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:
Apr. 09, 2002
Filed:
Nov. 10, 1997
Kevin S. Donnelly, San Francisco, CA (US);
Andy Chan, San Jose, CA (US);
Thomas H. Lee, Cupertino, CA (US);
Wayne Richardson, Cupertino, CA (US);
Jared L. Zerbe, Palo Alto, CA (US);
Chaofeng Huang, San Jose, CA (US);
Clemenz L. Portmann, Cupertino, CA (US);
Grace Tsang, Los Altos, CA (US);
Rambus Inc., Los Altos, CA (US);
Abstract
A low pass filter having a first mode of operation and a second mode of operation. The low pass filter includes a charging circuit, a capacitor circuit, and low power circuitry coupled to the capacitor circuit and the charging circuit. The capacitor circuit stores a first differential voltage when the low pass filter is operating in the first mode of operation. The capacitor circuit stores a second differential voltage when the low pass filter is operating in the second mode of operation. The second differential voltage is substantially equal to the first differential voltage. The charging circuit may include a charging current source coupled to a current steering circuit. The low pass filter may further include a load circuit coupled to the current steering circuit and the low power circuitry. The low pass filter may be used in a delay locked loop circuit or a phase locked loop circuit.