What is Operational amplifier: Definition and 48 Discussions
An operational amplifier (often op amp or opamp) is a DC-coupled high-gain electronic voltage amplifier with a differential input and, usually, a single-ended output. In this configuration, an op amp produces an output potential (relative to circuit ground) that is typically 100,000 times larger than the potential difference between its input terminals. Operational amplifiers had their origins in analog computers, where they were used to perform mathematical operations in linear, non-linear, and frequency-dependent circuits.
The popularity of the op amp as a building block in analog circuits is due to its versatility. By using negative feedback, the characteristics of an op-amp circuit, its gain, input and output impedance, bandwidth etc. are determined by external components and have little dependence on temperature coefficients or engineering tolerance in the op amp itself.
Op amps are used widely in electronic devices today, including a vast array of consumer, industrial, and scientific devices. Many standard IC op amps cost only a few cents; however, some integrated or hybrid operational amplifiers with special performance specifications may cost over US$100 in small quantities. Op amps may be packaged as components or used as elements of more complex integrated circuits.
The op amp is one type of differential amplifier. Other types of differential amplifier include the fully differential amplifier (similar to the op amp, but with two outputs), the instrumentation amplifier (usually built from three op amps), the isolation amplifier (similar to the instrumentation amplifier, but with tolerance to common-mode voltages that would destroy an ordinary op amp), and negative-feedback amplifier (usually built from one or more op amps and a resistive feedback network).
Hi all, I attached my attempt at a solution in the attached picture. I am using the textbook titiled as ”electronic circuit analysis“ by David E. Johnson, and op amp is in chap 3;
while I did not find any example that attach the Vee and Vcc with amplifier . It seems that v+ = v- doesn’t hold in...
So basically I am trying to give an output of Vo = 10(V2-V1)
From Figure 9 Example Gain of first Op Amp = Rf / R1, if R1 & R2 are equal.
What's throwing me off is using 5 resistors to create a circuit rather than 6 or just 3. My initial thoughts were the following:
To use the first loop...
I've been given the following circuit and have been asked to find the input impedance and the impedance between the input terminal and ground. I've never encountered an operational amplifier configured like this.
I know that the voltages at the - and + terminals of the op amp are ideally equal...
Homework Statement
Calculate the output voltage of the amplifier
2. Homework Equations
[/B]
https://www.electronics-tutorials.ws/opamp/opamp32.gif
The Attempt at a Solution
I do not know how to approach a circuit with RC in series to inverting terminal of integrating op amp
i have build and simulated the op amp circuit, i have recorded the voltage gain at different frequencies, now i need to plot a graph for the two results in same graph paper, i have not plotted a graph before for the related task so i need to understand from the basics,
i need some one to...
So I've been reading an intro book to electronics and I got to a section about operational amplifiers. It talks about different uses of them and how they can be used as comparators. It then talks about a specific comparator called a window comparator which will output a positive voltage if the...
Homework Statement
Hello,
I am trying to Calculate The Resistance Rf and the value of the Voltage V2. The setup is a logarithmic Op amp connected to a differential Op amp. Both Op amps obey the Golden Rules.
Attached below is my attempt at the solution and the question.
Currently, I have an...
I want to build own circuit usinghttps://ez.analog.com/external-link.jspa?url=http%3A%2F%2Fwww.kynix.com%2FProduct%2FCate%2F470.htmland resistors. I have 12V power source (car accumulator) and 6V input voltage (Vin). I want to get 12V Vout and 25W at the output. So that is about 2A...
Homework Statement
The variation with time t of the potential Vin at the inverting input of the op-amp is shown in Fig. 10.2.
On the axes of Fig. 10.2, draw the variation with time t of the output potential of the op-amp.
(pictures attached)
Homework Equations
The potential divider equation to...
Homework Statement
What is the value of V2 in terms of Vos?
Homework EquationsThe Attempt at a Solution
In the class, we were told that this is just a non-inverting amplifier, thus V2= Vos x (R2/R1+R2).
However, I want to work out the solution by applying nullator hypothesis (voltage...
Homework Statement
Homework EquationsThe Attempt at a Solution
[/B]
Using the equations above, I'm not getting the right answer for beta which is 0.4926 V/A.
Is my model wrong ?
Homework Statement
(a) Derive the relationship
between the output voltage V and the input current I; i.e. if V = kI
find k in terms of R1, R2 and Rf.
(b) Calculate the current I if Rf = 10 MΩ, R1 = 90 kΩ, R2 = 10 kΩ
and V –0.1 V.
(c) Model the circuit using PSPICE [using an ideal opamp]
and...
Homework Statement
Good morning everybody,I'm french and my english isn't good but I need help for this exercice please:
I tried to do this exercice,however I'm not sure of my answers,can you tell me if they are good , or what mistakes I committed ?
Here the exercice :
2. Revelant equations...
Hello.
I really don't get a concept of a way to generates negative voltage as a one of the supply voltage to typical OP-AMP. (Operational Amplifier)
The output voltages is supposed to swing to more than 10 V thus supply voltages to OP-AMP should be +15V and -15V.
I'm thinking of supply these...
Does current flow through the feedback resistor without going through the op-amp at all? After all, the op-amp is supposed to have very high input impedance right, so if the current just flows through the feedback resistor, wouldn't there be nothing going through the op-amp?
Also, how does the...
Homework Statement
See ImageHomework Equations
Source Transformations
The Attempt at a Solution
The answer is given, but I do not understand how they got it. When I multiply 9mA and 947.308Ω resistor, I get 8.526...what am I doing wrong? Also, could someone explain how they went on to get...
Hello,
As I mentioned before, thank you for all the mentoring. It has been a huge help to my understanding.
So, I am trying to stay one - two weeks ahead of my operational amplifiers class. I know that we will soon be discussing the 741 Operational amplifier.
While reading about it, I...
Homework Statement
Op Amp powered from +-20V DC. Find V(out) in Volts. All Resistances/Batteries given.
http://imageshack.us/a/img805/2803/photoup.png
Help would be much appreciated
Hi all,
Does anyone know how do I connect an OTA if I want to use it as a voltage-controlled current source, meaning that it will ouput an AC current when i supplied an AC voltage?
Any guide I can refer to?
And how do I adjust the gain or transconductance, gm?
For example, OPA860 with...
Hi:
i have a project to design ECG system:
read ECG signal by using (DAQ)data aquestion and the Signal processing(bandpass& notch filter) will be done by using MATLAB program.
I was Intended to use instrument amplifier to obtain I,II or III signals
as this figure:
but my supervisor...
I'm studying for an exam and I'm struggling to understand op amps, here's my problem:
I understand that for an op amp to have a controllable gain, the difference between the input terminals must be very very close to zero (and you can assume it is zero). And to do this you use negative...
Hi,
Just I really short question. I have attached my assignment as a picture file. Don't worry I am not asking you to give me a solution.
I just want to know, in the question it tells us that there is a internal resistance of 1MΩ, and a supply voltage of 10V. I am really confuse, as all...
I'm making a simple circuit on the breadboard with a 741 op amp. The feedback resistor is 150 kohms, and the input resistor is 100 kilo ohms, means the gain is 1.5. The input voltage is about 5.33. The power supply is ±18 V. For some reason the output voltage is 0.98 V instead of the amplified...
Homework Statement
http://img51.imageshack.us/img51/1912/vout.jpg
Given the supply voltages of the operational amplifier are (plus and minus)15V, as well it is given that R1 = R2 = R3. We get that Vout is -15V
True or false?
Explain.The Attempt at a Solution
[SIZE="5"]False because it...
Homework Statement
See attached file for relevant questions. I'm finding the Op-amp questions in section A very difficult. Any help with these questions would be much apprietiated.
Homework Equations
The Attempt at a Solution
Hello. I believe there's a flaw in my understanding of the operational amplifier. I'm getting a bizarre result that I'd really appreciate if anyone can help me with. :)
1. http://tinyurl.com/6e9ovvp
The part I'm having problem with is Q9 (b) (iv).
2. V=IR
The Attempt at a...
Homework Statement
Derive an expression for the gain Vout/Vin. Express your answer in the form of A+jB.
Homework Equations
The Attempt at a Solution
If C is the capacitor in series with R1, gain = 1 + R2/[R1 + 1/(jwC)]. It says to express it in the form of A (real)+ jB (imaginary), but I'm...
Hi, I have a quick question regarding Operational Amplifier's. I understand in an ideal Op-Amp the current through the + and - input terminals should be zero. What is the point of the Op-Amp if no current goes through the inputs? How does it work?
thanks
The question is as given in the image attached entitled 'amplifier question' I would just like someone to check my working and verify whether it's correct or not. Thanks. And also want to ask on the second part which is 'what mathematical operation does this circuit perform?' Any help would be...
why is an inverting amplifier and not a non-inverting amplifier used as a summing amplifier ?
Why must the input voltages be inverted in a summing amplifier ?
I am told that a summing amplifier is used as mixer in concerts where different music produced by different instruments go through...
Homework Statement
Given the attached figure (with values as shown on the op-amp) find Vo and io.
Homework Equations
None
The Attempt at a Solution
I figure that we're looking at an inverting operational amplifier and I used a voltage divider to find the input voltage...
Homework Statement
The question is about the concept of the operational amplifier in electronics.
For an ideal op. amp., it is said that the input impedance is infiinite and the current allowed by the op.amp. through its input terminal zero or in the case of a practical op.amp., it is...
Homework Statement
Look up the offset current for the LM353 op-amp and predict the time rate of change of the output for the circuit below after the switch opens. (Find dVo/dt)
Homework Equations
offset current = 50 pA
i+ = i-, ideally
v+ = v-, ideallyThe Attempt at a Solution
I really don't...
I read in a book that perfect integration using inverting op-amp is possible only when the time constant of the circuit(R1Cf) is lesser than the time period of the input signal.
I have trouble in understanding this concept.
Lets assume i give a square wave as input at the inverting terminal.Now...
Hi I was just wondering what the nodal voltage Vb would be if you shorted the 1k resistor shown in this pic: http://img401.imageshack.us/my.php?image=opampem4.jpg
also with that resistor in place what would the nodal voltage Vb be? i get 90.1mV
ty in advance
Homework Statement
How can the open loop voltage gain of an operational amplifier with AC input voltage be determined experimentally?
Supply voltage for op amp is +9V.
Homework Equations
The Attempt at a Solution
I'm really stuck here. I would appreciate some outline of...
Good evening.
Right. My question is one of a simple nature, I think.
Anyways, consider the following non-inverting Op-Amp design:
http://www.freewebs.com/mushg/FWThumbnails/OpAmp.bmp
Now, the basic formula for any non-inverting opamp is of course \frac{V_{O}}{V_{S}} = 1 +...
hi...
can anyone help with the problem i attached
thanks in advance...
I think a good start would be to convert the current source into a voltage source
Homework Statement
1) Consider an inverting operational amplifier as shown in figure. Suppose R1= 1000 ohm & Rf = 10^6 ohm. It is said that the input impedance=R1=1000 ohm and the Output impedance= 0.
2) Consider a non inverting operational amplifier as shown in figure. Suppose R1= 3500...
Homework Statement
I have some problems determining the tension output value for this circuit and this confusion comes from the presence of positive feedback and an alternate current.Since I'm used to negative feedback circuits and direct current it confuses me a bit,so any help is deeply...
I want to inform you that our course about operational amplifier at university has such of the following topics:
adder amplifier(inverting and non inverting)- integrator-diffrentiator-comparator- schmitt trigger-rectangular waveform generator-triangular waveform generator...and some active...
Hi Guys,
I'm trying to amplify a millivolt signal from an electrode that has a high input resistance (~ 200 MOhm). To avoid losses over the series resistance I'm using a high input impedance Op Amp TL071CP as a voltage follower. The problem I'm having though is that for some reason when the...
I'm trying to make a sine wave oscillator with unipolar amplifiers, and all the circuits I find are for bipolar amplifiers.
I've tried to modify the bipolar circuit, but it doesn’t work.
Can anybody give an idea or a circuit?
thank you for your attention.