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)
When the magnitude of Vcc and Vee of op-amp are different the op-amp produces waveforms equal in the size of each rail.
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 .
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.
An op amp is made from transistors, resistors and capacitors. It is enclosed in a "chip". A basic instrumentation amp is made of 2 op-amps. you can't have a single op-amp perform as good as a instrumentation amp, although it can perfrom the same task. An i-amp has much better CMMR (common-mode rejection) and a higher input impedance.
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.
op-amp can be nulled using offset voltage about +/- 1.5 mv to offset pins
This may vary from one op-amp to another, consult the datasheet.
op-amp
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.
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.
When the feedback of the output terminal of an Op-Amp is given to the non-inverting terminal [pin 3 for IC-741] of that Op-Amp , then , that circuit is called non-inverting amplifier using Op-Amp. This circuit is called non-inverting because the output signal of this circuit is in phase with the input signal.
i know that an op amp can be used as an amplifier and a switch, but i want to have more uses of the component or device.