Abstract:
A sense-amplifier circuit can be used with a non-volatile memory device having a memory array with memory cells arranged in word lines and bit lines and coupled to respective source lines. The circuit has a first circuit branch and a second circuit branch, which receive on a respective first comparison input and second comparison input, during a reading step of a datum stored in a memory cell, a cell current from the bit line associated to the memory cell and a reference current, from a reference bit line in a differential reading operation or from a current-reference generator in a single-ended reading operation. The first and second circuit branches generate, during the datum-reading step, a first output voltage and a second output voltage, as a function of the difference between the cell current and the reference current.
Abstract:
A phase-change memory device includes a memory array including a first memory cell and a second memory cell, each comprising a phase-change element and a selector, connected respectively to a first local bitline and a second local bitline, which are in turn connected, respectively, to a first main bitline and a second main bitline. The parasitic capacitance of the main bitlines is precharged at a supply voltage. When the local bitlines are selected to access a respective logic datum stored in the phase-change element, the parasitic capacitance of the local bitlines is first charged using the charge previously stored in the parasitic capacitance of the main bitlines and then discharged through the respective phase-change elements. Reading of the logic datum is made by comparing the discharge times.
Abstract:
A reading circuit for a charge-retention circuit stage is provided with a storage capacitor coupled between a first biasing terminal and a floating node, and a discharge element coupled between the floating node and a reference terminal. The reading circuit further has an operational amplifier having a first input terminal that is coupled to the floating node and receives a reading voltage, a second input terminal receives a reference voltage, and an output terminal on which it supplies an output voltage, the value of which is a function of the comparison between the reading voltage and the reference voltage and indicative of a residual charge in the storage capacitor. A shifting stage shifts the value of the reading voltage of the floating node, before the comparison is made between the reading voltage and the reference voltage for supplying the output voltage.
Abstract:
A level shifter circuit is designed to shift an input signal that switches within a first voltage range to supply an output signal that switches within a second voltage range, higher than the first voltage range. A first inverter stage has an input receiving the input signal and also has an output. A first capacitive element is connected between the output of the first input inverter stage and a first holding node. A latch stage is connected between the first holding node and a second holding node that is coupled to an output terminal, on which the output signal is present. The first input inverter stage is designed to operate in the first voltage range, and the latch stage is designed to operate in the second voltage range.
Abstract:
A device includes a first and second inverters each having a signal input, signal output, high voltage supply terminal, and low voltage supply terminal. The signal input of the first inverter is coupled to the signal output of the second inverter, and the signal input of the second inverter is coupled to the signal output of the first inverter. A first transistor has a first conduction terminal coupled to a power supply node, a second conduction terminal coupled to the high voltage supply terminal of the first inverter, and a control terminal coupled to a first node. A second transistor has a first conduction terminal coupled to the power supply node, a second conduction terminal coupled to the high voltage supply terminal of the second inverter, and a control terminal coupled to a second node. First and second bit lines are capacitively coupled to the first and second nodes.
Abstract:
A method for operating a non-volatile memory device uses a sense amplifier that includes a first branch and a second branch. During a pre-charging step, a bit line of a memory array of the non-volatile memory device is biased in order to pre-charge the bit line. During the pre-charging step, an offset between the first branch and the second branch is detected and stored. During a reading step subsequent to the pre-charging step, a cell current is received from the bit line at the first branch and a reference current is received from a current-reference structure at the second branch. During the reading step, and amplified voltage is generated as a function of the cell current and the reference current. During the reading step, an output voltage is generated based on the amplified voltage compensated by the offset stored during the pre-charging step.
Abstract:
An input signal is amplified into an output signal that is to be applied to an electrical load including a capacitive component. An amplifier stage includes a pre-amplifier module to receive a first supply voltage, and an output module to receive a second supply voltage. The pre-amplifier module includes a first gain block to pre-amplify the input signal into a first pre-amplified signal, and a second gain block to pre-amplify the input signal into a second pre-amplified signal. A feedback block feeds back the output signal as a feedback signal. A combination element combines the first pre-amplified signal and the feedback signal into a combined signal. The output module combines the combined signal and the second pre-amplified signal into the output signal.
Abstract:
An amplifier circuit may include an input amplification stage comprising a first amplifier having first and second differential inputs and a first output, and a second amplifier having first and second differential inputs and a second output. The amplifier circuit also includes an output amplification stage having first and second inputs respectively coupled to the first and second outputs of the input amplification stage, and an output configured to supply an output voltage based upon the input voltage by an amplification factor. The amplifier circuit comprises a feedback stage with a common-mode control stage configured to implement a comparison between the first differential voltage and the second differential voltage, and a reference voltage, and generate respective regulation currents on the first and second inputs of the output amplification stage to compensate for a common-mode variation of the first differential voltage and the second differential voltage.
Abstract:
A memory device may include memory cells. The method may include receiving a request of reading a selected data word associated with a selected code word stored with an error correction code, and reading a first code word representing a first version of the selected code word by comparing a state of each selected memory cell with a first reference. The method may include verifying the first code word, setting the selected code word according to the first code word in response to a positive verification, reading at least one second code word representing a second version of the selected code word, verifying the second code word, and setting the selected code word according to the second code word in response to a negative verification of the first code word and to a positive verification of the second code word.
Abstract:
A decoding system for a phase change non-volatile memory device having a memory array may include a column decoder that selects at least one column of the memory array during programming operations. The decoding system includes a selection circuit that includes selection switches on a number of hierarchical decoding levels for defining a conductive path between at least one column and a driving stage. A biasing circuit may supply biasing signals to the selection switches for defining the first conductive path and bringing the selected column to a programming voltage value. The programming selection circuit may have protection elements between columns and the selection switches. The selection switches and the protection elements may include metal oxide semiconductor (MOS) transistors having an upper threshold voltage level lower than the programming voltage.