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:
Sep. 28, 2010
Filed:
Jun. 29, 2007
Ki-ho Kim, Kyoungki-do, KR;
Kee-teok Park, Kyoungki-do, KR;
Ki-Ho Kim, Kyoungki-do, KR;
Kee-Teok Park, Kyoungki-do, KR;
Hynix Semiconductor Inc., Gyeonggi-do, KR;
Abstract
An impedance matching circuit performs a ZQ calibration for a test on a wafer process of a semiconductor memory device. The impedance matching circuit of the semiconductor memory device includes a first pull-down resistance unit, a first pull-up resistance unit, a second pull-up resistance unit and a second pull-down resistance unit. The first pull-down resistance unit supplies a ground voltage to a first node in response to a calibration test signal. The first pull-up resistance unit calibrates its resistance to that of the first pull-down resistance unit to thereby generate a pull-up calibration code. The second pull-up resistance unit supplies a supply voltage to a second node in response to the pull-up calibration code. The second pull-down resistance unit calibrates its resistance to that of the second pull-up resistance unit to thereby generate a pull-down calibration code.