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:
Jun. 30, 1998
Filed:
Apr. 30, 1997
James Stuart Irwin, Paige, TX (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A phase locked loop (PLL) system receiving a reference frequency and generating an output frequency has a charge pump (28), loop filter (38), an N frequency divider (32), an R frequency divider (24), a Voltage Controlled Oscillator (30) and a phase detector (26). The charge pump (28) has a high current output (62) and a low current output (60). The loop filter (38) responsively coupled to the charge pump (28) has a first pole filter that includes a high current first pole filter capacitor (66), a high current first pole damping resistor (70), a low current first pole filter capacitor (64), a low current first pole damping resistor (68), and a first pole filter capacitor (72). A second pole filter can be added that includes a second pole filter capacitor (76), a second pole damping resistor (74), and a feed forward capacitor (78).