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:
Jan. 15, 2008
Filed:
Nov. 29, 2005
Tatsuya Kawashimo, Kokubunji, JP;
Hiroki Yamashita, Hachioji, JP;
Masayoshi Yagyu, Hanno, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
This invention provides a semiconductor device in which an ESD protection circuit and a termination circuit can be realized with a small die area. A PMOS transistor having an ESD protection function is placed between a signal node on a line from an signal terminal to an input buffer and a supply voltage node. Furthermore, a voltage generator circuit is placed to supply a reference voltage to the gate of the PMOS transistor. By the reference voltage controlled by the voltage generator circuit, a source drain resistance of the PMOS transistor is set. Thereby, the PMOS transistor can be made to function as a terminating resistor whose resistance can be set adaptively to a characteristic impedance of a transmission line, for example, connected to the signal terminal in addition to the ESD protection function.