Hello everyone,
I need to block the DC or keep the DC at a constant level in the output of the op amp and amplify the AC using the same op amp.
Currently the DC shift in the input is between 1.6V to 2V
i don't need any gain for the DC and the gain required for AC is 10 and above.
When i try to block the DC using the capacitor there is so much of noise in the output.
I am uploading some of my test circuit and its results.
please help me to solve this out.

 

Wild guess - use a coupling capacitor?

 

Welcome to AAC!

I need to block the DC or keep the DC at a constant level in the output of the op amp and amplify the

You didn't complete your description...

To block DC, you can AC couple the signal. If you want a fixed or variable DC offset in the output, you can use a summing amplifier to add an offset.

 

Welcome to AAC!
You didn't complete your description...

To block DC, you can AC couple the signal. If you want a fixed or variable DC offset in the output, you can use a summing amplifier to add an offset.

Thank you for your update.
sorry that my description is not complete.
I need to block the DC or keep the DC at a constant level in the output of the op amp and amplify the AC using the same op amp.
Currently the DC shift in the input is between 1.6V to 2V
i don't need any gain for the DC and the gain required for AC is 10 and above.
When i try to block the DC using the capacitor there is so much of noise in the output.
I am uploading some of my test circuit and its results.
please help me to solve this out.

Actually the signal is an output of hall effect sensor,the problem is the DC offset is varying with some sensors.So in this case will the summing amplifier work.

 

When i try to block the DC using the capacitor there is so much of noise in the output.
I am uploading some of my test circuit and its results.

Your PDF attachment is 6.6MB. Kindly post smaller files and delete the one in your last post; only one copy is needed.

 

Wild guess - use a coupling capacitor?

Thank you for your update.
I need to block the DC or keep the DC at a constant level in the output of the op amp and amplify the AC using the same op amp.
Currently the DC shift in the input is between 1.6V to 2V
i don't need any gain for the DC and the gain required for AC is 10 and above.
When i try to block the DC using the capacitor there is so much of noise in the output.
I am uploading some of my test circuit and its results.
please help me to solve this out.

 

Your PDF attachment is 6.6MB. Kindly post smaller files and delete the one in your last post; only one copy is needed.

Sure,
please find the attachment

 

please find the attachment

Still too large. Post JPG's of appropriate resolution to convey information.

I question the way R2 is connected. I have never seen the gain setting resistor not having a DC path to ground.

 

Still too large. Post JPG's of appropriate resolution to convey information.

I question the way R2 is connected. I have never seen the gain setting resistor not having a DC path to ground.

please find the attached files,
The R2 and the capacitor will act High pass filter and block the DC.

 

we need the data sheet on the sensor.......and any other components between sensor and amp.

 

Can you post your .asc file?

 

The R2 and the capacitor will act High pass filter and block the DC.

It doesn't work that way. R3 and R2 set the gain. DC blocking is done by putting a coupling cap on the opamp input.

 

DC blocking is done by putting a coupling cap on the opamp input.

That is, between Vin and R4.

 

That is, between Vin and R4.

C1 is in parallel with R4, that's not an AC coupling cap.

EDIT: I get it. You're not telling me where the cap is, you're telling the OP where to put it.

 

we need the data sheet on the sensor.......and any other components between sensor and amp.

please find the data sheet of the sensor

 

C1 is in parallel with R4, that's not an AC coupling cap.

EDIT: I get it. You're not telling me where the cap is, you're telling the OP where to put it.

Currently in board there is no amplifier b/w sensor and ADC,so because of the DC shift in the o/p of the sensor is different from one another the data what we got from the ADC are not proper.
so i am thinking of blocking the dc and amplify the AC .
please let me know if there is any circuit that will meet my requirement
please find the datasheet of the sensor

 

Can you post your .asc file?

Currently in board there is no amplifier b/w sensor and ADC,so because of the DC shift in the o/p of the sensor is different from one another the data what we got from the ADC are not proper.
so i am thinking of blocking the dc and amplify the AC .
please find the datasheet of the sensor and the .asc file.
please let me know if there is any circuit that will meet my requirement

 

Try this mod of your asc file.
Note that your circuit currently has a gain of ~100, so the amp is driven into saturation. Is that your intention?

 

Try this mod of your asc file.
Note that your circuit currently has a gain of ~100, so the amp is driven into saturation. Is that your intention?

Actually i need a gain should grater than 10,
That we can adjust

 

Try this mod of your asc file.
Note that your circuit currently has a gain of ~100, so the amp is driven into saturation. Is that your intention?

Thanks a lot for you update ,
let me rig this circuit and let you know how it is working.