Active common mode feedback for unbalanced input and feedback signals and methods thereof
AssigneeTripath Technology, Inc.
InventorCary L. Delano
Life of this patent
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Abstract
A noise shaped differential amplifier having a reduced common mode signal in accordance with an embodiment of the invention is described. In the described embodiment, the noise shaped differential amplifier includes a noise shaper having a common mode signal controlled by an attenuation operational amplifier that is coupled to a voltage divider circuit and a sense resistor divider. In this arrangement, the attenuation operational amplifier controls a virtual ground applied to the sense resistor divider.
Claims7
An attenuation circuit arranged to reduce a common mode potential in an amplifier having a noise shaper circuit, comprising:
- a sense resistor divider;
- a voltage divider circuit coupled to the sense resistor divider;
- and
- an attenuation operational amplifier (op amp) connected to the sense resistor and the voltage divider circuit.
A method for attenuating a common mode potential by a common mode potential attenuation circuit, comprising:
- providing a sense resistor divider;
- providing a voltage divider circuit;
- and
- providing an attenuation operational amplifier (op amp) having an output node, a attenuation op amp first input node, and a attenuation op amp second input node.
A method for attenuating a common mode potential by a common mode potential attenuation circuit, comprising:
- providing a sense resistor divider;
- providing a voltage divider circuit;
- providing an attenuation operational amplifier (op amp) having an output node, an attenuation op amp first input node, and an attenuation op amp second input node;
- and
- providing a virtual ground to a center of the sense resistor divider thereby setting a common mode potential Vcm developed at an input of the attenuation op amp and to reduce a common mode feedback voltage swing of the amplifier.
An apparatus for attenuating a common mode potential by a common mode potential attenuation circuit, comprising:
- means for providing a sense resistor divider;
- means for providing a voltage divider circuit;
- means providing an attenuation operational amplifier (op amp) having an output node, an attenuation op amp first input node, and an attenuation op amp second input node;
- and
- means for providing a virtual ground to a center of the sense resistor divider thereby setting a common mode potential Vcm developed at an input of the attenuation op amp and to reduce a common mode feedback voltage swing of the amplifier.
An apparatus for attenuating a common mode potential by a common mode potential attenuation circuit, comprising:
- means for providing a sense resistor divider;
- means for providing a voltage divider circuit;
- means providing an attenuation operational amplifier (op amp) having an output node, an attenuation op amp first input node, and an attenuation op amp second input node.
Dependencies are inferred from the claim text.