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. 10, 2004
Filed:
Dec. 20, 2001
Frank Gasparik, Monument, CO (US);
LSI Logic Corporation, Milpitas, CA (US);
Abstract
A the charge pump suitable for use in phase-locked loop (PLL) circuits employed by mixed signal integrated circuits (IC) is disclosed. The PLL charge pump includes a constant current source that generates constant current source references with high power supply rejection for the P- and N-channel devices of the charge pump. Pass-gate transistors are inserted between the output terminals and the drains of the respective P- and N-channel devices. The switching transients power supply and ground are confined to the turn on/off leads of the pass-gate transistors and, thus, are isolated from the constant current source P- and N-channel devices. In exemplary embodiments of the invention, the constant current of the P- and N-channel devices may be made programmable and used for controlling the range of the current controlled oscillator of the PLL circuit.