Differential Amplifier with Modified Common Mode Rejection, and to a Circuit with an Improved Common Mode Rejection Ratio
AssigneeAnalog Devices Global
InventorJonathan Ephraim David Hurwitz
Life of this patent
Estimating the term…
Abstract
An amplifier circuit having improved common mode rejection is provided. This can be achieved by estimating the common mode value of an input signal and using this to adjust a target common mode voltage at the output of the amplifier. This can help avoid the differential gain becoming modified by the common mode voltage.
Claims22
A differential amplifier comprising:
- a target output common mode voltage input node configured to receive, via a feed forward path, an input signal to set a target common mode output voltage of the differential amplifier,
- wherein the differential amplifier is configured to generate a common mode voltage at an output node of the differential amplifier as a function of the received signal that represents a common mode signal at differential inputs of the differential amplifier.
(canceled)
A method of improving the common mode rejection performance of a differential amplifier having a control node for controlling a target common mode output voltage of a differential output of the amplifier, the method comprising:
- feeding forward a control signal to the target common mode voltage control node to set the target common mode output voltage of the differential amplifier;
- and
- generating a common mode voltage an output node of the differential amplifier as a function of the control signal that represents a common mode signal at differential inputs of the differential amplifier.
A differential amplifier comprising:
- a target output common mode voltage input node configured to receive, via a feed forward path, an input signal to set a target common mode output voltage of the differential amplifier;
- and
- means for generating a common mode voltage an output node of the differential amplifier as a function of the received input signal that represents a common mode signal at differential inputs of the differential amplifier.
Dependencies are inferred from the claim text.