Apparatus and method for long term storage of analog signals
US4809223A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 18, 1987 |
| Grant date | Feb 28, 1989 |
| Priority date | — |
| Expiry date | Jun 18, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C27/024
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A state analog memory device for storing approximations of analog signals for prolonged periods of time converts the analog signal in an n-ary digitizer to the one of a plurality of a discrete levels which is the next greater in magnitude than the applied signal. This digitized signal is then serially stored in an analog storage element comprising connected master and slave sample and hold circuits by a two stage control signal. Periodically, at intervals shorter in duration than the time in which the stored signals would droop to the next lower n level, the stored signal is refreshed by feeding the signal stored in the slave sample and hold circuit back to the digitizer which boosts it back up to the one level which is reentered in the master/slave sample and hold circuits. A state analog dynamic RAM utilizes an array of the analog store elements and a plurality of n-ary digitizers for simultaneously refreshing rows of the storage elements at a time. In addition a shift register utilizing a number of series connected state analog memory devices is disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.