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I don't have a circuit right now, but let's say you wanted to add DC offset to a signal (ex. to prepare a signal for an Op amp stage) but then afterwards center that signal on 0v.

Is this possible with a clamp for adding offset, and then using a high pass filter for removing offset?

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  • \$\begingroup\$ Welcome to EE.SE. Why add a DC offset just to remove it later? Could you clarify the reasons for doing this please. The usual goal with an amplifier chain is to NOT have any offsets at all. You null them out with trim pots. \$\endgroup\$ – Sparky256 Sep 28 '18 at 20:18
  • \$\begingroup\$ Well if you are limited to 12V and 0V rails, you would want the signal entering the op amp to be always in between 12 and 0 for it to amplify without clipping. \$\endgroup\$ – Jerome Sep 28 '18 at 20:27
  • \$\begingroup\$ This special signal's transceiver reads a high and low centered around 0V, so you want the output of the op amp to be centered around 0V. \$\endgroup\$ – Jerome Sep 28 '18 at 20:28
  • \$\begingroup\$ Do you need to recover the DC level of your original signal? Or can we assume the signal is purely AC? \$\endgroup\$ – The Photon Sep 28 '18 at 20:41
  • \$\begingroup\$ Why not just use a high-pass filter up front to remove the DC offset? Now you have a capacitive input amplifier with a 12 volt supply. Your putting the cart in front of the horse, and the horse has a puzzled look. \$\endgroup\$ – Sparky256 Sep 28 '18 at 20:47
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Your question is very unclear, but nevertheless I try to give you some general advice on AC signal shifting:

If you have an AC signal „centered“ at a DC operating point, you can change this operating point with a simple serial capacitor. The output terminal of the capacitor will not be defined in terms of DC operating point, so you can define that with a (high impedance) resistor to whatever voltage potential you like.

So a capacitor acts like „some kind of coupling device“ between different DC operating points of an AC signal.

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