Current sensing circuitry
AssigneeCirrus Logic, Inc.
InventorsWei Xu, Ravi Kummaraguntla, Paul Wilson, Mujo Kozak, Christian Larsen, John L. Melanson, Yongjie Cheng
Life of this patent
Estimating the term…
Abstract
A system may include a front end differential amplifier having two input terminals, two input resistors, each of the two input resistors coupled to a respective one of the two input terminals, and an input common mode biasing circuit for an output stage of the front end differential amplifier, the input common mode biasing circuit comprising two current sources configured to generate currents for biasing the output stage of the front end differential amplifier.
Claims26
A system comprising:
- a front end differential amplifier having two input terminals;
- two input resistors, each of the two input resistors coupled to a respective one of the two input terminals;
- an input common mode biasing circuit for an output stage of the front end differential amplifier, the input common mode biasing circuit comprising two current sources configured to generate currents for biasing the output stage of the front end differential amplifier;
- a back end differential amplifier coupled to the output stage of the front end differential amplifier;
- an output common mode biasing circuit for an output stage of the back end differential amplifier;
- and
- a common mode feedback circuit coupled to virtual grounds of the back end differential amplifier in order to minimize common mode current flowing through feedback resistors of the back end differential amplifier.
A system comprising:
- a front end differential amplifier having two input terminals;
- two input resistors, each of the two input resistors coupled to a respective one of the two input terminals, wherein the two input terminals of the front end differential amplifier are configured to receive an input signal via the two input resistors, wherein the input signal is generated by a sense resistor;
- an input common mode biasing circuit for an output stage of the front end differential amplifier, the input common mode biasing circuit comprising two current sources configured to generate currents for biasing the output stage of the front end differential amplifier;
- and
- circuitry for detecting a common mode voltage of the sense resistor, wherein supply rails for the front end differential amplifier are generated based on the common mode voltage.
A system comprising:
- a front end differential amplifier having two input terminals;
- two input resistors, each of the two input resistors coupled to a respective one of the two input terminals, wherein the two input terminals of the front end differential amplifier are configured to receive an input signal via the two input resistors, wherein the input signal is generated by a sense resistor;
- an input common mode biasing circuit for an output stage of the front end differential amplifier, the input common mode biasing circuit comprising two current sources configured to generate currents for biasing the output stage of the front end differential amplifier;
- and
- circuitry for detecting a common mode voltage of the sense resistor, wherein a reference voltage for virtual grounds of the front end differential amplifier are set based on the common mode voltage.
A method in a system comprising a front end differential amplifier having two input terminals, a back end differential amplifier coupled to an output of the front end differential amplifier, and two input resistors, each of the two input resistors coupled to a respective one of the two input terminals, the method comprising:
- generating, with two current sources of an input common mode biasing circuit for an output stage of the front end differential amplifier, currents for biasing the output stage of the front end differential amplifier;
- biasing an output stage of the back end differential amplifier with an output common mode biasing circuit;
- and
- minimizing common mode current flowing through feedback resistors of the back end differential amplifier with a common mode feedback circuit coupled to virtual grounds of the back end differential amplifier.
A method in a system comprising a front end differential amplifier having two input terminals, and two input resistors, each of the two input resistors coupled to a respective one of the two input terminals, and wherein the two input terminals of the front end differential amplifier are configured to receive an input signal via the two input resistors, and further wherein the input signal is generated by a sense resistor, the method comprising:
- generating, with two current sources of an input common mode biasing circuit for an output stage of the front end differential amplifier, currents for biasing the output stage of the front end differential amplifier;
- detecting a common mode voltage of the sense resistor;
- and
- generating supply rails for the front end differential amplifier based on the common mode voltage.
A method in a system comprising a front end differential amplifier having two input terminals, and two input resistors, each of the two input resistors coupled to a respective one of the two input terminals, and wherein the two input terminals of the front end differential amplifier are configured to receive an input signal via the two input resistors, and further wherein the input signal is generated by a sense resistor, the method comprising:
- generating, with two current sources of an input common mode biasing circuit for an output stage of the front end differential amplifier, currents for biasing the output stage of the front end differential amplifier;
- detecting a common mode voltage of the sense resistor;
- and
- setting a reference voltage for virtual grounds of the front end differential amplifier based on the common mode voltage.
Dependencies are inferred from the claim text.