Amplifying and filtering small AC signal with large DC offset

Thread Starter

dmccric

Joined Apr 2, 2019
3
I am trying to extract a small AC signal (~50mV Pk - Pk) from an Instrumentation Amplifier using a Single Supply voltage (+5V) and I want to get rid of the DC Offset (+2.5V) so I can amplify and filter the AC part (1kHz mid frequency). I want to produce a clean signal of around 700mV Pk - Pk.

Is it possible to remove the DC Part and then filter the AC signal? I can do this with a dual rail supply but this adds further noise.

The circuit is attached.
 

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ericgibbs

Joined Jan 29, 2010
9,860
hi dm,
Welcome to AAC.
It is possible to AC couple the output from the IA amplifier.
What are the range of frequencies required.?
E
EDIT:
This similar circuit shows the method to remove the DC offset.
AA1 02-Apr-19 12.48.gif
 
Last edited:

Thread Starter

dmccric

Joined Apr 2, 2019
3
I think I'm going to have to reduce the frequency range to 30Hz to 250Hz. Interesting circuit, applying the mid point to the positive input terminal.
I am not getting the same output yet but I am doubling checking my circuit now.
Thank you.
 
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