# Which operational amplifier should i use?

#### d.akkas3

Joined Aug 3, 2022
12
I have a project it is desired to amplify AC signal.I decided to use Op-Amp. I 'll amplify the signal by 20 times. and searched ,looked opamp sheets but i 'm so confused . If u knew pls recommend opamp?Do u have any idea ? Thanks

#### ronsimpson

Joined Oct 7, 2019
2,246
What is the supply(s) voltages you have available?
How bit is the signal? Input X 20 = output
What frequency range? audio, video, RF?
What are you driving? Speaker, 50 homs, meter?
What is the input from?

#### Papabravo

Joined Feb 24, 2006
18,968
I'd guess that "in-stock" and costs less than \$1.00 might be good criteria for starters.

#### ag-123

Joined Apr 28, 2017
259
here you go

$\frac{V_{out}}{V_{in}} = 1 + \frac{R_2}{R_1}$

common numbers are:
LM741
LM148, LM248, LM348
LM358 (single supply) dual - may have cross-over distortion, single supply - may have trouble with A/C signal
LMV358 rail to rail single supply - may have trouble with A/C signal
TLC2272 Dual, Low-Noise, Rail-To-Rail Operational Amplifier - this one looks good (note output currents is low, check specs, rail-to-rail is given for 1mA output for 5v VDD, drawing more currents would likely pull the max Vout lower. these are ok if it is simply used as a buffer say to an ADC)

I think there are lots more better ones
https://blog.snapeda.com/2019/10/23/the-top-10-operational-amplifiers/
https://components101.com/articles/...s-and-selecting-one-for-your-next-application
https://en.wikipedia.org/wiki/List_of_LM-series_integrated_circuits

Last edited:

#### d.akkas3

Joined Aug 3, 2022
12

#### dl324

Joined Mar 30, 2015
14,897
I have a project it is desired to amplify AC signal.I decided to use Op-Amp. I 'll amplify the signal by 20 times. and searched ,looked opamp sheets but i 'm so confused .
Is this really homework? What is the input voltage and frequency range? What supply voltage(s)?
If u knew pls recommend opamp?Do u have any idea ?
Most of us prefer not to read text-speak. Please spell out the words and try to use proper punctuation.

#### d.akkas3

Joined Aug 3, 2022
12
Is this really homework? What is the input voltage and frequency range? What supply voltage(s)?
Most of us prefer not to read text-speak. Please spell out the words and try to use proper punctuation.
OK.

#### ericgibbs

Joined Jan 29, 2010
15,976
hi d.
Which OPA do you have on the bench.
Is your input signal DC or AC, tell us what the signal is.?
E

#### d.akkas3

Joined Aug 3, 2022
12
hi d.
Which OPA do you have on the bench.
Is your input signal DC or AC, tell us what the signal is.?
E
My signal is AC with dc offset 25 mv. Now i'm doing simulation on many draft (my project is adjustable gain briefly,switching nmos and noninverting amplifer combination ). I used OPA07 OP777 but signal is so osilated and overshoot .Thus if you have any suggestion i'll try it

#### ericgibbs

Joined Jan 29, 2010
15,976
hi d.
Is your circuit like this version.?
E

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