Op. amplifier practical gain.

[AAOAA]

Hello,

I am using LT1037, I used Rf1=200K, Rf2=100 as feedback resistors which equals to 2000 gain, but what I am getting is only 600!!
could someone give me an explanation for this?

Thanks

 

[FvM]

Gain of 2000 can be easily achieved with the said resistors, you're obviously doing somthing wrong. More information needed.

 

[dick_freebird]

Gain of 2000 is about 66dB, which does not really seem to
challenge most decent op amps' AVOL.

But that much gain could easily rail the amplifier, only need
7.5mV input difference to make 15V at the output under
that gain setting. Might look to see whether the output
is clipping.

 

[crutschow]

What is the frequency of the signal?

Post your circuit diagram.

 

[LvW]

Assuming a maximum open-loop gain of 106 dB and a first pole at 10Hz a closed-loop gain of 66 dB is possible up to several hundreds Hz only.
EDIT (because of the next post from FvM): The foregoing statement assumes a unity-gain compensated opamp.

 

[FvM]

Assuming a maximum open-loop gain of 106 dB and a first pole at 10Hz a closed-loop gain of 66 dB is possible up to several hundreds Hz only.

With decompensated LT1037, the bandwidth is > 10 kHz.

 

[AAOAA]

What is the frequency of the signal?

Post your circuit diagram.

Thank you guys, I think this is the answer I have a gain around 50dB at 100kHz (I am still beginner)