Abstract: In a semiconductor device, a charge pump operates in accordance with a clock signal and thereby generates a boosted voltage of a polarity which is the same as or reverse to the polarity of an input voltage. An oscillation circuit generates and outputs a clock signal. The oscillation circuit cyclically fluctuates a frequency of the clock signal within a predetermined fluctuation range. Thereby, EMI noise generated corresponding to the frequency of the clock signal for driving the charge pump is reduced.

Abstract: A normally operable decoder circuit is obtained without entailing a delay in decoding operation, an increase in circuit area, and an increase in circuit design cost. An NMOS transistor in a high-voltage circuit portion is inserted between the output of a NAND gate and a node, and receives an input signal at the gate electrode thereof. A load current generating portion in the high-voltage circuit portion includes PMOS transistors coupled in series between a high power supply voltage and the node. One of the PMOS transistor receives a control signal at the gate electrode thereof. The other PMOS transistor receives a control signal at the gate electrode thereof. An inverter receives a signal obtained from the node as an input signal, and outputs the inverted signal thereof as an output signal.

Abstract: A normally operable decoder circuit is obtained without entailing a delay in decoding operation, an increase in circuit area, and an increase in circuit design cost. An NMOS transistor in a high-voltage circuit portion is inserted between the output of a NAND gate and a node, and receives an input signal at the gate electrode thereof. A load current generating portion in the high-voltage circuit portion includes PMOS transistors coupled in series between a high power supply voltage and the node. One of the PMOS transistor receives a control signal at the gate electrode thereof. The other PMOS transistor receives a control signal at the gate electrode thereof. An inverter receives a signal obtained from the node as an input signal, and outputs the inverted signal thereof as an output signal.

Abstract: A normally operable decoder circuit is obtained without entailing a delay in decoding operation, an increase in circuit area, and an increase in circuit design cost. An NMOS transistor in a high-voltage circuit portion is inserted between the output of a NAND gate and a node, and receives an input signal at the gate electrode thereof. A load current generating portion in the high-voltage circuit portion includes PMOS transistors coupled in series between a high power supply voltage and the node. One of the PMOS transistor receives a control signal at the gate electrode thereof. The other PMOS transistor receives a control signal at the gate electrode thereof. An inverter receives a signal obtained from the node as an input signal, and outputs the inverted signal thereof as an output signal.

Abstract: A normally operable decoder circuit is obtained without entailing a delay in decoding operation, an increase in circuit area, and an increase in circuit design cost. An NMOS transistor in a high-voltage circuit portion is inserted between the output of a NAND gate and a node, and receives an input signal at the gate electrode thereof. A load current generating portion in the high-voltage circuit portion includes PMOS transistors coupled in series between a high power supply voltage and the node. One of the PMOS transistor receives a control signal at the gate electrode thereof. The other PMOS transistor receives a control signal at the gate electrode thereof. An inverter receives a signal obtained from the node as an input signal, and outputs the inverted signal thereof as an output signal.

Abstract: A normally operable decoder circuit is obtained without entailing a delay in decoding operation, an increase in circuit area, and an increase in circuit design cost. An NMOS transistor in a high-voltage circuit portion is inserted between the output of a NAND gate and a node, and receives an input signal at the gate electrode thereof. A load current generating portion in the high-voltage circuit portion includes PMOS transistors coupled in series between a high power supply voltage and the node. One of the PMOS transistor receives a control signal at the gate electrode thereof. The other PMOS transistor receives a control signal at the gate electrode thereof. An inverter receives a signal obtained from the node as an input signal, and outputs the inverted signal thereof as an output signal.

Abstract: A normally operable decoder circuit is obtained without entailing a delay in decoding operation, an increase in circuit area, and an increase in circuit design cost. An NMOS transistor in a high-voltage circuit portion is inserted between the output of a NAND gate and a node, and receives an input signal at the gate electrode thereof. A load current generating portion in the high-voltage circuit portion includes PMOS transistors coupled in series between a high power supply voltage and the node. One of the PMOS transistor receives a control signal at the gate electrode thereof. The other PMOS transistor receives a control signal at the gate electrode thereof. An inverter receives a signal obtained from the node as an input signal, and outputs the inverted signal thereof as an output signal.

Abstract: After data writing is performed by injecting electrons into a floating gate from a semiconductor substrate of a memory cell, the gate voltage is set at ?3 V, and the source voltage, the drain voltage and the substrate voltage are set at 0 V, thereby detrapping the electrons trapped in an oxide film during data writing. The gate voltage (?3 V) is set at a negative voltage value that is smaller in absolute value than the gate voltage (?10.5 V) applied during data erasing.

Abstract: In a bit line reference potential (VBL) generating circuit, a pad is connected via a transfer gate to a reference node in a reference stage. During a device evaluation test, the transfer gate is turned on in response to a test signal so that a voltage is applied to the reference node with a tester driver via the pad to control a potential of an output node in an output stage. Thus, the semiconductor memory device is capable of stably controlling the bit line reference potential VBL regardless of the drivability of the tester driver during the device evaluation test.

Abstract: In a bit line reference potential (VBL) generating circuit, a pad is connected via a transfer gate to a reference node in a reference stage. During a device evaluation test, the transfer gate is turned on in response to a test signal so that a voltage is applied to the reference node with a tester driver via the pad to control a potential of an output node in an output stage. Thus, the semiconductor memory device is capable of stably controlling the bit line reference potential VBL regardless of the drivability of the tester driver during the device evaluation test.