Which is better for amplifying gain, transistor or op-amp?

[huji]

single transistor and opamp configuration

Hi,
Both Transistor and op-amp can amplify gain but which one is more preferable and why?
Thanks

 

[EEHardware]

transitor amp

of course op-amp , i think

 

[IanP]

Re: Transistor vs op-amp

There are no preferences here..
Depending on what you are trying to do, a transistor amplifier, in many cases, will do the same job as an opamp, and in some cases (RF applications in particular), one will not use an opamp, but a transistor.
After all, opamps are build of transistors in certain configuration, and if you want to have advantages of these configuration, you will use opamps.
If you need a basic amplification stage - you will employ transistors..
Regards,
IanP

 

[gszczesz]

Re: Transistor vs op-amp

A transistor is a building block, you still need to bias it and put it into a gain configuration. A single transistor can not give you differential gain. However, a single transistor gain stage does have limitted gain and can be degenerated to give you the gain required without any multi-stage feedback. This means it won't oscillate and give you a very high frequency response.

An op-amp on the other hand has differential inputs, usually will provide rail-to-rail output, very low output resistance and very high input resistance. However, it needs feedback to set its gain and does not give high frequency gain (for the same technology).

Greg

 

[muruga86]

Re: Transistor vs op-amp

the reason to choose opamps than transistor for audio signal amplification is

1. opamps provide more gain(1000) than transistor(75-100). so more amplification can be obtained by fewer stages.

2. No biasing, stabilising components required because its is build-in in opamp.

3. Common mode gain is reduced (which creates humming effect) thereby increase the quality of o/p sound

 

[djalli]

Re: Transistor vs op-amp

of course op-amp , i think

heh! the answer is correct op-amp is better in terms of "applicability" because it is easier to build an amplifier for example just using op-amps just simple formulas.

But in terms of power(especially this reason!) and mass-production in applications transistor is the one better.

 

[power-twq]

Re: Transistor vs op-amp

that's up to the specific application,

transistor amplifier is simple, cheap and

can achieve high speed easily,

but the gain precision is not as good as OP,

OP can achieve good precision, but for

very high speed, OP is expensive.


best regards

Hi,
Both Transistor and op-amp can amplify gain but which one is more preferable and why?
Thanks

 

[mohsen asloni]

Transistor vs op-amp

Both transistor and OP-AMP amplify the signal but the gain of OP-AMP is most. OP-AMP has high input impedance. OP-AMP is slower than transistor and occupies the most area, for this reason it consumes most power.

 

[asmat]

Re: Transistor vs op-amp

simple transistor.
transistor amplifier is simple, cheap and (gain =70-75 percent)
op amplifier.
is the combination of different transistor ,that uses external feedback to controll its functionalities.An electronic amplifier is a device for increasing the power of a signal . It does this by taking power from a power supply and shaping the output to match the input signal. This process invariably introduces some noise and distortion into the signal, and the process cannot be 100% efficient—amplifiers will always produce some waste heat but op amp is more apropriate than transistor because of common mode rejection ratio(amplification 80-90 percent)

op amp has better results than simple transistor

 

[pinkmouse]

Re: Transistor vs op-amp

As with all things, neither is better, it all depends on your application. Sometimes you might just want a simple gain block to drive, say, a relay. Why use a 50c op-amp, when a 1c trannie will do. Then again, if you're building a steep rolloff filter, then you wouldn't even think of using trannies, it would be op-amps all the way.

 

[A.Anand Srinivasan]

Re: Transistor vs op-amp

it just depends on the application
because op-amp has more gain and has slew rate and error voltages
and bjt has less gain and other considerations

 

[shrikant.turkar]

Re: Transistor vs op-amp

Hi,
Both Transistor and op-amp can amplify gain but which one is more preferable and why?
Thanks

ans-


*op-amp preffered over transistor ,
because op-amp has ideally infinite input impedance,
in real circuit it is very high compared to the transistor

*also other advantage is in op-amp amplification is done differential input, in transistor it amplified input

 

[abcyin]

Transistor vs op-amp

Transistor amp is simple, cheap and can achieve high speed easily, and is prefered in rf area.
You can get a stable gain with OP amp by its feedback,and it has infinit input impedance and low output impedance.

 

[pankaj waghmare]

Re: Transistor vs op-amp

op-amp is a high gain amplifier ideally its gain is infinite.
while transistor is not having that much gain as opamp have

 

[neils_arm_strong]

Transistor vs op-amp

transistor is the best for simple amplication purposes.Using a transistor will also help us a lot in understanding the operation of op-amps(;ike the various configurations used there).You have a choice to make when using transistors unlike op-amps.i.e you can choose the transistor based on your power dissipiation,gain,bandwidth etc.

 

[japholix]

Re: Transistor vs op-amp

for high power applications, you have to resort to discrete transistors as op-amps simply cannot handle it

 

[eda_freak]

Re: Transistor vs op-amp

You must have a clear picture of what u are supposed to design..see an op-amp is just another transistor based circuit...so if the job can be done with the help of few discreet transistor units then using op-amp is waste on resources. then you have some implementations on op-maps that require minimal knowledge of the op-map internals and the job is well done....under such situations you may like to use an op-amp....so, suggestion is read some good book on transistors then read about op-amps and do a comparision on what suits ur design and what are the constraints. i'm confident that doing that would be able to direct/guide you in a much better way...
gud luck
aman

 

[Naveed Alam]

Re: Transistor vs op-amp

Transistor...better to use it in simple circuits, with low cost, simple biascing (from normal batteries or cells), and for low gains..

OP-AMP..better to use it when want to have higher gains..
OP-AMP comes with many varieties, like some are very good in terms of Window Coparator (with gain)....

 

[ahmad_abdulghany]

Re: Transistor vs op-amp

Please everyone who shared this topic, check that one also for general benifit..


Thanks alot in advance,
Ahmad,

 

[tjr]

Re: Transistor vs op-amp

opamp is preferable bcoz its high input impedance and high gain