gate it goes under the gate needed voltage why ?

[@InTheMirrorr]

Thank you for doing this

[@balcazar8529]

great tips thank you very much! I'm making an H bridge for a robot the video came in good time, I would like to see more about power control of DC motors and protection systems, greetings from Brazil

[@MicroTypeEngineering]

Thank you! I'm actually planning a project for a high-power brushed DC motor driver. Will use discrete MOSFETs for the H-Bridge :) Probably won't be ready to film it for a little while longer, but it is coming!

[@balcazar8529]

@@MicroTypeEngineering great! I'm waiting for that, good luck with the project

[@aarondcmedia9585]

@@MicroTypeEngineering Very keen to see that one - take your time editing / producing though, your video quality makes it well worth the wait IMO. Particularly keen to see how to design the flyback diode stage / considerations.

[@WayneMcNab]

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.

[@abhayp9]

I am new to Electronics, I want to know Using Mosfet Gate Driver you said it can supply 10A in that case I have to provide 10 A power supply to Mosfet Gate Driver ?

[@col0342]

One has "Turn-On Delay Time", "Rise Time", "Turn-Off Delay Time ", "Fall time" to consider too, with the Rise/Fall times being the ones that the most significant power loss happens. E.g. the IRFS7530TRL7PP datasheet places the total of those timed at 373ns (for over 3A as the gate charging current) - which places the absolute upper limit on the switching freq at 2.6MHz.

[@RexxSchneider]

I completely disagree with your conclusions about logic-level mosfets and the the reasons you gave. Your "incredible trade-offs" don't seem very incredible to me. Take a look at your objections: "basically the Rds(on), the amount of gate charge". Check the datasheets for a couple of popular mosfets and their logic-level equivalents: IRLZ44: Qg = 66nC; Rds(on)=28mΩ @Vgs=5V IRFZ44: Qg = 67nC; Rds(on)=28mΩ @Vgs=10V IRL530: Qg = 28nC; Rds(on)=160mΩ @Vgs=5V IRF530: Qg = 26nC; Rds(on)=160mΩ @Vgs=10V Now are you going to tell me with a straight face that those differences in Rds and Qg are indicative of "incredible trade-offs"? Unless I _need_ a mosfet gate driver, I'm always going to specify a logic-level mosfet if I'm controlling it from a 5V or 3.3V microcontroller, and I'd strongly recommend others do the same.

[@dalenassar9152]

Can the mosfet gate resistor be placed AHEAD of the gate-driver??...or must it always be directly connected to the mosfrt gate pin? THANKS MUCH FOR THE VERY INFORMATIVE VIDEO!!!

[@mattrothe149]

Thank you. Well done. I like how you slow down as you drill down through layers of abstraction. I also like the orders of magnitude short cuts. As in, I don't actually know how far it is to Jupiter but, I won't be driving there, no need to get hung up on the math at this point.

[@wills3212]

Perhaps the best instructional video for mosfets really clear thank you

[@ashfaqjuna]

Is the gate resistor really that important? Gate capacitance of smaller MOSFETs are not going to be that large..the gate resistors are really useful for reducing ' ringing' and EMI issues. I would not be worried about short circuit type currents into the gate from uCs... I have not come across any issues so far...unless I am wrong. Pull-down resistor however is a must

[@MicroTypeEngineering]

Yeah you're "mostly" right. It typically won't cause an issue with small FETs. But, when you have that gate resistor there, you know exactly what the resistance is, and you can vary it to test. You'd be surprised what a little gate resistance will do to help ringing and EMI compliance issues.

[@gedtoon6451]

In 2023, logic level Mosfets are much better than you say. The low cost IRF3708 can deliver 12 Amps with a gate voltage of 4.5V and has an Rdson of 10 milli ohms.

[@ShopperPlug]

Please show how to make high frequency laser drivers, used to make greyscale engravings. I have a low powered UV diode laser and would like to make PCB boards using photo-lithography process. Need to make a laser driver for it. It will be connected to a 3D printer to modulate it using PWM. Great video. Thanks.

[@cliffordjohnathan6140]

I tried to drive IRFP460 ( Vge 10Volt ) with TC4420 ( 18Volt power supply ) but the max output of TC4420 is 7,56 Volt with not enough volt to fully open IRFP460. Anyhelp ? How much voltage goes the NCP81074 give ?

[@jjones503]

Wonderful video sir! I'm brand new and trying to learn. Would you recommend a gate driver for something like running a outdoor LED light? I am working on a project for my home built RV and I'm designing a switch/remote relay for my external LED light banks. My thoughts after your video are that I should use one versus just straight N mosfet. But would like clarification if this is high enough power requirements to need such a design. Thanks!

[@Swenser]

I'm confused. I thought applying voltage to gate only allows for a tiny current? It is a voltage controlled device compared to bjt as a current controlled one. You say it will be like a short?

[@chrispac6264]

fantastic video really appreciate this. What is the program you’re using for the schematics please? KiCad?

[@leeleezi5862]

Man you deserve more views

[@MicroTypeEngineering]

I appreciate it!