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:
Aug. 17, 1999
Filed:
Sep. 17, 1997
Philippe Silvestre, Antibes, FR;
Augusto Gallegos, Sophia Antipolis, FR;
VLSI Technology, Inc., San Jose, CA (US);
Abstract
The present invention comprises a ringer interface circuit for generating a ringer signal for controlling a telephone ringer. The circuit of the present invention includes a first frequency divider, a second frequency divider, and a third frequency divider. The first frequency divider is adapted to receive a ringer clock signal and generate a first divider frequency output therefrom. The second frequency divider is coupled to receive the first divider frequency output and is adapted to generate a second divider frequency output using the first divider frequency output. The second frequency divider is further adapted to generate a oversampled audio frequency signal. The third frequency divider is coupled to receive the second frequency divider output and is adapted to generate a period signal using the second frequency divider output. The circuit of the present invention also includes a modulator coupled to receive the oversampled audio frequency signal from the second frequency divider and the period signal from the third frequency divider. The modulator is adapted to generate a ringer frequency output having a pulse width according to the oversampled audio frequency signal and a level setting and a period according to the period signal. The modulator is further adapted to output the ringer signal to control a telephone ringer.