Lapis Semiconductor Co., Ltd.

Oki Semiconductor Co., Ltd.

Hiroyuki Tanikawa

Bunsho Kuramori

Nobukazu Murata

Teruhiro Harada

Yuji Nagashima

A reference voltage generation circuit including: a first diode including a first conductive area; a second diode including a second conductive area that is larger than the first conductive area; a generation section configured to generate a reference voltage using a voltage based on the first diode and a voltage based on the second diode; and a first capacitor connected between a node of dividing resistors and an output of the generation section, the dividing resistors being connected between the output of the generation section and the second diode.

Reference voltage generation circuit and semiconductor device

A charge pump unit including a capacitor that accumulates a charge on an output node according to a first clock signal and a transfer gate that takes in and applies a voltage of an input node to the output node according to a second clock signal received at a control terminal is controlled in the following manner. If the ratio of the total time of periods in which the voltage of the output node is higher than a target voltage in a predetermined monitoring period is smaller than or equal to a first threshold, i.e., if the charge pump unit executes a boosting operation for a relatively long period, a pulse voltage value of the second clock signal is increased.

Booster circuit

A power supply circuit and a semiconductor storage device that can achieve low power consumption of the power supply circuit that includes a charge pump circuit are provided. The semiconductor storage device includes a charge pump unit which generates and outputs a boosted voltage by boosting a source voltage, a voltage monitoring unit that performs comparison and determination on magnitudes of a divided voltage obtained by dividing the boosted voltage and a predetermined reference voltage, a charge pump control unit that causes the charge pump unit to operate when the divided voltage is equal to or lower than the reference voltage and causes the charge pump unit to stop when the divided voltage is higher than the reference voltage based on a result of the comparison and determination, and a voltage monitoring control unit that causes the voltage monitoring unit to intermittently stop.

Power supply circuit and semiconductor storage device

A nonvolatile semiconductor memory device and a method of reusing the same that allow a good use of the semiconductor device without degrading characteristics even when reused. The semiconductor memory device comprises information holding means for holding information that indicates an operation mode of said memory cell array, a decoder for generating, to said memory cell array, a selection signal to designate at least a read address of said memory cell array in accordance with an address signal that comprises plural bits; and mode setting means for fixing a logical value of at least one bit of said plural bits of said address signal in accordance with the information held by said information holding means, and supplying said address signal, on which fixing of the logical value is effected, to said decoder.

Nonvolatile semiconductor memory device and method of reusing same

In a semiconductor nonvolatile memory device, nonvolatile memory cells are plurally arranged in a memory array portion. An output circuit outputs setting information selected from plural sets of setting information to generate reference currents with different current values. A reference current circuit generates a reference current with a current value according to the setting information outputted from the output circuit. An amplifier circuit compares a cell current outputted from a selected memory cell of the memory array portion with the reference current generated by the reference current circuit.

Semiconductor nonvolatile memory device

There is provided a non-volatile storage device including: a bit line that is connected to a non-volatile storage element and is applied with a voltage of magnitude corresponding to the logic value stored in the storage element; a charging section that charges the bit line to a voltage of equivalent magnitude to the reference voltage; a voltage generation section that is connected between the reference voltage line and the bit line, comprises a capacitance load for generating coupling charge when charging by the charging section has been performed, and employs the capacitance load to generate a voltage according to a difference between the magnitude of the voltage of the reference voltage line and the magnitude of the voltage of the bit line as a voltage expressing the comparison result; and a charge absorbing section for absorbing the coupling charge generated by the capacitance load.

Non-volatile storage device

In a semiconductor nonvolatile memory, plural first nonvolatile memory cells are arranged in the memory array. Plural memory areas are arranged in the memory array and have plural second nonvolatile memory cells which store the same predetermined information. A sequence circuit generates a memory address, a latch selection signal, and a control signal at predetermined timings when a power is turned on. A write-read unit writes and reads information to and from the memory array and the memory areas based on the memory address and the control signal. A latch circuit latches the predetermined information, read by the write-read unit, based on the latch selection signal. A selection-drive unit selects the first or second nonvolatile memory cells based on the memory address and the predetermined information latched by the latch circuit, and applies a predetermined voltage to drive the selected first or second nonvolatile memory cells.

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Tokyo, Japan

Hiroyuki Tanikawa