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:
Oct. 09, 2007
Filed:
Jul. 12, 2005
Jiro Shinbo, Takasaki, JP;
Satoshi Arayashiki, Isesaki, JP;
Hirotaka Oosawa, Isesaki, JP;
Toshiya Uozumi, Takasaki, JP;
Satoru Yamamoto, Takasaki, JP;
Jiro Shinbo, Takasaki, JP;
Satoshi Arayashiki, Isesaki, JP;
Hirotaka Oosawa, Isesaki, JP;
Toshiya Uozumi, Takasaki, JP;
Satoru Yamamoto, Takasaki, JP;
Renesas Technology Corp., Tokyo, JP;
Abstract
In a PLL circuit including an oscillator, a phase comparator, a charge pump circuit, and a loop filter, without providing a plurality of capacitative elements, that is, without increasing the occupied area so much, the characteristics of the PLL circuit can be adjusted according to manufacture variations in a resistive element and a capacitative element, and a loop filter can be formed on a chip. A resistive element and a capacitative element of a loop filter are formed on a semiconductor chip. As the resistive element, a plurality of elements having different resistance values are provided and switched by a switch, thereby enabling the resistance value to be adjusted. Current in a charge pump circuit is also made adjustable, and the current of the charge pump circuit is adjusted according to switching among the resistance values of the resistive elements.