Resistor-input transconductor including common-mode compensation
AssigneeGigle Semiconductor Limited
InventorsAdrià Bofill-Petit, Robert K. Henderson, Jonathan Ephriam David Hurwitz
Life of this patent
Estimating the term…
Abstract
A resistor-input transconductor includes a circuit configured to generate a common-mode compensation current. The common-mode compensation current is used to compensate for the common-mode voltage of the inputs. A current output of the resistor-input transconductor is proportional to a voltage difference between the two inputs and essentially independent of a common-mode voltage of the two inputs. The resistor input transconductor may be applied in a variety of applications including, for example, communications.
Claims22
A system comprising:
- a first voltage input;
- a second voltage input;
- a first voltage-to-current converter comprising:
- a first circuit configured to provide a virtual ground,
- an input resistor Rp disposed between the first voltage input and the virtual ground, and
- a circuit configured to generate an output current Ioutp responsive to current flowing through the resistor Rp;
- a second voltage-to-current converter comprising:
- a second circuit configured to provide the virtual ground,
- an input resistor Rn disposed between the second voltage input and the virtual ground, and
- a circuit configured to generate an output current Ioutn responsive to current flowing through the resistor Rn;
- a third voltage-to-current converter comprising:
- a third circuit configured to provide the virtual ground,
- an input resistor Rcmp disposed between the first voltage input and the virtual ground,
- an input resistor Rcmn disposed between the second voltage input and the virtual ground, and
- a circuit configured to combine currents flowing through the input resistors Rcmp and Rcmn, and to generate an output current IRcm proportional to the combined currents;
- and
- a circuit configured to provide the output current IRcm to the first voltage-to-current converter and the second voltage-to-current converter so as to compensate for a common-mode voltage between the first voltage input and the second voltage input.
A system comprising:
- means for receiving a first input voltage and generating a first output current using the first input voltage;
- means for receiving a second input voltage and generating a second output current using the second input voltage;
- means for generating a common-mode current representative of a common-mode voltage between the first input voltage and the second input voltage;
- and
- means for providing the common-mode current to the means for generating a first output current and to the means for generating a second output current, such that the first output current and the second output current are compensated for the common-mode voltage.
A method comprising the steps of:
- receiving a first voltage at a first input;
- applying the first voltage to a first input resistor to generate a first input current;
- receiving a second voltage at a second input;
- applying the second voltage to a second input resistor to generate a second input current;
- generating a common-mode current representative of a common-mode voltage of the first voltage and the second voltage;
- using the first input current and the common-mode current to generate a first output current;
- and
- using the second input current and the common-mode current to generate a second output current, a difference between the first output current and the second output current being proportional to a difference between the first voltage and the second voltage.
Dependencies are inferred from the claim text.