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. 22, 1998
Filed:
Oct. 29, 1996
Masakazu Chikyu, Tokyo, JP;
Ando Electric Co., Ltd., Tokyo, JP;
Abstract
A relay control circuit is provided to perform on/off control on multiple kinds of relays, each having a different operation speed, which are contained in a source-voltage supply circuit which is employed by an IC tester to perform DC-parameter measurement on ICs. The relay control circuit contains a timer-A and a timer-B, to which different relay-operation wait times are arbitrarily set, wherein the timer-A is set in response to a relay whose operation speed is slowest within the multiple kinds of relays. When a test instruction is executed in accordance with a test program, relay-select-information, representing at least one of the multiple kinds of relays, is generated. A relay-operation monitoring circuit, contained in the relay control circuit, monitors a driving relay by detecting coincidence between current relay-select-information, regarding a current test, and previous relay-select-information regarding a previous test. Both of the timers operate in response to a relay-on signal with respect to the driving relay. However, the timer-A is started only when the relay-operation monitoring circuit fails to detect the coincidence. An OR gate produces a relay-operation-wait control signal based on outputs of the timers, which represents a wait time for an operation of the driving relay. In short, one of the timers is selectively driven in conformity with an operation speed of the driving relay. This results in reduction of a test time for the IC tester.