Abstract: An input transistor unit includes a first transistor having a control electrode to which a reference voltage is supplied. An output transistor unit includes a diode-connected second transistor. At least one of the input transistor unit and the output transistor unit further includes a third transistor that is diode-connected and connected in series with the corresponding first transistor or the second transistor and outputs a current in the same direction as the corresponding transistor does. The number of transistors included in the input transistor unit and the number of transistors included in output transistor unit are different from each other. The size of transistors included in the input transistor unit differs from that of transistors included in the output transistor unit.

Abstract: A member for a push-button switch has key top members positioned close to each other through a distance of 1.5 mm or shorter at low cost and with high yield. The member has multiple key top members having resin key top cores and thermoplastic films covering the key top cores other than the lower surfaces thereof. The key top members are formed so that an interval between at least one set of adjacent key top members is 1.5 mm or shorter. In the key top members adjacent to each other through a distance of 1.5 mm or shorter, the maximum thickness of the thermoplastic films covering the key top cores is within the range of 75 to 350 ?, and the ratio of the minimum thickness of the thermoplastic films covering the key top cores to the maximum thickness is within the range of 0.4 to 0.9.

Abstract: A member for a push-button switch has key top members positioned close to each other through a distance of 1.5 mm or shorter at low cost and with high yield. The member has multiple key top members having resin key top cores and thermoplastic films covering the key top cores other than the lower surfaces thereof. The key top members are formed so that an interval between at least one set of adjacent key top members is 1.5 mm or shorter. In the key top members adjacent to each other through a distance of 1.5 mm or shorter, the maximum thickness of the thermoplastic films covering the key top cores is within the range of 75 to 350?, and the ratio of the minimum thickness of the thermoplastic films covering the key top cores to the maximum thickness is within the range of 0.4 to 0.9.

Abstract: An input transistor unit includes a first transistor having a control electrode to which a reference voltage is supplied. An output transistor unit includes a diode-connected second transistor. At least one of the input transistor unit and the output transistor unit further includes a third transistor that is diode-connected and connected in series with the corresponding first transistor or the second transistor and outputs a current in the same direction as the corresponding transistor does. The number of transistors included in the input transistor unit and the number of transistors included in output transistor unit are different from each other. The size of transistors included in the input transistor unit differs from that of transistors included in the output transistor unit.

Abstract: A key top member for a push button switch structure capable of facilitating change and modification of a design while eliminating deformation and misregistration of a display section, being accommodated to a variety of data, being increased in design properties and visibility, and being reduced in manufacturing cost. An upper resin sheet made of thermoplastic resin and having display sections such as a letter, a symbol, a pattern or the like printed thereon is formed with projections having configurations conforming to outer configurations of key top elements. The projections are each securely provided therein with a filler member made of photo-setting resin directly or through an adhesive.

Abstract: A manner of generating internal voltages such as a high voltage, an intermediate voltage and an internal power supply voltage is switched in accordance with a power supply level setting signal. When the voltage level of an external power supply voltage is low, a current drive transistor receiving an output of a comparing circuit and an auxiliary drive transistor are forcedly set in a conductive state, and external power supply voltage is transmitted on an internal power supply line. At this time, the comparing operation of the comparing circuit is stopped. When the level of the external power supply voltage is high, the comparing circuit is activated down convert the external power supply voltage for generating a peripheral power supply voltage on the internal power supply line.

Abstract: Data pad regions are arranged in four divided regions of a semiconductor memory chip of a rectangular shape, respectively, and data pads are selectively utilized in each of the four divided regions in accordance with a word structure. Thus, it is possible to implement a semiconductor memory chip capable of being assembled in both a single chip package and a multi chip package.

Abstract: The semiconductor memory device includes a refresh timer for determining a refresh cycle of self-refresh operation. The refresh timer includes a voltage regulator, a ring oscillator and a counter. The voltage regulator generates a bias voltage having positive temperature characteristics. The ring oscillator varies an oscillation cycle of a pulse signal according to the bias voltage. The counter counts a prescribed number of pulse signals and generates a refresh signal for executing refresh operation. The semiconductor memory device thus varies the refresh cycle according to a temperature change, and executes refresh operation with an appropriate refresh cycle.

Abstract: A row address decoder of a semiconductor memory device generates internal row address signals RAD<0:11> and /RAD<0:11> by switching most significant bit and least significant bit of row address signals RA<0:11> and /RA<0:11> that correspond to address signals A0 to A11, respectively. In a twin cell mode, the least significant bits RAD<0> and /RAD<0> of the internal row address signals corresponding to the most significant bits RA<11> and /RA<11> of the row address signal that are not used are selected simultaneously by row address decoder, and two adjacent word lines are activated simultaneously. Consequently, the configuration of memory cell in the semiconductor memory device can electrically be switched from the normal single memory cell type to the twin memory cell type.

Abstract: A clock buffer of a DRAM includes: a first NAND gate which is driven by a first internal power supply voltage (2.5 V) and which determines the level of an input clock signal if the DRAM is used for a TTL-system interface (MLV=2.5 V); and a second NAND gate which is driven by a second internal power supply voltage (1.8 V) and which determines the level of the input clock signal if the DRAM is used for a 1.8 V-system interface (MLV=0 V). Accordingly, in each of the first and second NAND gates, sizes of four MOS transistors can be set at optimum values, respectively.

Abstract: A semiconductor memory device includes banks, predecoders, a latch circuit, a counter, a fuse and buffers. The bank includes a plurality of memory cells arranged in rows and columns, and others. The predecoders are disposed in a central portion of the semiconductor memory device. The predecoder produces a predecode signal for selecting each of the banks based on a bank address received from the buffer, and outputs the predecode signal to the banks. The predecoder produces the predecode signal for selecting each of the banks based on the bank address, and outputs the predecode signal to the banks. Consequently, interconnections in the central portion can be reduced in number.

Abstract: The semiconductor memory device includes a refresh timer for determining a refresh cycle of self-refresh operation. The refresh timer includes a voltage regulator, a ring oscillator and a counter. The voltage regulator generates a bias voltage having positive temperature characteristics. The ring oscillator varies an oscillation cycle of a pulse signal according to the bias voltage. The counter counts a prescribed number of pulse signals and generates a refresh signal for executing refresh operation. The semiconductor memory device thus varies the refresh cycle according to a temperature change, and executes refresh operation with an appropriate refresh cycle.

Abstract: A key top member for a push button switch structure capable of facilitating change and modification of a design while eliminating deformation and misregistration of a display section, being accommodated to a variety of data, being increased in design properties and visibility, and being reduced in manufacturing cost. An upper resin sheet made of thermoplastic resin and having display sections such as a letter, a symbol, a pattern or the like printed thereon is formed with projections having configurations conforming to outer configurations of key top elements. The projections are each securely provided therein with a filler member made of photo-setting resin directly or through an adhesive.

Abstract: Data pad regions are arranged in four divided regions of a semiconductor memory chip of a rectangular shape, respectively, and data pads are selectively utilized in each of the four divided regions in accordance with a word structure. Thus, it is possible to implement a semiconductor memory chip capable of being assembled in both a single chip package and a multi chip package.

Abstract: A row address decoder of a semiconductor memory device generates internal row address signals RAD<0:11>and /RAD<0:11>by switching most significant bit and least significant bit of row address signals RA<0:11>and /RA<0:11>that correspond to address signals A0 to A11, respectively. In a twin cell mode, the least significant bits RAD<0>and /RAD<0>of the internal row address signals corresponding to the most significant bits RA<11>and /RA<11>of the row address signal that are not used are selected simultaneously by row address decoder, and two adjacent wold lines are activated simultaneously. Consequently, the configuration of memory cell in the semiconductor memory device can electrically be switched from the normal single memory cell type to the twin memory cell type.

Abstract: A manner of generating internal voltages such as a high voltage, an intermediate voltage and an internal power supply voltage is switched in accordance with a power supply level setting signal. When the voltage level of an external power supply voltage is low, a current drive transistor receiving an output of a comparing circuit and an auxiliary drive transistor are forcedly set in a conductive state, and external power supply voltage is transmitted on an internal power supply line. At this time, the comparing operation of the comparing circuit is stopped. When the level of the external power supply voltage is high, the comparing circuit is activated down convert the external power supply voltage for generating a peripheral power supply voltage on the internal power supply line.

Abstract: A clock buffer of a DRAM includes: a first NAND gate which is driven by a first internal power supply voltage (2.5 V) and which determines the level of an input clock signal if the DRAM is used for a TTL-system interface (MLV=2.5 V); and a second NAND gate which is driven by a second internal power supply voltage (1.8 V) and which determines the level of the input clock signal if the DRAM is used for a 1.8 V-system interface (MLV=0 V). Accordingly, in each of the first and second NAND gates, sizes of four MOS transistors can be set at optimum values, respectively.

Abstract: Pad lines are placed on the peripheral region of a chip along EAST band and WEST band (E/W band). In order to allow the chip with pads arranged on the peripheral region to be adaptable to a TSOP, VDD and VSS pads are arranged on the edge region on NORTH band and SOUTH band (N/S band) near the center of the N/S band. Moreover, in consideration of frame design for the TSOP, some pads on the ends of the pad lines among the pads included in the pad lines are arranged in reverse order relative to the order of pins. Further, VDDQ and VSSQ pads are arranged in the same order as that of pins for a package which requires no consideration of frame design. On the other hand, for use in a BGA package, VDD and VSS pads are arranged in pairs at respective ends of the pad lines. A semiconductor memory device with this pad arrangement is accordingly adaptable to various types of packages.

Abstract: A key top member for a push button switch structure capable of facilitating change and modification of a design while eliminating deformation and misregistration of a display section, being accommodated to a variety of data, being increased in design properties and visibility, and being reduced in manufacturing cost. An upper resin sheet made of thermoplastic resin and having display sections such as a letter, a symbol, a pattern or the like printed thereon is formed with projections having configurations conforming to outer configurations of key top elements. The projections are each securely provided therein with a filler member made of photo-setting resin directly or through an adhesive.

Abstract: Pad lines are placed on the peripheral region of a chip along EAST band and WEST band (E/W band). In order to allow the chip with pads arranged on the peripheral region to be adaptable to a TSOP, VDD and VSS pads are arranged on the edge region on NORTH band and SOUTH band (N/S band) near the center of the N/S band. Moreover, in consideration of frame design for the TSOP, some pads on the ends of the pad lines among the pads included in the pad lines are arranged in reverse order relative to the order of pins. Further, VDDQ and VSSQ pads are arranged in the same order as that of pins for a package which requires no consideration of frame design. On the other hand, for use in a BGA package, VDD and VSS pads are arranged in pairs at respective ends of the pad lines. A semiconductor memory device with this pad arrangement is accordingly adaptable to various types of packages.