Power MOSFET drivers

[@TYGAMatt]

Possibly the best explanation on the planet. Brilliant. Thank you Sir.

[@sambenyaakov]

Thanks

[@AccidentalScience]

Best explanation I ever found so far on KZbin, and from elsewhere (including some webinars from semiconductor manufacturers). I'll recomment your video to everybody who'd like to know more on this topic, and on my own videos if it comes the chance. Thank you for posting, greetings from the Alps.

[@sambenyaakov]

Thanks. I appreciate it.

[@samshoushan2881]

Yes he is

[@SathnimBandara]

This is THE best MOSFET driver tutorial on the internet. Thank you professor!

[@sambenyaakov]

Thanks🙂

[@samshoushan2881]

Yes

[@Magneticitist]

This is the best mosfet explanation I've ever seen, much appreciated.

[@sambenyaakov]

Thanks😊

[@IsaacOLEG]

@@sambenyaakov Helllo, I appreciate also, I am following your explanations even if i am a "false beginner" (my true job is piano tuning and regulation/repairs). I think I grasp % may be, often going back until I have it, but my impressions is that it helps to shape my mind in regard of "what is a mosfet used for in the first stages of laptop alimenations " it make mosfet and drivers more familiar, I am sure it helps me ! Thank you

[@nguyenduke83]

One of the best MOSFET driver tutorials that you can find on the internet. As usual, clips of Pro. Sam Ben-Yaakov are very practical and his explanation is intuitive and can not be clearer. Watching hours of his lectures on KZbin saves me days on the labs. These are some of my favorites on his channels: PWM controllers (signature is peak control mode), MOSFET drivers, Ground looping, inductor/transformers. I just wonder is there any book that he has published which covers those topics, i definitely stock it up on my shelf

[@sambenyaakov]

Thanks. No, have not published books.

[@archie6586]

true

[@alocin110]

Thank you Prof. Ben-Yaakov, well-explained and very thorough. Videos like this help millions of students who cannot afford expensive books and after-school institutions. You are a teacher of millions: what a big class you have Prof. Ben? Thank you for running a school without boundries and with A-class level. God bless you and your team.

[@sambenyaakov]

Thanks for warm words. Comments like yours keep me going.

[@jamesjohnston9319]

Thank you Professor, I love how your videos are the perfect blend of applied engineering and theory/maths! Its very hard to find that.

[@sambenyaakov]

🙏😊

[@BRR999]

This is by FAR FAR the BEST no bullshit down to earth explanation on the internet!!! Thank you thank you thank you.

[@sambenyaakov]

This is by FAR FAR one of the BEST comments I got. Thanks.

[@carmelpule6954]

Such elegance in every depicted detail can only come about through a long experience of dedicated work. Congratulations and thank you for your presentations.

[@sambenyaakov]

Thanks

[@Black26Jack]

Thank you, Mr. Ben-Yaakov. Easy explanation. You are talented teacher!

[@sambenyaakov]

Thanks

[@davidsecades6633]

Informative, concise, well-explained... It is clear how much you really love teaching, and we all appreciate it. I am an electronics degree student and even though some of these concepts have been mentioned in class (while talking about converters) only with your explanation do I begin to understand how much there is to know about this subject. I am eager to rewatch the video with time and patience to really soak up everything you said. I would be happy if one day I would be able not only to interiorize the knowledge but to explain it half as good as you do. Thank you very much.

[@sambenyaakov]

Thanks Davis for the kind note. Comments like yours keep me going.

[@idiragouni5520]

Your explanation is simple, deep and educational at the same time. It's been a week that I try to find a solution to control the mosfets of a speed variator for three-phase Asynchronous motor. A floating power supply was essential, and the methods using transformers or optocouplers did not satisfy me. You just saved my life with this IF2110, thank you so much. In addition let me congratulate you on the English used, simple and concise while in the technical field I am more used to French.

[@sambenyaakov]

Thanks for comment.

[@GluonToo]

Thanks from Poland! Very interesting lectures, clear manner of transmission, information beyond the basics. Something like this I was looking for.

[@sambenyaakov]

Thanks.

[@BillySugger1965]

That is outstanding! I’m an electronics engineer and design power circuits. I have saved many, many videos on machining and other engineering topics to learn from, but this is the first electronics video I have ever felt the desire to save for future reference. Simply superb!

[@sambenyaakov]

Thanks for kind note.

[@y.e.d5660]

ı am following you over 2 years and sir you are a really good person. because you are sharing with us amazing informations. ı respect you very much. thanks for tutorial. be safe.

[@sambenyaakov]

Thanks. Comments like yours keep me going.

[@filipradulovic_]

8:30 is best explanation of Miller Capacitance I found out there. Thank you!

[@sambenyaakov]

👍🙏

[@movax20h]

Very useful presentation. I like the methodical approach of showing the problem and then a solution. It makes everything easier and show the real engineering and design process. Now I understand a lot of nuances better.

[@sambenyaakov]

Thanks.

[@ohmedarick1]

Wow this is the best explanation on power tutorial I'm trying to build a two phase ---two three phase inverter. Thank you you cleared up so many questions i had...

[@IsaacOLEG]

'intuitive " is the word, your reasoning is so clear it is amazing how I can follow you despite being not real electronician, merely hobbyist trying to repair laptops tvs and other ! Thank you so much

[@sambenyaakov]

Thnks for comment

[@IsaacOLEG]

​@@sambenyaakov great you appreciated it, thanks. I have been lost after "gate power loss" (mainly I can understant the preambules of chapters, which is probably enough for me, but the following make me "loose the Arianne's thread" ;) ) of the explanations. Now wondering if I'd better begin by watching the 2 parts on Mosfet's datasheets , (or some other ?) what do you think ? Thank you again

[@habtamusium8646]

your video is very useful for pupil in confusion on MOSFET like me. now i am in settling my disturbance and do not afraid to observe at PCB of electronics and give advice for those who turn their face away from PCB. thank you sir !

[@sambenyaakov]

Thanks for taking the time to write the comment.

[@franklinw7320]

Very excellent explanation, professor. I learnt a lot from your video series and got a better understanding of what is really happening in power generators. Thanks again!

[@sambenyaakov]

😊

[@vtgastulo]

Thanks for taking the time to share your knowledge of power electronics Prof. Ben-Yaakov!

[@sambenyaakov]

Thanks

[@burakaltay7485]

I couldn't be more grateful for such an amazing video. Even if I am already graduated, this video helped me understand drivers better than any other lesson.

[@sambenyaakov]

Thanks for taking the time to write the note.

[@DaFratRat]

I love how you frame it from an engineering design point of view. It seems obvious now that you have said it. I'm excited to read through all your series. I hope to be able to apply this knowledge at work soon!

[@sambenyaakov]

Thanks for comment. Welcome abroad😊

[@kolinevans9127]

Wow ‘DC restore’ , there is always some gold hidden in your videos thanks for sharing.

[@sambenyaakov]

👍😊

[@jerrychan1471]

Thank you for your detailed explanations, they are truly educational and practical. I feel like the fog has been lifted in my mind pertaining to this subject matter!

[@sambenyaakov]

Thanks. Comments like yours keep me going.

[@drsanjaykemkar7313]

Quality explanation. Great!! Lot of issues are addressed. Probably best on KZbin.

[@sambenyaakov]

Thank for note.

[@ecstazyrm]

Best electronics channel on KZbin by far! Thanks!

[@sambenyaakov]

Wow, thanks!

[@세상에예거]

your lecture is fantastic, it's very helpful to understand power electronics. thank you, dear.

[@sambenyaakov]

Thanks (Korea?)

[@Spark-Hole]

Best preparation, thorough. This vidio will be on KZbin for hundreds of year.Big salute, Thank you.

[@sambenyaakov]

Thank you. You warmed my heart.

[@sambenyaakov]

Thanks for comment.

[@sambenyaakov]

Respectable (or not) Niksa, just seen your comments. AS you know, I don't work for you so I really do not have to answer any of your questions. But, as a service to the community I do my best to answer queries that are sent to me. If you would repeat your question in a civilized manner I will answer (unless I miss the question as might happen considering the many questions I receive). Have a wonderful day.

[@arthurm7846]

Your channel is gold, thanks Prof. Sam!

[@sambenyaakov]

I appreciate that!

[@andrewferg8737]

Best explanation I've heard so far! Thanks for the education.

[@sambenyaakov]

Thanks

[@zainaabdin]

Though I am late to ur lesson but it was marvelous...as an amateur I encountered tons of problems connecting to mosfets in simple and naive methods which by accident worked but mostly either not perfect or doomed to failure....ur a teacher....but a professional one....so many thanks

[@sambenyaakov]

Thanks for comment

[@arthurswanson3285]

You are a teacher par excellence, Professor.

[@sambenyaakov]

Thanks for kind words.

[@ruixiong5237]

It is thorough tutorial both in theory and in practice. Thanks a lot.

[@sambenyaakov]

Thanks

[@richsmith46]

One of the clearest explanations of this topic I've seen. Thanks for sharing

[@sambenyaakov]

😊

[@kareemdawood4053]

Thanks for the nice explanation. I have been testing some SiC NMOS and I prototyped a rig with some wires and terminal blocks to see how much switching frequency I can drive the mosfet to with air cooling. I have stray inductance every where of course since it is not a pcb. The circuit is a low side drive of a resistor bank, I observe a weird waveform accross Vds when with the falling edge of the pwm driver. It is not the typical ringing, it is rather a very high spike in voltage that is followed by negative voltage and then the typical ringing around the supply voltage. Snubbing is not getting rid of the first spike.

[@sambenyaakov]

Thanks for sharing. A PCB with a good layout is a must.

[@davejohnson1589]

Very many thanks Professor for such a prompt reply. As always the more one finds out about a situation the complex it can become. Seems likely my problem has much to do with using 6 MOSFETs in parallel & poor dynamic current sharing. Variation in Vth can result in some devices switching quicker causing others to go out of S.O.A.. Advice appears contradictory as fast switching, am told, coupling gates using low or zero series gate Rg & hard switching helps reduce this effect. Am also told that parasitic oscillation can occurr for the same reason & increasing Rg & fitting your recommended Fe bead on each gate cures. In my case looks like some Rg value between these arguments is needed. Experiment is called for. Thanks again. Dave

[@sambenyaakov]

Have you seen kzbin.info/www/bejne/d6KUeqpsd96Ld9k ?

[@scollyer.tuition]

I've only just discovered this channel, but it looks to be a gem - a real breath of fresh air, with enough attention being paid to the underlying circuit physics to make genuinely useful derivations, as opposed to the vigorous hand-waving available on most KZbin treatments of the material. However, I have a question: in your derivation of the Miller effect, starting from about 5:55, you seem to be claiming that the voltage across C_{gd} is V_{GS} + V_O. From your diagram, the top of C_{gd} is at V_O and the bottom is at V_{GS} - I would therefore expect the voltage across that cap. to be V_O - V_{GS} I am clearly misunderstanding something, but I can't see what it is - maybe I'm making a sign error somehow?

[@sambenyaakov]

Thanks for comment. This is indeed confusing. Look at this this way: Looking from the gate, Cgd was initially charge to -Vo, and then charge to Vgs. So the total charge needed is (Vo+Vgs)Cgd

[@Azagro]

Very great presentation, covers every aspect about MOSFET driving. Thank you for listening to my request!

[@sambenyaakov]

Thanks. Will see what I can add in next videos. Thanks again for the encouragement.

[@Azagro]

Sam Ben-Yaakov Thank you for your effort, we highly appreciate it.

[@mohammedradoan3928]

This was a very informative and well-explained video!!! Thank you sir, for the dedication u put into it!!

[@sambenyaakov]

Thanks for taking the time to write comment.

[@yamensaad6832]

One of the best videos in youtube Thank you

[@sambenyaakov]

Thanks👍

[@osamaalkassem5676]

Amazing excellent course thanks for every minute of your time .... ❤

[@sambenyaakov]

Thanks

[@PSPS437]

Very well explained Dr. Sam

[@sambenyaakov]

Thanks.

[@davejohnson1589]

I omitted, in my question regarding fast turn-off diodes shunting MOSFET series gate resistors, to say that I do not know much about the original drive speed or frequency but I do know each Rg was 47R with no fast turn-off diode. My question really should have been is relability improved, maybe at a reduction of efficiency, by using a slower drive edges? I have attempted to comply with your recommendations with snubbers & safely limitted my device overshoot although admit I have not verified my circuit at the full 6kW. Thank you again. Dave johnson

[@sambenyaakov]

Hi Dave, I have seen the two part of your query. Fast turn off could be beneficial to improve the efficiency. The 47Ohm will slow down turn on and hence help reduce the reverse recovery spikes.

[@ChrisSmith-tc4df]

I used a form of that DC restorer circuit to develop a solid state version of a gate driver for a very large SCR that needs a many amps to turn-on quickly and reliably yet one wants that to be brief to reduce unnecessary gate power dissipation. Selection of a quality pulse capacitor that can handle that repetitive peak current turned out to be key for reliability.

[@sambenyaakov]

Thanks for sharing.

[@power-max]

At 15:00, with this method, shouldn't there by a multiple of 2 for the switching frequency? Because every cycle you need to turn the element on, then off? Therefore you have to dissipate Q*Vgs twice per cycle, so the resultant formula should be *2* * f_s * Q * V_gs

[@sambenyaakov]

No. Think about the energy that comes out of the driver (only at turn on)

[@power-max]

@@sambenyaakov I see! I though about it some-more and realized the classic physics formula of energy in a capacitor is 1/2*C*V^2. Well at a fixed/constant 'V' if only half the energy is stored in the capacitor, the other half must be dissipated in the resistor. Both times charging and discharging through it. Not sure if that's the right way to think about it (kind of 'hand wavy' description) would you agree?

[@thisoldjeepcj5]

Very useful. Very good presentation.

[@sambenyaakov]

Thanks

[@alexshei5061]

The best tutorials on power engineering!!

[@sambenyaakov]

Thanks😊

[@alirezaeskandari2287]

Thank you very much professor!🙏 Your video helped me a lot.

[@sambenyaakov]

Thanks

[@ottoomen5076]

I appreciate you more everyday.

[@sambenyaakov]

😊🙏

[@LEO22116]

Your videos are the best. I, as a Master's student of Power electronics, get most of my concepts cleared on your channel. Please explain the effects of body diode in MOSFET and how this varies when we use IGBT.

[@sambenyaakov]

This issue is discussed in some other videos of mine. In short: the body diode of a Si MOSFET is a rather slow diode so there might be a problem of reverse recovery. IGBTs doe no have an intrinsic diodes so you can parallel them with fast diodes.

[@LEO22116]

Could you please share the title of the video?

[@sambenyaakov]

Go to www.advicepoweracademy.com/video-tutorials and search for diode

[@ankitkherodiya2961]

Great video. Detailed explanation of gate drivers Thanks a lot

[@sambenyaakov]

Thanks for comment.

[@jellyguo2450]

Wow, it still helps people like me trying to overcome the ringring of the high side MOSFET.

[@sambenyaakov]

👍

[@dimtsk838]

Great explanation. Thank you for sharing your knowledge!

[@sambenyaakov]

Thanks

[@peterhemmings2929]

What a superb lecture, thank you so much

[@sambenyaakov]

Thanks

[@santiagoverne]

I appreciate very much your explanations. I wish to ask you if middle trace in 11:02 should be falling instead of rising, given that Igate is positive. Thank you Professor!

[@sambenyaakov]

Wow, you got me there. You are correct if this is the voltage on the MOSFET Vds

[@BB-iq4su]

At 23:09 I believe Vt of both the PMOS and NMOS should be greater than 1/2 Vc.

[@sambenyaakov]

This is preferred but many circuit operate with Vt

[@kristhetrader5029]

Indeed VER well explained from the first minute already! Excellent stuff, would be nice to have a PDF of this...

[@rodrigolindemberga]

Boa tarde! Gostaria de agradecer os ensinamentos que estou tentando em vários vídeos que você está produzindo. São os melhores. Parabéns, ótimo trabalho! Obrigado!

[@KamleshGadhvana]

thank you very much from India.

[@sambenyaakov]

Thanks

[@pallavishirsat]

Hi, thanks for video. i have question --> can you please explain effect (positive , negative)of body diode of MOSFET in H bridge application(consider all four are N channel MOSFETs). Also why H bridge configuration with all mosfet as N channel mosfet. what is disadvantage with use of 2 p channel mosfet as High side driver and 2 N channel MOSFETs as Low side driver in H bridge application

[@mortenrolsing7137]

Fantastic video, thanks a lot, it helped me understand gate charges, it has always been very difficult for me to realy understand. Greatings from Denmark Morten

[@sambenyaakov]

Thanks

[@babylonfive]

This is great stuff as usual. Thanks for helping remind me how my HV motor driver gate drivers behave! Best regards.

[@sambenyaakov]

Thanks

[@donaldwright2426]

I realy like your presentation and also, took notes. However, I'm designing a 144Vdc 6phase inverter at 100A to drive a dual stator PMSM that I've design and currently being built. Just when do we need to isolate (galvinize) the power side of the logic side? Is it just a question of preferences or is it most likely due to different codes or standards if an electronic device is intended to be commercialize ? For a start, I've decide to have a none isolated power and logic power and the choosen driver is the IRS21864PBF which does have a seperate logic ground (VSS) and hi volt power gound (COM) just as you explained and will have to be tie together. At least, I've got this part of my project right! Thanks.

[@sambenyaakov]

Hi Donald, The purpose of gate drive isolation is not isolation per se, but ground separation. The grounds can (and recommended to be) connected at one point. Without isolation the digital signal reaching the gate driver (which should be close to switches) may and usually be corrupted due to the voltage drop along the ground. Some of this is partially covered in kzbin.info/www/bejne/q37IaqSqncidiZY . If not confidential, love to hear about your dual stator drive and motor.

[@donaldwright2426]

​@@sambenyaakov Thanks for your answer. For now, I will stick with my non-isolated drivers since I'm exploring different options! My motor project is not confidential. I invite you to read here: openvolta.blogspot.com/ and my youtube chanel : kzbin.info/www/bejne/aYabaKpor9yifs0. I've not been very good at updating my blog or youtube channel. Since, there has been a couple of updates to design that has enhanced the torque and the efficiency. Theoretically, according to the simulations in in FEMM, it can reacht a maximum efficiency of 97%. It's not taking into account the mechanical losses. Also, according to research that I've read, the rotor design is prone to a lot of eddy current losses. So heat is expected and demagnetizing the PM is an other issue. This motor is intedned to be a direct drive. It output 99Nm à 100A nominal. The copper losses are low. THe outer stator has 7 wound turns and the inner stator as 4 turns. At a certain point, the outer stater will not be injected with current and only the inner stator will be energized. Again thank you!

[@sambenyaakov]

@@donaldwright2426 Thanks for sharing. Interesting. Will study it.

[@donaldwright2426]

​@@sambenyaakov Here's my email donald.wright @ openvolta.org if ever you would like to have my raw data of the FEMM simulations. Also, thank you very much, and thanks you in advance if ever you do comment about my motor project. Best regards, Donald W.

[@vincenzodemaio7175]

Clear and interesting explanation....Thanks a lot

[@sambenyaakov]

Thanks

[@rayking3483]

Sam, Thank you for your explanation of the concerns of power mos gate driving. I did notice one circuit that was given up too quickly. That was the p and n fet totem pole gate drive that was given up on because of shoot-through. If the input gate resistor is moved from the power fet to the source of the driver p fet you get a fast turn off and a reduced turn on current which is desirable with out shoot-through. Respectfully, Ray

[@sambenyaakov]

Hi Ray, Thanks for comment. Please indelicate which slide no. or video minute you are referring to. I am always happy to learn but I am not sure what you meant.

[@rayking3483]

Sam, I was not ready for such a fast response. The DC-DC Converters page 8-18. The lower schematic of the cmos gate driver. Thank you. Ray

[@sambenyaakov]

Good point if you want an symmetrical drive. In fact you can put two resistors in series between the drains of the drive FETs and connect the gate of power transistor to midpoint.

[@stanislavsubrt886]

Thank you very much! Outstanding explanation, practical topics...

[@mohammadhafeezkhanraja4758]

Thanks prof.Ben for detailed lesson on Mosfet

[@sambenyaakov]

Thanks.

[@biswajit681]

@1:27 after Q2(x axis) isn't it it charges only Qgs not Qgs+Qgd .. because till now all the app notes I have found everywhere it has been mentioned only Qgs not Qgs+Qgd .. Correct me if I am wrong

[@sambenyaakov]

You may be correct in saying that in the app notes you have seen, the charge is Cgs, but this is incorrect. If this charge would have been Cgs, why do you see the flat portion? This plateau is due to Miller effect caused by the charging of Cgd. All this is explained in video.

[@biswajit681]

@@sambenyaakov Sir I am referring after Miller platue region ( at the end of Miller platue region Cgd charges fully) when VGS rises futher at that time only Cgs charges to reduce RDSon.....but in your videos it shows QGS+QGD both charges. Am I making any mistakes?

[@sambenyaakov]

@@biswajit681 Yes you do. Once the plateau ended Cgs and Cgd are in PARALLEL and both continue to charge (no Miller effect)

[@wariskn7096]

I really loved it....the drawings are too clean!!!

[@sambenyaakov]

👍😊

[@samlee1089]

Learn a lot from this video! Thank you sir!

[@mkaras98]

Do changes in the depleted area during on/off switching of the MOSFET significantly affect the capacitance of Cgd and Cds? great channel greetings

[@sambenyaakov]

Thanks. I don't think so.

[@maksudulhossainjewel378]

Hello Dr. Yaakov, can you please upload something on double pulse testing explanations, pitfalls etc. ?

[@sambenyaakov]

A good subject. Will try.

[@marcinszajner2924]

I think is usefull use term "critical resitance" for oscillation. Critical resitance is Rcrit = 2*sqr(L/C) which give no oscillation beatween L and C, because it gave critical aperiodic course of voltage. Thanks for great material, which take all important information in one lecture.

[@sambenyaakov]

Thanks for comment.

[@karastom2304]

Hi Dr Sam thanks so much you are very smart and wonderful in teaching, i have question about IGBT, how can i get ride of the problem of higher dv/dt, turning IGBT off with negative voltage does is not effective , so how i can prevent IGBT from blowing up due to dv/dt. Thanks,

[@sambenyaakov]

Thanks for comment. The simple way to controls dv/dt is by increasing gate resistor.

[@karastom2304]

Thanks Dr. Same, but the switching losses will increase, is there another solution

[@sambenyaakov]

You can use a turn off lossless snubber. This will decrease dv/dt.

[@royalsingh]

Thanks for the informative talk. Just a question, if you are open to talking them - Once the Gate capacitors charge enough and it starts conducting - how is any additional current flowing from the driver supposed to be handled (Lets say we wish to maintain that position for long). Is the resistor @ driver supposed to sink in all that excess charge or the grounding resistor would start to share it?

[@sambenyaakov]

Happy to answer. For the MOSFET to conduct, there is no need for a current. Once the gate voltage is above the threshold it will conduct. The driver charges the gate until the gate voltage equals the driver's output voltage and the current flow will stop, save some bleeding if the is a resistor between gate and source.

[@royalsingh]

@@sambenyaakov ​Thanks. I have a Power MOSFET - IRF1404 which requires total gate charge of 196nC but the driver I have in mind (2N7000) has Max drain current of 200mA. Do you think it could drive the Mosfet easily - actually it needs to drive 4 such Mosfets in parallel. Individual drivers to each Mosfet is the way to go or should this single one be enough to drive all of them in its sweet time?

[@sambenyaakov]

@@royalsingh A single driver can drive the 4 transistors. Think about it as a voltage source charging four capacitors in parallel. But... the turn on time will be relativity long so if the switching frequency is high you will have heavy switching losses which will heat up the transistors. If you use one driver better to use separate (series) gate resistors for each. There are drivers with much higher current.

[@royalsingh]

​ @Sam Ben-Yaakov Brilliant! Many thanks for your suggestion. Switching frequency is almost negligible, they would be utilized to switch a BMS input supply. Have a Good Day!

[@rickdalesandro1109]

How about a high side switch that gets Gate Drive from the High Side Voltage and is switched by an NPN transistor to GND. Not isolated, but you don't always need isolation

[@sambenyaakov]

Possibly. Have you seen: kzbin.info/www/bejne/lXPKlauDjJh7orM kzbin.info/www/bejne/g5rMfqika5uZbZo

[@cyberphox1]

Great video prof. Thank you 🙏

[@sambenyaakov]

Thanks

[@Berilium65]

Excellent explanation! Very well done!

[@sambenyaakov]

😊👍

[@Stelios.Posantzis]

Excellent lecture series!

[@sambenyaakov]

Thanks.

[@binzhao2544]

Very useful. Thank you, Professor.

[@sambenyaakov]

😊

[@johnregis5320]

Dear Prof Yaakov, thanks for this comprehensive tutorial. I only have one question: at 9:39, it is shown that the total charge Q can be read from datasheet but when I get into manufacturer data, I see that it refers to specific operating values for Vo, Id, Vgs which in general are different from the values in my application. Straightforward question: starting from datasheet information is there a procedure or even a rule of thumb to extrapolate Q for different operating values of the previously mentioned parameters ?

[@sambenyaakov]

Hi John., thnks for note, The main correction needed is for a change in voltage. The others are really minor. AS a first approximation the length of the flat portion of the v=f(Q) curve is proportional to Vo.

[@johnregis5320]

@@sambenyaakov Thanks!

[@samshoushan2881]

you are very kind human person

[@sambenyaakov]

😊Thanks

[@abrahamtareke9995]

Thanks professor for the Great video with lots of useful information. I have one confusion regarding the Vgs plot during turn in. Does the Vgs stay constant at the threshold voltage or at the plateau voltage corresponding to the drain current. I think the flat portion should be the plateau voltage.

[@sambenyaakov]

Have you seen kzbin.info/www/bejne/iZDSkJ-qga92jbs ?

[@rashmiranjannayak3251]

Hi, Sir Sam Ben Yaakov, really its your maturity in cool engineering.

[@sambenyaakov]

Thanks.

[@MRTOPHAMHATRIEU]

thanks for the knowledge. would you please also share the slide of the lecture for this. This would be great.

[@sambenyaakov]

Sorry for being unable to share the slides

[@Pudersepp]

Thank you very much for sharing your knowledge in such a structured manner! I'd love to be your student at the university :)

[@elvismao3924]

Great tutorial ! Thank you very much!

[@sambenyaakov]

Thanks

[@mcfan1956]

Thanks!! i like all your videos. im glad i can be your student on youtube. respect, sir!

[@sambenyaakov]

Thanks for comment.

[@vssabah]

What will happen if I select a weak driver ie .25A gate driver for a power MOSFET where ideally 4A driver is required. What's the worst case effect of the above

[@sambenyaakov]

Higher switching losses.

[@karastom2304]

Thanks Dr Sam , I learn a lot from your lectures, for the DC Restorer if I have dead time between the 2 signals I will have plateau in the secondary side, how can I get from this plateau

[@sambenyaakov]

I am not clear about your question. Please explain.

[@karastom2304]

please Dr Sam , can you open this link forum.allaboutcircuits.com/threads/gate-drive-signal-plateau-problem.145228/

[@sambenyaakov]

Sorry, could not enter. Not a member. Please send to [e-mail]

[@chunchiehwang5663]

Dr. Sam. regarding Ton of MOSFET you mention at page [8-9] ,can I find this data in MOS datasheet or calculate it? Thanks!

[@sambenyaakov]

Ton is in fact the rise time YOU want. To completely charging the gate.

[@chunchiehwang5663]

@@sambenyaakov Dr. Sam. Thanks for reply, on the other hand, it means if I set driving current of MOSFET,then Ton time can be calculated,right?

[@arshadiqbal4809]

What will be the ratings of high side Push-pull fets/bjts acting as gate driver boosters to an igbt based h-bridge if Input to h-bridge is 600v. Should they also be of 600v or less. Plz reply urgently if my question is not clearly understandable to you. You are explaining it at 22:30 time in this video

[@sambenyaakov]

The pus- pull driver transistors rating is related to the drive voltage - not total voltage .

[@arshadiqbal4809]

@@sambenyaakov Thanx sir

[@bikefarmtaiwan1800]

So interesting! Thanks for teaching.

[@sambenyaakov]

Thanks for comment.

[@furqanpak]

thanks for excellent lecture.One question at 18:53 how voltage at emitter of PNP is -VT?

[@sambenyaakov]

Thanks. MOSFET is enhancement mode N channel so it is positive threshold

[@ijayess]

I am a bit confused as to why turning off fast has the drain voltage rise slowly thus limiting switching losses. I would think turning off slow would make the drain voltage increase slowly. But seems to be the opposite. Can someone explain that a bit more?

[@sambenyaakov]

If you turn the current fast and the voltage rises slowly, there will be minimum overlap which causes losses.

[@ijayess]

@@sambenyaakov would this just be because the turn on is way faster than the capacitor can respond and charge up. So turn off fast, cap absorbs some charge but isn’t fast enough to drive up the drain voltage. Being that Vds is a term in switching losses and is low it drives down the losses? Would you want turn on to be some percentage less than the rc time constant, using esr as the r? Thanks for the reply by the way, I am so happy that I found your videos. Been watching and taking notes for weeks now:)

[@danielhadjibashi4519]

Professor, any chance you could do a video on dead time, and how to achieve it for 3 phase inverter circuits. Thanks

[@sambenyaakov]

What do mean by "how to achieve it"?

[@danielhadjibashi4519]

@@sambenyaakov I mean how to determine how much dead time is required in order to avoid shoot through when designing half bridge, H bridge or 3 phase inverter circuits. e. g. In a situation where you have high side and low side MOSFETs. Also is dead time implemented in code, hardware or both? Can it be calculated? if you could do a lecture on this matter that would be great 😊😀

[@sambenyaakov]

OK. Got it. This is indeed a good topic but not easy as there atre many caveats. Will see. Thanks for your suggestion.

[@sirousmohseni4]

Excellent video. Thanks

[@sambenyaakov]

Thanks