Data storage device employing amplifier feedback for impedance matching
AssigneeWestern Digital Technologies, Inc.
InventorsJohn T. Contreras, Joey M. Poss
Life of this patent
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Abstract
A data storage device is disclosed comprising a head actuated over a magnetic media, wherein the head comprises a read element configured to generate a read signal when reading data from the magnetic media. A common-source common-gate (CS-CG) differential amplifier is coupled to the read element through a transmission line having a transmission line impedance Z0. A feedback circuit is coupled between an output of the CS-CG differential amplifier and an input of the CS-CG differential amplifier, wherein the feedback circuit is configured so that an input impedance of the CS-CG differential amplifier substantially matches the transmission line impedance Z0.
Claims22
A data storage device comprising:
- a magnetic media;
- a head actuated over the magnetic media, wherein the head comprises a read element configured to generate a read signal when reading data from the magnetic media;
- a common-source common-gate (CS-CG) differential amplifier coupled to the read element through a transmission line having a transmission line impedance Z0;
- and
- a feedback circuit coupled between an output of the CS-CG differential amplifier and an input of the CS-CG differential amplifier, wherein the feedback circuit is configured so that an input impedance of the CS-CG differential amplifier substantially matches the transmission line impedance Z0.
A data storage device comprising:
- a magnetic media;
- a head actuated over the magnetic media, wherein the head comprises a read element configured to generate a read signal when reading data from the magnetic media;
- a common-source common-gate (CS-CG) differential amplifier coupled to the read element through a transmission line;
- a source follower feedback circuit coupled between an output of the CS-CG differential amplifier and an input of the CS-CG differential amplifier;
- and
- a biasing circuit configured to bias a source voltage of the source follower feedback circuit to substantially match a common mode input voltage at the input of the CS-CG differential amplifier.
Control circuitry comprising:
- a common-source common-gate (CS-CG) differential amplifier configured to be coupled to a read element of a head of a data storage device through a transmission line having a transmission line impedance Z0;
- and
- a feedback circuit coupled between an output of the CS-CG differential amplifier and an input of the CS-CG differential amplifier, wherein the feedback circuit is configured so that an input impedance of the CS-CG differential amplifier substantially matches the transmission line impedance Z0.
Control circuitry comprising:
- a common-source common-gate (CS-CG) differential amplifier configured to be coupled to a read element of a head of a data storage device through a transmission line;
- a source follower feedback circuit coupled between an output of the CS-CG differential amplifier and an input of the CS-CG differential amplifier;
- and
- a biasing circuit configured to bias a source voltage of the source follower feedback circuit to substantially match a common mode input voltage at the input of the CS-CG differential amplifier.
Dependencies are inferred from the claim text.