Thank you for video. I would add that this circuit does not have the disadvantages of other transformer-based gate drive circuits that use decoupling capacitors that can keep the MOSFET on for a very long time when the input signal stops switching or suddenly changes duty cycle.
@@sambenyaakov Mr.Professor, you underestimate the level of your lectures, they are conducted so well and at such a high level that they are understandable to specialists in any language - the electronics diagram is musical notes is a universal language - thank you again
I first suspected turn-off for the high-side MOSFET would be very slow, driven only by the magnetizing current, but realize now that the body diode of the small signal MOSFET fixes this issue. Neat. I think I have seen this or a similar circuit before.
I have designed many commercially sucessful products that use transformer based Gate drivers. There are typically more design challenges than using purpose built Gate drive solutions, however the cost advantage is significant for a mass production design
I frequently have wanted transformers for this purpose, but I had a lot of difficulty sourcing them. Do you have any recommendations for sourcing these transformers? I noticed in the schematic you showed, it referenced a 760301302, but, that is a massive transformer, for something I was hoping to find in a 3x3mm SMT package, something more like a ATB322515-0110-T000. So frequently transformers feel like a great solution needing to driving mosfets on challenging rails -- But I just can't figure out how to source appropriate ones for smaller applications.
@@sambenyaakov when it comes to custom transformers do you happen to know a good way to craft them? as in i know the math for a certain E or P core but how do i chose that initial core + PCB mounting thing ( plastic part where you wind the wire) Also for gate drive transformers how practical is to to repurpose them for small power isolated power supplies? (gate driver ic on one side +50% PWM shifted 180deg and simple rectifiers on the other side?
@@sanjikaneki6226 In most case you can just specify to the mnufacturer the need and you will get a good design. Yes mst gate drive transformer are usefull for aux powersupply design. See: th-cam.com/video/RQboLY1zP3Q/w-d-xo.html th-cam.com/video/0Nb7uE_p5-w/w-d-xo.html
@@sambenyaakov THX i will study those videos and regarding custom transformers i never asked the manufacturers since i am afraid of huge development costs and large MOQs with expensive parts
@@sanjikaneki6226 I really do hope more of the pre-canned kinda basic small transformers come along. It's hard to get small and cheap when you have to do custom orders. It happened for inductors, and there are starting to be a few good transformers in < 3mm x 3mm packages. They're just so uncommon right now.
Nice video, very informative. Do you have any videos that cover conducted rfi caused by line voltage switching? I'd love to learn more about that topic. From my understanding it has a lot to due with different fet technologies planar vs mesh, but was not sure if there are other techniques that could be used to mitigate conducted rfi noise.
"I guess there might be a reason for that". The reason is probably that they don't want to spoil the surprise when you see the world's ugliest drive waveform...
Dear sir, the uppermost waveform is the Vgs one of the secondary-side mosfet. Am I right? The yellow waveform is the Vds one of the upper mosfet, which more or less can tell us its Vgs waveform.
You mentioned that these days isolated gate drivers tend to replace gate transformers but most of those ics tend to need a isolated supply so you need a transformer for that anyway, or some capacitor based supply. Also is that push pull bjt really needed or it is just to be on the safe side?
Hi sir .. could you please make video on self synchronous rectification method... advantages and challenges present in the design And also active snubber circuit
Hello professor and thank you for sharing always excellent content. But why to complicate your life in this way? Why not using a gate drive transformer with 2 secondaries with dc restore and use each secondary to drive the 2 fets? With all the parasitics involved in such arrangement it is strange how this circuit can "work". Strangely enough TI does not present the gate waveform of the high side fet. I see only potential problems with this circuit and not even a cost advantage.
I had so many aha moments. This is by far the cleanest way I've seen for a high-side gate driver using only discretes. Thank You.
😊👍🙏
Professor, I love your productivity. Thank you for that much of content.
👍🙂🙏
Thank you for video. I would add that this circuit does not have the disadvantages of other transformer-based gate drive circuits that use decoupling capacitors that can keep the MOSFET on for a very long time when the input signal stops switching or suddenly changes duty cycle.
Thanks for input.
Dziękuje Panie Profesorze za tak wiele cennego materiału --- naprawiam zasilacze impulsowe
👍🙏 and thaks to Google translate.
@@sambenyaakov Mr.Professor, you underestimate the level of your lectures, they are conducted so well and at such a high level that they are understandable to specialists in any language - the electronics diagram is musical notes is a universal language - thank you again
@@adambury2251 thank you for your warm words. Happy new year.
@@adambury2251Thank you for your warm words. Happy new year.
I first suspected turn-off for the high-side MOSFET would be very slow, driven only by the magnetizing current, but realize now that the body diode of the small signal MOSFET fixes this issue. Neat. I think I have seen this or a similar circuit before.
Thanks for input.
I have designed many commercially sucessful products that use transformer based Gate drivers. There are typically more design challenges than using purpose built Gate drive solutions, however the cost advantage is significant for a mass production design
Thanks for the useful input.
Sir, it seems from the labelling (Q902), the first waveform is vgs for secondary side flyback sw.
Oops, you are correct. But the point is that they do show Vgs of Q900.
It is a pure pleasure to watch your videos. Thank you, Professor Ben-Yaakov!
😊🙏
👍🙏❤
Thanks😊
I frequently have wanted transformers for this purpose, but I had a lot of difficulty sourcing them. Do you have any recommendations for sourcing these transformers? I noticed in the schematic you showed, it referenced a 760301302, but, that is a massive transformer, for something I was hoping to find in a 3x3mm SMT package, something more like a ATB322515-0110-T000. So frequently transformers feel like a great solution needing to driving mosfets on challenging rails -- But I just can't figure out how to source appropriate ones for smaller applications.
The best is to custom order. 3X3 seems a bit small unless you use exotic materials which will make it expensive
@@sambenyaakov when it comes to custom transformers do you happen to know a good way to craft them? as in i know the math for a certain E or P core but how do i chose that initial core + PCB mounting thing ( plastic part where you wind the wire)
Also for gate drive transformers how practical is to to repurpose them for small power isolated power supplies? (gate driver ic on one side +50% PWM shifted 180deg and simple rectifiers on the other side?
@@sanjikaneki6226 In most case you can just specify to the mnufacturer the need and you will get a good design. Yes mst gate drive transformer are usefull for aux powersupply design. See: th-cam.com/video/RQboLY1zP3Q/w-d-xo.html th-cam.com/video/0Nb7uE_p5-w/w-d-xo.html
@@sambenyaakov THX i will study those videos and regarding custom transformers i never asked the manufacturers since i am afraid of huge development costs and large MOQs with expensive parts
@@sanjikaneki6226 I really do hope more of the pre-canned kinda basic small transformers come along. It's hard to get small and cheap when you have to do custom orders. It happened for inductors, and there are starting to be a few good transformers in < 3mm x 3mm packages. They're just so uncommon right now.
Nice video, very informative. Do you have any videos that cover conducted rfi caused by line voltage switching? I'd love to learn more about that topic. From my understanding it has a lot to due with different fet technologies planar vs mesh, but was not sure if there are other techniques that could be used to mitigate conducted rfi noise.
"I guess there might be a reason for that". The reason is probably that they don't want to spoil the surprise when you see the world's ugliest drive waveform...
👍🙂
Hello, thanks . Minutes: 05:08 how does adding the Zener diode increase the negative voltage ?
Because the negative voltage on the primary increases
Sir please make vedio on how diodes like zener,shottkey are used for protection in various applications
Good topics. I will try. Thanks.
Happy 2024 !
Thanks. Same to you.
Dear sir, the uppermost waveform is the Vgs one of the secondary-side mosfet. Am I right? The yellow waveform is the Vds one of the upper mosfet, which more or less can tell us its Vgs waveform.
You mentioned that these days isolated gate drivers tend to replace gate transformers but most of those ics tend to need a isolated supply so you need a transformer for that anyway, or some capacitor based supply.
Also is that push pull bjt really needed or it is just to be on the safe side?
IN most cases one can use bootstrap supply. The schematic was borrowed fromanothe study. Buffers are clearly not needed here.
Hi sir .. could you please make video on self synchronous rectification method... advantages and challenges present in the design
And also active snubber circuit
Good subjects. I will try.
Hello professor and thank you for sharing always excellent content.
But why to complicate your life in this way? Why not using a gate drive transformer with 2 secondaries with dc restore and use each secondary to drive the 2 fets? With all the parasitics involved in such arrangement it is strange how this circuit can "work". Strangely enough TI does not present the gate waveform of the high side fet. I see only potential problems with this circuit and not even a cost advantage.
Yes, I agree, this is a problematic circuit. I brought it for educational purposes, it does include clever ideas.
❤
Thanks
Hello Sir, can you share the link of flyback transformer design.
th-cam.com/video/Y0WWj2dO_h8/w-d-xo.html