I hope this clarified this topic that so confused me when I was learning about MOSFETs - if you'd like to see the written tutorial this is based on, please check it out here: www.circuitbread.com/tutorials/nmos-vs-pmos-and-enhancement-vs-depletion-mode-mosfets Have a great day!
Thanks; I watched a video recently where an amplifier restorer was working on a Sony V-FET output type circuit. He mentioned that V-FETs are depletion mode devices and when adjusting the bias voltage he wound the potentiometer feeding them all they up and then adjusted it down. Now I understand, hopefully, what he meant.
@@CircuitBread keep at er buddy. no one else is doing as good a job on the finer points. I love how your video expressed how YOU struggled w/ the explanations way back when you learned it. The terminology does suck for mosfets and IGBTs.
This has been an extremely helpful video. Any chance there's a video on this channel that explains how raising the drain to source voltage above the overdrive voltage creates a gap between the channel pinch off and the Drain region?
Thank you for creating a high-level educational videos, it seems that this video's speed was modified (by mistake in the editing proses or on purpose), please advise.
Yeah, watching this back it seems a bit on the fast side. I think it's just tricky sometimes to create a consistent speed between videos and this one used a slightly different template than some of our other videos. I think we've likely become more consistent over time.
@1:08 when we apply + to the gate here just hole flow(meaning there is lack electron) so that gate has enough charge to create field effect? at the same time P type has no electric charge to get fill up themselves as electron both gate and p type has lack of electron in valence band
Nice video explanation and summary of the MOSFETs! I love the animation as well. I would be interested to learn about the difference between those MOSFETs in application, like I sometimes hear NMOS is more stable than PMOS but I have no idea if that's true and why it is.
I've heard that PMOS tends to have a much higher impedance than an equally sized NMOS due to the lower drift velocity of holes versus electrons but other than that, I'm not really sure. Once all of this world-craziness blows over, I'd like to go see the professor who double-checked to make sure our scripts were accurate and see if she has any insights on this or further requests on this topic. Thanks for your feedback and we'll see what we can do!
this was over my head... where do i start? i just need to troubleshot and replace(buy) new ones. later ill care more about what it all means ;) .. i do wanna know
Hi Rush - it depends on exactly what you need. If you have a board and the FETs are burned out and you just need to replace them, I'd just search for their part number (hopefully etched on the top) and buy direct replacements. If you're looking at getting a better understanding of how they work, I'd start with this tutorial: www.circuitbread.com/tutorials/how-a-mosfet-works-at-the-semiconductor-level All of our MOSFET related tutorials are all conceptual at the moment, though, so if you need to do any calculations, we don't have anything for that yet.
Thank you! May I ask what is the on voltage defined as? Is it if it reaches a certain current because I think it is ambiguous since the device is never going to have totally 0 current
That's an excellent question! I believe manufacturers have different levels that they consider the cut-off point and that information can be found in their datasheets (it's usually either a note, subscript or superscript) and the voltage provided will referred to as where the FET turns on. They will also have information about what their leakage current is - the current that you get when it's supposedly off. This same question/issue also occurs with diodes and LEDs as the on/off points aren't perfectly clear either.
Hi! CMOS is just when you use both NMOS and PMOS transistors to create logic - I don't know if you've seen the tutorial on how MOSFETs work ( www.circuitbread.com/tutorials/how-a-mosfet-works-at-the-semiconductor-level ) but if you understand how an NMOS works, you'll understand how a PMOS works, and that will mean you know everything you need for CMOS. Hope that helps!
STMicro makes complementary n-type and p-type mosfets (STB80NF55 and STB80PF55). The data sheets for both show drain current as a function of Vgs. Can you explain why in both cases the gate to source voltage is positive? - Thanks!
That's a great question! It confused me as well when looking over the datasheets, but I found this note at the bottom of the Electrical Characteristics section of the STB80PF55 datasheet "For the P-CHANNEL MOSFET actual polarity of voltages and current has to be reversed" Now, why they don't just show the negative signs in the boxes? I don't know. Probably easier somehow.
In short - forward bias. In an NMOS, if you have a positive gate to source voltage, it means that you are applying a higher voltage to the p-type substrate (through the oxide) so you'll have a forward bias between the higher voltage at the p-substrate than the lower voltage at the n-type source. The weird thing is that the higher the gate voltage, you're actually converting a small slice of that p-type substrate into n-type, creating that channel. So it arguably is not even biased as you're creating an entire channel of n-type material.
![[UNCUT] The Loyal Pin ปิ่นภักดิ์ EP.15 (1/4)](http://i.ytimg.com/vi/TLBjiHvkKtE/mqdefault.jpg)
I hope this clarified this topic that so confused me when I was learning about MOSFETs - if you'd like to see the written tutorial this is based on, please check it out here: www.circuitbread.com/tutorials/nmos-vs-pmos-and-enhancement-vs-depletion-mode-mosfets Have a great day!
This channel is saving me before exams
It's a P (positive) channel then?
Tomorrow is my exam lol
Lost count of how many times I had to rewind and re-watch but have finally understood the concept. Thanks!
A good teacher can teach a full topic in just 3 min , bcz everything is to the point
Wow!
This video covered a lot in 3 min.. GREATWORK
This channel deserves more♥
Thank you so much 😀
Thanks; I watched a video recently where an amplifier restorer was working on a Sony V-FET output type circuit. He mentioned that V-FETs are depletion mode devices and when adjusting the bias voltage he wound the potentiometer feeding them all they up and then adjusted it down. Now I understand, hopefully, what he meant.
This is like the only video which was able to explain this in an understandable fashion. Thank you!
You're welcome! I'm glad it was clear!
How come this channel has only 5k subscribers ? It deserved 5M !
Thanks! We're trying...
Very helpful video. Thank you! I’ve been trying to build the table you presented near the end. Just what I needed.
Extremely good video.
Cleared up a lot of mumbling from my Prof.
I am also very much confused about MOSFET.
But this videos has helped me a lot.
Thank you.
Great job explaining the basics! Thanks
The last table for comparison was nice.
Loved the table that you put up together! It was indeed very helpful! Thanks for sharing!
Awesome, glad it was helpful!
Wow, that was an efficient mini lecture.
Thanks a lot for it!
best explanation/best animation on the internet. Had to slow video playback to .75 to keep from stumbling with all those poorly named concepts. 9.9 =)
Thanks Adam. I’m trying to slow it down for future videos, thanks for the feedback and glad that this was helpful!
@@CircuitBread keep at er buddy. no one else is doing as good a job on the finer points. I love how your video expressed how YOU struggled w/ the explanations way back when you learned it. The terminology does suck for mosfets and IGBTs.
i appreciate your effort , thank you for sharing this vedio
Thanks. This is exactly what I want to know.
This has been an extremely helpful video. Any chance there's a video on this channel that explains how raising the drain to source voltage above the overdrive voltage creates a gap between the channel pinch off and the Drain region?
I think the closest we have is this video: th-cam.com/video/o3M2sOCGCKs/w-d-xo.html I hope it's helpful!
Very helpful! Thanks.
Thank you kind TH-cam man. Cheers
FINALLY I understand now :) thank you
Thank you for creating a high-level educational videos, it seems that this video's speed was modified (by mistake in the editing proses or on purpose), please advise.
Yeah, watching this back it seems a bit on the fast side. I think it's just tricky sometimes to create a consistent speed between videos and this one used a slightly different template than some of our other videos. I think we've likely become more consistent over time.
Thank you very much Sir.
@1:08 when we apply + to the gate here just hole flow(meaning there is lack electron) so that gate has enough charge to create field effect? at the same time P type has no electric charge to get fill up themselves as electron both gate and p type has lack of electron in valence band
nicest man in the world
why do we mention n type as n+ on both drain and source
real compact, super cool
Glad so many seem to like this video. Just sounds like word salad to me. More confused than before i watched this.
Nice video explanation and summary of the MOSFETs! I love the animation as well. I would be interested to learn about the difference between those MOSFETs in application, like I sometimes hear NMOS is more stable than PMOS but I have no idea if that's true and why it is.
I've heard that PMOS tends to have a much higher impedance than an equally sized NMOS due to the lower drift velocity of holes versus electrons but other than that, I'm not really sure. Once all of this world-craziness blows over, I'd like to go see the professor who double-checked to make sure our scripts were accurate and see if she has any insights on this or further requests on this topic. Thanks for your feedback and we'll see what we can do!
this was over my head... where do i start?
i just need to troubleshot and replace(buy) new ones. later ill care more about what it all means ;) .. i do wanna know
Hi Rush - it depends on exactly what you need. If you have a board and the FETs are burned out and you just need to replace them, I'd just search for their part number (hopefully etched on the top) and buy direct replacements. If you're looking at getting a better understanding of how they work, I'd start with this tutorial: www.circuitbread.com/tutorials/how-a-mosfet-works-at-the-semiconductor-level All of our MOSFET related tutorials are all conceptual at the moment, though, so if you need to do any calculations, we don't have anything for that yet.
Not sure why but in tech school they focused on BJTs and not so much on FETs.
Thank you! May I ask what is the on voltage defined as? Is it if it reaches a certain current because I think it is ambiguous since the device is never going to have totally 0 current
That's an excellent question! I believe manufacturers have different levels that they consider the cut-off point and that information can be found in their datasheets (it's usually either a note, subscript or superscript) and the voltage provided will referred to as where the FET turns on. They will also have information about what their leakage current is - the current that you get when it's supposedly off. This same question/issue also occurs with diodes and LEDs as the on/off points aren't perfectly clear either.
Can you explain how CMOS works? I'd love to watch it
Hi! CMOS is just when you use both NMOS and PMOS transistors to create logic - I don't know if you've seen the tutorial on how MOSFETs work ( www.circuitbread.com/tutorials/how-a-mosfet-works-at-the-semiconductor-level ) but if you understand how an NMOS works, you'll understand how a PMOS works, and that will mean you know everything you need for CMOS. Hope that helps!
@@CircuitBread If I'm correct, I think CMOS is used to create NAND gates
Yes, you are correct! They use 2 PMOS FETs and 2 NMOS FETs.
STMicro makes complementary n-type and p-type mosfets (STB80NF55 and STB80PF55). The data sheets for both show drain current as a function of Vgs. Can you explain why in both cases the gate to source voltage is positive? - Thanks!
That's a great question! It confused me as well when looking over the datasheets, but I found this note at the bottom of the Electrical Characteristics section of the STB80PF55 datasheet "For the P-CHANNEL MOSFET actual polarity of voltages and current has to be reversed" Now, why they don't just show the negative signs in the boxes? I don't know. Probably easier somehow.
Sir, Vgs positive means forward bias or reverse bias
In short - forward bias. In an NMOS, if you have a positive gate to source voltage, it means that you are applying a higher voltage to the p-type substrate (through the oxide) so you'll have a forward bias between the higher voltage at the p-substrate than the lower voltage at the n-type source. The weird thing is that the higher the gate voltage, you're actually converting a small slice of that p-type substrate into n-type, creating that channel. So it arguably is not even biased as you're creating an entire channel of n-type material.
@@CircuitBread thank you sir
Thank you , Sir
Great !!
hatsoff you sir
you are the best!
Thanks!
Great😊
great video but still confused RIP
nice
Thanks!
I love u
Too much talking