Help!! Checking of Amplifier Gain

[chenjk09]

Hi everyone,

Can someone teach me how to check the gain of the amplifier I set is correct?
Base on the input of 5mV and 10Hz. How to see from the graph is the gain 25.7 is set correct?

Attach file is how I connect and the output

Hope you guys can help
Thank

 

[ericgibbs]

Hi everyone,

Can someone teach me how to check the gain of the amplifier I set is correct?
Base on the input of 5mV and 10Hz. How to see from the graph is the gain 25.7 is set correct?

Attach file is how I connect and the output

Hope you guys can help
Thank

hi,
With a 5mV peak signal input on a Instrumentation OPA [its effectively doubled as its a push pull signal] and a Gain of 25.7, you would expect an output of 257mV Pk

 

[chenjk09]

Hi,

how to work reverse engineering from the graph? I want to check is the gain is it correct as what i set?

Thanks

 

[Mr RB]

Assuming the output waveform looks good (looks the same shape as the input waveform) then voltage gain is very simple;
Vgain = Vout / Vin.

 

[chenjk09]

Can't get the gain base on the data sheet

Hi,

base on the data sheet Page 10 gain equation is G= (49.4k / Rg) + 1
i set 2k for Rg so the gain is about 25.7

i take G= Vout/Vin
i can't get 25.7 what is wrong?
G = (2.5mV*200mV)/(5mV*2) =0.05
so i wrong. anyone can help?

Thanks

 

[chenjk09]

How to check the gain?

The result is not match what i calculated.
or the way i calculated is wrong?

 

[ericgibbs]

Hi,

base on the data sheet Page 10 gain equation is G= (49.4k / Rg) + 1
i set 2k for Rg so the gain is about 25.7

i take G= Vout/Vin
i can't get 25.7 what is wrong?
G = (2.5mV*200mV)/(5mV*2) =0.05
so i wrong. anyone can help?

Thanks

Whats wrong with my post #2, explanation.?

When you say 5mV input signal, is that Vpeak or Vpeak to peak.??

 

[chenjk09]

Hi,

The Vout = 2.5*200mV = 0.5
Vin = 5mVp = 0.01Vpp
Vgain = Vout / Vin
Vgain = 0.5/0.01= 50
So the gain i set is not correct ?

base on the data sheet is not correct ?