I know this will probably get lost in the comments but I have to say it. I absolutely have a high respect for people like you who share knowledge so freely and willingly. People like you are a godsend. Thank you sincerely.

Nine years later, this is still the best and most understandable intro to Op Amps ever.

this video got me my first electronic job i watched this video before my interview and they quizzed me on op amps! the luck!

"The gain is almost infinite" spoken like a true engineer!

I Learned more in 10 min of your video than 1 month of my Power Control Electronics class. Thank you!!!!!

As a retired Senior Applications Engineer at Burr-Brown and Texas Instruments, I must compliment you on this presentation! It is very similar to the "factory" technical presentations that we used to give to audiences around the globe. The technical level is just right, not to basic and not too advanced. Good job! To be a good teacher it takes far more than just knowledge of the subject. A teacher's job is to impart knowledge to his student; if the student doesn't understand, the teacher is not doing his job. Some PhDs can teach, others can't- Richard Feynman was an example of a fellow who not only thoroughly understood his subject but who could teach it as well.... and do it in an interesting and entertaining manner.

5.300 students are very grateful you uploaded this video

In my whole electronics major shit , I have never seen a person who explains virtual ground like this. #RESPECT

Very intuitive and easy to understand. Best explanation of op-amps I could find on KZfaq. Thank you so much!

I find myself revisiting this tutorial as a refresher every time I need to incorporate an OpAmp into one of my projects. Thanks Dave! 👍🏻

what makes you a gorgeous teacher is that you not only talk about what is going on but also about what the follower might think is going on but actually is not and why. i had so many frustrating experiences in the past because of teachers that did'nt care about that. i truly love your lessons.

Regarding the puzzle at the end, the low resistance effect is an increased current at the OA output. the OA at approximately Vout= -0.5V should sink 50uA which is higher than the value in the datasheet/figure13 of 30uA max. so the virtual ground voltage fluctuates and so does the output at approx. -0.5V.

Been a tech for 43 years and I have never seen it explained so concise. Thanks and I am turning the junior techs onto this video. Cheers!

You have left a legacy on KZfaq for the coming generations. You are immortal. Salutes.

Interestingly I just recently recommended someone to look into using an opamp for their project... EEVblog never disappoints.

I have been watching this as a kid and now it feels so nostalgic after i have passed my electronics engineering school , it really so nostalgic

The fact we can learn this and not have to go into debt... your a gift to engineering Dave!

Read this after 12:23 and listen to buffer amplifier again. The primary objective of buffer circuit is to boost the current in any circuit at any stage. Buffer circuits are mainly used where a signal has very low current input(high input impedance) which needs to be increased maintaining the same voltage levels. So, this buffer circuits draws current from power source and adds it to the signal. Buffer amp is also called as voltage follower or unity gain amplifier . Hope this makes sense now !

FINALLY!!!! A video that ACTUALLY EXPLAINS HOW IT WORKS!!!!! Dave, this video was a godsend.

7 years on and your videos are still helping new technicians. I really appreciate this, thank you.

One of the most sensible ways of explaining the basics of op amps. Great work Dave

When I learned how to use Op-Amps, the 741 was the state of the art at the time. Yes, had to learn them the hard way back in those days. What a great refresher course for this young man born 9-11-1946. Great job Dave and thank you. Respectfully, Steve

If anyone is interested the gain of the non-inverting config can be derived from the voltage divider equation: Vin = Vout*R1/(R1+Rf) Vin/Vout = R1/(R1+Rf) Vout/Vin = (R1+Rf)/R1 Vout/Vin = 1+Rf/R1 And the gain of the inverting config can be found from the currents: I(Rf) = Vout/Rf I(R1) = -Vin/R1 -> Current through both resistors is equal so... -Vin/R1 = Vout/Rf Vout/Vin = -Rf/R1 :)

Hi dave I've been watching your channel a lot for the last couple years now and it's fantastic! I'm currently doing my honors in electronics engineering and my University here in hamilton New Zealand has instructed my class to watch this video on the current section we are covering on op-amps. You have finally made it to university level teaching my friend!

i always catch myself smiling while watching this guy

This brings back memories. I learned all this in studying for by BSEE degree that I got in 1976. I have no idea why KZfaq sent me here. The last video I watched was on modeling an MOV surge protector in LTSpice. I dozed off and wound up here. Back in 1976 we had a saying: *_”Four years ago I couldn’t spell ‘injuneer’ and now I are one!”_*

Thumbs-up for the vid on properly terminating op-amps please Dave ;)

This is my new favorite KZfaq channel!!! I am a marine engineer by trade, but I started getting bored, so I signed up for an online electronic engineering programme at my local university, to put my spare time into good use. I have never gained much from sitting in a classroom listening to a lecturer bleating for two hours at a blackboard, so I was thrilled, when I got the opportunity to work at getting a degree, working by myself at home. These videos are an absolutely excellent supplement to all the videos available from my university. Thank you!!!

It's so great to see fellow Australians showing up on KZfaq. Especially for something like explaining electricity. Bringing fame and reputation to our country!

Some people really got the "art of sincere teaching". This is the best I've seen so far regarding Op amp basics. God bless you Sir.

Very helpful. I'm an electronics technician and you see this stuff when you're doing repairs or troubleshooting but you never get down to the nitty gritty details especially after 30+ or so years goes by from your initial electronics training so it was really nice of you to explain this especially on layman's terms. Someone else mentioned in this blog about cutting and pasting working circuits into projects and calculating as you went along to fit your needs which is pretty much what I've done in the past so this has really been a BIG help in the memory refresh department. Thank you ten times over and may the "electro" Gods shine good fortune down upon you sir!

Yes for an op-amp terminating video.

Back in May of 1978 I started work at an aerospace company that made the engine controllers for a military jet aircraft. The engine controller was a low frequency (less than 10 KHz) precision analogue computer that had amplifier gains & offsets calibrated to +/- 2 mV with select on test 1% tolerance resistors. Some critical circuits in the controller used 0.1% tolerance resistors. Positive 10 V and negative 10 V references were used throughout, and as well as the usual feedback loop components there were two 10.6 V Zener diodes in each loop. All of the virtual earths were connected to a virtual earth monitor that used a high gain amplifier to indicate any opamp failures. After a few years the engine controller was redesigned around 12 MHz 16 bit microprocessors and was considered to be not as good as the analogue version because at full speed the aircraft would travel about 50 feet before the software loop was reiterated. Some of the circuitry in the analogue version was very unusual and complex and I learned a lot about circuit design with opamps. It was a great place to work because there were occasions when batches of high grade components were thrown into a skip, and the company didn't care where they went. To this day I have a huge stock of mostly obsolete but still useful components that I use for making projects and stuff that can't be purchased off the shelf. Thanks for the video.

as an electrical engineering student, this channel is priceless. thank you for this channel and to so many other folks who do the same...

Truly one of the best reviews of OP Amps. This validates everything I have learned about OP Amps. -Thanks

The concept of virtual ground was delivered precisely. Thank you Dave!!!!

I have watched this umpteen times. Best tutorial EVER. Thank you.

I spent few years in school to learn this (hundreds of years ago) but no teacher was able to present it so clearly like you did - thank you bro

Thanks for doing teaching vids, Dave! I took many electrical engineering courses in college and we did a lot with op-amps, but I'm embarrassed to admit I've completely forgotten everything about them since then. These practical introduction videos are perfect for people like me who want to reconnect to something we learned in the past. Thanks again!

Wow, huge thanks for a crystal clear explaination! I have watched several other videos where others tried to show how awesome opamps are and after those videos I became more confused. At last, thanks to your awesome video I understand what it is and how I can use them. Awesome Dave, it´s like christmas following your videos.

Took years to comprehend this stuff. Especially when it came to more complex circuitry and control of DC motors from controlling speed, current, volts, positioning, etc. Great video and spot on! Thanks

Your video is gold. I modeled both inv amp and non-inv amp in LTspice with MAX4352 op-amp. Input voltage: [0,0.5] volts. Vcc:+5v, Vee: GND. Worked perfect. Thanks for your work!

I am in my senior year for EE and we had a whole 8 weeks in one of my circuit theory classes dedicated solely to op amps. We got to delve deep into these and do some really fun design problems and lab experiments. This video really is a great refresher and good start for anyone new to them.

Yeah! perfect explanation about virtual ground. Thanks Dave!

Never gave money to a KZfaqr ever, until now. Started this hobby six months ago. Tried to make a little lab myself but made mistakes. Then I watched your video on how to start an electronics lab. Followed your advice and now everything is set up and working perfectly. makes it so much easier! My learning curve has advanced leaps and bounds. Cant thank you enough.

This explanation is superb! It is THE best I've ever seen from any book or professor. Truly, a gold nugget.

If only I had the opportunity to watch this when I was learning about OpAmps some decades ago ! So much simpler to understand with you, Dave !

Dave, this is amazing. Thank you for these mini classes, honestly it’s worth more than any electronics class I ever paid for. Negative feedback op-amps just clicked into place for me about 10 minutes in. I had been struggling with this concept for days. Thank you so much.

Love these. More, please. I've been using Op Amps and Comparators for decades and still learned a couple tricks watching this video!

I love this guy.. Very savvy, but breaks it down for the general population.

What the hell just happened? I felt like I had watched a 10 min video. By the time I looked at the time line, 49 minutes had already passed. Magic OOOOoooooo. XD

Excellent discussion. Takes me back 35 years to my intro to op-amps. My professor explained what was to us an amazing and confusion subject just as you did and within a day or so we couldn't wait for the lab. I'm now hooked on your channel. atb Opal

tonight i learned 10x more about op-amps, and with a deeper understanding, than i did in a whole semester in a suffocating classroom. Thank you for your time.

i'm literally crying, thank you so much. my physics midterm is tomorrow and i truly thought i was screwed. but now i think i can save my grade, subscribed x

Happy 600th EEVBlog Dave!

You are really great at this. I'm in a 3rd semester EET student and I learned a thing or two about op-amps from you. I should be paying you tuition!

This is probably the most comprehensive and effective explanation I've ever watched about opamps. You sir are a pedagogical genius!

Dave is really passionate about electronics that's why he took all the explanation to a whole new level! Thank you!

Hi Dave, Please do a video on how to terminate OP-AMP, it's an important topic as well. Good job, thank you.

This was the Video that made me fall in love with electronics! What an awesome tutorial !!

If my college lecturer in the 1970s in England had been just half as good as explaining things as you, I could have saved myself 40 years of stress thinking that I was an idiot. Keep up the excellent work, you obviously love passing on your knowledge and are brilliant at doing it. I am now totaly gripped.

Dude, best explanation of opamps I've ever heard! My professor in college back in the day was an asshole, making this so complicated.

And now we need a second part, where you show us the non-common circuits, as let say...Gyrator-stuff, Log-converters, average/peak rectifiers, and "interferences" when using OpAmps in RF circuits (like input pin reversion)....;)

This video made everyone think I'm a genius when we were taught this in class!

Someone in my class has been spreading around this video to everyone and they're all raving about how useful your video is.

You are a brilliant teacher. Your ability to explain these concepts in an easily understood and straightforward way is a precious gift. I say this as someone who, many many decades ago, struggled as a student trying to understand so many instructors who did not have the ability to convey their knowledge to their students.

Well, I secured more marks than my friends in our exam just by watching this video 2 hour prior to my exam. Thanks Dave.

Great explanations. I used OpAmps before, but more copy-and-paste style, just using the standard circuits without thinking about it. Now it makes sense why it works, and with the two rules I might even create equations to analyze more complex circuits, like the differential amplifier, where you've lost me a bit.

This video literaly saved me :), right now in the university everything is going on-line and some teacher are just an assholes that don't care if we are learning with this new method and I mean, there is this one teacher that literaly send us to read a book and that´s it, nothing more, and well, I think this is the best class about op amps I have right now. Thank you so much

Thanks Dave. I watched this as a refresher for an Engineer II technical interview. They asked all Op Amp questions! Passed it!

Great explanation, you just took the best OP-Amp explanation until now from:YT- John Santiago Op Amp Design Basics - Inverting Amplifier - Part 3 (i was actually wondering when you will do that 8-). While you mentioned ohm's law you might add Kirchhoff circuit law in the part where you "wonder" about where current goes and that lack of minus in inv. OP gain formula was bugging me until you corrected it... For the end, you put smaller resistor which drives 10x larger current form output trough feedback resistor to "match/counter" input current (100uAmpsp rise into 1mAp) so output stage switches into B class (whole chip with 2xOPAmps has less then 1mA quiescent current and output stage probably uses about 70% of that) and you see clear crossover distortion on the output waveform (where OP-Amp loses control hence the spikes on the input, you can represent that as vehicle steering wheel dead play for mechanical types) Great video, just took best opamp explanation title,cant wait for #2,3,....

I love you. You should have been my EE professor for every class at my uni

First theory then practical implementation with real equipments, and all in 50 minutes... thanks Dave for your time.

8 yrs passed till now , I never had seen such an video anywhere , It's Awesome really cool.

your enthusiasm is awesome! You remind me so much of my high school science teacher. He made it exciting and fun. As you would say “good on ya mate!”

Excellent video Dave! Concerning the puzzle on the end. I think it's the reduced current sinking capabilities of the LM358 when Vout is small in respect to ground. If look up the "Output Characteristics Current Sinking" graph in the datasheet you can see that the LM358 can sink very little current at low output voltages. As you have a 1k R1 and 2Vpp input voltage you have 2mApp of current, which is still too much to sink for the LM358 at low output voltages. So the LM358 can't keep the virtual ground equal with the "real" ground trough it's FB network. Therefore you get those spikes and the sagging and rising of the virtual ground in between.

Just great, a topic I always left apart until you discover it to me. I suppose there are LOTS of applications but it's great to learn that way. A lot of things I discovered! Thank you so much!

Dave, though i've never met you or even had a two-way communication with you i do see you as my friend and tutor. Maybe it's simply because you come across as a really nice guy in your vblog, and i've seen so much of your face and so much appreciate your educational skills. Maybe it's becuse with you as my major source of education i've had the best grades in every course i've taken over the last 18 months, spending close to no time at all studying, giving me time to earn some well needed cash for equipment, working as a private tutor for other students, and that was not even deliberate. I was approached by peers who wanted tutoring and insisted on paying me for it, reasoning that their parents were prepared to pay the tripple amount to an actual professor who would no likely be any better than any of our own teachers, working out of the same curriculum, and that they knew from class that they understood me way better than any teacher. Because every teacher we've ever had can take hours trying to explain these concepts to no avail, but using sometimes slightly modified (just enough to fit exactly the concept we're studying and the specific questions the sometimes slighly slow teacher wants answered at that moment) versions of what you've taught me i can explain concepts so that my peers understand them well enough to get at least a C in a matter of a few sentences. No matter what knowledge gaps my teachers have left behind i can fill them in, in a matter of minutes and almost never having to explain something twice to anyone, ever, using your pedagogic models! 9/10 times when i explain something the answer is something like "Ahaaa! Oh my god i feel so dumb, it's not even that complicated!" A lot of people don't appeciate the fact that the ability to understand something better than others, doesn't magically give you the ability to describe it in a way so that those that don't understand it can also do so! It's not just that i have complete confidence in the quality of the information you provide, it's your ability to explain thing that would have taken me hours or days to figure out, if at all, in a matter of seconds or minutes. In fact the service you provide me, absolutely for free, saves me so much time (generally in between 10-20 hours a week in school. Is this even real?!!!!! o____0 ) since i don't have to study anymore to get top grades and not be the teacher's pet but rather his assistant! So... The fact of the matter Dave, is that i basically owe you roughly 17% of my total spare time, weekends included! Those are 17% of the part of my life that i get to spend as my heart desires. And i simply just can't thank you for that in writing, because whatever words i chose would be an insult to your genius! But still, i do have to say something so a simpler thank you will have to suffice. Thank you professor Dave, thank you so very very much! The quality of the service you provide is in my experience unprecedented in any and all forums from the web to actual traditional education in a "real" school. I hope that you love doing what you're doing as much as i love watching you do it, and that you will keep doing this for a long, long time! Your devoted fan and pupil, Fredrik Sjöblom, Stockholm, Sweden.

This is the best explanation I've seen on the virtual ground. Nice! P.S: Next time, please consider giving an intro to DSPs, would be awesome!

Hey Dave, can your next video be on the stuff you crossed out? I wanted to cry there for a sec. There are tons and tons of resources about the basics of op amps, there a dime a dozen. However, there are very very few complete videos on op amp internals. Finding videos on the basics is utterly simple but finding well presented videos on more advance material such as op amp internals is painfully difficult.

I studied and played around with this stuff over 40 years ago, it's quite refreshing watching these videos. I went into digital for many years practically ignoring analog. Thank you Dave.

Even after 30 years away from electronics I got the gist of you lesson, thanks you explain it very well and in manner I just love. I worked in the dept of Navy as a trainee and we had two parts, one was a TAFE course the other was direct from Naval lecturers. The naval lecturers were like you extremely conversant and able to explain in a much more understandable manner.

Thank you Dave! This video has saved me headaches on multiple occasions. Everything is so well explained. I keep coming back to it for reference.

I wish you could do one like this for transistors!

Dave Cad works for me! I'm getting more info from you than I received making my way to an AAS ET degree. Thanks so much!

On behalf of every each one of electronics students thank You are saving my university career 🙏🙏🙏🙏

The things that were written on the board at the starting is exactly what my university wants me to learn

For the love of Tesla, I was so friggin' nervous when you forgot the 'negative' of inverting gain!

LOrd! Where do I start. This is the best tutorial I've ever experienced. You literally just saved me failure in less than an hour while other lectures are taking entire semesters to attempt doing so and still failing. THANK YOU!

Thanks, Dave - at last! an understandable demonstration of the OpAmp c/w bells and whistles. Good one! Thanks a mill.

good ol crossover-distortion. the LM358 has a class-B output stage and has to be biased properly or you get crossover distortion. instead of having diodes in the output stage, they tied the bases together. They were designed to be low power, so they did this. a proper load resistor between the output and negative supply will fix this problem. decreasing the feedback resistors increase the load by decreasing the overall impedance to the "virtual-ground", causing more and more crossover distortion. There is a tradeoff, by putting a resistor in the output stage to -ve, you also get a much higher idle current. Much more than of a standard class-ab op-amp. So that blows the "low-power" rating into the rubbish bin. Edited as my first couple attempts didnt sound, or come out right.

I spent 10 minutes waiting to see a correction for the inverting op amp, didn't want to comment too soon but finally my mind is at rest :)

+EEVblog Best Educators mostly are in the wrong position watching your videos just keeps motivation high ! subscribed.

Majestic explanation. I'm always amazed how things can become clear after your videos. Unbelievable.

You just solved my question for a project.. there we go.. another step forward.

I got it now! Man! you're totally Awesome!

Hi Dave! I just want to say thank you so much for sharing your knowledge with us! And providing us with great content which not only educate but also inspire! I finally understood op amps by watching your video! The textbooks I have read don't do justice and make it so hard for beginners to understand op amps.

Thanks to you, and your videos I am today a successful engineer working in semiconductor industry. I am just coming back, years after I watched this video for the first time. I was having problems passing the only one remaining subject to get my degree and was searching for a helpful video on opamps. Not only you helped me, but also inspired me with your positive personality! Keep up the good work!

OMG THANKS SO MUCH!! T^T You just saved my exams:')