Abstract: A method and circuit for accessing a memory location comprising at least one respective ferroelectric storage unit of a matrix of ferroelectric storage units, the memory location is selected by connecting a first terminal of a ferroelectric storage element of the at least one respective storage unit to a respective access line to the memory location; at least another memory location to which is not intended to be accessed is also selected. A second terminal of the ferroelectric storage element is biased to a prescribed access electric potential, and an electric potential on the access line is sensed; the second terminal of the ferroelectric storage elements of the other memory location is also biased to the access potential.

Abstract: A ferroelectric semiconductor memory includes an arrangement of memory units comprising at least one row of memory units. The memory units of the at least one row are associated with a respective word line of the arrangement. The arrangement of memory unit includes a plurality of local word lines branching off from the word line associated with the at least one row, each local word line being connected to a respective group of memory units of the line. Selective connection means allow to selectively connect one of the local word lines to the respective word line. The arrangement of memory units further includes a plurality of local plate biasing lines, each one associated with the memory units of a respective group of memory units, for selectively driving the memory units of the respective groups.

Abstract: A sense amplifier for a memory includes a comparator and a bit line polarization circuit. The comparator receives a first signal representative of a current flowing through a memory cell and a second signal representative of a reference current. Additionally, the comparator includes a stage in a common source configuration and an active load for the stage, and the bit line polarization circuit provides a polarization voltage level that is independent of the supply voltage level. In a preferred embodiment, the sense amplifier also includes an output stage that improves switching time at high supply voltages.

Abstract: A circuit for sensing a ferroelectric non-volatile information storage unit comprises a pre-charge circuit for applying a prescribed pre-charge voltage to a storage capacitor of the information storage unit. The pre-charge voltage causes a variation in a polarization charge of the storage capacitor, depending on an initial polarization state of the storage capacitor. A charge integration circuit integrates an electric charge proportional to the variation in polarization charge experienced by the storage capacitor. The charge integration circuit thus provides an output voltage depending on the polarization state of the storage capacitor.

Abstract: A method of sensing a ferroelectric non-volatile information storage unit comprising two ferroelectric storage capacitors in mutually opposite polarization states, and a sensing circuit for actuating the method.

Abstract: A method of reading and restoring data stored in a ferroelectric memory cell is disclosed. The cell includes a first transistor and first ferroelectric capacitor connected, in series with each other, between a first bitline and an auxiliary line, a second transistor and second ferroelectric capacitor connected, in series with each other, between a second bitline and the auxiliary line, the first and second transistors having respective control terminals connected to a common wordline. The reading method includes precharging the first and second capacitors, applying a read pulse to the cell such that the state of the first capacitor is changed, reading the cell by a sensing means, and restoring the first capacitor to an initial state.

Abstract: A sense amplifier of the type coupled to a reference bit line and at least one cell array bit line. The sense amplifier includes an amplifying stage and a current voltage conversion circuit that compare a reference current from the reference bit line and a cell current from the cell array bit line. The current-voltage conversion circuit includes a voltage setting circuit for setting predetermined voltages on the reference bit line and the cell array bit line, a load circuit for the reference bit line and the cell array bit line, and current mirror circuits for mirroring the reference current and the cell current into the amplifying stage. The load circuit for the reference bit line and the current mirror circuit for the reference current are different circuits, and the load circuit for the reference bit line includes a transistor that mirrors a predetermined current that is generated outside of the sense amplifier.

Abstract: A sense amplifier for a memory includes a comparator and a bit line polarization circuit. The comparator receives a first signal representative of a current flowing through a memory cell and a second signal representative of a reference current. Additionally, the comparator includes a stage in a common source configuration and an active load for the stage, and the bit line polarization circuit provides a polarization voltage level that is independent of the supply voltage level. In a preferred embodiment, the sense amplifier also includes an output stage that improves switching time at high supply voltages. Additionally, there is provided a method for sensing logic levels in a memory device. According to the method, a bit line is polarized at a polarization voltage level, and a first signal representative of a current flowing through a memory cell is compared with a second signal representative of a reference current. The polarization voltage level is independent of the supply voltage level.

Abstract: An EEPROM is organized in matrix form in word lines and bit lines. Storage cells are placed at the intersections of these lines. The cells include floating gate storage transistors. Groups of cells having separate bit lines but sharing a word line are created. Each group is connected to a group selection transistor. The group selection transistor selectively connects the control gates of the storage transistors to control lines, which provide potentials for enabling programming, erasure or reading of the storage transistors.

Abstract: Disclosed is a charge pump type of negative voltage generator circuit, constructed on a P type substrate and supplying a negative voltage at one output by the pumping of negative charges in n series-connected pumping cells, n being an integer, these pumping cells including P type transistors whose wells are connected to a node to be positively biased. This circuit includes a switching circuit for selectively supplying, at the node, a voltage for biasing of the wells that is greater than or equal to the potential present at the output so long as this potential is greater than a positive reference voltage, and provides a voltage of fixed value for biasing of the wells when the potential present at the output is smaller than the reference voltage. Thus, the appearance of latchup phenomena in the transistors of the pumping cells is prevented.

Abstract: A selector switch circuit comprises an input terminal to receive a positive voltage, an input terminal to receive a negative voltage, a command input terminal to receive a first command logic signal and an output terminal to provide an output voltage. The output is connected selectively to one of the input terminals, the first and second input terminals being connected to the output terminal by means of a first transistor and a second transistor and the circuit comprising control means for the production, as a function of the command signal, of the control voltages applied to the control gates of the transistors for the selective connection of the output terminal to one of the input terminals.

Abstract: A phase generator circuit cyclically produces a first pair of phase signals and a second pair of phase signals, comprising a first circuit to produce a first phase of each pair of phase signals, these first phase signals being non-overlapping and switching over between a voltage 0 and a voltage VCC, and second and third circuits for the production, from the first phase signals, respectively of the second phase of the first pair and the second phase of the second pair of phase signals, these second phase signals being non-overlapping with the first phase signals and switching over between a negative voltage -V and a voltage VCC. The disclosure finds application in the piloting of charge pump type of negative voltage generator circuit.

Abstract: The present invention concerns an electrically programmable memory and a method for writing within this memory. In order to avoid the degradation of information in a memory cell following a number of write cycles in the other cells of the same row, the present invention includes a sequence to be carried out before each write cycle of a word within a row. A systematic reading of all the words of a row by using three different read reference potentials is performed in order to find a cell that gives non-compatibility results between any two of the three read cycles. The words of the row are stored in a register. If a non-compatible result is found, which indicates a degradation of information in the row, a systematic re-write of all the words of the row is carried out.