发明名称 |
Protective circuit for a magnetoresistive element |
摘要 |
A protective circuit for a magnetoresistive (MR) element having a first and a second terminal in which a first current source is coupled to the first terminal of the MR element to produce a bias current through the MR element and a second current source is coupled to the second terminal of the MR element to produce a reference current. Circuit means coupled across the MR element senses the center potential of the MR element substantially midway between the first and second terminals, and a feedback circuit responsive to the sensed center potential is coupled to adjust the current output of the first current source to maintain the center potential to a selected reference voltage to protect the MR element from short circuits to a conductive area of the magnetic recording medium. A second feedback circuit is provided which comprises a pair of transistors coupled in a differential pair configuration and a transconductance stage which feeds back a signal as a current to the transistors which keeps the dc currents through each of the transistors equal, and the transistors provide an amplified output signal which is a function of the magnetic flux being sensed by the MR element.
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申请公布号 |
US4879610(A) |
申请公布日期 |
1989.11.07 |
申请号 |
US19880250784 |
申请日期 |
1988.09.28 |
申请人 |
INTERNATIONAL BUSINESS MACHINES CORPORATION |
发明人 |
JOVE, STEPHEN A.;KLAASSEN, KLAAS B.;NOMURA, CALVIN S.;VANPEPPEN, JACOBUS C. L. |
分类号 |
G11B5/39;G11B5/00;G11B5/02;G11B5/40;G11B19/04;H03F3/72 |
主分类号 |
G11B5/39 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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