Systems, methods and apparatus to read target memory cells having an associated reference memory cell configured to be representative of drift or changes in the threshold voltages of the target memory cells. The reference cell is programmed to a predetermined threshold level when the target cells are programmed to store data. In response to a command to read the target memory cells, estimation of a drift of the threshold voltage of the reference is performed in parallel with applying an initial voltage pulse to read the target cells. Based on a result of the drift estimation, voltage pulses used to read the target cells can be modified and/or added to account for the drift estimated using the reference cell.

Provided is an artificial neural network circuit including unit weight memory cells including weight memory devices configured to store weight data and weight pass transistors, unit threshold memory cells including a threshold memory device programmed to store a threshold and a threshold pass transistor, a weight-threshold column in which the plurality of unit weight memory cells and the plurality of unit threshold memory cells are connected, and a sense amplifier configured to receive an output signal of the weight-threshold column as an input and receive a reference voltage as another input.

A neuromorphic computing device a method of controlling thereof are provided. The neuromorphic computing device includes a first memory cell array including resistive memory cells that are connected to wordlines, bitlines and source lines, and configured to store data and generate read currents based on input signals and the data; a second memory cell array including reference resistive memory cells that are connected to reference wordlines, reference bitlines and reference source lines, and configured to generate reference currents; and an analog-to-digital converting circuit configured to convert the read currents into digital signals based on the reference currents, wherein a voltage is applied to the reference wordlines, the reference resistive memory cells are arranged in columns to form reference columns, and the reference columns are configured to generate column currents, and one of the reference currents is generated by averaging at least two of the column currents.

A memory device is disclosed. The memory device includes at least one reference cell and multiple sense amplifiers. The at least one reference cell having a first terminal coupled to a ground. Each of the sense amplifiers has a first terminal and a second terminal. The first terminal is coupled to one of multiple first data lines, and the second terminal is coupled to a second terminal of the at least one reference cell.

A resistive random access memory includes a memory cell including a resistive element having a resistance which varies according to a write operation and stores data according to the resistance of the resistive element, a reference resistive element having a resistance set to a first value, a voltage line set to a first voltage during a first write operation in which the resistance of the resistive element is varied from a second value higher than the first value to the first value, and a voltage control circuit arranged between first ends of the two resistive elements. The voltage control circuit adjusts a value of the first voltage supplied from the voltage line so as to reduce a difference between currents flowing through the two resistive elements during the first write operation, and supply the adjusted first voltage to the first ends of the two resistive elements.

Memory devices provide a plurality of memory cells, each memory cell including a memory element and a selection device. A plurality of first (e.g., row) address lines can be adjacent (e.g., under) a first side of at least some cells of the plurality. A plurality of second (e.g., column) address lines extend across the plurality of row address lines, each column address line being adjacent (e.g., over) a second, opposing side of at least some of the cells. Control circuitry can be configured to selectively apply a read voltage or a write voltage substantially simultaneously to the address lines. Systems including such memory devices and methods of accessing a plurality of cells at least substantially simultaneously are also provided.

According to one embodiment, a semiconductor storage device includes a memory cell, a bit line connected to the memory cell, and a sense circuit connected to the bit line, wherein the sense circuit includes a first transistor with a first end connected to the bit line, a second transistor with a first end connected to a second end of the first transistor, a third transistor with a first end connected to the bit line, a fourth transistor with a first end connected to a second end of the third transistor, and an amplifier connected to a second end of the second transistor and to a second end of the fourth transistor.

A circuit includes an operational amplifier including an inverting input terminal capacitively coupled to each of an OTP cell array and an NVM cell array and first and second output terminals, an ADC coupled to the first and second output terminals, thereby configured to receive a differential output voltage from the operational amplifier, and a comparator coupled to the ADC and configured to output a data bit responsive to a digital output signal received from the ADC. The circuit is configured to cause the operational amplifier to generate the differential output voltage based on each of a current received from an OTP cell of the OTP cell array and a voltage received from an NVM cell of the NVM cell array.

A read-out circuit and a read-out method for a three-dimensional memory, comprises a read reference circuit and a sensitive amplifier, the read reference circuit produces read reference current capable of quickly distinguishing reading low-resistance state unit current and reading high-resistance state unit current. The read reference circuit comprises a reference unit, a bit line matching module, a word line matching module and a transmission gate parasitic parameter matching module. With respect to the parasitic effect and electric leakage of the three-dimensional memory in the plane and vertical directions, the present invention introduces the matching of bit line parasite parameters, leakage current and transmission gate parasitic parameters into the read reference current, and introduces the matching of parasitic parameters of current mirror into the read current, thereby eliminating the phenomenon of pseudo reading and reducing the read-out time.

Disclosed is a memory structure with reference-free single-ended sensing. The structure includes an array of non-volatile memory (NVM) cells (e.g., resistance programmable NVM cells) and a sense circuit connected to the array via a data line and a column decoder. The sense circuit includes field effect transistors (FETs) connected in parallel between an output node and a switch and inverters connected between the data line and the gates of the FETs, respectively. To determine the logic value of a stored bit, the inverters are used to detect whether or not a voltage drop occurs on the data line within a predetermined period of time. Using redundant inverters to control redundant FETs connected to the output node increases the likelihood that the occurrence of the voltage drop will be detected and captured at the output node, even in the presence of process and/or thermal variations. Also disclosed is a sensing method.