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:
Jun. 20, 1995
Filed:
May. 16, 1994
Kazuhiko Kajigaya, Iruma, JP;
Tetsu Udagawa, Iruma, JP;
Kyoko Ishii, Tokyo, JP;
Manabu Tsunozaki, Ohme, JP;
Kazuyoshi Oshima, Ohme, JP;
Masashi Horiguchi, Kawasaki, JP;
Jun Etoh, Hachioji, JP;
Masakazu Aoki, Tokorozawa, JP;
Shin'ichi Ikenaga, Koganei, JP;
Kiyoo Itoh, Higashikurume, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A voltage conversion circuit of the present invention is equipped with means for generating a first voltage stabilized with respect to ground potential of a semiconductor integrated circuit device including the circuit, means for generating second voltage stabilized with respect to an external supply voltage of the semiconductor integrated circuit device, and selection means for selecting either the first voltage or the second voltage. The first voltage age, stabilized with respect to the ground potential, is selected and used as the voltage at the time of normal operation, and the second voltage, stabilized with respect to the external supply voltage, is selected and used at the time of aging test. In this case, means for trimming the first voltage and/or the second voltage is, preferably, provided to raise the voltage accuracy.