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:
Mar. 27, 2001
Filed:
Jun. 04, 1999
John M. Baker, Tuttle, OK (US);
Edward N. Jeffrey, Garland, TX (US);
Robert Whyte, Jr., Dallas, TX (US);
Seagate Technology LLC, Scotts Valley, CA (US);
Abstract
An apparatus and method for converting a pulse-width modulation (PWM) signal to an analog voltage signal. A current source is provided to supply electrical charge at a controllable rate to a ramp capacitor which, during successively occurring cycles of the PWM signal, alternatively receives electrical charge from the current source and discharges previously received electrical charge. A first sampling capacitor receives electrical charge from the ramp capacitor to output a feedback voltage to a feedback circuit to adjust the rate of electrical charge supplied by the current source, with the charge transferred to the first sampling capacitor determined in relation to the charge stored on the ramp capacitor over an entire PWM cycle. A second sampling capacitor receives electrical charge from the ramp capacitor to output the analog voltage, with the charge transferred to the second sampling capacitor determined in relation to the duty cycle of the PWM signal.