Semiconductor memory device with refresh timer circuit
US5485429A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 21, 1994 |
| Grant date | Jan 16, 1996 |
| Priority date | — |
| Expiry date | Oct 21, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C11/406
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A semiconductor memory device has a dynamic memory element constructed of a capacitor and a transistor; and a refresh timer circuit for automatically recharging the dynamic memory element at periodic time intervals corresponding to an electric charge holding time of the dynamic memory element which changes in accordance with an ambient temperature. Since the refresh timer circuit includes a current bias circuit for varying an electric current in accordance with the ambient temperature and an oscillation circuit for oscillating at a frequency corresponding to the electric current of the current bias circuit, the refresh cycle time changes in response to ambient temperature changes, thus reducing the requisite current capacity of the memory device power supply.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.