Abstract: A T/R switch applicable to an ultrasonograph and capable of transmitting a signal reflected from a living body over a wide band with low noise without causing erroneous operation of the switch or element destruction even when the potential of a transmission signal or reflected signal changes includes: a common source terminal commonly and serially coupling the source terminals of two MOS transistors; a common gate terminal commonly coupling the gate terminals of the two MOS transistors; a main switch, the drain terminals of which are connected to input/output terminals; and a floating voltage circuit which is connected to the common gate terminal and common source terminal, makes the common gate terminal potential follow, in phase, variation in the common source terminal potential, and sends a signal to turn the switch on or off to the common gate terminal.

Abstract: A T/R switch applicable to an ultrasonograph and capable of transmitting a signal reflected from a living body over a wide band with low noise without causing erroneous operation of the switch or element destruction even when the potential of a transmission signal or reflected signal changes includes: a common source terminal commonly and serially coupling the source terminals of two MOS transistors; a common gate terminal commonly coupling the gate terminals of the two MOS transistors; a main switch, the drain terminals of which are connected to input/output terminals; and a floating voltage circuit which is connected to the common gate terminal and common source terminal, makes the common gate terminal potential follow, in phase, variation in the common source terminal potential, and sends a signal to turn the switch on or off to the common gate terminal.

Abstract: There is provided a circuit whose output is free from high impedance to improve wrong transmission and waveform overshoot, realizing a semiconductor integrated circuit device in which plural channels is integrated with transmitter circuit as unit channel, in the transmitter circuit used in a medical ultrasound system and drives a transducer by voltage pulses having plural positive and negative electric potentials including ground potential. The transmitter circuit includes a conventional pulse generating circuit supplied with positive and negative voltage largest in absolute value, a P-channel analog switching pulse generating circuit supplied with positive voltage being the second largest therein, an N-channel analog switching pulse generating circuit supplied with negative voltage being the second largest, and an N-channel analog switching ground level damping circuit supplied with ground potential. The circuits are connected to output terminal.

Abstract: In a semiconductor integrated circuit device generating internal power from external power, an abnormal operation may occur due to an indefinite state of a control signal when the external power is applied and the internal power rises. The semiconductor integrated circuit includes an internal power generating circuit, a control circuit receiving internal power and supplying a first control signal, and a power-on reset circuit generating a reset signal at rising of the internal power. When internal power rises, the reset signal masks an indefinite state of the first control signal supplied from the control circuit.

Abstract: There is provided a circuit whose output is free from high impedance to improve wrong transmission and waveform overshoot, realizing a semiconductor integrated circuit device in which plural channels is integrated with transmitter circuit as unit channel, in the transmitter circuit used in a medical ultrasound system and drives a transducer by voltage pulses having plural positive and negative electric potentials including ground potential. The transmitter circuit includes a conventional pulse generating circuit supplied with positive and negative voltage largest in absolute value, a P-channel analog switching pulse generating circuit supplied with positive voltage being the second largest therein, an N-channel analog switching pulse generating circuit supplied with negative voltage being the second largest, and an N-channel analog switching ground level damping circuit supplied with ground potential. The circuits are connected to output terminal.

Abstract: In a protection circuit for protecting semiconductor integrated circuit devices from an electrostatic breakdown or a latch-up due to an external surge, etc, a drain terminal of a PMOS transistor MP1, having a source terminal connected to a power supply VDD and a gate terminal receiving a control signal VG1 which a control circuit 2 generates on the basis of a power supply GND, is connected to one end of a resistor R1, having the other end connected to the power supply GND, and to a gate terminal of an NMOS transistor MN1 having a drain terminal and a source terminal connected to the power supply VDD and the power supply GND, respectively, and outputs an internal signal VG2 to the gate terminal of the NMOS transistor. When a predetermined voltage or more is applied to the power supply, the power supply is short-circuited.

Abstract: In a semiconductor integrated circuit device generating internal power from external power, an abnormal operation may occur due to an indefinite state of a control signal when the external power is applied and the internal power rises. The semiconductor integrated circuit includes an internal power generating circuit, a control circuit receiving internal power and supplying a first control signal, and a power-on reset circuit generating a reset signal at rising of the internal power. When internal power rises, the reset signal masks an indefinite state of the first control signal supplied from the control circuit.

Abstract: A reproducing circuit for magnetic disks wherein a MR head bias voltage does not exceed the specified value during any malfunction of the power supply voltage including the cases of power supply ON/OFF, and the central voltage of the MR head is controlled to the ground. The reproducing circuit for magnetic disk apparatus is composed of a MR head, a bias circuit that provides bias voltage specified relative to the MR head, an amplifying circuit for amplifying the output signals of the MR head, a power supply voltage monitor circuit that monitors the changes in the power supply voltage, and a control circuit that is controlled by the power supply voltage monitor circuit. MR bias voltage does not exceed the specified value during any malfunction of the power supply voltage including the cases of power supply ON/OFF, and the central voltage of the MR head is controlled to the ground such that the MR head is protected.

Abstract: The storage media recording/writing system includes a media drive circuit, a head retaining means, a head moving means, a head drive circuit, a signal processing circuit, and a controller to control these. The head drive circuit possesses a first semiconductor integrated circuit having an amplifier that amplifies the read signal from the head, and a second semiconductor integrated circuit placed between the first semiconductor integrated circuit and the signal processing circuit, which has a circuit that receives write data from the signal processing circuit and generates a drive signal to drive a write head. Further, the first semiconductor integrated circuit is mounted on a part near the front of the head retaining means, and the second semiconductor integrated circuit is installed on the side of the moving means.

Abstract: A magnetic disk apparatus-purpose reproducing circuit capable of performing a high speed and under stable condition. In the magnetic disk apparatus-purpose reproducing circuit equipped with: a bias circuit for applying a bias voltage with respect to an MR (Magneto-Resistive) head, an amplification circuit for amplifying an output of the MR head, capacitors C0 and C1 for cutting a DC component contained in the output of the MR head, and a conductor amplifier for applying an input bias of the amplifier, a shortcircuit-purpose switch S0 for charging the DC cut capacitors are further provided. When a mode transition from a write mode to a read mode occurs, the shortcircuit-purpose switch S0 is turned ON so as to charge the DC cut capacitors, so that a mode transition characteristic capable of establishing a high speed characteristic and a stable characteristic can be obtained.

Abstract: The storage media recording/writing system includes a media drive circuit, a head retaining means, a head moving means, a head drive circuit, a signal processing circuit, and a controller to control these. The head drive circuit possesses a first semiconductor integrated circuit having an amplifier that amplifies the read signal from the head, and a second semiconductor integrated circuit placed between the first semiconductor integrated circuit and the signal processing circuit, which has a circuit that receives write data from the signal processing circuit and generates a drive signal to drive a write head. Further, the first semiconductor integrated circuit is mounted on a part near the front of the head retaining means, and the second semiconductor integrated circuit is installed on the side of the moving means.

Abstract: The storage media recording/writing system includes a media drive circuit, a head retaining means, a head moving means, a head drive circuit, a signal processing circuit, and a controller to control these. The head drive circuit possesses a first semiconductor integrated circuit having an amplifier that amplifies the read signal from the head, and a second semiconductor integrated circuit placed between the first semiconductor integrated circuit and the signal processing circuit, which has a circuit that receives write data from the signal processing circuit and generates a drive signal to drive a write head. Further, the first semiconductor integrated circuit is mounted on a part near the front of the head retaining means, and the second semiconductor integrated circuit is installed on the side of the moving means.

Abstract: The storage media recording/writing system includes a media drive circuit, a head retaining means, a head moving means, a head drive circuit, a signal processing circuit, and a controller to control these. The head drive circuit possesses a first semiconductor integrated circuit having an amplifier that amplifies the read signal from the head, and a second semiconductor integrated circuit placed between the first semiconductor integrated circuit and the signal processing circuit, which has a circuit that receives write data from the signal processing circuit and generates a drive signal to drive a write head. Further, the first semiconductor integrated circuit is mounted on a part near the front of the head retaining means, and the second semiconductor integrated circuit is installed on the side of the moving means.