Independent control loops to minimize positive and negative mismatch in differential amplifiers
AssigneeMACOM Technology Solutions Holdings, Inc.
InventorsDuy Nguyen, William Allen
Life of this patent
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Abstract
Independent control loops for mitigating positive and negative mismatch in differential amplifiers are provided. A method includes comparing a first voltage measured at a positive side output of an emitter follower with a reference voltage, resulting in a first voltage difference. The method also includes comparing a second voltage measured at a negative-side output of the emitter follower with the reference voltage, resulting in a second voltage difference. In addition, the method includes independently controlling the positive side and the negative side of the differential amplifier based on the first voltage difference and the second voltage difference.
Claims19
A method for correcting a positive side-negative side mismatch of a differential amplifier, comprising:
- determining a first direct current (DC) voltage at a positive side output of an emitter follower of the differential amplifier, resulting in a first output voltage;
- comparing the first output voltage with a reference voltage;
- based on a first result of the comparing, controlling a first DC current flowing through a positive side of a PFET and a load of a VGA stage of the differential amplifier;
- and
- connecting a resistor between an input voltage source and the positive side of the PFET.
A method for mitigating positive side-negative side mismatch in a differential amplifier, comprising:
- comparing a first voltage measured at a positive side output of an emitter follower with a reference voltage, resulting in a first voltage difference;
- comparing a second voltage measured at a negative side output of the emitter follower with the reference voltage, resulting in a second voltage difference;
- and
- independently controlling the positive side and the negative side of the differential amplifier based on the first voltage difference and the second voltage difference.
A circuit for mitigating positive side-negative side mismatches in a differential amplifier, comprising:
- a positive side transistor operatively connected to an input of a first control loop;
- a negative side transistor operatively connected to an input of a second control loop;
- an output of the first control loop that is operatively connected to an input node of the positive side;
- an output of the second control loop that is operatively connected to an input node of the negative side;
- a first resistor connected between an input voltage source and the positive side transistor;
- and
- a second resistor connected between the input voltage source and the negative side transistor.
Dependencies are inferred from the claim text.