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:
Jan. 23, 1996
Filed:
May. 18, 1994
Michael C Heath, Cary, NC (US);
Steve C Southward, Cary, NC (US);
Lord Corporation, Cary, NC (US);
Abstract
A waveform generator (20) for generating an analog wave which is synchronized with a signal from an input source (22). The waveform generator (20) includes a phase-locked loop (24) for receiving an input source signal and multiplying said signal by a multiplier. The multiplied square wave signal is then provided to a frequency divider (28) and to a first clock input (39) of a first switched-capacitor filter (29). The frequency divider (28) outputs a divided output signal that is received as an input to the phase-locked loop (25) and by the first switched-capacitor filter (35). As a result, the first switched-capacitor filter (29) outputs a first analog wave of a constant amplitude which is phase synchronized with the input source signal. This waveform generator (20) allows the 3 dB point of the filter to move as the input frequency changes. Further embodiments allow the addition of second switched-capacitor filter (50) and a shift register (45) for providing a second analog wave which is phase shifted from said input source signal yet is synchronized therewith.