Op-amp

[tuck]

Can anyone tell me what is the main features of an ideal operational amplifier, and how the pratical amplifier deviate from the idealizead model?

 

[ericgibbs]

Can anyone tell me what is the main features of an ideal operational amplifier, and how the pratical amplifier deviate from the idealizead model?

hi,

I would suggest you visit: www.analog.com and search the application notes for opa's,, there are also tutorials.

 

[tuck]

Can anyone juz give me the answer? coz i really need it later on.pls...

 

[ericgibbs]

Can anyone juz give me the answer? coz i really need it later on.pls...

hi tuck,
I am not being difficult, but to fully answer your question would take pages!

An ideal opa:
Infinite input impedance
Zero output impedance.
Zero voltage offset
Zero drift
Infinite bandwidth
Able to swing the Vout from rail to rail voltage.
........etc

The practical opa cannot meet all these requirements, in one way or another.

Does this help?

 

[ssylee]

Tuck, here's a snippet from wikipedia that would help: https://en.wikipedia.org/wiki/Operational_amplifier#The_ideal_op-amp

 

[tuck]

Thanks for all the information. I do found those defination at wikipedia, but i juz don't know how to explain "how and why pratical amplifier deviate from the idealized model".

 

[ssylee]

Keep in mind that opamps are physical electronics systems. Physical systems never have infinite anything, and they are susceptible to any kind of error exposed that you can think of.

 

[Leftyretro]

Thanks for all the information. I do found those defination at wikipedia, but i juz don't know how to explain "how and why pratical amplifier deviate from the idealized model".

Think of it as simply perfect theory Vs practical reality. For instance noise is not a component in a perfect op-amp but in reality they all generate a certain amount of internal noise. If low noise is a requirement then one would select from the many op amps available for the one with the lowest noise specifications that meets the circuit requirements. This same selection process would apply to all the various specifications and is part of any initial design, matching circuit parameter requirements to device specifications.

Lefty

 

[Hero999]

Can anyone tell me what is the main features of an ideal operational amplifier, and how the pratical amplifier deviate from the idealizead model?

This sounds like college work to me, when is the deadline?

 

[mneary]

Sounds like you missed yesterday's lecture and there will be a quiz tomorrow.

It's time to ask one of your classmates what they learned. Or read your textbook.

[edit] If you have the time, read the Wikipedia article. If you don't, then please stop wasting ours.[/edit]

 

[tuck]

Problem have been solved. thanks for all the help.

 

[Hero999]

hi tuck,
I am not being difficult, but to fully answer your question would take pages!

An ideal opa:
Infinite input impedance
Zero output impedance.
Zero voltage offset
Zero drift
Infinite bandwidth
Able to swing the Vout from rail to rail voltage.
........etc

The practical opa cannot meet all these requirements, in one way or another.

Does this help?

There isn't an op-amp that even meets any of the ideal criteria.

 

[ericgibbs]

There isn't an op-amp that even meets any of the ideal criteria.

I am fully aware of that fact!
I was keeping it as simple as possible in view of the OP's very limited knowledge.