发明名称 |
Method and circuit for checking multilevel programming of floating-gate nonvolatile memory cells particularly flash cells |
摘要 |
To check the programming of a nonvolatile memory cell storing an actual threshold value, the drain terminal of the cell is biased at a constant voltage; the gate terminal is biased at a check voltage; the cell is supplied with a predetermined current to determine a gate-source voltage drop related to the actual threshold value; and the voltage at the source terminal is supplied to an input of an operational amplifier. In an open-loop configuration, the desired threshold value of the set predetermined current is supplied as the check voltage; the amplifier compares the source voltage with the ground; and switching of the amplifier indicates the desired threshold value has been reached. In a closed-loop configuration, the output of the operational amplifier is connected directly to the gate terminal of the cell, and supplies the desired threshold value directly. |
申请公布号 |
US5880993(A) |
申请公布日期 |
1999.03.09 |
申请号 |
US19970941882 |
申请日期 |
1997.09.30 |
申请人 |
SGS-THOMSON MICROELECTRONICS, S.R.L. |
发明人 |
KRAMER, ALAN;CANEGALLO, ROBERTO;CHINOSI, MAURO;GOZZINI, GIOVANNI;ROLANDI, PIER LUIGI;SABATINI, MARCO |
分类号 |
G01R31/28;G11C11/56;G11C16/02;G11C16/34;G11C29/12;G11C29/50;(IPC1-7):G11C16/06 |
主分类号 |
G01R31/28 |
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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