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An op-amp is a phase-inverting voltage amplifier (high input-impedance, low output-impedance) with a large voltage gain. Shunt feedback is connected through an impedance between the output and input terminals.
In the simplest configuration there is a shunt feedback resistor - call that R2. If another resistor R1 is conncted in series with the input signal, the op-amp then produces a voltage gain of R2/R1.
The new voltage gain is considerably less than the gain without any feedback, and the practical result of this is that the input terminal of the op-amp, which is also the junction of the two resistors, always has an extremely low signal voltage on it and it is termed a 'virtual earth'.
The operation of the circuit can be considered by having the signal voltage inducing a signal current equal to Vin/R1 through R1, which then flows through R2 to produce a signal voltage of Vin R2/R1.
If the feedback resistor R2 is replaced by a capacitor C, then the gain of the amplifer is the ratio of the capacitor's impedance and the input resistor, R, or Vout/Vin = 1/jwCR. This is know as an 'integrator' because the output voltage is the time integral of the input voltage: it has a phase-lag of 90 degrees and an amplitude that decreases at the rate of 6 dB per octave.
If a constant current of i amps is applied to the input terminal, the output voltage rises on a ramp with a slope of i/CR volts per second; and if a variable current is applied, the output voltage is 1/(CR) integral i.dt. This is why an op-ap with a feedback capacitor and a series resistor i known as an analogue integrator.
What else can I help you with?
Why op amp do not work in high frequency?
the op amp is a one IC which does not work at hige volteg so the IC not consumed the high frequncy
What happens when magnitude of Vcc and Vee of op-amp are different?
When the magnitude of Vcc and Vee of op-amp are different the op-amp produces waveforms equal in the size of each rail.
How does an op-amp differ from other amplifier suchas common emitter transistor amplifier?
A: They both use transistors. In actuality before an op amp becomes an op amp a discrete transistor made is made to provide it capabilities before it gets integrated into a substrate chip we call op amp. OP AMP have two input to work as a differential amplifier the input are bases closely match to provide virtual no voltage or current offset. Single ended amplifier has one input its reference is the signal source return.
How an op amp differs from a basic amp?
A basic, single transistor amplifier differs from an op amp: 1. The op amp has more gain 2. The op amp may have higher input resistance (so it loads the circuit less) 3. The op amp may have a lower output resistance (so it can drive larger currents) 4. The op amp likely has a lower frequency response (due to the high gain, unless you provide some sort of feedback loop) 5. The op amp is ridiculously complex compared to a simple amplifier 6. The op amp will require a positive and negative voltage (may be unnecessary with a single transistor amplifier)
Which characteristics of Op-Amp is responsible for virtual ground?
The main parameter responsible for virtual ground of an Op-Amp is Input Impedance . Generally , for an Op-Amp it is very high . So , we can conclude that the characteristics of an Op-Amp responsible for virtual ground is high input impedance .
What is LM312T?
op-amp
Why feedback is used in op-amp?
Feedback in used in an op-amp to limit and control the gain. An op-amp, by itself, has very high gain, often more than 100,000. (A theoretical op-amp has infinite gain.) The external feedback loop forms a divider, more correctly a bridge, that is maintained in balance by the op-amp, giving the desired real gain.
How can an OP-AMP be nulled?
op-amp can be nulled using offset voltage about +/- 1.5 mv to offset pins
What is use of 8th pin in op-amp?
This may vary from one op-amp to another, consult the datasheet.
How can an op amp comparator circuit be used for converting sine to square wave?
The wording are confusing an op-amp is an op-amp a comparator is another animal. an op-amp can be used as square wave generator by overdriving it but the results are not desirable. However a comparator will be a switch on-off at the set level.
What are the ideal op-amp approximations?
Ideal op amp approximations: -no current goes into the positive or negative input of the op amp. -The open loop gain is infinite. -Voltage at positive input is the same as the negative input.
How gain varies with bandwidth in an op-amp?
The gain of an op amp varies with frequency. After an op amp reaches the half-power point, the gain falls appreciably. And then once it hits the transition frequency, the op amp no longer provides any gain.
