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. 30, 1999
Filed:
Jan. 15, 1997
Vikram Kowshik, San Jose, CA (US);
Programmable Microelectronics Corp., San Jose, CA (US);
Abstract
The frequency of a clocking signal is adjusted in response to fluctuations in the power supply voltage. In one embodiment, a control circuit has a plurality of clock input terminals each coupled between selected adjacent ones of the stages of a multiple-stage ring oscillator circuit and has an output clock terminal coupled to an input terminal of the ring oscillator circuit. In this manner, the control circuit may implement a plurality of loops each including a different variety of the stages of the ring oscillator circuit, wherein the clocking signal associated with each of the loops has a unique frequency. A plurality of trip voltages each being equal to a unique predetermined fraction of the power supply voltage are compared to a reference voltage. The control circuit selects, in response to the comparison of the trip voltages and the reference voltage, one of the loops mentioned above to provide its clocking signal to an output terminal of the oscillator. Thus, fluctuations in the power supply voltage are reflected in the trip voltages and result in a selection of a loop which has associated therewith a clocking signal having a frequency appropriate for the power supply voltage.