Mitsubishi Denki Kabushiki Kaisha

Alps Electric Co., Ltd.

Renesas Technology Corp.

Mitsubishi Electric Engineering Company, Limited

Secom Co., Ltd.

Hideki Miyake

Shin Kinouchi

Nobuyuki Ichimiya

Takahiro Yashita

Keisuke Kawakita

Toshitaka Toyomi

Hideki Arimoto

Daisuke Takai

Takehiko Umeyama

Yukio Kodama

Shinichi Sasagawa

Seishi Namioka

Tsutomu Kamifuji

Akira Ohmichi

Chikao Makita

Seisi Namioka

One circuit generates a constant positive potential, another circuit generates a constant negative potential. The positive potential and the negative potential are applied to a magneto-resistive head that reads data from and writes data to a magnetic disk. The positive potential is generated using a positive voltage source, an operational amplifier, and an NMOS transistor. The negative potential is generated using a negative voltage source, an operational amplifier, and a PMOS transistor.

Low impedance semiconductor integrated circuit

A semiconductor device includes a power transistor group and a signal circuit on the same substrate. The substrate is grounded at an isolation region at an end of the substrate adjacent to the power transistor group so that the grounded portion of the substrate is distant from the signal circuit.

Inductive load driving and control circuits inside isolation regions

An alarm tag releasing device is provided for a theft monitoring device. The theft monitoring device has a gate installed in a desired position and producing a theft monitoring region of a predetermined range by transmitting radio waves at a predetermined wavelength. A buzzer tag is attached to a protected item by a built-in lock mechanism so as not to be detached, and an alarm circuit operated by a built-in battery to sound an alarm when the radio waves at the predetermined wavelength are received when the buzzer tags enters the monitoring region, said alarm tag releasing device comprising: an insertion part having a shape corresponding to the outer diameter of the buzzer tag and into which the buzzer tag can be inserted, such that the lock mechanism provided in the buzzer tag is unlocked when the buzzer tag is inserted into the insertion part.

Magnetic alarm tag releasing device for a theft monitoring device

A portable anti-theft monitor comprises a case; a detection conductive wire led out of said case, having a loop portion; an engaging member provided in said case so as to freely get it in and out, for engaging by catching the loop portion of said detection conductive wire in a state in which it has been pressed in said case; and a locking member for locking said engaging member in the state in which said engaging member has been pressed into said case, and for being attracted by a magnet to be moved in the unlocking direction.

Portable wire loop anti theft alarm with magnetic unlocking

An amplifying circuit includes a first amplifier having a first input terminal, a second input terminal, and an output terminal for pushing an output current; a second amplifier having a first input terminal, a second input terminal, and an output terminal for pulling an output current; a circuit for detecting the output current of an operational amplifier in the second amplifier; and an offset voltage generating circuit for generating an offset voltage. In the amplifying circuit, the offset voltage is applied between the first input terminal of the first amplifier and the first input terminal of the second amplifier, the first input terminal of the first amplifier is connected to a first input signal terminal, the second input terminal of the first amplifier and the second input terminal of the second amplifier are connected to the second input signal terminal, and the output terminal of the first amplifier and the output terminal of the second amplifier are connected to each other, and the amplifying circuit supplies an output current from the connecting point. The amplifying circuit reduces the power consumption caused by the offset voltage of an operational amplifier and a relative error of the resistance value of resistors used in the circuit when no signal is input, and reduces the cross-over distortion of an output signal.

Amplifying circuit using offset value variable circuit

A semiconductor integrated circuit device for driving a motor and including a p-type semiconductor substrate having spaced apart first and second areas; power transistors in the semiconductor substrate within the first area; a small signal system circuit in the semiconductor substrate within the second area; and an n-type isolating region in the semiconductor substrate separated from the first and second areas and disposed at least partially between the first and second areas, the n-type isolating region being connected to ground.

Semiconductor device for a motor driving circuit

A variable gain amplifier circuit includes four transistors. The pair of first and third transistors and the other pair of second and fourth transistors are provided with signals (V.sub.A, V.sub.C) and (V.sub.B, B.sub.D), respectively, which are obtained through application of the first and second biases to the differential input signals. Then, both pairs perform a differential operation in response to the respective signals applied thereto. On the other hand, in the pair of first and second transistors and the other pair of third and fourth transistors, each pair divides a current which is provided thereto between respective transistors. Differential output signals can be obtained from the pair of second and fourth transistors, and a gain thereof can be controlled according to the current flowing through the first and third transistors. As compared with the prior art, the number of transistors which are connected in series is reduced by one, so that signals to be processed becomes larger by a collector-emitter saturation voltage of the transistor.

Differential amplifier circuit having reduced power supply voltage

There is disclosed an amplifier circuit wherein a first differential amplifier consisting of an I/O circuit (11) and a constant-current circuit (31) and a second differential amplifier consisting of an I/O circuit (12) and a constant-current circuit (32) are connected to both first and second input terminals (1, 2), and current synthesizing circuits (21 to 24) synthesize the signals output from the first and second differential amplifiers to apply the synthesized signal to a current-to-voltage converter circuit (9), and wherein a clamp circuit (51) inhibits the operation of the first differential amplifier when the input signals at the input terminals (1, 2) are not less than (V.sub.cc -V.sub.sat), and a clamp circuit (52) inhibits the operation of the second differential amplifier when the input signals at the input terminals (1, 2) is not more than V.sub.sat. The second and first amplifiers substantially process the input signals which deviate from first and second ranges, respectively, to apply the output signal to the output terminal, thereby achieving the amplifier circuit having a wide input signal potential range.

Amplifier circuit

In a sampling mode, a servo signal sampling and holding switch (4.sub.a) and a reference voltage sampling and holding switch (30.sub.a) are turned off, so that transistors (Q.sub.7a, Q.sub.5a) are turned on. In response to on states of the transistors (Q.sub.7a, Q.sub.5a), capacities (C.sub.3a, C.sub.30a) are charged with the peak voltage (V.sub.ref +(1/2)V.sub.s) of a servo signal and a reference voltage (V.sub.ref), respectively. In a holding mode, the sampling and holding switches (4.sub.a, 30.sub.a) are turned on, so that the transistors (Q.sub.7a, Q.sub.5a) are turned off. the charging voltages (D, E) of the capacitors (C.sub.3a, C.sub.30a) are discharged through post-stage buffers (5.sub.a, 3.sub.a), so that they include offsets which are canceled through a subtractor (6.sub.a).

Growing community of inventors

Tokyo, Japan

Hideki Miyake