The timestamps for the different topics covered in the video: 0:20 How to Design the peak detector circuit (Using Diode and capacitor) and its working 2:29 Precision peak detector Circuit 3:05 Effect of load on the peak detector circuit 4:26 Precision peak detector Circuit with Buffer 5:16 Modified Peak detector circuit for the fast signals (High-Speed Peak Detector)
Could anyone explain how at 7:24, the output voltage of the circuit becomes equal to the inverting terminal input of the first op-amp? If they are equal wouldn't R be acting like a short?
sir i have a doubt, in the modified peak detector circuit diode d2 is not in the voltage follower loop then how it can work as a super diode. kindly clarify
If we connect the input voltage to the inverting terminal of the opamp, and connect the feedback Path to the non-inverting terminal of the opamp, will the output peak lie in the negative y-direction???
That works because that current is being sunk at the first opamp's output (your input is less than the peak, so current flows through the feedback resistor R). So the opamp's output follows Vin as long as it is less than Vpeak, with a negative peak of (-Vpeak - Vdiode1), so the max reverse voltage of D2 is 2*Vpeak+Vdiode1. Based on this, I would make sure the first opamp has enough slew rate for the frequency range you are working with.
6:58 why D1 is reverse biased while D2 is forward biased? Last video you taught us the opposite of this. when Vin>0 D1 was conducting while D2 is not conducting. whats the difference now? why didn't you explain it?
Sir one question ..which was asked in my barc interview..its not related to exactly this ckt but somewhat related concept. .how the current can go inside opamp from output side..means if suppose diode is ideal in above ckt and if current is supposed to go inside opamp then how it will go...is it possbl fr current to go inside opamp from output terminal( m not considering input side of opamp for above questn)
Similar to the source current there is a sink current, the current which is flowing into the output terminal. So, yes, the current can flow into the output terminal of the op-amp. Not only just for the op-amp but it is also applicable to other devices.
@@ALLABOUTELECTRONICS sir one more thing....please provide vdo on design of frequency devider ,pulse stretcher,pulse width modulator using 555 timer...can i expect this from ur side sir...it would be amazing n very helpful sir...actually this wil be helpful for barc ,isro interview as well
If it is designed using the op-amp then basically its unity gain follower circuit. The buffer as its name suggest, provides isolation between the input and output. Since op-amp provides very high input impedance and low output impedance, it can be used as a buffer circuit. I hope it will clear your doubt.
Great video sir But can you please explain about the reseting using transistor switch When do we want it to discharge?? Like when Vin becomes 0 So can we use a PMOS so that it's ON when Vin is 0 or below Vt and thus connects Capacitor C to ground and discharge it (Maybe foolish) Thanks again
Yes, the transistor can be used as a switch and can be connected in parallel to the capacitor to discharge it when you want to reset it. There is readily available CMOS Switch. (CD4066B), which can be connected in parallel to the capacitor.
@@ALLABOUTELECTRONICS oh so it's like in places where we need everything to be accurate instead of using discrete transistor switch we use s CMOS IC for its advantages Thank you so much
Sir when u connected the buffer the capicitors holds the voltage for more time because of high impedence of op amp what about the fast responce of the capacitor to the input voltage how did you resolve it
@@neerajhebbar7313 I think it won't because as you said, you want to use it for fast switching application, so before it drops to a certain degree, it will find another peak or a signal while dropping. But of course, the value of R should be selected carefully.
Yes, it can be used as the envelope detector. But during the design, RC time constant of the circuit (During discharging) should be such that it follows the envelope.
It is one of the same thing. The envelope detector is the other name of the peak detector. (perticuallry when it is used in demodulation of the signal.)
Inadequate explanation for third circuit didn't explain about this point "When diode d2 will be reverse biased diode d2 will prevent the opamp to enter into negative saturation then diode d1 will be forward biased that means it will be short circuited then first opamp will act just like a buffer then vin will be equal to vout .After this what will happen .Explanation needed about this
The timestamps for the different topics covered in the video:
0:20 How to Design the peak detector circuit (Using Diode and capacitor) and its working
2:29 Precision peak detector Circuit
3:05 Effect of load on the peak detector circuit
4:26 Precision peak detector Circuit with Buffer
5:16 Modified Peak detector circuit for the fast signals (High-Speed Peak Detector)
Our professor often suggests your video instead of any books. Thank you for such a good content.
Circuit design is not easy, takes a lot of experience. Programming much easier. Great video. Your the best!
Why would you dislike this!!!!
Its amazing!!!!
Good explanation. It could be even clearer if you avoid anticipatory...
pauses just before the last word in the...
op amp. ;-)
Underrated comment
Your written notes in the description make your channel unique and different
Could anyone explain how at 7:24, the output voltage of the circuit becomes equal to the inverting terminal input of the first op-amp? If they are equal wouldn't R be acting like a short?
no
Great explanation!! Thank you!
thank you, this circuit works great! And for some reason I had better results without the feedback resistor.
sir i have a doubt, in the modified peak detector circuit diode d2 is not in the voltage follower loop then how it can work as a super diode. kindly clarify
If we connect the input voltage to the inverting terminal of the opamp, and connect the feedback Path to the non-inverting terminal of the opamp, will the output peak lie in the negative y-direction???
Good expert in subject please upload more videos in electronics
great explainer
When D1 is FB and D2 is RB (Vin
That works because that current is being sunk at the first opamp's output (your input is less than the peak, so current flows through the feedback resistor R). So the opamp's output follows Vin as long as it is less than Vpeak, with a negative peak of (-Vpeak - Vdiode1), so the max reverse voltage of D2 is 2*Vpeak+Vdiode1. Based on this, I would make sure the first opamp has enough slew rate for the frequency range you are working with.
6:58 why D1 is reverse biased while D2 is forward biased? Last video you taught us the opposite of this. when Vin>0 D1 was conducting while D2 is not conducting. whats the difference now? why didn't you explain it?
Nicely Done.
Thank you, very educational.
8:56 op amp operates in open loop @ Vin slightly positive making op amp go to +Vsat it isnt detecting peaks
One doubt in last circuit capacitor charge is equal to peak voltage - diode drop right??
Great explanation 👍👍
Sir one question ..which was asked in my barc interview..its not related to exactly this ckt but somewhat related concept. .how the current can go inside opamp from output side..means if suppose diode is ideal in above ckt and if current is supposed to go inside opamp then how it will go...is it possbl fr current to go inside opamp from output terminal( m not considering input side of opamp for above questn)
Similar to the source current there is a sink current, the current which is flowing into the output terminal.
So, yes, the current can flow into the output terminal of the op-amp.
Not only just for the op-amp but it is also applicable to other devices.
@@ALLABOUTELECTRONICS sir one more thing....please provide vdo on design of frequency devider ,pulse stretcher,pulse width modulator using 555 timer...can i expect this from ur side sir...it would be amazing n very helpful sir...actually this wil be helpful for barc ,isro interview as well
I have already made videos on 555 timer. If you just go through the playlist oscillator and multivibrators then you will get all the videos.
Can you make a vedio on half wave peak detector using pnp transistor
Thank you 🙏
What is Rd here across diode?
can you help me on this problem "Design and implementation of Metal detector Circuit based on op-amp"
no
What is a buffer circuit
If it is designed using the op-amp then basically its unity gain follower circuit. The buffer as its name suggest, provides isolation between the input and output. Since op-amp provides very high input impedance and low output impedance, it can be used as a buffer circuit.
I hope it will clear your doubt.
Sir plz explain us phase detector
Please tell me the diode and RL value
Great video sir
But can you please explain about the reseting using transistor switch
When do we want it to discharge??
Like when Vin becomes 0
So can we use a PMOS so that it's ON when Vin is 0 or below Vt and thus connects Capacitor C to ground and discharge it
(Maybe foolish)
Thanks again
Yes, the transistor can be used as a switch and can be connected in parallel to the capacitor to discharge it when you want to reset it.
There is readily available CMOS Switch. (CD4066B), which can be connected in parallel to the capacitor.
@@ALLABOUTELECTRONICS oh so it's like in places where we need everything to be accurate instead of using discrete transistor switch we use s CMOS IC for its advantages
Thank you so much
Sir diode resistor capacitor value tell me
Sir when u connected the buffer the capicitors holds the voltage for more time because of high impedence of op amp what about the fast responce of the capacitor to the input voltage how did you resolve it
In such a case, you can use a resistor before the op-amp, so that the circuit can follow the fast changing signal.
@@ALLABOUTELECTRONICS adding resistor drops some voltage so it cant detect the exact peak sir
@@neerajhebbar7313 I think it won't because as you said, you want to use it for fast switching application, so before it drops to a certain degree, it will find another peak or a signal while dropping. But of course, the value of R should be selected carefully.
@@ALLABOUTELECTRONICS yessss sir thanxxxx for your time i will see the circuit behaviour in the simulator thanxxx for the reply sir
Modified peek detector circuit outer loop diode have any drop depends upon diode type
Sir, what is your qualification?
Please check the about section of the channel.
Can i use it as envelope detector ?
Yes, it can be used as the envelope detector. But during the design, RC time constant of the circuit (During discharging) should be such that it follows the envelope.
can we use envelop detector??
It is one of the same thing. The envelope detector is the other name of the peak detector. (perticuallry when it is used in demodulation of the signal.)
I am having a hard time simulating this in LT spice. Do you have any confidence in simulation software ?
Try Multisim online simulator. It is easy to use and you will get all basic circuit components as well.
sir , Is it called sample and hold circuit
they are just similar! Because "sample and hold circuit" follows the input signal, whereas it only holds the highest peak value.
Inadequate explanation for third circuit didn't explain about this point
"When diode d2 will be reverse biased diode d2 will prevent the opamp to enter into negative saturation then diode d1 will be forward biased that means it will be short circuited then first opamp will act just like a buffer then vin will be equal to vout .After this what will happen .Explanation needed about this
Yeah true😑
👌👌
Superb
Ahhhh seriously confusing
also the explanation has so many assumptions that one reaches nowhere if he/she tries to understand or follow the logic.
Nicely Done.