Non-volatile programmable bistable multivibrator in predefined initial state for memory redundancy circuit
US5606523A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 30, 1995 |
| Grant date | Feb 25, 1997 |
| Priority date | — |
| Expiry date | Jan 30, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C14/00
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The disclosure relates to memories in integrated circuit form. A programmable non-volatile memory cell of the bistable type is described. This memory cell can take one stable state or another depending on whether either one of two floating-gate transistors of the cell has been programmed. In the initial state, neither of the two transistors is programmed so that the cell cannot remain in this state and at least one of the transistors has to be programmed. To avoid this, there is provided an additional transistor controlled by the output of the cell to set up imbalance in the cell which can then take a well-determined stable state even if no transistor is programmed, while at the same time ensuring that there is no consumption of current by the cell even in this case. The disclosure can be applied to the redundancy circuits of large-capacity memories to memorize the defective addresses. It makes it possible to avoid having to program the cells when the memory has no defective addresses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.