US 11,088,665 B2 · Linear broadband transconductance amplifier

Abstract

An amplifier circuit comprises a differential input stage and a differential output stage. The differential input stage includes a first differential input transistor pair coupled to a differential input of the amplifier circuit, and a second differential input transistor pair coupled to the differential input and the differential output stage; a degeneration impedance coupled between first transistors of the first and second differential input transistor pairs and second transistors of the first and second differential input transistor pairs; and a feedback circuit coupled to the first and second differential input transistor pairs and the degeneration impedance, wherein output current is provided from the differential input stage to the differential output stage by the feedback circuit and transition current is provided to the output stage by the second differential input transistor pair.

Claims22

Dependent claims

An amplifier circuit comprising:

a differential input stage and a differential output stage, the differential input stage including:
a first differential input transistor pair coupled to a differential input of the amplifier circuit, and a second differential input transistor pair coupled to the differential input and the differential output stage, wherein the first and second transistors of the first and second differential input transistor pairs are a first transistor type;
a degeneration impedance coupled between first transistors of the first and second differential input transistor pairs and second transistors of the first and second differential input transistor pairs;
and
a feedback circuit coupled to the first and second differential input transistor pairs and the degeneration impedance, wherein output current is provided from the differential input stage to the differential output stage by the feedback circuit and transition current is provided to the output stage by the second differential input transistor pair, and wherein the feedback circuit includes transistors of a second transistor type complementary to the first transistor type.

2 more elements

A method of operating an amplifier circuit, the method comprising:

providing an output current from a differential input stage of the amplifier circuit to a differential output stage of the amplifier circuit;
regulating the output current using a feedback circuit connected to a first differential input transistor pair, a second differential input transistor pair, and a degeneration impedance;
and
when an input signal to the amplifier circuit has a frequency within a cut-off frequency bandwidth of the feedback circuit, providing the output current to the differential output stage using the feedback circuit and providing transition current to the differential output stage using the second differential input transistor pair;
and
when the input signal has a frequency greater than the cut-off bandwidth of the feedback circuit, providing the output current and the transient current to the output stage using the second differential input transistor pair.

3 more elements

A transconductance amplifier circuit comprising:

a differential input stage and a differential output stage, the differential input stage including:
a first differential input transistor pair coupled to a differential input of the amplifier circuit;
a degeneration impedance coupled between transistors of the differential input transistor pair;
a second differential input transistor pair coupled to the degeneration impedance;
and
a feedback circuit coupled to the first and second differential input transistor pairs and the degeneration impedance, wherein output current is provided from the differential input stage to the differential output stage by the second differential transistor pair and the feedback circuit, wherein the feedback circuit has a cut-off frequency bandwidth, and for input signals with frequencies greater than the cut-off frequency bandwidth, the output current is provided to the output stage by the second differential input transistor pair.

3 more elements

Dependencies are inferred from the claim text.

Linear broadband transconductance amplifier

Life of this patent

Linear broadband transconductance amplifier

Life of this patent

Abstract

Claims22