Atmel Corporation

Stmicroelectronics S.r.l.

Davide Manfre′

Simone Bartoli

Lorenzo Bedarida

Massimiliano Frulio

Fabio Enrico Carlo Disegni

Andrea Sacco

Cesare Torti

Giorgio Oddone

Marco Pasotti

Marcella Carissimi

Stefano Surico

Laura Capecchi

Donato Ferrario

Gabriele Pelli

Massimo Fidone

A non-volatile memory device includes a memory array, a reading circuit, a column decoder stage, and a read supply voltage generator. The column decoder stage includes selectable bitlines and selection switches. A read supply voltage generator includes a voltage regulation circuit and a dummy column decoder coupled to an output of the voltage regulation circuit and having electrical characteristics correlated to the selected read path. The voltage regulation circuit is configured to receive a first electrical quantity correlated to a desired voltage value on the selected bitline and a second electrical quantity correlated to a desired current value for the selected bitline and to generate a regulated read supply voltage for the column decoder stage.

Non-volatile memory device having a reading circuit operating at low voltage

According to one embodiment, a PCM memory device includes a memory matrix having memory cells of the phase-change type organized in a plurality of word lines and bit lines. Each memory cell has a storage element and an access element including at least one MOS transistor, which is controlled to allow access to the storage element and to carry out read/programming storage operations, in which source terminals of the MOS transistors of access elements of the memory cells of the same word line are connected to the same source line. The source lines of the memory matrix are electrically short-circuited in groups. A single source line driver element for each group of source lines is configured in such a manner as to generate a respective source line driver signal in order to bias in a corresponding manner all the source lines of the respective group.

Phase change memory device with selector MOS transistors and source line clustering

A memory device includes an array of phase-change memory cells and a word line. The memory device includes a control circuit, a first pull-up MOSFET and a second pull-up MOSFET connected in series between a first power-supply node set at a first supply voltage and the word line, a first pull-down MOSFET and a second pull-down MOSFET connected in series between the word line and a second power-supply node set at a reference potential, and a biasing MOSFET connected between the word line and a third power-supply node set at a second supply voltage higher than the first supply voltage. The first and second pull-up MOSFETs and the first and second pull-down MOSFETs have breakdown voltages lower than the breakdown voltage of the biasing MOSFET.

Phase-change memory device with drive circuit

A sense amplifier circuit for reading the state of memory cells. In one aspect of the invention, the sense amplifier circuit includes a first stage receiving a cell current derived from the memory cell and a reference current derived from a reference cell, and a second stage receiving the cell current and the reference current. A comparator, coupled to the first stage and the second stage, provides an output indicative of the state of the memory cell based on a difference of the voltages provided by the first stage and the second stage, where the state indicated by the comparator is substantially unaffected by capacitive current components provided by transient behavior of the first and second stages.

Sense amplifier with stages to reduce capacitance mismatch in current mirror load

A method and apparatus for discharging a memory cell in a memory device. In one implementation, the memory cell includes a capacitor having a first plate and a second plate, and the method includes initially discharging the first plate of the capacitor through a first discharge circuit and discharging the second plate of the capacitor through a second discharge circuit. After the initial discharge, the method further includes completely discharging the first plate of the capacitor and the second plate of the capacitor by coupling both the first plate of the capacitor and the second plate of the capacitor to ground.

Method and apparatus for discharging a memory cell in a memory device after an erase operation

A method and system for managing a buffered program operation for plurality of words is described. In one aspect, the method and system include providing an internal buffer including a plurality of locations and at least one bit location for the plurality of locations. Each of the words is stored in a location of the plurality of locations. The words are associated with internal address bits for the locations. At least one of the internal address bits is at least one group address bit that corresponds to all of the words. A remaining portion of the internal address bits is associated at least one of the words. The at least one bit location stores the at least one group address bit for the words. Thus, in one aspect, the method and system include storing each of the words one of the buffer locations. The method and system also include associating the at least one group address bit with the buffer location for each of the words.

Method and system for managing address bits during buffered program operations in a memory device

Regulating a program voltage value during multilevel memory device programming includes utilizing a program path duplicate in an output pump regulator circuit. Further, the output pump regulator circuit is utilized to provide a regulated program voltage for memory cell programming, the regulated program voltage correcting for a program path voltage drop.

Method and system for regulating a program voltage value during multilevel memory device programming

Regulating a program voltage value during multilevel memory device programming includes utilizing a program path duplicate in an output pump regulator circuit. Further, the output pump regulator circuit is utilized to provide a regulated program voltage for memory cell programming, the regulated program voltage correcting for a program path voltage drop and compensating for temperature variation.

A method for discharge in a flash memory device includes: initiating a discharge of a memory cell after an erase operation; coupling a first discharge circuit to a first plate of a gate-bulk capacitor, and a second discharge circuit to a second plate of the gate-bulk capacitor, where the first plate represents the common gate node of the memory cell and the second plate represents the bulk-source node of the memory cell; and coupling the common gate node and the bulk-source node to ground to provide for a complete discharge. The current injected into the first plate approximately equals the current extracted from the second plate. In this manner, dangerous oscillations of the gate and bulk-source voltages as they go to ground are eliminated without complicated designs or voltage limitators, and without sacrificing the fast discharge after the erase operation. The reliability of the discharge operation is thus significantly improved.

Growing community of inventors

Bologna, Italy

Davide Manfre′