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. 03, 1996
Filed:
Dec. 27, 1994
Kenneth C Weng, Austin, TX (US);
Chia S Weng, Austin, TX (US);
Motorola Inc., Schaumburg, IL (US);
Abstract
An integrated circuit identification device (10) includes a plurality of inverters (12-16), a first bus (24), an address bus (26), a plurality of drivers (18-22), a pre-charge circuit (28) and an identification code access (30). Each inverter (12) includes a P-channel FET (32-36) and an N-channel FET (38). An identification code is written to the device (10) by selectively breaking down the gate-well dielectric layer (112) of the N-channel FET which permanently alters the FET. When the address bus provides a read signal to the gate drivers, each N-channel FET that has been altered will be unable to turn on, thus the precharging of the P-channel FET keeps the output of the inverter at a logic '1'. N-channel FETs that have not be altered will be on when the read signal is provided, thus providing a logic '0'.