Signal conditioning circuit apparatus and method

A signal conditioning circuit comprising, in combination:

• an op-amp having a first input terminal, a second input terminal, an output terminal and bias voltage terminals;
• a regulated bias voltage means operatively coupled to a power supply via a pair of supply/return lines and to said bias voltage terminals for providing a bias voltage for said op-amp;
• said first input terminal receiving and applying an input signal to said op-amp, and
• said op-amp outputting a conditioned output signal to said output terminal;
• a transistor operatively coupled to said output terminal of said op-amp and between the supply/return lines for receiving said conditioned signal and buffering said conditioned signal onto the supply/return lines which is superimposed with said regulated bias voltage across the supply/return lines wherein the supply/return lines double as means for supply current to said circuit and receiving and outputting said conditioned signal to a means for monitoring characteristics of said conditioned signal.

A signal conditioning circuit comprising, in combination:

• an op-amp having a first input terminal, a second input terminal, an output terminal and bias voltage terminals:
• bias voltage means operatively coupled to said bias voltage terminals for providing a bias voltage for said op-amp:
• said first input terminal receiving and applying an input signal to said op-amp, and
• said op-amp outputting a conditioned output signal to said output terminal:
• means for combining the conditioned signal with the bias voltage wherein the conditioned signal rides on top of the bias voltage:
• wherein said bias voltage terminals are operatively coupled to the bias voltage means via a pair of supply/return lines:
• further including a regulated biasing means operatively coupled to the supply/return lines and to the bias voltage terminals of said op-amp for receiving current from the bias voltage means and effecting a stable DC bias voltage across said bias voltage terminals of said op-amp and across the supply/return lines operatively coupled to said bias voltage terminals;
• and
• further including a transistor operatively coupled to said output terminal of said op-amp and between the supply/return lines for receiving said conditioned signal and buffering said conditioned signal onto the supply/return lines which is superimposed with said regulated bias voltage across the supply/return lines wherein the supply/return lines double as means for supply current to said circuit and receiving and outputting said conditioned signal to a means for monitoring characteristics of said conditioned signal.

A method for conditioning an input signal by self-biasing a circuit having an op-amp which includes an inverting signal input terminal, a noninverting signal input terminal, bias voltage terminals and a signal output terminal;

• the steps including:
• providing a bias voltage for the op-amp through the bias voltage terminals,
• directing an input signal into at least one signal input terminal of the op-amp,
• outputting a conditioned signal from the output terminal, and
• combining the conditioned signal with the bias voltage;
• whereby performance of the amplifier is self-adjusted by characteristics of the conditioned signal such that the conditioned output signal rides on top of the bias voltage.