Approach to provide high external voltage for flash memory erase
US6240027A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 23, 2000 |
| Grant date | May 29, 2001 |
| Priority date | — |
| Expiry date | Oct 23, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C16/16
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In this invention external high voltages are connected to a chip containing a flash memory that are connected to selected cells to be erased. Internal pump circuits contained on the chip are turned off while the external voltages are used. The external voltages, a high negative voltage and a high positive voltage, are connected to gates and sources respectively of selected cells to be erased by a voltage control module. The external voltages are used during manufacture during program/erase operations to perform the erase function efficiently. The internal high voltage pump circuits are used to erase flash memory cells after being assembled on a circuit board by a user. Two level shifter circuits are disclosed that form a part of the voltage control module. The level shifter circuits apply voltages to the flash memory cells and provide voltages that select and deselect the cells for erasure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.