Dynamic magnetic information storage or retrieval – General processing of a digital signal – Head amplifier circuit
Reexamination Certificate
2006-04-11
2006-04-11
Hudspeth, David (Department: 2651)
Dynamic magnetic information storage or retrieval
General processing of a digital signal
Head amplifier circuit
C360S025000, C360S031000, C360S032000, C360S067000
Reexamination Certificate
active
07027245
ABSTRACT:
An apparatus for providing head amplitude characterization using gain loops is disclosed. A variable gain amplifier (VGA) receiving input signals and generates a VGA output signal. A digital-to-analog converter (DAC) circuit provides a desired input signal to the VGA and a gain control loop drives the VGA to gain lock the VGA to the provided desired input signal. An analog-to-digital converter (ADC) provides a digital output representing an ADC code spread in response to the VGA output. A controller drives the DAC to provide the desired input signal to the VGA and generates control signals for controlling the ADC, the controller further determines read head channel amplitude based upon the signal provided to the DAC, the ADC code spread received from the ADC and gain code provided by the gain control loops.
REFERENCES:
patent: 4635142 (1987-01-01), Haugland
patent: 4750058 (1988-06-01), Hirt et al.
patent: 5375145 (1994-12-01), Abbott et al.
patent: 5576906 (1996-11-01), Fisher et al.
patent: 5737342 (1998-04-01), Ziperovich
patent: 5854714 (1998-12-01), Reed et al.
patent: 5886842 (1999-03-01), Ziperovich
patent: 6369741 (2002-04-01), Demicheli et al.
patent: 6429988 (2002-08-01), Bhaumik et al.
patent: 6441983 (2002-08-01), Philpott et al.
patent: 6476989 (2002-11-01), Chainer et al.
patent: 6519103 (2003-02-01), Cyrusian
patent: 6661590 (2003-12-01), Cyrusian et al.
patent: 6891885 (2005-05-01), Imaizumi
Mary McCarthy, “Peak-to-Peak Resolution Versus Effective Resolution,” Analog Devices, Application Note, AN-615, Jul. 11, 2003, pp. 1-2, www.analog.com.
“DC Characterization of an ADC,” Pre-Lab, ENTC 351 Lab 7, 1999, http://ee.tamu.edu/˜jinseok/entc351/prelab7—1999.pdf.
Mitchell Chad E.
Pipal Vicki L.
Poss Joey M.
Richetta Raymond A.
Chambliss Bahner & Stophel P.C.
Hitachi Global Storage Technologies - Netherlands B.V.
Hudspeth David
Lynch David W.
Merceds Dismery
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