US 7,898,339 B2Granted

Amplifier circuit

AssigneesKabushiki Kaisha Nihon Micronics, Nes Co., Ltd.

InventorsMasato Ikeda, Tokio Miyashita

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Abstract

An amplifier circuit with favorable linearity is provided. An amplifier of the present invention is provided with an amplifier MOS transistor, a diode-connected transistor block for negative feedback source impedance constituted by series-parallel connection of the limited number (including 0) of the diode-connected MOS transistors and connected to a source side of the amplifier MOS transistor, and a diode-connected transistor block for load constituted by series-parallel connection of the limited number of the diode-connected MOS transistors and connected to a drain side of the amplifier MOS transistor. A voltage gain is configured to be determined by a ratio of the sum of source impedance of the amplifier MOS transistor and the impedance of the diode-connected transistor block for negative feedback source impedance to the impedance of the diode-connected transistor block for load.

Claims7

Dependent claims

An amplifier circuit comprising

an amplifier unipolar transistor having a gate as an input terminal of the amplifier circuit;
a diode-connected transistor block for negative feedback source impedance constituted by series-parallel connection of the limited number (including 0 piece) of the diode-connected unipolar transistors for connecting a gate and a drain so as to make between the drain and source into a diode and connected to the source side of the amplifier unipolar transistor;
a diode-connected transistor block for load constituted by the series-parallel connection of the limited number of the diode-connected unipolar transistors connecting a gate and a drain so as to make between the drain and source into a diode and connected to the drain side of the amplifier unipolar transistor;
and
a voltage output terminal connected to a drain-side end of the amplifier unipolar transistor of the diode-connected transistor block for load, wherein
a voltage gain is determined by a ratio of impedance of the sum of source impedance of the amplifier unipolar transistor and the impedance of the diode-connected transistor block for negative feedback source impedance to the impedance of the diode-connected transistor block for load.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/465,974Filed 14 May 2009
Priority: JP 2008-14008828 May 2008
Published: US 2009/0295480 A13 Dec 2009
Granted: 1 Mar 2011
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

H03F 1/3211
Modifications of amplifiers to reduce non-linear distortion: in differential amplifiers
H03F 1/223
By use of cascode coupling, i.e. earthed cathode or emitter stage followed by earthed grid or base stage respectively: with mosfet's
H03F 3/45183
Using MOSFET transistors as the active amplifying circuit: long tailed pairs
H03F 3/45475
Characterised by the way of implementation of the active amplifying circuit in the differential amplifier: using IC blocks as the active…