What is Operational amplifier (op-amp)?
An amplifier with differential inputs and very high gain. Used with negative feedback in amplifiers, filters and more.
Operational amplifier (op-amp) in the explanations
An ideal op-amp is assumed to have infinite input impedance (no current into the inputs), zero output impedance (output voltage independent of load) and infinite open-loop gain.
Which combination correctly describes an ideal op-amp?At DC, the op-amp's offset is also integrated until the output saturates, so practical circuits add a large resistor across C.
What is the circuit called in which the feedback resistor o…An internally compensated op-amp's open-loop gain falls at −20 dB/decade, so gain × bandwidth is roughly constant.
An op-amp with a gain-bandwidth product (GBW) of 1 MHz is u…
Questions that mention Operational amplifier (op-amp) (18)
- Which combination correctly describes an ideal op-amp?
- In an inverting amplifier using an ideal op-amp, with input resistor Ri = 10 kΩ and feedback resistor Rf = 100 kΩ, what is the voltage gain?
- In a non-inverting amplifier using an ideal op-amp, with input-side resistor R1 = 10 kΩ and feedback resistor R2 = 90 kΩ, what is the voltage gain?
- Which correctly describes a voltage follower using an op-amp?
- What is the circuit called in which the feedback resistor of an op-amp inverting amplifier is replaced by a capacitor?
- An op-amp with a gain-bandwidth product (GBW) of 1 MHz is used to build a non-inverting amplifier with a gain of 10. What is the approximate bandwidth?
- What does the slew rate of an op-amp mean?
- In an ideal op-amp circuit with negative feedback, what is the property called by which the two input terminals have almost the same voltage?
- Which correctly describes the input offset voltage of an op-amp?
- Which circuit converts a photodiode current into a voltage by feeding the current into the inverting input of an op-amp and converting it with a feedback resistor?
- What is the circuit called in which the input resistor of an op-amp inverting amplifier is replaced by a capacitor?
- In an inverting amplifier using a bipolar-input op-amp, why is a resistor equal to the parallel value of the input and feedback resistors placed between the non-inverting input and ground?
- What is the main reason for placing a driver circuit, such as an op-amp, in front of a successive-approximation AD converter?
- What does a differential pair, with the emitters of two transistors connected to a common current source, do?
- What is the advantage of an active load, which uses a transistor acting as a current source instead of a load resistor in an amplifier?
Related terms
Negative feedback Virtual short Voltage follower Phase margin Gain-bandwidth product (GBW) Slew rate Photodiode Transimpedance amplifier Scanner CMOS