Technique to prevent deprogramming a floating gate transistor used to directly switch a large electrical signal
US5457653A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 5, 1994 |
| Grant date | Oct 10, 1995 |
| Priority date | — |
| Expiry date | Jul 5, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C16/3418
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A novel method of connecting and operating an NVM transistor in the switching circuit is provided. A full voltage signal can be switched across an NVM transistor. The device is turned on prior to the signal switching and the electrical characteristics of the NVM device relative to the associated circuitry is carefully regulated to prevent the source-drain voltage from rising above a preselected maximum voltage (e.g. 1 v). Two embodiments of the present invention are described. In the first embodiment, the relative impedances of the NVM transistor and its driving circuit are controlled. The driver circuit and the NVM transistor switch act as a resistor divider circuit with a percentage of the full switching voltage appearing across the NVM transistor and the driver circuit according to their relative impedances. The second embodiment is applicable when the NVM transistor switch drives a capacitive load. The rise time of the signal to be switched is controlled. This can be done by controlling the driver circuit turn-on time, the relative resistor-capacitor (RC) risetime on either side of the NVM switch, or a combination of the two techniques. If the risetime of the switching signal i…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.