The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 24, 2003
Filed:
May. 24, 2001
Jaydip Bhaumik, Rochester, MN (US);
Raymond Alan Richetta, Rochester, MN (US);
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
A method and apparatus are provided for optimizing calibration of a tunable filter over a wide range of frequencies in a data channel of a direct access storage device (DASD). Calibration codes are received for low corner frequency, banding, and high corner frequency. A programmable diode is provided with a DC portion and a tunable digital-to-analog converter (DAC). A calibration control current is generated for calibrating the tunable filter utilizing the programmable diode and the calibration codes. The programmable diode is used to vary the calibration control current to calibrate the tunable filter to a correct low corner frequency and high corner frequency. The programmable diode can be programmed over a large range.