Dynamic magnetic information storage or retrieval – General recording or reproducing – Specifics of biasing or erasing
Patent
1997-10-14
2000-05-02
Hindi, Nabil
Dynamic magnetic information storage or retrieval
General recording or reproducing
Specifics of biasing or erasing
360 46, 360 67, G11B 509, G11B 503, G11B 502
Patent
active
060579722
ABSTRACT:
A low noise current source circuit is disclosed for biasing a magnetoresistive (MR) read head. The current source comprises a field-effect transistor (FET) cascoded to a second transistor which, in turn, is coupled to the MR element. A filter device including a capacitor is coupled across the gate-source junction of the FET, and a sensing device, such as a resistor, is coupled to the gate of the FET for detecting current flowing into said capacitor. Boost circuitry, coupled to the sensing device, boosts the charge/discharge rate of the filter capacitor when the voltage of the sensing device exceeds a certain threshold.
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Hindi Nabil
International Business Machines - Corporation
Neal Regina Y.
Walsh Robert A.
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