In practical op-amps, what is the effect of high frequency on its performance?

In practical op-amps, what is the effect of high frequency on its performance?
by

1 Answer

Answer :

The open-loop gain of op-amp decreases at higher frequencies due to the presence of parasitic capacitance. The closed-loop gain increases at higher frequencies and leads to instability.
by

Related questions

What is the need for frequency compensation in practical op-amps?

Description : What is the need for frequency compensation in practical op-amps?

Last Answer : Frequency compensation is needed when large bandwidth and lower closed loop gain is desired. Compensating networks are used to control the phase shift and hence to improve the stability.

How frequency to voltage converted on OP-AMPS.

Description : How frequency to voltage converted on OP-AMPS.

Last Answer : A Frequency to voltage converter produces an output voltage, whose amplitude is a function of frequency of the input signal. The input signal may be a sinewave, a square wave or a pulse train. The F/V converter is essentially an FM detector or discriminator.

Mention some of the non – linear applications of op-amps

Description : Mention some of the non – linear applications of op-amps

Last Answer : Rectifier, peak detector, clipper, clamper, sample and hold circuit, log amplifier, anti –log amplifier, multiplier are some of the non – linear op-amp circuits. 

Mention some of the linear applications of op – amps.

Description : Mention some of the linear applications of op – amps.

Last Answer : Adder, subtractor, voltage –to- current converter, current –to- voltage converters, instrumentation amplifier, analog computation ,power amplifier, etc are some of the linear opamp circuits.

Which of the following systems uses frequency band 870-885 MHz as a transmit band of its base station? A. TACS B. NTT C. NMT D. AMPS

Description : Which of the following systems uses frequency band 870-885 MHz as a transmit band of its base station? A. TACS B. NTT C. NMT D. AMPS

Last Answer : B. NTT

Draw the circuit diagram for Instrumentation amplifier using three OP-AMPs. State its advantages and applications.

Description : Draw the circuit diagram for Instrumentation amplifier using three OP-AMPs. State its advantages and applications.

Last Answer : Application: 1. In Data acquisition from low output transducers such as strain gauges, Thermocouples, Wheatstone bridge measurements e.t.c 2. In Medical instrumentation, Navigation, Radar ... video data acquisition and imaging 5. High frequency signal amplification in cable RF systems 

The three devices which make up the circuit shown in the illustration are ____________. EL-0087 A. flip-flops B. exclusive 'OR' gates C. summing op amps D. function generators

Description : The three devices which make up the circuit shown in the illustration are ____________. EL-0087 A. flip-flops B. exclusive 'OR' gates C. summing op amps D. function generators

Last Answer : Answer: A

An OP-AMPs can amplify _______ (a) D.C (b) A.C (c) both A.C & D.C (d) none of aboveAn OP-AMPs can amplify _______ (a) D.C (b) A.C (c) both A.C & D.C (d) none of above

Description : An OP-AMPs can amplify _______ (a) D.C (b) A.C (c) both A.C & D.C (d) none of above

Last Answer : b) A.C

What are op amps used for?

Last Answer : Op amp is operational amplifier. Operational amplifier are use in ADC, zero crossing detector ,DAC, filters, Voltage regulators, Current regulators, etc.

What is the type of feedback used in an op-amp Schmitt trigger?

Description : What is the type of feedback used in an op-amp Schmitt trigger?

Last Answer : The type of feedback used in an op-amp Schmitt trigger is positive feedback.

What is the basic building block of an op-amp?

Description : What is the basic building block of an op-amp?

Last Answer : The basic building block of an op-amp is differential amplifier.

What is the type of feedback employed in the inverting op-amp amplifier?

Description : What is the type of feedback employed in the inverting op-amp amplifier?

Last Answer : Negative feedback is employed in the inverting op-amp amplifier.

What are the DC characteristics of an op-amp?

Description : What are the DC characteristics of an op-amp?

Last Answer : a. input bias current b. Input offset current c .Input offset voltage d. Thermal drift

What are the AC characteristics of an op-amp?

Description : What are the AC characteristics of an op-amp?

Last Answer : a. Frequency response b. Slew rate

What is compensated op-amp?

Description : What is compensated op-amp?

Last Answer : Op-amp, which uses a capacitor internally for compensation, is called a compensated op-amp. This op-amp has a high gain stability and low bandwidth.

What is an op-amp?

Description : What is an op-amp?

Last Answer : The operational amplifier is a multi-terminal device, which is quite complex internally. An operational amplifier is a direct coupled high gain amplifier usually consisting of one or more ... as well as ac input signals and was originally designed for computing such mathematical functions.

Write transfer function of op amp as an integer.

Description : Write transfer function of op amp as an integer.

Last Answer : The transfer function of the integer is  LAL=1/MR1cf

What are the areas of application of non-linear op- amp circuits?

Description : What are the areas of application of non-linear op- amp circuits?

Last Answer : 1. Industrial instrumentation 2. Communication 3. Signal processing

Define CMRR of an op-amp.

Description : Define CMRR of an op-amp.

Last Answer : The relative sensitivity of an op-amp to a difference signal as compared to a common – mode signal is called the common –mode rejection ratio. It is expressed in decibels. CMRR= Ad/Ac

Define input offset current. State the reasons for the offset currents at the input of the op-amp.

Description : Define input offset current. State the reasons for the offset currents at the input of the op-amp.

Last Answer : The difference between the bias currents at the input terminals of the op-amp is called as input offset current. The input terminals conduct a small value of dc current to bias the input transistors.Since the input transistors cannot be made identical,there exists a difference in bias currents.

Define virtual ground of a OP-Amp?

Description : Define virtual ground of a OP-Amp? 

Last Answer : A virtual ground is a ground which acts like a ground. It is a point that is at the fixed ground potential (0v),though it is not practically connected to the actual ground or common terminal of the circuit.

Why open loop OP-AMP configurations are not used in linear applications?

Description : Why open loop OP-AMP configurations are not used in linear applications?

Last Answer : The open loop gain of the op-amp is not a constant and it varies with changing the temperature and variations in power supply.Also the bandwidth of the open loop op-amp is negligibly small.For this reasons open loop OP-AMP configurations are not used in linear applications.

The speech coding rate in D-AMPS is ____. A. 8 kbps B. 13 kbps C. 15 kbps D. 20 kbps

Description : The speech coding rate in D-AMPS is ____. A. 8 kbps B. 13 kbps C. 15 kbps D. 20 kbps

Last Answer : A. 8 kbps

Deemphasis in the receiver in effect attenuates modulating signal components and noise in what frequency range? A. dc B. low C. intermediate D. high

Description : Deemphasis in the receiver in effect attenuates modulating signal components and noise in what frequency range? A. dc B. low C. intermediate D. high

Last Answer : D. high

In radio High frequency communications the higher the radio frequency the ______. A. Higher it can reach B. Shorter it can reach C. Effect is null D. Longer it can reach

Description : In radio High frequency communications the higher the radio frequency the ______. A. Higher it can reach B. Shorter it can reach C. Effect is null D. Longer it can reach

Last Answer : D. Longer it can reach

Top loading is used in an antenna in order to increase its ______. A. practical height B. beamwidth C. effective height D. input capacitance

Description : Top loading is used in an antenna in order to increase its ______. A. practical height B. beamwidth C. effective height D. input capacitance

Last Answer : C. effective height

A practical dBrn measurement will almost always in a _______ number. A. positive B. negative C. imaginary D. fractional

Description : A practical dBrn measurement will almost always in a _______ number. A. positive B. negative C. imaginary D. fractional

Last Answer : A. positive

The effect of adding parasitic elements of a Hertz dipole is to A. make the antenna more omnidirectional B. reduce its resonant frequency C. increase the antenna’s power gain D. All of these

Description : The effect of adding parasitic elements of a Hertz dipole is to A. make the antenna more omnidirectional B. reduce its resonant frequency C. increase the antenna’s power gain D. All of these

Last Answer : C. increase the antenna’s power gain

What is the effect of adding a capacitor in series with an antenna? A. The antenna’s resonant frequency will increase B. The antenna’s resonant frequency will decrease C. The antenna will be physically 5% longer than its electrical length D. A capacitor is never added in series with an antenna

Description : What is the effect of adding a capacitor in series with an antenna? A. The antenna’s resonant frequency will increase B. The antenna’s resonant frequency will decrease C. The antenna will be physically 5% longer than its electrical length D. A capacitor is never added in series with an antenna

Last Answer : A. The antenna’s resonant frequency will increase

Which frequency reuse method is less effective because of Faraday’s effect? A. Dual polarization B. Reducing antenna beamwidth C. Zonal rotation D. Spin stabilization

Description : Which frequency reuse method is less effective because of Faraday’s effect? A. Dual polarization B. Reducing antenna beamwidth C. Zonal rotation D. Spin stabilization

Last Answer : A. Dual polarization

In acoustics, _____ is the apparent change in frequency or pitch when a sound source moves either toward or away from a listener. A. flanking B. reverberation C. Doppler effect D. echo

Description : In acoustics, _____ is the apparent change in frequency or pitch when a sound source moves either toward or away from a listener. A. flanking B. reverberation C. Doppler effect D. echo

Last Answer : C. Doppler effect

What does the noise weighting curve shows? A. Noise signals measured with a 144 handset B. Power levels of noise found in carrier systems C. The interfering effect of other frequencies in a voice channel compared with a reference frequency of one kilohertz D. Interfering effects of signals compared with a 3-kHz tone

Description : What does the noise weighting curve shows? A. Noise signals measured with a 144 handset B. Power levels of noise found in carrier systems C. The interfering effect of other frequencies in a voice ... a reference frequency of one kilohertz D. Interfering effects of signals compared with a 3-kHz tone

Last Answer : C. The interfering effect of other frequencies in a voice channel compared with a reference frequency of one kilohertz

In a 741 Op-Amp, there is 20 dB/decade fall-off starting at a relatively low frequency. This is due to the

Description : In a 741 Op-Amp, there is 20 dB/decade fall-off starting at a relatively low frequency. This is due to the (A) applied load (B) internal compensation (C) impedance of the source (D) power dissipation in the chip

Last Answer : In a 741 Op-Amp, there is 20 dB/decade fall-off starting at a relatively low frequency. This is due to the internal compensation

An OP amp has a slew rate of 1V/µs. At a signal frequency of 0.1 MHz, the maximum undistorted sine wave ...

Description : An OP amp has a slew rate of 1V/µs. At a signal frequency of 0.1 MHz, the maximum undistorted sine wave amplitude is (a) 8V (b) 4.82 V (c) 2.02 V (d) 1.592 V

Last Answer : Slew rate = 2πfv where v is the amplitude V=(1/2π*0.1) = 1.592V

For a shortened vertical antenna, where should a loading coil be placed to minimize losses and produce the most effective performance? A. As low as possible on the vertical radiator B. Near the center of the vertical radiator C. As close to the transmitter as possible D. At a voltage node

Description : For a shortened vertical antenna, where should a loading coil be placed to minimize losses and produce the most effective performance? A. As low as possible on the vertical radiator B. Near the center of the vertical radiator C. As close to the transmitter as possible D. At a voltage node

Last Answer : B. Near the center of the vertical radiator

One of the following is not a useful quantity for comparing the noise performance receivers. A. Input noise voltage B. Equivalent noise resistance C. Noise temperature D. Noise figure.

Description : One of the following is not a useful quantity for comparing the noise performance receivers. A. Input noise voltage B. Equivalent noise resistance C. Noise temperature D. Noise figure.

Last Answer : A. Input noise voltage

A figure of merit used to measure the performance of a radiation detector. A. Noise equivalent power B. Ripple factor C. Safe factor D. Quality factor

Description : A figure of merit used to measure the performance of a radiation detector. A. Noise equivalent power B. Ripple factor C. Safe factor D. Quality factor

Last Answer : A. Noise equivalent power

RS-232, RS-449, RS-530, V, 24 and X.21 are examples of ____________. A. standards for interfaces between modems and transmission facilities B. standards for various types of transmission channels C. standards for interfaces between terminals and modems D. standards for end to end performance of data communications system

Description : RS-232, RS-449, RS-530, V, 24 and X.21 are examples of ____________. A. standards for interfaces between modems and transmission facilities B. standards for various types of ... for interfaces between terminals and modems D. standards for end to end performance of data communications system

Last Answer : C. standards for interfaces between terminals and modems

How do you eliminate radio frequency variation of an oscillator transmitter caused by its supply voltage? A. Use new power supply B. Lossen power supply shielding C. Use of regulated power supply D. Use of high capacitor in the supply circuit

Description : How do you eliminate radio frequency variation of an oscillator transmitter caused by its supply voltage? A. Use new power supply B. Lossen power supply shielding C. Use of regulated power supply D. Use of high capacitor in the supply circuit

Last Answer : C. Use of regulated power supply

A device that converts high frequency current into electromagnetic wave. A. Antenna B. Loudspeaker C. Microphone D. Transducer

Description : A device that converts high frequency current into electromagnetic wave. A. Antenna B. Loudspeaker C. Microphone D. Transducer

Last Answer : A. Antenna

A porous material is far more efficient at high than low frequency absorption. How to improve sound absorption at lower frequencies using this absorber? A. Increase the thickness B. Decrease the thickness C. Mount with and airspace behind D. Both A and C above

Description : A porous material is far more efficient at high than low frequency absorption. How to improve sound absorption at lower frequencies using this absorber? A. Increase the thickness B. Decrease the thickness C. Mount with and airspace behind D. Both A and C above

Last Answer : D. Both A and C above

What type of balun (balanced-to-unbalanced) is used in high frequency applications? A. Transformer type balun B. A specially configured coaxial transmission line C. A specially configured parallel-wire line D. A λ/2 transformer balun

Description : What type of balun (balanced-to-unbalanced) is used in high frequency applications? A. Transformer type balun B. A specially configured coaxial transmission line C. A specially configured parallel-wire line D. A λ/2 transformer balun

Last Answer : B. A specially configured coaxial transmission line

What is the frequency range of an aircraft’s Very High Frequency (VHF) communications? A. 118.000 MHz to 136.975 MHz (worldwide up to 151.975 MHz) B. 108.000 MHz to 117.95 MHz C. 329.15 MHz to 335.00 MHz D. 2.0000 MHz to 29.999 MHz

Description : What is the frequency range of an aircraft’s Very High Frequency (VHF) communications? A. 118.000 MHz to 136.975 MHz (worldwide up to 151.975 MHz) B. 108.000 MHz to 117.95 MHz C. 329.15 MHz to 335.00 MHz D. 2.0000 MHz to 29.999 MHz

Last Answer : A. 118.000 MHz to 136.975 MHz (worldwide up to 151.975 MHz)

What is the high frequency sound that cannot be heard by the human ear? A. Ultrasonic B. Transonic C. Subsonic D. Supersonic

Description : What is the high frequency sound that cannot be heard by the human ear? A. Ultrasonic B. Transonic C. Subsonic D. Supersonic

Last Answer : A. Ultrasonic

One of the following is a high powered RF ac basic transmitter that has two or more stages, the oscillator stage which determines the frequency opereation and RF amplifier stage orstages that develop the high power output. The purpose of which is to develop a good frequency stability. A. Goldsmith B. MOPA C. Alexanderson D. Hartley

Description : One of the following is a high powered RF ac basic transmitter that has two or more stages, the oscillator stage which determines the frequency opereation and RF amplifier stage orstages that develop the ... to develop a good frequency stability. A. Goldsmith B. MOPA C. Alexanderson D. Hartley

Last Answer : B. MOPA

Determine from the following radio frequency that falls under the very high frequency band of the radio spectrum. A. 345.00 MHz B. 144.50 MHz C. 235.50 MHz D. 450.00 MHz

Description : Determine from the following radio frequency that falls under the very high frequency band of the radio spectrum. A. 345.00 MHz B. 144.50 MHz C. 235.50 MHz D. 450.00 MHz

Last Answer : C. 235.50 MHz

The extremely high frequency (EHF) band is in the radio spectrum range of _______. A. 30 to 300 kHz B. 30 to 300 GHz C. 3 to 30 MHz D. 3 to 30 GHz

Description : The extremely high frequency (EHF) band is in the radio spectrum range of _______. A. 30 to 300 kHz B. 30 to 300 GHz C. 3 to 30 MHz D. 3 to 30 GHz

Last Answer : B. 30 to 300 GHz

A radio frequency in the ultra high frequency band of the radio spectrum band. A. 235.50 MHz B. 450.50 MHz C. 150.50 GHz D. 0.31250 GHz

Description : A radio frequency in the ultra high frequency band of the radio spectrum band. A. 235.50 MHz B. 450.50 MHz C. 150.50 GHz D. 0.31250 GHz

Last Answer : D. 0.31250 GHz