04807188 is referenced by 33 patents and cites 4 patents.

An electrically alterable, non volatile memory device capable of enduring a high number of cycles utilizes an array of "semidouble" cells, each formed by a pair of elementary EEPROM cells connected substantially in parallel and a single select transistor. A special program lines biasing circuit generating a bias voltage representative of a condition wherein one of the two elementary EEPROM structure is broken and sense amplifiers comprising a comparator circuit comparing the current flowing through an addressed semidouble memory cell with the current flowing through a reference cell comprising a pair of virgin EEPROM type elementary cells to ensure operability of each bit of the memory also when one of the two elementary cells supporting the bit fails. Different from known memories, only the EEPROM structure is duplicated while column lines, select lines and ancillary circuitry don't require duplication.

Title
Nonvolatile memory device with a high number of cycle programming endurance
Application Number
7/199077
Publication Number
4807188
Application Date
May 26, 1988
Publication Date
February 21, 1989
Inventor
Giulio Casagrande
Vignate
IT
Agent
Pollock Vande Sande & Priddy
Assignee
SGS Thomson Microelectronics s p a
IT
IPC
H03K 3/01
G11C 7/00
G11C 11/34
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