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:
Oct. 22, 1996
Filed:
Aug. 23, 1995
Yoshikado Sanemitsu, Itami, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
An IC card according to the present invention includes a lithium cell that, when the IC card is disconnected from a system, supplies power required for retention of data in a volatile static random access memory (SRAM); a first capacitor connected in parallel with the lithium cell in order to accumulate charge, a second capacitor connected in parallel with the lithium cell in order to accumulate charge, and a switch for connecting the first capacitor and the second capacitor in series with each other during replacement of the lithium cell. The series circuit of the first and second capacitors serves as a backup power source during replacement of the lithium cell. As a result, the time available for cell replacement without loss of stored data is increased.