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:
Jul. 20, 1999
Filed:
Jul. 15, 1997
Powersmart, Inc., Shelton, CT (US);
Abstract
A method for fabricating an application specific integrated circuit (ASIC) from a multitude of silicon layers, including upper silicon layers and lower silicon layers. A processor for performing defined calculations and a random access memory (RAM) for storing a plurality of variable data values are formed in the lower layers of the application specific integrated circuit. A read only memory (ROM) is formed in the uppermost layer of the application specific integrated circuit using a metal mask. The plurality of control functions and constant data values stored in the read only memory are required for operation of a particular type of battery with a particular type of battery chemistry, such as a rechargeable nickel metal hydride battery, or a rechargeable lithium ion battery. The invention allows one core ASIC to be programmed into several separate final products, each with a different last mask ROM code layer. The method allows a wafer lot to be processed up to the last mask, and then one of several finishing options can be selected.