Multi-stage variable gain amplifier utilizing overlapping gain curves to compensate for log-linear errors
AssigneeSilicon Laboratories Inc.
InventorScott Dupuie
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Abstract
A multi-stage variable gain amplifier is disclosed that utilizes overlapping gain curves to compensate for log-linear errors. Each gain stage is configured to approximate a log-linear response with a sinusoidal error term such that a portion of the curve has positive errors and a portion of the curve has negative errors. In operation, the control signal inputs for the gain stages are driven such that the gain curves overlap and positive errors in each stage are offset by negative errors in the adjacent stage. The resulting combined gain is a more log-linear response.
Claims20
A multi-stage variable gain amplifier, comprising:
- two or more serially connected gain stages, each gain stage having a gain response with a positive error portion and a negative error portion, each gain stage having a control input signal that determines the gain response for the stage, and each control input signal being configured to transition from a minimum value to a maximum value;
- and
- control circuitry configured to provide the control input signals to the gain stages such that positive error portions overlap with negative error portions.
A method for controlling a multi-stage variable gain amplifier to achieve improved linearity, comprising:
- providing two or more serially connected gain stages, each gain stage having a gain response with a positive error portion and a negative error portion;
- and
- controlling the gain stages so that positive error portions overlap with negative error portions.
Dependencies are inferred from the claim text.