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:
Sep. 03, 1991
Filed:
Feb. 02, 1990
David M Lewis, Santa Cruz, CA (US);
Seagate Technology, Inc., Scotts Valley, CA (US);
Abstract
An oscillator circuit is tuned to the frequency of reference pulses, for example, the spindle index pulses of a rotating magnetic storage system. A ring oscillator circuit includes a series transmission gate. The transmission gate is controlled by the output signal from a programmable delay line to interrupt operation of the ring oscillator and, in effect, provide fine tuning of the ring oscillator frequency in programmed steps. The output signal of the ring oscillator is divided down in a programmable divider, which provides a coarse frequency adjustment for an output pulse signal provided by the divider. Output signals from the divider are also provided as inputs to the programmable delay line. The frequency of the output pulse signal is compared to the frequency of the reference pulses to generate control signals for the programmable delay line. The control signals are generated by a microprocessor.