Hitachi, Ltd.

Ablic Inc.

Sii Semiconductor Corporation

Hiroyasu Yoshizawa

Satoshi Hanazawa

Yoichiro Kobayashi

Toshio Shinomiya

Shunsuke Kubota

Na Li

Yoshihiro Hayashi

Masaki Yoshinaga

Tatsuya Odawara

Noriyuki Fujii

Kenji Maio

Shinya Kajiyama

Ichiro Somada

Nao Miyamoto

Tetsuhiro Shimizu

Yasuyuki Ookuma

A transmission circuit for ultrasonic diagnosis includes a delay processing circuit that delays a transmission signal pattern and an operational circuit that calculates a delay time. A transmission timing for supplying the transmission signal pattern to a plurality of piezo electric elements corresponding to a plurality of channels is approximated by a multi-dimensional polynomial with locations of the plurality of piezo electric elements being variables so that the transmission timing becomes linear or arc-like. Coefficients in the multi-dimensional polynomial are supplied to the transmission circuit for ultrasonic diagnosis. The delay time in the delay processing circuit is determined by a first coefficient. The operational circuit calculates the delay time based on a second coefficient. The transmission signal pattern is supplied to the plurality of piezo electric elements at a transmission timing including the delay time according to the first coefficient and the delay time according to the second coefficient.

Transmission circuit for ultrasonic diagnosis and method for transmitting ultrasonic wave

An electronic circuit includes a first level shift circuit, a second level shift circuit, an internal circuit, a high voltage circuit, first and second transistors, and first and second protective circuits. The first and second protective circuits perform control the first and second transistors so as to make them non-conductive when at least one of a plurality of types of power supply voltages becomes equal to or less than a predetermined value.

Electronic circuit and semiconductor device

A semiconductor integrated circuit device that has a high-voltage analog switch circuit and is operable at a low power-supply voltage, and which has a first high-voltage MOSFET HN, a second high-voltage MOSFET, and a first floating gate voltage control circuit. The first floating gate voltage control circuit operates at a voltage of 5 V or lower, and when turning on the first high-voltage MOSFET and the second high-voltage MOSFET, the first floating gate voltage control circuit sets a voltage in the source terminal of the first high-voltage MOSFET as a reference voltage, adds a floating voltage corresponding to the power-supply voltage to the reference voltage, and supplies the added voltage to the gate terminals of the first high-voltage MOSFET and the second high-voltage MOSFET.

Semiconductor integrated circuit device

Provided is a switching circuit capable of transmitting a signal with large amplitude and large current while suppressing deterioration when a small-amplitude signal is transmitted. The switching circuitincludes a first terminal a, a second terminal b, a first switch, a second switch, a first separation switch, and a second separation switch. The first switchconnects the first terminal a and the second terminal b according to a control signal. The second switchhas a first node nand a second node n, and connects between the nodes in synchronization with the first switch. The first separation switchtransmits a signal of the first node nto the second node nwhen an electric potential of the first node nis higher than that of the second node nby more than a predetermined electric potential. The second separation switchtransmits a signal of the first node nto the second terminal b when an electric potential of the first node nis higher than an electric potential of the second node nby more than a predetermined electric potential.

Switching circuit and semiconductor integrated circuit device

Provided is a transmission drive circuit which can reduce distortions of a transmission signal and transmission noise, and is isolable from a signal line. A transmission drive circuitincludes a drive transistorand an isolation diodeconnected between a node ncoupled to a signal line SL commonly used to propagate a transmission signal and a reception signal and a power source line HVP, and further includes an isolation diodeand a drive transistorconnected between the node nand a voltage line HVM. Furthermore, the transmission drive circuitincludes a switchconnected between a node nbetween the drive transistorand the isolation diode, and a node nof a ground voltage Vs, and a switchconnected between a node nbetween the drive transistorand the isolation diode, and a node n. When the transmission signal is propagated through the signal line SL, the switchesandare turned off by the clamp switch control circuitsuch that bias current flows through the drive transistor, the isolation diode, the isolation diodeand the drive transistor

Transmission drive circuit and semiconductor integrated circuit device

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.

Switch circuit and semiconductor circuit

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. Switch control signals drive ultrasound transducers by turning on and off the circuits.

Semiconductor integrated circuit device having pulse generating circuits

A semiconductor integrated circuit having a plurality of ultrasound pulsers corresponding to a plurality of respective channels, and integrally formed on a small area. The ultrasound pulsers each include a MOSFET gate drive circuit in which an input voltage pulse is converted into a current pulse, and the current pulse is converted again into a voltage pulse on the basis of a high potential side voltage +HV, and a low potential side voltage &#x2212;HV, applied to a transducer drive circuit, and in which a voltage level shift in the input voltage pulse is attained, and a voltage pulse swing is generated by the MOSFET gate drive circuit on the basis of the high potential side voltage +HV, and the low potential side voltage &#x2212;HV. The MOSFET gate drive circuit is DC-coupled with the transducer drive circuit.

Semiconductor integrated circuit capable of directly coupling low-voltage signals with high-voltage signals

A variable gain amplifier of such configuration that can yield continuously and log-linearly variable gains in relation to control voltage and, at the same time, that does not use an attenuator, an element which otherwise would entail cause of increased noise. The amplifier includes a plurality of gm amplifiers connected in parallel with input signal, exponential multipliers connected respectively to the gm amplifiers, a control section to vary the multiplication coefficient of the exponential multipliers according to the external gain control signal, and an I-V converter circuit to aggregate current output after multiplication and convert the aggregated current output to voltage. A continuously variable gain characteristic can be obtained without the use of an attenuator but by varying multiplication coefficient according to control voltage.

Variable gain amplifier

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.

Storage media reading writing system

The present invention provides a disk storage system with a low error rate, which is suitable for reduction in size. The other end of the signal line, which is connected with a read head at one end, is connected with a head bias circuit to apply a sense current to the read head and a pair of first and second capacitance elements for allowing the read signal element formed by the read head to pass, a loop is provided for amplifying the read signal obtained through the first and second capacitance elements by supplying the read signal to an input terminal of a differential amplifying circuit and for converting the amplified signal into the current by transconductance and providing a positive feedback of the amplified signal to the input terminal of the differential amplifying circuit.

Disk storage systems

A magnetic head driving circuit includes a main driving circuit symmetrical with respect to a centered recording coil, and at least two pairs of adding circuits, each pair including a positive pulse adding circuit and a negative pulse superposed circuit symmetrical with respect to the centered coil. And, by reversing the direction of the magnetic head coil current, at least one of the adding circuits is made to operate and make it as a magnetic head driving circuit for adding a potential equal to or higher than the power supply, thereby to drive as a sub-driving circuit arranged symmetrically with respect to the centered coil, which promotes the reversal of the magnetic head coil current, and which drives stably with a central potential of the coil at about the disk potential.

Growing community of inventors

Ome, Japan

Hiroyasu Yoshizawa