How to use MOSFET as a Switch ? MOSFET as a Switch Explained
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- เผยแพร่เมื่อ 12 พ.ค. 2024
- In this video, how the MOSFET can be used as a switch is explained.
Timestamps for the different topics covered in the video:
0:00 Introduction
0:22 MOSFET vs BJT as a Switch
4:22 Why Enhancement type MOSFETs (E-MOSFET) are used as a Switch
5:37 E-MOSFET ( N-channel MOSFET) as a Switch and Design Consideration
12:38 P-channel MOSFET as a Switch
14:10 Total Gate charge of MOSFET and its impact on Switching Speed of MOSFET
The MOSFET as a Switch.
Similar to BJT, the MOSFET can also be used as a switch. But the MOSFET has a certain advantage over BJT Switch.
Advantages of MOSFET as a Switch over BJT:
1) The MOSFET is easy to drive than BJT (Since it is voltage controlled Device)
2) At high frequency, in continuous switching applications, the MOSFET is more power-efficient
3) MOSFET is more thermally stable than BJT
Generally, the Enhancement type MOSFET is used as a switch. The Depletion type MOSFET (D-MOSFET) is normally ON device. That means even when voltage Vgs is zero, the MOSFET is in the ON condition and the current is flowing through the MOSFET.
While Enhancement type MOSFETs (E-MOSFET) are normally OFF devices and their transfer characteristics are more suitable to use them as a switch.
When the MOSFET is used as a switch, then it is operated between the linear or ohmic region and the cut-off region.
In this video, how n-channel and p-channel MOSFETS (E-MOSFETs) can be used as a switch is explained along with design considerations. And during the design, what factors in the datasheet should be taken into consideration is also explained.
The link for the other useful videos related to MOSFET:
1) Enhancement type MOSFET:
• MOSFET - Enhancement T...
2) Depletion Type MOSFET:
• MOSFET- Depletion Type...
This video will be helpful to everyone in understanding, how the MOSFET can be used as a switch.
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Music Credit: www.bensound.com - วิทยาศาสตร์และเทคโนโลยี
Timestamps for the different topics covered in the video:
0:00 Introduction
0:22 MOSFET vs BJT as a Switch
4:22 Why Enhancement type MOSFETs (E-MOSFET) are used as a Switch
5:37 E-MOSFET ( N-channel MOSFET) as a Switch and Design Consideration
12:38 P-channel MOSFET as a Switch
14:10 Total Gate charge of MOSFET and its impact on Switching Speed of MOSFET
I AM ELECTRICIAN AND I HAVE LEARNED ELECTRONIC IN THIS YOU TUBE CHANNEL! !!THANK YOU!!! PAX AND LUX! !!!!
EXCELLENT video about MOSFET's and BJT's. I had many questions about sizing an N-channel mosfet for driving some LED's and a small vibrator motor. Comprehensive discussion....I watched the entire video 2 times. Excellent job and thank you for your help.
Thanks for showing all the graphs that relate the resistance to voltage and switching time and current
You explain better than all of my teachers
Pls continue this series as in new syllabus mosfet and it's application and it's ac DC analysis is included 👍🙏🙏🙏
Thank you very much for this easy to understand and very helpful tutorial...
Thank you souch for detailed information 🙏
Thanks for the great videos, these are of the highest quality I've found so far. Please check the MOSFET symbol at 14:22, SS/B should be connected to S, not D. Otherwise, again a fantastic video.
Yes, that's true. Thanks for the correction.
best video on whole youtube.
keep it brother and provide content like this only.
Even though we say MOSFETs are gate voltage driven, for high frequency operations we need to look at gate current as well.
Could you please elaborate more
@@AkbarNurPribadi Gate has capcitance and to charge capacitor you need current.
Excellent explanation, thank you very much
hey man i love ur videos theyre info packed easy to understand what ur tryin to explain and the graphics are quality to, can i please make one very respectfully intended suggestion?? if u spoke a tiny bit clearer ppl wouldnt have to rewind and it would help show how intelligent u obviously r-the way u pronounce stuff makes a huge impression on ppl, helping business communicate with other businesses basically with the most profit in the end is my thing
is drain and source position is fixed for nmos switch? i mean can i rotate this and will still gate same results?
Meaningful class👏🏻
Can the pull down resistor be anywhere from 10K to 100K ? Great informative video.
Very nice explanation ❤
good morning sir, thank you for this video I have only one question for you. at 14:27 four p-channel MOSFETs are drain and the supply nodes reversed? Thank you.
best video
i got to know new things too
thanks
You are the best!!! Thank you!
What if your drain current is very small? Im designing a motion activated LED using a toggle flip-flop to activate the 2N7000. My calculated Id is less than 10 milliamps.
Good explanation!
In addition, this video describes a low side switch. A N mosfet can also be used as a high side switch, but will need a isolated gate driver.
Also: a mosfet always has a body diode, which will conduct if the current is reversed form drain/source to source/drain (inductive spikes will pass)
Very helpfull video, thanks a lot really
hi
hope all is well, I need help with a single dc input into multiple dc outputs can you help?
Excellent ❤️
One question - the pull down circuit has been shown to be just a simple R connected to ground. But when the control circuit provides a high on gate terminal, wont this resistor R provide a path to the ground always sinking current, creating power loss? Or is this R very high so this current is minimal ? In practice is the pull down circuit this simple?
Thank you for this... video
If I’m trying to power a 50W led which requires 36v and 1750mA what should my Vgs and Vdd be irf510 mosfet
Sir please explain What will be the gate current
I have IRFZ44N n channel mosfet it conducts current automatically when left in off condition for sometime
I think any transistor in switch condition working cutoff and saturation and amplifier in linear region.
For MOSFET, the terminology is little different. The flat region is referred as saturation region, where even after increasing the voltage Vgs, the current remains relatively flat. ( In BJT it is called linear region, where it is used as an amplifier). And the linear region is the one, where current voltage relation is linear.
Excellent 👍❤️
Hi I am having a very big issues understanding how mosfet conduct with positive and ground connections together work because I am trying to build a inverter I built mircro controller working will but when I try invert with mosfet the 2 mosfet or connect to transformer the mosfet blow I try getting help to get a inverter work in my country the knowledge is very little so I have no one to turn to for information on way mosfet blow the negative voltage conduct very well but when I connected the positive to drain and negative to source the mosfet blow everytime and that how inverter works positive to drain and negative to source but I blow 500 husband trying to turn them on like the inverter circuit I see online I try all on them and I just keep getting blow mosfet
Hello bro, I need help of design a circuit can you help on this please.
Sir how to control igbt for ac circuits pls make the video
Thank you in advance, please tell me why in p-type MOSFET you put the load after the MOSFET,I mean at the drain side and not on the source side?
For the P- type MOSFET, to turn it ON, Vsg should be positive. (Vsg > |Vt|) Or Vgs should be negative. So, what is usually done is, the source is directly connected to supply voltage. And through a pull-up resistor, the gate is connected to supply voltage. Based on the control input, the gate terminal either connected to ground or supply voltage. If it connected to ground, then Vsg is positive ( is equal to supply voltage) and MOSFET is ON. If it is connected to supply voltage then Vsg is zero and MOSFET is ON.
The load is connected to drain side. If the load is connected on the source side, then depending on the current drawn, there will be a voltage drop across it. If the voltage drop is too large, then Vs might be less than Vg. And in that case MOSFET will not turn on. By connecting the load on the drain side, turning ON and OFF becomes much more easier. I hope it will clear your doubt.
I am currently working on Mosfet driving inductive load (brush coreless dc) .The current which the mosfet currently draws at max Vgs is less than required .What should I do so that the current drawn by mosfet increases at max Vgs.
Use wider MOSFET
I.e increase width or use parallel MOSFET devices
Thank you very much
9:41 Where did 150mA come from? Anyone can explain?
Thankyou 👍🏻
how to calculate the value of pull down resistor?
source should be connected always to gnd?
thanks
Depending on if your fet is n or p channel source and drain might be other way round and no you can have your load between the source and gnd insted I think not sure tho
Awesome explanation, please suggest me the good reference book to study electronics
Electronics for Dummies.
Awesome video
Great video. Why does the load need to follow the drain side when using a p-channel? Couldn't there be a way to keep the load on the top on the source side?
The thing is VGS is control voltage. In case of PMOS, when VSG > VT, then MOSFET will turn on. If we connect load on the source side, then depending on the current drawn by load, the source voltage Vs will change. And that can effect the control voltage VSG (VS- VG).
If we connect the load on the drain side, then voltage VSG will remain independent of the load.
I hope, it will clear your doubt.
@@ALLABOUTELECTRONICS Yes that clears it up, thank you!
How do you calculate the value of R, the pull down or pull up resistor? Thanks.
Typically, any resistor value between 1K to 10K would do the job.
Wonderful
I might miss this, but what is VDD? Is it supposed to be connected to power supply? Great video, though.
Yes, thats right !!
Please make video on CMOS inverter
Hi. Is it possible to calculate the value of minimum Vdd if I have logic level IRL540?
I want to control 5V LED strip by PWM from arduino?
Yes, based on the required current, you can select Vdd and the series resistor with the LED strip.
@@ALLABOUTELECTRONICS Thank you. But I have led strip with resistors on it and it has to be supply by 5V, so I do not know if this 5V is enough to supply drain of this logic level mosfet. What do you think?
@@UP-pb2pg well the exact design depends, how many LEDs are there in the strip. And in how many rows they are connected. What is the series resistance of it? what is the typical current drawn by the LED strip? Considering all these aspects, the Vdd and external series resistor (if required) can be decided.
@@ALLABOUTELECTRONICS i will check it, thank you for your answer
Why does the Vd decrease when mosfet is switching on and Id is increasing at 17:15?
Since MOSFET acts as a switch, so VDS will be very less when it is ON. Vs is at ground, so Vd will also be near to that. That means when MOSFET is used as a switch and when it is ON, then Vd will be low. And since MOSFET is ON, so current will flow through it. But it will not happen instantaneously. It will happen gradually. That's why when Vd is reducing when Id is increasing. I hope, it will clear your doubt
8:34 graph is of nchannel or pchannel E MOSET ?
N- channel E-MOSFET. The P-channel is covered from 12:38 onwards.
what is meant by triangles in switching losses
During the switching, the current increase and the voltage reduce or vice versa, the voltage in increasing and current is reducing. Because of that, momentarily the power consumption increases, reaches its peak, and once again starts reducing. The triangle indicates that switching loss.
Please do video about microcontroller
Great 👍 lesson, thank you.
@12:39 how do you compute for the value of the pull down resistor R?
The value of R should be in 10s of kilo ohm. If it is too low (in ohm) then when microcontroller input is low, it will draw a lot of current. It should not damage the controller pin. If the value of R is too large (in MΩ), then it is comparable to the input impedance of the microcontroller pin. And it may form a voltage divider circuit with the input impedance. And the actual voltage appearing at the gate will be less than 5V (for 5V microcontroller). So, it should be 1/10th of the input impedance of the microcontroller pin. (The input impedance may be between 100KΩ to 1 MΩ) range. If not sure about the internal impedance of the microcontroller pin, then you may use 10k resistor.
@@ALLABOUTELECTRONICS thanks
Plz explain everything in detail
Man I swear, sometimes I think you pre-record some lines and when you ask something you just paste the answers in the audio. cuz the tone is so different
This is all nice theory but can you give us an practical example of an channel mosfet with an inductive load and to be turned on with say 1Khz . This frequency must reflect on the load because the load can be a transformer. Thank you for the explanation. Thumb up.
Yes, it's main point
How to use MOSFET as a normaly close Switch?
32khz, 62khz frequency give to piezoelectric from arduino. and using mosfet to increase voltage 12v of signal. please tell me solution which circuit i use?
good video
Despite of the accent that made me tired, this video is great.
I've always wondered why Indian English speakers seem to do this thing when teaching where they say stuff like "As you know the BJT can be used as a? ..... switch".
We don't do this in other English speaking nations. What is this? Some cultural thing that indicates "I'm teaching you something, and therefore I'm going to randomly pause 1/2 second before saying a noun at the end of a sentence?" It seems very consistently done.
😊👍🏻👍🏻👌🏻
Good
i find it hard to understand these topics if lines are just drawn as ccts😮💨😔
Ohh... If only I had seen this video before spending all day trying to use a N-channel mosfet with no resistors. (It may have also been used as a high side switch)
Let me know if you ever see a depletion type MOSFET, because I have never seen one.
7:11 / 18:07 usar como switch
🎯 Key Takeaways for quick navigation:
00:06 🔌 MOSFET vs. BJT for Switching
01:31 ⚡ Advantages of MOSFET for Switching
04:22 📏 Types of MOSFETs and Their Characteristics
06:42 🌐 Operating Characteristics of MOSFET as a Switch
10:52 🧾 Control Circuit and Protection for MOSFET Switching
15:07 ⏱️ Fast Switching and Gate Charge
Made with HARPA AI
🎉
10:27 some says its Ohmic Region, Triode region, you say its linear region.
Yes, different text books and datasheet MOSFET represents that region by different names.
@@ALLABOUTELECTRONICS one more question. meaning of as "switch" is selecting one of the curve based on VGS input? in my meaning switch is just on and off. but switch meaning here, off and (can choose one of the curve) yes? its like variable resistor ? why called switch? why not called switch variable resistor? and switch in my meaning its like memory register, on and off. 0 and 1. , so its analogue switch ?? enlight me please. thank you.
At 6:30 you say that as the gate to source voltage increases, the slope of the line (the resistance of FET from drain to source) will reduce, which is incorrect. As the gate to source voltage increases the slope of the line (resistance from drain to source) increases as well
well, I was saying the same thing. See, when the slope reduces, the resistance increase. Slope is y/x. Slope is inversely proportional to resistance.
@@ALLABOUTELECTRONICS yeah I made the mistake not you, I was thinking the slope was the resistance but you're right its the inverse of the resistance, thanks!
🔥💗🔥👦🔥
3:15 / 18:07
wow 😁😁😂😂😁 ji 😀🤣😃😄 w
you didnt even explain the graph
It is already explained in detail in the earlier videos of the MOSFET. Please check the MOSFET playlist on the channel.
@@ALLABOUTELECTRONICS I'm confused why Vd decreases as Id increases...i saw the earlier videos..but I don't get it...I'm talking about the last waveform
The last graph shows the switching and the power loss in the MOSFET. Initially, when the MOSFET is OFF, then no current is flowing ( Id is almost 0). As soon as it is turned ON, then it offers very low resistance and current starts flowing through it. And as it offers very low resistance, the drain voltage reduces (close to 0). Ideally, it should happen instantaneously. But in reality the switching happens gradually. That means, gradually, Vd reduces to zero and Id increases from 0 to max. value. I hope, it will clear your doubt.
हिंदी मे भी समझाया करो purely English samaz nhi aati
...What is with the random pauses and speech speed. It's completely disorientating and I can't actually pay attention to what you say because you keep pausing and emphasizing seemingly every other word to a point where it's meaningless.
You should try to improve your accent