Identification of repaired integrated circuits
US4480199A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 19, 1982 |
| Grant date | Oct 30, 1984 |
| Priority date | — |
| Expiry date | Mar 19, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A circuit for providing an identification signal indicative of whether or not an integrated circuit has been repaired includes a circuit which operates at potentials outside the normal range of the integrated circuit. The circuit includes at least one transistor T1 serially connected between a TTL pin 10 of the integrated circuit and a fuse F1. The fuse F1 is also connected to a potential source V.sub.CC. If the integrated circuit is repaired the fuse F1 is opened, and consequently, application of a potential outside the normal range will cause current to flow if fuse F1 has not been opened, and cause no current to flow if fuse F1 has been opened.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.