US 2006/0186961 A1 · Variable gain differential amplifier, and variable degeneration impedance control device and method for use in the same

Abstract

Disclosed are a variable gain differential amplifier, and variable degeneration impedance control device and method for use in the variable gain differential amplifier, which can adjust an amplification gain and ensure linearity. A DC level of a differential signal to be amplified by the amplifier is adjusted according to a control signal to adjust a gain of the amplifier, and the impedance of a variable degeneration impedance part is adjusted according to the differential signal of which the DC level is adjusted. That is, the gain of the differential amplifier is adjusted and the linearity is ensured by varying the impedance of the variable degeneration impedance part using the differential input signal of which the DC level is adjusted.

Claims9

Dependent claims

A variable gain differential amplifier comprising:

a variable degeneration impedance part which varies a gain of the variable gain differential amplifier by varying an impedance of the variable degeneration impedance part according to a control signal from an outside;
and
a differential amplification part comprising a first terminal which receives a differential signal, a second terminal connected to a power supply through a load, and a third terminal connected to the variable degeneration impedance part;
wherein the variable degeneration impedance part comprises:
a DC level adjustment unit which adjusts a DC level of the differential signal according to the control signal;
and
a variable impedance unit where the impedance of the variable impedance unit is adjusted according to the differential signal of which the DC level is adjusted.

4 more elements

A variable degeneration impedance control device for use in a variable gain differential amplifier, comprising:

a DC level adjustment unit which adjusts a DC level of a differential signal to be amplified by the amplifier according to a control signal to adjust a gain of the amplifier;
and
a variable impedance unit which is connected to the DC level adjustment unit, and where the variable impedance unit adjusts the impedance of the amplifier according to the differential signal of which the DC level is adjusted;
wherein the gain of the variable gain differential amplifier is varied by adjusting the control signal.

1 more element

Dependencies are inferred from the claim text.

Variable gain differential amplifier, and variable degeneration impedance control device and method for use in the same

Life of this patent

Variable gain differential amplifier, and variable degeneration impedance control device and method for use in the same

Life of this patent

Abstract

Claims9