Abstract: According to an aspect of the present invention, there is provided a voltage generation circuit including: first and second reference terminals to output first and second reference voltages, respectively; first PMOS and first NMOS transistors connected between high and low level power supply lines in series; an output terminal connected between the first PMOS and first NMOS transistors; a first operational amplifier including: first input terminals each including a gate of a PMOS transistor to be connected to one of the second reference terminal and the output terminal, and a first output terminal connected to the first PMOS transistor; and a second operational amplifier including: second input terminals each including a gate of an NMOS transistor to be connected to one of the first reference terminal and the output terminal, and a second output terminal connected to the first NMOS transistor.

Abstract: According to an aspect of the present invention, there is provided a reference voltage generation circuit including: a first transistor having a first gate, a first source and a first drain; a second transistor having a second gate connected to the first gate, a second source connected to the first source and a second drain; a first diode connected between a ground and a V? node; a first resistor connected between the V? node and the first drain; a second diode and a second resistor connected between the ground and a V+ node; a third resistor connected between the V+ node and the first drain; an operational amplifier including input ports connected to the V+ node and the V? node and an output port connected to the first gate and the second gate; and a fourth resistor connected between the ground and the second drain.

Abstract: According to an aspect of the invention, there is provided, a semiconductor device, including an internal voltage generation circuit generating a prescribed voltage, a first test circuit connecting to a voltage-supplying wiring, one end of the voltage-supplying wiring being connected to a source wiring and the other end of the voltage-supplying wiring being connected to the internal voltage generation circuit, the first test circuit being supplied an outer voltage from the source wiring and a voltage of the internal voltage generation circuit through the voltage-supplying wiring, the first test circuit generating a prescribed resistance value on a basis of a control input from an outer portion in a test mode.

Abstract: A discharge order control circuit includes a pool circuit, a delay circuit and a discharge unit to control a discharge order of internal power supplies. The pool circuit stores electric charges provided from a potential of an external power supply. The delay circuit operates on the electric charges stored in the pool circuit and delays a discharge signal generated when potential of the external power supply is lowered to a predetermined potential level. The delay circuit includes an inverter array having a plurality of stages each containing an inverter. The plurality of stages include a final stage that outputs the delayed discharge signal. Only the inverter of the final stage generates an RC delay. The discharge unit discharges a internal power supply included in the internal power supplies in response to the delayed discharge signal output from the inverter of the final stage of the inverter array.

Abstract: In this reference voltage generating circuit, the first current generating circuit generates the first constant current irrespective of the power supply voltage, when temperature is constant. When temperature changes, the magnitude of the first current changes according to the change. The second current generating circuit generates a second current depending on the power supply voltage. An output circuit outputs the output voltage. It has a resistor element for flowing the third current as an addition of the first current and the second current. An output voltage is output by the voltage drop of this resistor element.

Abstract: A chain type ferroelectric random access memory has a memory cell unit including ferroelectric memory cells electrically connected in series to each other, a plate line connected to an electrode of the memory cell unit, a bit line connected to the other electrode of the memory cell unit via a switching transistor, a sense amplifier which amplifies the voltages of this bit line and its complementary bit line, and a transistor inserted between the switching transistor and the sense amplifier. A value, being the minimum value of the gate voltage in the transistor obtained during elevation of the plate line voltage and comparative amplification, is smaller than a value, being the maximum value of the gate voltage in the transistor obtained during fall of the plate line voltage and comparative amplification. With these features, decrease in the accumulated charge of polarization in the memory cell is reduced and occurrence of disturb is prevented during read/write operations.

Abstract: A reference voltage generator circuit comprises a first current path and a second current path. The first current path is formed between an input terminal supplied with a first reference voltage and an output terminal and including a first diode and a first resistor serially connected from the input terminal. The second current path is formed between the input terminal and the output terminal and including a second diode, a second resistor and a third resistor serially connected from the input terminal. A comparator is supplied with a voltage on a node between the first diode and the first resistor and a voltage on a node between the second resistor and the third resistor for comparative amplification. A transistor is connected between the output terminal and a second reference voltage and having a control terminal to receive an output from the first comparator.

Abstract: A supply voltage sensing circuit comprises an internal power supply circuit, which provides a constant output voltage regardless of the supply voltage. A delay circuit generates a delayed signal by delaying a variation in the output voltage. A divider circuit generates a divided voltage by dividing the supply voltage at a certain division ratio. A p-type MOS transistor has a source given the delayed signal and a gate given the divided voltage and turns on when the supply voltage lowers below a certain value. An output circuit provides an output voltage based on a drain voltage on the p-type MOS transistor.

Abstract: A semiconductor memory device includes a memory cell array, a sense amplifier, and a voltage generator. The memory cell array has a plurality of memory cells. Each of the memory cells is written with “0” or “1” as reference data after “0” or “1” as cell data has been read out from the memory cell. The sense amplifier compares and amplifies the reference data and the cell data read from a memory cell. The voltage generator keeps constant rate of change with time of at least one potential supplied for a read operation for the time interval from readout of the cell data is started until completion of readout of the reference data.

Abstract: A first bit line is connected to a memory cell. A second bit line is connected to a dummy cell having a dummy capacitor, and supplied with an electric potential which is complementary to the electric potential of the first bit line. A sense amplifier compares and amplifies the first and second bit lines. A sense amplifier supply voltage generation circuit supplies the sense amplifier with a sense amplifier supply voltage to be used in the comparison and amplification by the sense amplifier. The sense amplifier supply voltage is supplied to a reference potential generation circuit. When data is read out from the memory cell to the first bit line, the reference potential generation circuit supplies, to the second bit line via the dummy cell, a reference potential which fluctuates with a positive correlation to the fluctuation in sense amplifier supply voltage.

Abstract: A circuit for detecting a power-on voltage of power supply encompasses a voltage divider connected between a first power supply and a second power supply, the potential of the second power supply is lower than the potential of the first power supply, and a detecting circuit connected between the first power supply and the second power supply. The voltage divider includes a series circuit encompassing a diode, a first dividing resistor connected to the diode and a second dividing resistor connected between the first dividing resistor and the second power supply. The detecting circuit includes a pMOS transistor whose gate electrode is connected to a connection node between the first dividing resistor and the second dividing resistor, a source resistor connected between the first power supply and the source electrode of the pMOS transistor and a drain resistor connected to the drain electrode of the pMOS transistor and the second power supply.

Abstract: A unit cell is formed by a ferroelectric capacitor and first MOS transistor, and a block is formed by connecting a plurality of unit cells in series. The gates of the first MOS transistors in the individual unit cells are connected to word lines, which are selectively driven by a word line driver on the basis of a row address signal. A plate line is connected to one terminal of the block, and driven by a plate line driver. A bit line is connected to the other terminal of the block via a second MOS transistor for block selection, and selected by a column decoder on the basis of a column address. A driver/controller controls the plate line driver and column decoder to apply a potential difference between the plate line and bit line, while a plurality of word lines are kept off.

Abstract: A power supply voltage control circuit supplying a power supply voltage to a memory cell array, including word lines extending along row direction, bit lines extending along column direction, plate lines extending along the row direction, and a plurality of unit cells disposed at intersections of word lines and bit lines, includes a word line control circuit for supplying a first voltage to the word lines; and a plate line control circuit for supplying a second voltage to the plate lines; and the power supply voltage control circuit provides an amount of current flow from the first voltage so as to keep the first voltage potential almost constant during increasing a value of the second voltage in a power-on sequence, firstly increasing a value of the higher voltage of two potential voltages: the first voltage and the second voltage capacitive coupled, and then increasing a value of the lower second voltage.

Abstract: A semiconductor device comprises a memory cell array, bit line, /bit line complementary to the bit line, reference voltage generating circuit and sense amplifier. The bit line is connected to the memory cells and applied with a voltage read from each memory cell of the memory cell array. The /bit line is supplied with a reference voltage. The reference voltage generating circuit generates the reference voltage that has temperature dependence for compensating a change in the voltage, read to the bit line, due to temperature. The reference voltage generating circuit controls the reference voltage such that the reference voltage assumes a midpoint of trails of a signal value distribution indicative of “0” data and a signal value distribution indicative of “1” data. The sense amplifier compares the voltage, read to the bit line, with the reference voltage supplied to the /bit line, and amplifies the difference therebetween.

Abstract: A chain type ferroelectric random access memory has a memory cell unit including ferroelectric memory cells electrically connected in series to each other, a plate line connected to an electrode of the memory cell unit, a bit line connected to the other electrode of the memory cell unit via a switching transistor, a sense amplifier which amplifies the voltages of this bit line and its complementary bit line, and a transistor inserted between the switching transistor and the sense amplifier. A value, being the minimum value of the gate voltage in the transistor obtained during elevation of the plate line voltage and comparative amplification, is smaller than a value, being the maximum value of the gate voltage in the transistor obtained during fall of the plate line voltage and comparative amplification. With these features, decrease in the accumulated charge of polarization in the memory cell is reduced and occurrence of disturb is prevented during read/write operations.

Abstract: A dummy capacitor drive potential VDC is given to one electrode of a dummy capacitor, and a reference potential for determining a data value of a memory cell is generated in the other electrode thereof. A potential generator circuit for generating the potential VDC is composed of a BGR circuit outputting a potential VBGRTEMP having temperature dependency, and resistors R3 and R4, which are series-connected between an output terminal of the BGR circuit and a ground point. The potential VDC is output from a connection point of the resistors R3 and R4. Temperature dependency of the potential VDC is adjusted based on a resistance ratio of resistors R1-1, R1-2 and R2, and the absolute value is adjusted based on a resistance ratio of resistors R3 and R4.

Abstract: A phase-change memory device includes memory cells, a memory cell array, a first electrode layer, a word line, and a bit line. The memory cell includes a phase-change layer formed on a semiconductor substrate. The memory cell array has the memory cells arranged in a matrix. The phase change layer includes first regions which contact the semiconductor substrate in units of memory cells and a second region which connects the first regions arranged in a same column. The first electrode layer is formed on the second region. A contact area of each first region and the semiconductor substrate is smaller than a contact area of the second region and the first electrode layer. The bit line is electrically connected to the first electrode layer. The bit line is connects in common the phase-change layers of the memory cells arranged in the same column.

Abstract: A semiconductor storage device comprises first and second memory cells, each connected to the first pair of word line and bit line and a second pair of word line and bit line, a sense amplifier connected between the first and second bit lines, a first capacitor whose storage electrode being connected to the first bit line, a second capacitor whose storage electrode being connected to the second bit line, first and second wires respectively connected to the first and second plate electrodes of the first and second capacitors, wherein the first and second bit lines are in a complementary relation, and when “0” is read to the first bit line, the first capacitor has an operation to increase a potential of the first plate electrode through the first wire before the sense amplifier operates.

Abstract: A chain type ferroelectric random access memory has a memory cell unit including ferroelectric memory cells electrically connected in series to each other, a plate line connected to an electrode of the memory cell unit, a bit line connected to the other electrode of the memory cell unit via a switching transistor, a sense amplifier which amplifies the voltages of this bit line and its complementary bit line, and a transistor inserted between the switching transistor and the sense amplifier. A value, being the minimum value of the gate voltage in the transistor obtained during elevation of the plate line voltage and comparative amplification, is smaller than a value, being the maximum value of the gate voltage in the transistor obtained during fall of the plate line voltage and comparative amplification. With these features, decrease in the accumulated charge of polarization in the memory cell is reduced and occurrence of disturb is prevented during read/write operations.

Abstract: A phase-change memory device includes memory cells, a memory cell array, a first electrode layer, a word line, and a bit line. The memory cell includes a phase-change layer formed on a semiconductor substrate. The memory cell array has the memory cells arranged in a matrix. The phase change layer includes first regions which contact the semiconductor substrate in units of memory cells and a second region which connects the first regions arranged in a same column. The first electrode layer is formed on the second region. A contact area of each first region and the semiconductor substrate is smaller than a contact area of the second region and the first electrode layer. The bit line is electrically connected to the first electrode layer. The bit line is connects in common the phase-change layers of the memory cells arranged in the same column.