Systems and methods for common mode detection
AssigneeTexas Instruments Incorporated
InventorsSumantra Seth, Kanan Saurabh
Life of this patent
Estimating the term…
Abstract
Various systems and methods for common mode detection are disclosed. As one example, a common mode detection circuit including a differential input stage, a common mode replica stage, and an amplifier is disclosed. The differential input stage exhibits an input common mode, and includes two differential inputs. A signal from the differential input stage representing the input common mode is electrically coupled to an input of the amplifier. Another input of the amplifier is electrically coupled to the common mode replica stage, and the amplifier outputs a signal indicative of the input common mode.
Claims19
A common mode detection circuit, the circuit comprising:
- an amplifier having a first input terminal and a second input terminal;
- a differential input stage, wherein the differential input stage includes a first differential input and a second differential input, wherein the differential input stage exhibits an input common mode and also an error component in said input common mode, and wherein the differential input stage is electrically coupled to said first input terminal of the amplifier;
- a common mode replica stage to generate a replica signal inclusive of said input common mode and said error component, wherein the replica signal is electrically coupled to said second input terminal of the amplifier;
- and
- whereby the amplifier drives a signal indicative of the input common mode with said error component being canceled at least substantially.
A differential receiver, the differential receiver comprising:
- a differential input stage, wherein the differential input stage includes a first
- differential input and a second differential input, wherein the differential input stage exhibits an input common mode;
- and wherein the differential input stage is electrically coupled to an amplifier;
- a common mode replica stage, wherein the common mode replica stage is electrically coupled to the amplifier;
- wherein the amplifier drives an amplifier output, and wherein the amplifier output is indicative of the input common mode;
- and
- a comparator, wherein a first input of the comparator is electrically coupled to the amplifier output, wherein a second input of the comparator is electrically coupled to a reference voltage, and wherein the comparator is operable to drive a comparator output, and
- wherein the comparator output is a non-differential representation of a received differential signal.
A common mode detection circuit, the circuit comprising:
- a common mode extractor circuit, wherein the common mode extractor circuit provides a signal offset from the common mode;
- and
- a differential input circuit, wherein the differential input circuit includes a first transistor electrically coupled to a first differential input, a second transistor electrically coupled to a second differential input, and wherein a source of the first transistor and a source of the second transistor are each electrically coupled to the signal offset from the common mode,
- wherein a signal indicative of the common mode is a first signal indicative of the common mode, wherein the common mode extractor circuit includes:
- a differential input stage, wherein the differential input stage includes a first input that is electrically coupled to the first transistor, wherein the differential input includes a second input electrically coupled to the second differential input, wherein the differential input stage exhibits the common mode;
- and wherein the differential input stage is electrically coupled to an amplifier;
- a common mode replica stage, wherein the common mode replica stage is electrically coupled to the amplifier;
- and
- wherein the amplifier drives the signal indicative of the common mode.
Dependencies are inferred from the claim text.