Abstract:
A Flash EEPROM comprises negative voltage generator means (8) for generating a negative voltage to be supplied to control gate electrodes (CG) of memory cells (2) for erasing the memory cells (2). The Flash EEPROM comprises first positive voltage generator means (10) for generating a first positive voltage (VO), independent from an external power supply (VCC) of the Flash EEPROM, to be supplied to source regions (S) of the memory cells (2) during erasing.
Abstract:
A data output stage (1) of the buffer type for CMOS logic circuits, being of the type having at least one pair of MOS transistors (M1,M2) associated to drive an output node (3) of said stage (1), comprises first (8) and second (9) feedback loops which are structurally independent and respectively connected between said node (3) and a corresponding gate electrode (G1,G2) of each transistor (M1,M2) to pre-charge said output node (3) at a predetermined voltage value and reduce the noise to ground during the switching phase.
Abstract:
The invention concerns a method of avoiding disturbance during the step of programming and erasing an electrically programmable, semiconductor integrated non-volatile memory device which comprises a matrix of memory cells divided into sectors and programmable in a byte mode. An operation of verification of the contents of the byte to be programmed, to be carried out for each individual bit, is provided even before the first program pulse is applied. The invention further provides for the parallel erasing of several sectors during an erase step, and a verification of the erase step for each sector in the matrix. If the verification shows that a sector has been erased, the sector is applied no further erase pulses.
Abstract:
To reduce the read and write errors caused by depleted memory array cells being turned on even when not selected, the nonselected memory cells are so biased as to present a floating terminal and a terminal at a positive voltage with respect to the substrate region. In this way, the threshold voltage of the above cells (the minimum voltage between the gate and source terminals for the cell to be turned on) increases due to the "body effect", whereby the threshold voltage depends, among other things, on the voltage drop between the cell terminal operating as the source and the substrate, and increases alongside an increase in the voltage drop.
Abstract:
The device comprises a source bias generator (4) suitable for conferring upon the EPROM cell (2) during the reading step a source voltage that varies linearly with the power supply voltage so as to keep constant the voltage between gate and source of the above cell (2).
Abstract:
A data output stage (1) of the buffer type for CMOS logic circuits, being of the type having at least one pair of MOS transistors (M1,M2) associated to drive an output node (3) of said stage (1), comprises first (8) and second (9) feedback loops which are structurally independent and respectively connected between said node (3) and a corresponding gate electrode (G1,G2) of each transistor (M1,M2) to pre-charge said output node (3) at a predetermined voltage value and reduce the noise to ground during the switching phase.
Abstract:
The EPROM memory comprising a semiconductor substrate (1) with source (3) drain (2) and channel (4) areas, a control gate (5) and a floating gate (6) uses for programming a drain voltage no higher than the low power supply voltage (Vcc) employed for normal operation of the memory and a control gate voltage taken from said power supply voltage (Vcc) through a voltage booster (8).