US 7,061,320 B2Granted

Differential amplifier

AssigneeMatsushita Electric Industrial Co., Ltd.

InventorsHiroshi Kimura, Shigeki Furuya

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Abstract

A differential amplifier according to the present invention comprises, in addition to a differential amplifier circuit and an output-stage amplifier circuit, a first source follower circuit for buffering a first output signal of the differential amplifier circuit, a second source follower circuit for buffering the first output signal of the differential amplifier circuit, and a source ground amplifier circuit, to a source of which an output terminal of the second source follower circuit is connected, and driven by a second output signal of the differential amplifier circuit, wherein a first-polar transistor in the output-stage amplifier circuit is driven by an output signal of the first source follower circuit, and the second-polar transistor is driven by an output signal of the source ground amplifier circuit.

Claims22

Dependent claims

A differential amplifier comprises:

an input-stage differential amplifier circuit having a first and a second input terminals and a first and a second output terminals;
a first source follower circuit having a first-polar transistor, wherein the first output terminal of the differential amplifier circuit is connected to a gate;
a second source follower circuit having a first-polar transistor, wherein the first output terminal of the differential amplifier circuit is connected to a gate;
a source ground amplifier circuit having a first-polar transistor, wherein an output terminal of the second source follower circuit is connected to a source, the second output terminal of the differential amplifier circuit is connected to a gate, and a load resistance is connected to a drain;
and
an output-stage amplifier circuit comprised of a first-polar transistor, wherein an output terminal of the first source follower circuit is connected to a gate, and a second-polar transistor, wherein an output terminal of the source ground amplifier circuit is connected to agate, serially connected to each other.

3 more elements

Dependencies are inferred from the claim text.