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:
Nov. 23, 2004
Filed:
Jan. 24, 2002
Toshihiro Nomura, Yokohama, JP;
NPTest Inc., San Jose, CA (US);
Abstract
A comparator circuit includes at least one transconductance stage that receives two test voltages and two reference voltages. The transconductance stage produces two test currents that are proportional to the test voltages and two reference currents. A switching circuit is coupled to the transconductance stage. The switching circuit has two output terminals that are coupled to a conventional comparator stage. The switching circuit can combine the test currents with the reference currents to realize a differential swing comparison mode and a common-mode comparison mode as required for testing differential signals. Moreover, by disabling appropriate output signals from the at least one transconductance stage, a single-ended comparison mode is realized. By using two identical transconductance amplifiers, the non-linearity of the transconductance stage is advantageously canceled out.