US 7,622,993 B2Granted

Current mirror circuit

AssigneeSemiconductor Technology Academic Research Center

InventorsYoshiki Niki, Haruo Kobayashi, Koichiro Mashiko

Life of this patent

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Abstract

A current mirror circuit including: a first resistance element having one terminal connected to a first potential, and the other terminal connected to a second potential lower than the first potential; an operational amplifier having a high-potential input terminal connected to the first potential and the one terminal of the first resistance element; a second resistance element having one terminal connected to a low-potential input terminal of the operational amplifier, and the other terminal connected to the second potential; and a transistor having a first electrode connected to an output terminal of the operational amplifier, a second electrode connected to the low-potential input terminal of the operational amplifier and the one terminal of the second resistance element, and a third electrode used as an output terminal, wherein the first and second resistance elements both start to operate from a linear area having lower voltage than a saturation area.

Claims8

Dependent claims

A current mirror circuit comprising:

a first resistance element having one terminal connected to a first potential and the other terminal connected to a second potential lower than the first potential;
an operational amplifier having a high-potential input terminal connected to the first potential and the one terminal of the first resistance element;
a second resistance element having one terminal connected to a low-potential input terminal of the operational amplifier and the other terminal connected to the second potential;
and
a transistor having a first electrode connected to an output terminal of the operational amplifier, a second electrode connected to the low-potential input terminal of the operational amplifier and the one terminal of the second resistance element, and a third electrode used as an output terminal;
wherein a potential of a connection node of the high-potential input terminal of the operational amplifier with said one terminal of the first resistance element is set to a value equal to a potential of a connection node of the low-potential input terminal of the operational amplifier with said one terminal of the second resistance element and the second electrode of the transistor;
wherein the first resistance element and the second resistance element both start to operate from a linear area having lower voltage than a saturation area.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/189,044Filed 8 Aug 2008 · division
Priority: JP 2005-06817910 Mar 2005
Published: US 2008/0297203 A14 Dec 2008
Granted: 24 Nov 2009
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

H03F 3/45273
Using MOSFET transistors as the active amplifying circuit: mirror types
H03F 3/04
Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements: with semiconductor devices only
H03F 3/345
With semiconductor devices only: with field-effect devices
H03F 3/45183
Using MOSFET transistors as the active amplifying circuit: long tailed pairs

Family

Application11/370,630Parent of this division · filed 8 Mar 2006
US 2008/0297203 A1Pre-grant publication · published 4 Dec 2008
US 7,425,870 B2Parent of this division
US 2006/0202763 A1Published application
US 7,622,993 B2This patent

From the US filing history. Foreign family members aren’t listed.