Title:
増幅回路
Document Type and Number:
Japanese Patent JP4014740
Kind Code:
B2
Abstract:
The object of the invention is to realize an MR amplifier circuit that is operable with a single power supply voltage, and in which the CMRR can be maintained large. Current supply circuit (10) supplies a prescribed current (IB) to MR element (20) in response to a control signal (SD), the current of resistive element (R2) that is connected between node (ND2) and ground potential is set by means of the equivalent current circuit (40), the current that flows in resistive element (R2) is controlled in response to potential changes of node (ND2) when a noise is applied to MR element (20), and current changes of MR element (20) are suppressed. Due to the fact that a voltage drop that is generated in MR element (20) is amplified by amplifier (30) that is operated with a single power supply voltage, and since the resistance changes of MR element (20) accompanying changes in the magnetic field are detected, an amplifier circuit can be realized wherein the strength of the magnetic field can be detected, the CMRR can be kept high, and the effects due to in-phase noise can be minimized.
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Inventors:
Fumio Yoneno
Application Number:
JP31802898A
Publication Date:
November 28, 2007
Filing Date:
November 09, 1998
Export Citation:
Assignee:
Texas Instruments Japan Ltd.
International Classes:
G11B5/02; G01R33/09; H03F3/45; G11B5/00; G11B5/40
Domestic Patent References:
| JP6103506A |
Attorney, Agent or Firm:
Takahisa Sato