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:
May. 17, 2011
Filed:
Jan. 28, 2008
Noboru Masuda, Tokorozawa, JP;
Noboru Masuda, Tokorozawa, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
High precision of various feedback systems represented by a PLL circuit and the like is realized. For example, in a charge pump circuit in the PLL circuit, a first to a third PMOS transistors connected in series in three stages are provided between a power source voltage and an output node, and a first to a third NMOS transistors connected in series in three stages are provided between a ground voltage and the output node. And, the second PMOS transistor and the second NMOS transistor are driven ON when establishing conductivity between the power source voltage or the ground voltage and the output node by a first pulse signal, and the first PMOS transistor and the third NMOS transistor are driven OFF when the conductivity is shut down by a second pulse signal. Accordingly, the conduction time can be set by time difference between one edge of the first pulse signal and one edge of the second pulse signal, and therefore, short conduction time can be set, as a result, a charge amount of the charge pump circuit can be controlled precisely.