Data storage device and method of using a ferroelectric capacitance divider
US4853893A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 2, 1987 |
| Grant date | Aug 1, 1989 |
| Priority date | — |
| Expiry date | Jul 2, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C14/00
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A transpolarizer is employed as a programmable capacitance divider. Two ferroelectric capacitors are coupled in series to form a common node and two extreme poles. The polarization of the two capacitors is set by grounding the two poles and then bringing them both up to VCC while impressing a voltage at the common node corresponding to data to be stored. Later, while one pole is held at VSS, the other pole is pulsed from VSS to VCC with the common node floating. A voltage develops at the common node which is above or below the midpoint between VSS and VCC, and will be indicative of the stored data. The capacitance divider is programmed in accordance with data. One such divider is added to a DRAM memory cell to form a shadow DRAM cell. Two such dividers are added to a static RAM memory cell to form a shadow static RAM cell. The same divider arrangement is operable in both volatile and non-volatile modes. An improvement arises by using PZT as dielectric in 54:46 mole ratio.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.