Fujitsu Corporation

Yuzo Usui

Noriyuki Matsui

Yasuhiro Arai

Makoto Suwada

Masaki Tosaka

Kazunori Kasuga

Shuichi Inoue

Masao Matsuda

A noise elimination method is characterized in that when transmitting signals in the same direction on at least two distributed constant lines, a resistance of a terminating resistor at a far-end is set so that voltages propagated to the far-end become equal between two kinds of propagation modes on coupled distributed constant lines. The two kinds of propagation modes are a common mode which propagates with respect to a ground plane and a differential mode which propagates between the coupled lines.

Noise elimination method and transmission circuit

An IC card-type radio communication device includes a main body of equipment, a storage unit, a sound input unit, a sound output unit and a modulation-demodulation unit. The main body of equipment has an interface which is in accordance with a predetermined standard and forms a physical shape which is in accordance with the standard. The main body of equipment is inserted into an entry installed on an external terminal unit. The storage unit is installed on the main body of equipment and stores an attribute information and an information necessary for data communication with the terminal unit. The sound input unit inputs a sound signal when a conversation is executed and the sound output unit outputs the sound signal. The modulation-demodulation unit modulates and demodulates data of the terminal unit on the basis of the information stored in the storage unit when the main body of equipment is inserted into the entry installed on the terminal unit, and modulates and demodulates the sound signal when the conversation is executed.

IC card-type radio communication device

A LCD driving circuit drives a LCD panel having a data electrode and a common electrode by applying a periodically inverted signal to the common electrode. The LCD driving circuit includes a parallel resonant circuit which has a static capacitance of the LCD panel and is coupled to the common electrode and ground. The parallel resonant circuit has a parallel resonance frequency equal to a frequency of the signal applied to the common electrode.

Liquid crystal display driving circuit and liquid crystal display having

A power supply noise eliminating method eliminates power supply noise in a semiconductor integrated circuit having a plurality of first terminals coupled to a first power supply voltage and one or a plurality of second terminals coupled to a second power supply voltage which is different from the first power supply voltage. The power supply noise eliminating method includes the steps of (a) supplying the first power supply voltage to one of the first terminals, and (b) supplying the second power supply voltage to another one of the first terminals via an impedance circuit, thereby eliminating the power supply noise with respect to at least the first power supply voltage.

Power supply noise eliminating method and semiconductor device

A memory drive circuit includes at least one memory module constructed of a plurality of memory elements, a memory controller for driving said memory module, and a buffer, disposed between the memory module and the memory controller, for receiving a drive signal from the memory controller and transmitting the received drive signal to the memory module. Signal reflection noises produced in the memory module are absorbed by the buffer.

Waveform stabilizing drive circuit for modularized memory

A memory device having a memory element including a plurality of memory cells each designated by a row address signal and a column address signal, and a circuit for detecting a transition between the row address signal and the column address signal to thereby effect an equalize operation on the memory element. The supply of a row/column address signal including the row address signal and the column address signal to the memory element is cut off during a logical indeterminate period at the time of the transition. The row/column address signal immediately before its cutoff is held and the held signal is supplied to the memory element during the logical indeterminate period. Thus, a high-speed operation can be done by the equalize operation and the cutoff can provide the prevention of occurrence of a malfunction due to noise such as a glitch or the like.

Memory device and memory control circuit

A constant current circuit having an output current I.sub.2 which changes with the change of the power source voltage V.sub.cc, and an oscillating circuit whose oscillation frequency is made variable by the change of I.sub.2 in the constant current circuit. The constant current circuit comprises bipolar transistors coupled to form a differential amplifier, wherein one of the transistors is supplied with a reference voltage and another is supplied with a divided voltage of V.sub.cc, and a resistor connecting the emitters of the transistors is provided for controlling the slope of the V.sub.cc -I.sub.2 characteristic curve of the constant current circuit. The oscillating circuit comprises a capacitor charged with I.sub.2 and a switching circuit for discharging the capacitor when it is closed and a voltage detecting circuit operating to close or open the switching circuit according to the detection of the voltage at an end of the capacitor. Thus, the switching circuit operates on and off to generate pulses with frequency depending on I.sub.2, hence, depending on V.sub.cc. Methods for controlling the frequency range of the oscillating circuit and the rise time to fall time ratio of the pulses by introducing additional constant current supplying sources are also disclosed.

Constant current circuit and an oscillating circuit controlled by the

A delay element is introduced into a transistor-transistor logic circuit having a totem-pole-connected inverter transistor and an off-buffer transistor, in order to ensure a safe and correct operation even in the case where the transistor-transistor logic circuit is used as an element of multiple-connected transistor-transistor logic circuits.

Growing community of inventors

Kawasaki, Japan

Yuzo Usui