发明名称 |
Fast flash EPROM programming and pre-programming circuit design |
摘要 |
A circuit for speeding up the pre-programming of floating gate storage transistors such as FLASH EPROMS, and particularly speeding up the pre-programming of a block or array of floating gate storage transistors includes a controllable voltage source that supplies gate programming potential across the control gate and source of the FLASH EPROM transistor cells to be programmed. A control circuit is provided that controls the voltage source to vary the gate programming potential during a programming interval as a function of time in order to decrease the time required for a given amount of charge movement to program the selected floating gate transistors. The wordline voltages are varied, while the source voltage is held constant. By starting at a lower wordline voltage, and increasing during the programming interval to a high wordline voltage, the programming speed is increased, and the high final turn-on threshold voltage for the programmed floating gate storage transistors is achieved. In addition, in order to speed up pre-programming, a programming potential is applied to four wordlines in parallel during a single programming interval. Further, the load on cells being programmed is adjusted to improve programming speed.
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申请公布号 |
US5956273(A) |
申请公布日期 |
1999.09.21 |
申请号 |
US19980106525 |
申请日期 |
1998.06.29 |
申请人 |
MACRONIX INTERNATIONAL CO., LTD. |
发明人 |
LIN, TIEN-LER;SHONE, FUCHIA;YIU TOM DANG-HSING;WAN RAY L;HSIAO LING-WEN |
分类号 |
G11C16/10;G11C16/12;G11C16/16;G11C16/24;(IPC1-7):G11C7/00 |
主分类号 |
G11C16/10 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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