Abstract: A synchronous motor including therein a three-phase inverter and position sensors, having a unit for calculating a digital input current value from the analog output of an input current detection circuit that detects the input current flowing into the DC input terminal of the three-phase inverter, and a digital feedback speed control unit for adjusting the amplitudes and frequency of the AC voltages outputted from the three-phase inverter in such a manner that the motor speed calculated by a motor speed calculation unit 41 on the basis of the outputs of the position sensors approaches a speed command value received by a communication reception unit from outside the synchronous motor. The synchronous motor further includes therein a communication transmission unit for transmitting the input current value and the motor speed to outside the synchronous motor.

Abstract: The semiconductor device includes: a base; a first mount placed on the bottom of the base; a second mount placed on the top of the base; a first light-emitting element placed on the bottom of the first mount; and a second light-emitting element placed on the top of the second mount for emitting light. The first light-emitting element and the second light-emitting element are placed so that the emission direction of light from the second light-emitting element is at an angle of depression with respect to the emission direction of light from the first light-emitting element and that the emission direction of light from the first light-emitting element and the emission direction of light from the second light-emitting element substantially coincide with each other as viewed from above the base.

Abstract: The synchronous motor driving apparatus including position sensors provided in the synchronous motor, a current polarity detection circuit for detecting the polarities of the currents in the respective phase windings of the synchronous motor, an inverter driving the synchronous motor, a motor speed calculation unit calculating the rotational speed of the synchronous motor depending on the output signals from the position sensors, a speed control unit outputting a first voltage adjusting component (q-axis current command value Iq*) to cause the rotational speed of the synchronous motor to approach a speed command value and a phase control unit outputting a second voltage adjusting component (d-axis current command value Id*) to cause the phase differences between the phases of the position sensor signals and of the currents in the respective phase windings of the synchronous motor to become a predetermined value.

Abstract: The synchronous motor driving apparatus including position sensors provided in the synchronous motor, a current polarity detection circuit for detecting the polarities of the currents in the respective phase windings of the synchronous motor, an inverter driving the synchronous motor, a motor speed calculation unit calculating the rotational speed of the synchronous motor depending on the output signals from the position sensors, a speed control unit outputting a first voltage adjusting component (q-axis current command value Iq*) to cause the rotational speed of the synchronous motor to approach a speed command value and a phase control unit outputting a second voltage adjusting component (d-axis current command value Id*) to cause the phase differences between the phases of the position sensor signals and of the currents in the respective phase windings of the synchronous motor to become a predetermined value.

Abstract: In order to prevent a short circuit of top and bottom arms of a motor driving IC when noise is added to six control signals for controlling six switching elements, there is provided a semiconductor device for driving a motor, being sealed with resin as one package and comprising: six switching elements for driving a three-phase motor; three output terminals for outputting voltages to the three-phase motor; at least one driving circuit for driving the six switching elements; three control signal input terminals; and a function) of generating six control signals for control of the six switching elements based on three control signals inputted through the three control signal input terminals.

Abstract: The synchronous motor driving apparatus including position sensors provided in the synchronous motor, a current polarity detection circuit for detecting the polarities of the currents in the respective phase windings of the synchronous motor, an inverter driving the synchronous motor, a motor speed calculation unit calculating the rotational speed of the synchronous motor depending on the output signals from the position sensors, a speed control unit outputting a first voltage adjusting component (q-axis current command value Iq*) to cause the rotational speed of the synchronous motor to approach a speed command value and a phase control unit outputting a second voltage adjusting component (d-axis current command value Id*) to cause the phase differences between the phases of the position sensor signals and of the currents in the respective phase windings of the synchronous motor to become a predetermined value.

Abstract: The semiconductor device includes: a base; a first mount placed on the bottom of the base; a second mount placed on the top of the base; a first light-emitting element placed on the bottom of the first mount; and a second light-emitting element placed on the top of the second mount for emitting light. The first light-emitting element and the second light-emitting element are placed so that the emission direction of light from the second light-emitting element is at an angle of depression with respect to the emission direction of light from the first light-emitting element and that the emission direction of light from the first light-emitting element and the emission direction of light from the second light-emitting element substantially coincide with each other as viewed from above the base.

Abstract: A synchronous motor including therein a three-phase inverter and position sensors, having a unit for calculating a digital input current value from the analog output of an input current detection circuit that detects the input current flowing into the DC input terminal of the three-phase inverter, and a digital feedback speed control unit for adjusting the amplitudes and frequency of the AC voltages outputted from the three-phase inverter in such a manner that the motor speed calculated by a motor speed calculation unit 41 on the basis of the outputs of the position sensors approaches a speed command value received by a communication reception unit from outside the synchronous motor. The synchronous motor further includes therein a communication transmission unit for transmitting the input current value and the motor speed to outside the synchronous motor.

Abstract: A semiconductor element 22 is mounted on a stem 24 where a flat surface serving as the mounting part of the semiconductor element 22 is provided on a part of a cylindrical part, and the stem 24 is inserted and hermetically sealed into a cap 25 such that the cylindrical part comes into contact with the cap 25. The size of the cylindrical shape of the stem 24 is minimized as a width of the mounting part so large as to mount the semiconductor element 22. Thus it is possible to achieve high heat dissipation and reduce the thickness of a semiconductor device 100, and further reduce the sizes of an optical pickup device and an optical disk drive unit.

Abstract: In order to prevent a short circuit of top and bottom arms of a motor driving IC when noise is added to six control signals for controlling six switching elements, there is provided a semiconductor device for driving a motor, being sealed with resin as one package and comprising: six switching elements for driving a three-phase motor; three output terminals for outputting voltages to the three-phase motor; at least one driving circuit for driving the six switching elements; three control signal input terminals; and a function) of generating six control signals for control of the six switching elements based on three control signals inputted through the three control signal input terminals.

Abstract: The synchronous motor driving apparatus including position sensors provided in the synchronous motor, a current polarity detection circuit for detecting the polarities of the currents in the respective phase windings of the synchronous motor, an inverter driving the synchronous motor, a motor speed calculation unit calculating the rotational speed of the synchronous motor depending on the output signals from the position sensors, a speed control unit outputting a first voltage adjusting component (q-axis current command value Iq*) to cause the rotational speed of the synchronous motor to approach a speed command value and a phase control unit outputting a second voltage adjusting component (d-axis current command value Id*) to cause the phase differences between the phases of the position sensor signals and of the currents in the respective phase windings of the synchronous motor to become a predetermined value.