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What are the ideal values of different parameters of an op-amp?
An “ideal” or perfect operational amplifier is a device with certain special characteristics such as infinite open-loop gain AO, infinite input resistance RIN, zero output resistance ROUT, infinite bandwidth 0 to ∞ and zero offset (the output is exactly zero when the input is zero).
What are the limitations of basic integrator using op-amp How do you overcome it?
The ideal integrator suffers from two main limitations. One comes from the fact that the output voltage of the opamp can not exceed the supply voltage. The output of the integrator is inversely proportional to the time constant τ = RsCf. The larger the time constant τ, the longer it takes to saturate the integrator.
What are the practical limitations of μa741 op-amp?
One of the practical op-amp limitations is that the input impedance finite, though very high compared to discrete transistor amplifiers. For the 741 the input resistance measured to one input with the other grounded is about 2 Megohms. For FET input devices it is typically 10^12 ohms.
What are the key parameters to evaluate the performance of an amplifier?
The gain of an amplifier is a measure of the “Amplification” of an amplifier, i.e. how much it increases the amplitude of a signal. More precisely it is the ratio of the output signal amplitude to the input signal amplitude, and is given the symbol “A”.
Why are comparators used instead of op amps?
Comparators, on the other hand, are generally designed to operate open loop, with outputs slewing between specified upper and lower voltage limits in response to the sign of the net difference between the two inputs. Since they do not require the op amp’s compensation capacitors, they can be quite fast.
Why are comparators not multiplied by loop gain?
Using a low value of pull-up resistance yields improved switching speed and noise immunity—but at the expense of increased power dissipation. Because comparators are rarely configured with negative feedback, their (differential) input impedance is not multiplied by loop gain, as is characteristic of op amp circuits.
What should the low output of a comparator be?
The comparator’s “low” output value (logic 0) is specified at less than 0.4 V max in comparators with TTL-compatible outputs, while for a low-voltage amplifier, the low output value is very close to its negative rail (e.g., 0 V in a single-supply system).
Do you need capacitors for an op amp?
Since they do not require the op amp’s compensation capacitors, they can be quite fast.