摘要:
The voltage generator comprises a negative feedback loop including a programmable voltage divider having a feedback node. The voltage divider comprises a programmable resistor disposed between the output of the voltage generator and the feedback node and having variable resistance. The programmable resistor includes a fixed resistor and a plurality of additional resistors arranged in series with each other and defining a plurality of intermediate nodes. The additional resistors may be selectively connected by means of switches disposed between the output of the voltage generator and a respective intermediate node so as to define an output voltage V0 programmable on the basis of command signals supplied to the switches.
摘要:
Circuit for the regulation of the word line voltage in a memory, including a voltage regulator suitable to generate an output regulated voltage to be supplied to one or more word lines of the memory when said one or more word lines are being selected, and charge accumulation means that are selectively connectable with the output of the voltage regulator and suitable to accumulate a compensation charge for a voltage drop that takes place on said regulated voltage upon the selection of said one or more word lines of the memory.
摘要:
Described herein is a nonvolatile memory comprising a memory array organized according to global word lines and local word lines; a global row decoder; a local row decoder; a first supply stage for supplying the global row decoder; and a second supply stage for supplying the local row decoder; and a third supply stage for biasing the drain and source terminals of the memory cells of the memory array. Each of the supply stages comprises a respective resistive divider formed by a plurality of series-connected resistors, and a plurality of pass-gate CMOS switches each connected in parallel to a respective resistor. The nonvolatile memory further comprises a control circuit for controlling the pass-gate CMOS switches of the supply stages, and a switching circuit for selectively connecting the supply input of the control circuit to the output of the second supply stage during reading and programming of the memory, and to the output of the third supply stage during erasing of the memory.
摘要:
A voltage generator formed of a charge circuit and a discharge circuit having a common programmable voltage divider with variable resistance; the programmable voltage divider including a plurality of resistors arranged in series and selectively connectable to define alternatively a step-wise increasing program voltage and a fixed verify voltage. The charge circuit formed of a voltage regulator supplying at the output the precise voltage value determined by the programmable voltage divider, and the discharge circuit intervening when the output voltage must be switched in a controlled manner from a higher value to a lower value.
摘要:
A circuit for the regulation of the word line voltage in a memory, comprising a voltage regulator suitable to generate an output regulated voltage to be supplied to one or more word lines of the memory when the one or more word lines are being selected. The circuit includes a voltage boosting circuit that is coupled to the output of said voltage regulator and that can be activated upon the selection of one or more memory word lines in order to boost the regulated voltage upon the selection of the one or more memory word lines.
摘要:
Presented is a voltage regulating circuit for a capacitive load, which is connected between first and second terminals of a supply voltage generator. The regulating circuit has an input terminal and an output terminal, and includes an operational amplifier having an inverting input terminal connected to the input terminal of the regulating circuit and a non-inverting input terminal connected to an intermediate node of a voltage divider. The voltage divider is connected between an output node, which is connected to the output terminal of the regulating circuit, and the second terminal of the supply voltage generator. The operational amplifier has an output terminal connected, for driving a first field-effect transistor, between the output node and the first terminal of the supply voltage generator. The output terminal of the operational amplifier is also connected to the output node through a compensation network. The voltage regulating circuit also includes a second field-effect transistor connected between the output node and the second terminal of the supply voltage generator, which has its gate terminal connected to a constant voltage generating circuit means.
摘要:
A method for programming a nonvolatile memory cell envisages applying in succession, to the gate terminal of the memory cell, a first and a second programming pulse trains with pulse amplitude increasing in staircase fashion, in which the amplitude increment between one pulse and the next in the first programming pulse train is greater than the amplitude increment between one pulse and the next in the second programming pulse train. The programming method envisages applying, to the gate terminal of the memory cell and before the first programming pulse train, a third programming pulse train with pulse amplitude increasing in staircase fashion, in which the amplitude increment between one pulse and the next may be less than the amplitude increment in the first programming pulse train and substantially equal to the amplitude increment in the second programming pulse train, or else may be greater than the amplitude increment in the first programming pulse train.
摘要:
An analog-to-digital conversion method and device for a multilevel non-volatile memory device that includes a multilevel memory cell. The method comprises a first step of converting the most significant bits contained in the memory cell, followed by a second step of converting the least significant bits. The first step is completed within a time interval corresponding to the rise transient of the gate voltage, and the second step is initiated at the end of the transient. Also disclosed is a scheme for error control coding in multilevel Flash memories. The n bits stored in a single memory cell are organized in different “bit-layers”, which are independent from one another. Error correction is carried out separately for each bit-layer. The correction of any failure in a single memory cell is achieved by using a simple error control code providing single-bit correction, regardless of the number of bits stored in a single cell.
摘要:
A voltage regulator having a comparator with an output terminal that is the output of the regulator, terminals for connection to a voltage supply, a source of a reference voltage connected to an input terminal of the comparator, and a feedback circuit connected between the output terminal and the other input terminal of the comparator. To prevent transients upon the transition from the standby state to the active state, there is provided a second reference-voltage source that provides a reference voltage substantially equal to that of the first source, a switch for connecting the second source to the other input terminal of the comparator, and a control circuit that can activate the supply of the regulator and can close the switch for a predetermined period of time when the supply of the regulator is activated.
摘要:
A circuit device for performing hierarchic row decoding in semiconductor memory devices of the non-volatile type, which memory devices include an array of memory cells with column-ordered sectors, wherein each sector has a respective group of local wordlines linked to a main wordline. The circuit device includes a main wordline driver provided at each main wordline, and a local decoder provided at each local wordline. This circuit device further comprises, for each main wordline, a dedicated path connected between the main wordline and the local decoders of the associated local wordlines and connected to an external terminal arranged to receive a read/program voltage, the dedicated path enabling transfer of the read/program voltage to the local decoders.