| 摘要 |
A magnetic recording channel front-end for a magnetic storage system includes a magnetoresistive element, an interconnect and a readback amplifier. The interconnect, which has a characteristic impedance, couples the magnetoresistive element to the readback amplifier. The readback amplifier includes a gain stage and an active termination. The gain stage, which has an associated impedance, has an input that is connected to the interconnect. The active termination is coupled to the input of the gain stage, such that an input impedance of the readback amplifier, which is formed by a combination of the impedance associated with the gain stage and the active termination, is substantially equal to the characteristic impedance of the interconnect. Additionally, the gain stage generates a first noise signal that has a first magnitude appearing at an output of the gain stage. The active termination generates a second noise signal that has a second magnitude that also appears at the output of the gain stage. The second magnitude is significantly less that the first magnitude, thereby the signal-to-noise ratio performance of the magnetic recording channel front-end is not adversely affected. When the gain stage is a current-sensing gain stage, the active termination provides positive feedback from the gain stage to the input of the gain stage. When the gain stage is a voltage-sensing gain stage, the active termination provides negative feedback from the gain stage to the input of the gain stage.
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