Abstract: A semiconductor integrated circuit including: a substrate of a first conductivity type; a buried insulating film provided on the substrate; an active layer of the first conductivity type provided on the buried insulating film; a first impurity region of a second conductivity type formed within the active layer; an electric field relaxation layer of the second conductivity type formed within the active layer and surrounding the first impurity region; a second impurity region of the first conductivity type formed within the active layer and surrounding the electric field relaxation layer; and a groove formed surrounding the second impurity region and reaching the buried insulating film.

Abstract: A semiconductor amplifier circuit comprises a semiconductor substrate of one conductivity type, a well region of the one conductivity type, formed in said semiconductor substrate, a well region defining region of the other conductivity type, including a side wall portion and a bottom portion defining the well region, a first transistor formed in the well region and a second transistor formed on a surface of another portion of the substrate other than a portion on which the well region is formed. When the first and second transistors are in operation, a potential of the substrate is set to a reference potential, a potential of the well region defining region is set equal to the potential of the substrate or set to a value at which a junction between the well region defining region and the substrate is reverse-biased and at least one of the electrodes of the first transistor is set to a potential at which a junction between the well region defining region and the well region is reverse-biased.

Abstract: A DC-DC converter includes an oscillation circuit for oscillating at a predetermined frequency and generating a pulse with a predetermined pulse width, a reference voltage generating circuit for generating a reference voltage, means mounted in the reference voltage generating circuit for slowly rising the reference voltage, a switching circuit for chopping the current inputted from a DC primary electric power source in accordance with the pulse, and feedback control means for stopping/restarting the oscillation of the oscillation circuit on the basis of the voltage that the output of the switching circuit is smoothed and including the reference voltage with a detection voltage upon stopping control, so that the DC-DC converter having a soft starting function is provided with a simple structure and a compact size without utilizing a PWM circuit and a VCO.

Abstract: A differential amplifier circuit which has a pair of transistors capable of differential operation with a predetermined bias voltage and a predetermined bias current being set for the base is combined with a dummy circuit having a transistor with a substantially equivalent load to one member of said transistor pair and which is biased in an equivalent relationship to said one transistor, a current mirror in which the base of an input transistor is not diode connected but connected to the base of an output transistor and supplied at the collector or emitter with a drive current flowing to the base of said transistor in said dummy circuit and in which said output transistor supplies each of the bases of said pair of transistors with said bias current which is substantially equal to the current flowing to the base of said transistor in said dummy circuit, and a control circuit that is connected to the base of said transistor in said dummy circuit and which receives the base voltage of said transistor in said dum

Abstract: In a regulated power supply circuit which includes a differential amplifier circuit and a current output circuit which receives the output from the differential amplifier circuit, wherein the current output circuit comprises a drive stage transistor which operates upon receipt of an output from the differential amplifier circuit at an input terminal thereof, a current output stage of a MOSFET which is driven by the drive stage transistor and a load resistor for the drive stage transistor connected to the output side thereof, and the load resistor and the drive stage transistor are provided between a power source line and a ground line and the MOSFET is driven by an output taken out via the load resistor.

Abstract: A DC/DC converter including a MOS transistor which is inserted in parallel with respect to a load and between a power source feeding line connected from a battery to the load and a ground line. the converter also has a first control circuit which generates a power of a boosted voltage via switching of the MOS transistor, receives the power of boosted voltage and controls the boosted voltage so as to be at a predetermined constant value in response to the boosted voltage. A bipolar transistor is inserted in parallel with the MOS transistor. A second control circuit receives power from the battery and causes switching of the bipolar transistor to generate a power of boosted voltage. When the boosted voltage is lower than an operable voltage of the first control circuit, the second control circuit is operated, and when the boosted voltage is equal to or more than the operable voltage, the operation of the second control circuit is stopped.

Abstract: A multi-loaded disk drive arrangement comprises a disk table for holding a plurality of disks arranged on the same circumference thereof, a loading mechanism for rotating the table to move a desired disk so that it is placed at a desired position, and a movement mechanism for moving an optical pick-up located below the table so that it is placed at a predetermined position and a single drive source.

Abstract: In a tone arm elevating mechanism, an elevator, which is arranged to raise and lower the tone arm, is driven by a solenoid, and the mechanism comprises a first rotary lever contactable with a portion of the elevator and a second rotary lever arranged to be driven by the solenoid, where the second rotary lever is operatively linked with the first rotary lever by means of an elastic member which prevents transmission of shock. Thus, the reciprocating movement of the solenoid is converted into rotational force to cause the elevator to rise gently and slowly. A viscous and resistive material may be provided to the elevator so that the elevator slowly lowers when the solenoid is deenergized. A portion of the elevating mechanism functions as an electrical switch to detect the highest position of the tone arm, while another portion may also function as another switch to detect the fact that the stylus has been placed on the record disk.