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:
Feb. 04, 2003
Filed:
May. 10, 2001
Kevin Paul Demsky, Rochester, MN (US);
Randolph B. Heineke, Rochester, MN (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A ring oscillator, such as a bipolar ring oscillator with enhanced, fast startup and shutdown includes a series of a plurality of inverting differential stages connected in a loop. The plurality of inverting differential stages includes a first multiplexer stage. The first multiplexer stage includes a first signal input, a second signal input and a select input. An oscillator feedback signal is applied to the first signal input of the first multiplexer stage. A startup circuit is coupled to the first multiplexer stage. The startup circuit includes a differential signal coupled to the second signal input of the first multiplexer stage for starting the bipolar ring oscillator. The startup circuit applies a full differential switching voltage signal to the second signal input of the first multiplexer stage to guarantee start of the bipolar ring oscillator after one delay of the series of the plurality of inverting differential stages connected in the loop. The startup circuit includes a fast transition run signal and a multiplexer select signal responsive to the run signal. The multiplexer select signal is coupled to the select input of the first multiplexer stage for controlling the first multiplexer stage to select the oscillator feedback signal or the static differential signal for stopping the bipolar ring oscillator.