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:
Apr. 18, 2000
Filed:
Oct. 14, 1998
Charles R Patton, III, Murrieta, CA (US);
George J Bennett, Murrieta, CA (US);
Western Digital Corporation, Irvine, CA (US);
Abstract
A digital-to-analog converter (DAC) is preferably employed to receive a digital input word and provide an analog output signal to a motor driver in a disk drive servo. The digital input word has a plurality of bit positions for establishing a resolution for the DAC. These bit positions define first and second groups of bits. The DAC comprises circuitry responsive to the first group of bits for producing a pair of analog signals defining a common-mode magnitude and a differential magnitude. The common-mode magnitude is a function of the value of the first set of bits and the differential magnitude is a function of the number of bit positions in the first group of bits. In the DAC: a clock generates a clocking signal; a state machine has an input for receiving the clocking signal, an input for receiving the second groups of bits, and an output for providing a time-varying control signal; switching circuitry has a pair of inputs for receiving the pair of analog signals, an input for receiving the time-varying control signal, and an output for providing a pulse-width and amplitude modulated signal; and averaging circuitry responds to the pulse-width and amplitude modulated signal to producing the analog output signal.