Your lectures are so clear, so informative, and you interact with the comments. I have even sat through some of your Hebrew lectures not knowing what you are saying BUT following along as best I can with your annotations! haha. Amazing person, thank you very much Prof. Ben-Yaakov.
I enjoy these lessons more and more. This is again an often used piece of circuits and so are the just learned insights not only interesting but such lessons are practical so very usefull. It is easy enough to follow but with much new insights or knowledge. No other youtubechannel teaches on this level that is so much more worth the efford of following(so with understanding) each word really good. I watch more and more of the older lessons and i look out for new lessons like this with more and more joy. I thank you só for making this lessons, free to follow here on youtube, for everyone who want or need to know practical electronics.. (I hope i may for long times keep learning from you!)
The di/dt induced Voltage effect in half bridge application can be avoided by the kelvin connection in the source terminal. The Kelvin connection will decouple the bound wire inductance and the gate drive terminal. Then the bipolar gate is effective for the of dv/dt reason predominantly not di/dt . The lecture is very good and mind intriguing.❤
Can back to back zener with coupling capacitor configuration be used with bootstrap circuitry? or alternative question would be is it duty independent? I am having a hard time figuring a driver circuit that involves negative bias with only one supply for three phase inverters
very useful video many thanks, here are my notes (not totally sure they are right though!) : - Method A does work but the capacitor needs a time constant (or 2-3 ) set by its capacitance and the pull down resistor on gate which can be in the order of a few milliseconds. - Method B cannot work because the zener prevents negative voltage on the gate (except the forward voltage of the zener) - Method C works, the capacitor time constant is minimal and set but zeners internal resistances (almost instant), and as a bonus you get gate protection from gate overvoltage so I guess method C is the best one of the mentioned?!
I think Dr. sam overlooked Method B. It needs an extra reverse zener connected to the 1st zener ( then it would anyhow become Method C). 22:57 and 24:59 are commonly used. Luxury Isolated based gate drive vs a non-luxury based bootstrap gate drive just to over come cdv/dt. Higher the negative gate voltage, worst is the VSD diode drop of GAN.
Hi, Thanks for useful comments. Method A is OK . No problem to keep the negative voltage flat with practical c an r values. Method B: oops, I missed drawing a diode in series with Zener to avoid clamping. Method C is nice but when input pulse voltage is higher than sum of Zener diodes' voltages, the capacitor is being charged an discharged which adds to power loss. Thanks for pointing to error in B 😊.
@@sambenyaakov Hi, I meant the initial time needed to charge the capacitor which for Method A is 1-2 taus -> τ= R_pulldown * C_series a few ms charge time would cause a few ms of shoot throughs at startup(if the gate's negative voltage is not enough) which "probably" would cause nothing but yet annoying :-) Method C charge time is almost instantaneous and has added bonus of gate protection, your point on choosing bad zener voltage might be true but I didn't see it in my simulations, also that would be a point for choosing the wrong components :D anyway, Method C is so useful and simple yet I hadn't see it anywhere else till your video, thanks again for sharing your knowledge Sam
Thanks a lot prof. Sam for this wonderful explanation 👍 ... It'd be very useful if you sir make a lecture about gate driver protection techniques (this is becoming an important design aspect especially when working with GaN eHEMT where the threshold voltage is low).
Thanks so much Dr. Sam is very useful lecture, in minute 12 you said when Rg is smaller during turning off is better and current will be low, but if Rg is low mean that it will turn off faster and dv/dt will be high and current will be high, so why Rg in turning off is better to be small? Thanks,
dv/dt will primarily be determined by Coss and the current of inductor. Small Rg during turn off will 1. lower switching losses and 2. lower the spike due to dv/dt passing via Cgd.
yes I did find it interesting ....as on several previous presentations, I get lost on the detail and I suspect you are missing key points in explanations such that it feels as though you have made mistakes in the presentation and for me it takes away from the learning flow. I like the subjects you cover however I am limiting my viewing as it frustrates me to be doubting and dismissing mistakes and or missing points. It is most likely me and not you as everyone else who has commented previously compliments you on fine presentations. I have not given you a negative score as I saw that you wanted feedback to improve your content....hence this comment.....there is much more I could add, perhaps not appropriate here.
Hi, thanks for the time and effort to write your comments. In as much that I rather not make mistakes in the presentations I am sharing, I have found during my many years of teaching, that mistakes in lectures are stimulating and adding to the absorbtion of the knowledge conveyed and certainly simulating exchange. See other comments to this video. I also think, with all due respect, that you do not appreciate the time and effort it takes to prepare these videos which I am contributing to the community for the enjoyment of giving and the frequent thanks I get.
@@sambenyaakov Thank you for the reply - I was not expecting one - or at least not on the public comments. Firstly I would like to repeat my comment - hidden in my last message "I like the subjects you cover" - and as a confirmation, I appreciate the time and effort to make these videos, I appreciate you are providing education for free, and appreciate that you are doing this - for all those that either don't have electronics training and those like me who want a reminder and or brush up on what we have forgotten or never covered (I did engineering a very long time ago) - I now have a hobby DIY interest - retired but still wanting to learn. As I said I am sure it is just me, but in an earlier video you asked if people made comments to assist you to improve your presentations - that is what I wanted to achieve here - rather than just clicking Thumbs Down, with you having no idea what or why it was negatively received. I do see you do get a large no. (the majority) of glowing likes and great comments - you have earned those. And for me (perhaps the only one) errors in presentations are fine if you know the subject matter intimately, but for me, I wish to understand every section so that it sticks in the right place in my understanding otherwise I loose the plot (while I am trying to make sense of something that may or may not fit with my earlier education). I also appreciate you are very knowledgeable and not only in one or two disciplines - but a very wide ranging engineering area - and I also acknowledge how knowing it so well and having produced/written the material - you cannot easily proof read/watch it as you are intimately connected and knowledgeable on the presentation - we or rather me, is not - I want to hang on every word and illustration - as it is the first time I see it, and so it is that proof readers cannot be good at their profession unless they are unaware of what you meant to say or illustrate - but have in this case a good general Electrical Engineering background.
I believe this isn't a channel where you shouldn't be "smothered" by details... Maybe you could find some other channels on TH-cam that would do the trick for you. Nevertheless Prof. Yaakov is often times the only person who is able to do presentations on such aspects that we need every possible detail we could get but somehow can't find in any other channel. I suppose you should realize the difference between "not liking" and "disliking". These videos may not meet your expectations but I don't think there is a reason even to consider disliking such effort gifted us by a valued person by their valuable time.
Your lectures are so clear, so informative, and you interact with the comments. I have even sat through some of your Hebrew lectures not knowing what you are saying BUT following along as best I can with your annotations! haha. Amazing person, thank you very much Prof. Ben-Yaakov.
Thanks Darren for taking the time to write the comment. Comments like yours keeps me going 😊
I enjoy these lessons more and more. This is again an often used piece of circuits and so are the just learned insights not only interesting but such lessons are practical so very usefull. It is easy enough to follow but with much new insights or knowledge. No other youtubechannel teaches on this level that is so much more worth the efford of following(so with understanding) each word really good. I watch more and more of the older lessons and i look out for new lessons like this with more and more joy. I thank you só for making this lessons, free to follow here on youtube, for everyone who want or need to know practical electronics.. (I hope i may for long times keep learning from you!)
Thanks Rob for comment
The di/dt induced Voltage effect in half bridge application can be avoided by the kelvin connection in the source terminal. The Kelvin connection will decouple the bound wire inductance and the gate drive terminal.
Then the bipolar gate is effective for the of dv/dt reason predominantly not di/dt .
The lecture is very good and mind intriguing.❤
Thanks for input. To which minute in the video are you referring?
8.17 to 10.08
Fantastic explanation Dr. Sam
Thanks Swaraj😊
Can back to back zener with coupling capacitor configuration be used with bootstrap circuitry? or alternative question would be is it duty independent? I am having a hard time figuring a driver circuit that involves negative bias with only one supply for three phase inverters
Not sure I follow you.
Toda, professor. That's very useful explanation
👍😊
very useful video many thanks, here are my notes (not totally sure they are right though!) :
- Method A does work but the capacitor needs a time constant (or 2-3 ) set by its capacitance and the pull down resistor on gate which can be in the order of a few milliseconds.
- Method B cannot work because the zener prevents negative voltage on the gate (except the forward voltage of the zener)
- Method C works, the capacitor time constant is minimal and set but zeners internal resistances (almost instant), and as a bonus you get gate protection from gate overvoltage so I guess method C is the best one of the mentioned?!
I think Dr. sam overlooked Method B. It needs an extra reverse zener connected to the 1st zener ( then it would anyhow become Method C). 22:57 and 24:59 are commonly used. Luxury Isolated based gate drive vs a non-luxury based bootstrap gate drive just to over come cdv/dt. Higher the negative gate voltage, worst is the VSD diode drop of GAN.
Hi, Thanks for useful comments. Method A is OK . No problem to keep the negative voltage flat with practical c an r values.
Method B: oops, I missed drawing a diode in series with Zener to avoid clamping.
Method C is nice but when input pulse voltage is higher than sum of Zener diodes' voltages, the capacitor is being charged an discharged which adds to power loss.
Thanks for pointing to error in B 😊.
Just noticed the comment by Swaraj. He was quicker.
@@sambenyaakov Hi, I meant the initial time needed to charge the capacitor which for Method A is 1-2 taus -> τ= R_pulldown * C_series
a few ms charge time would cause a few ms of shoot throughs at startup(if the gate's negative voltage is not enough) which "probably" would cause nothing but yet annoying :-)
Method C charge time is almost instantaneous and has added bonus of gate protection, your point on choosing bad zener voltage might be true but I didn't see it in my simulations, also that would be a point for choosing the wrong components :D
anyway, Method C is so useful and simple yet I hadn't see it anywhere else till your video, thanks again for sharing your knowledge Sam
Thanks for comment
Thanks a lot prof. Sam for this wonderful explanation 👍 ... It'd be very useful if you sir make a lecture about gate driver protection techniques (this is becoming an important design aspect especially when working with GaN eHEMT where the threshold voltage is low).
Thanks for comment. The protection and multilevel drive could be a good subject. Will see.
Thanks very clear explanation .
Thanks
Thanks so much Dr. Sam is very useful lecture, in minute 12 you said when Rg is smaller during turning off is better and current will be low, but if Rg is low mean that it will turn off faster and dv/dt will be high and current will be high, so why Rg in turning off is better to be small?
Thanks,
dv/dt will primarily be determined by Coss and the current of inductor. Small Rg during turn off will 1. lower switching losses and 2. lower the spike due to dv/dt passing via Cgd.
Outstanding ^ n as Usual .
Thanks Ashi
Thanks you sir
Thanks
yes I did find it interesting ....as on several previous presentations, I get lost on the detail and I suspect you are missing key points in explanations such that it feels as though you have made mistakes in the presentation and for me it takes away from the learning flow. I like the subjects you cover however I am limiting my viewing as it frustrates me to be doubting and dismissing mistakes and or missing points. It is most likely me and not you as everyone else who has commented previously compliments you on fine presentations. I have not given you a negative score as I saw that you wanted feedback to improve your content....hence this comment.....there is much more I could add, perhaps not appropriate here.
Hi, thanks for the time and effort to write your comments. In as much that I rather not make mistakes in the presentations I am sharing, I have found during my many years of teaching, that mistakes in lectures are stimulating and adding to the absorbtion of the knowledge conveyed and certainly simulating exchange. See other comments to this video.
I also think, with all due respect, that you do not appreciate the time and effort it takes to prepare these videos which I am contributing to the community for the enjoyment of giving and the frequent thanks I get.
@@sambenyaakov Thank you for the reply - I was not expecting one - or at least not on the public comments. Firstly I would like to repeat my comment - hidden in my last message "I like the subjects you cover" - and as a confirmation, I appreciate the time and effort to make these videos, I appreciate you are providing education for free, and appreciate that you are doing this - for all those that either don't have electronics training and those like me who want a reminder and or brush up on what we have forgotten or never covered (I did engineering a very long time ago) - I now have a hobby DIY interest - retired but still wanting to learn. As I said I am sure it is just me, but in an earlier video you asked if people made comments to assist you to improve your presentations - that is what I wanted to achieve here - rather than just clicking Thumbs Down, with you having no idea what or why it was negatively received. I do see you do get a large no. (the majority) of glowing likes and great comments - you have earned those.
And for me (perhaps the only one) errors in presentations are fine if you know the subject matter intimately, but for me, I wish to understand every section so that it sticks in the right place in my understanding otherwise I loose the plot (while I am trying to make sense of something that may or may not fit with my earlier education).
I also appreciate you are very knowledgeable and not only in one or two disciplines - but a very wide ranging engineering area - and I also acknowledge how knowing it so well and having produced/written the material - you cannot easily proof read/watch it as you are intimately connected and knowledgeable on the presentation - we or rather me, is not - I want to hang on every word and illustration - as it is the first time I see it, and so it is that proof readers cannot be good at their profession unless they are unaware of what you meant to say or illustrate - but have in this case a good general Electrical Engineering background.
I believe this isn't a channel where you shouldn't be "smothered" by details... Maybe you could find some other channels on TH-cam that would do the trick for you. Nevertheless Prof. Yaakov is often times the only person who is able to do presentations on such aspects that we need every possible detail we could get but somehow can't find in any other channel. I suppose you should realize the difference between "not liking" and "disliking". These videos may not meet your expectations but I don't think there is a reason even to consider disliking such effort gifted us by a valued person by their valuable time.