Semiconductor memory having self-refresh function
US5774404A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 25, 1995 |
| Grant date | Jun 30, 1998 |
| Priority date | — |
| Expiry date | Jul 25, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C11/406
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A semiconductor memory controls the timing of refreshing memory cells. The semiconductor memory has a capacitor for holding charges, a precharge circuit, and a current source. The precharge circuit has at least a transistor for precharging the capacitor. The current source has a positive temperature coefficient to increase a current as the temperature rises and discharges the capacitor. The timing of refreshing the memory cells is controlled according to a temporal change in the voltage of the capacitor. This arrangement is capable of refreshing the memory cells in a refresh period adjusted to the actual data hold time of the memory cells.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.