Abstract: A unidirectional DC-DC converter which has a simple control circuit without using multiple insulated power supplies or a transformer, uses an auxiliary inductor of a comparatively small capacitance, reduces the size and weight of the converter, and has a very great capacitance without switching of supply current. For example, a unidirectional DC-DC converter equipped with main IGBT101 which supplies and shuts off current for first inductor 108a and diode 107 which discharges energy from main inductor 108a to an the output. The DC-DC converter is further equipped with auxiliary IGBT104 which applies current to back-to-back-connected diode 102 by using energy stored in auxiliary inductor 108b which is magnetically coupled with main inductor 108a. This applies current to the back-to-back-connected diode in a short period including a time period in which the first switching element is turned on and accomplishes ZVZCS.

Abstract: A soft switching DC-DC converter is provided which includes circuitry for both a buck converter and a boost converter. The buck converter circuitry and the boost converter circuitry share a common transformer including a primary coil and first and second secondary coils. A first switching element is coupled to a first capacitor to provide the buck converter operation while another switching element is provided to provide the boost converting operation. The primary coil of the transformer is commonly used as a choke coil by both the buck converter and the boost converter. In this way, size and cost reduction can be obtained.

Abstract: A complex inductor according to the present invention changes its magnetic coupling polarity according to currents flowing its two inductors. The complex inductor includes a first magnetic member, around which first and third windings are formed, and a second magnetic member, around which second and fourth windings are formed. A first inductor is formed by connecting the first winding to the second winding, and a second inductor is formed by connecting the third winding to the fourth winding. The two magnetic members are made of a magnetic material having a magnetic permeability that gradually decreases as its magnetic flux density is increased. When the two windings are interconnected in a direction in which induced voltages generated in these windings by the current flowing in the second inductor weaken each other, the magnetic coupling polarity between the first and second inductors changes according to the current flowing in the inductors.

Abstract: A bi-directional DC-DC converter has a transformer for connecting a voltage type full bridge circuit connected to a first power source and a current type switching circuit connected to a second power source. A voltage clamping circuit constructed by switching elements and a clamping capacitor is connected to the current type switching circuit. The converter has a control circuit for cooperatively making switching elements operative so as to control a current flowing in a resonance reactor.

Abstract: A bidirectional DC-DC converter 10 has smoothing capacitors Cs1 and Cs2, a smoothing reactor Ls, resonant reactors Lr1 and Lr2, and a resonant capacitor Cr, as well as insulated gate bipolar transistors (IGBTs) Q1, Q2, and Q3 to which buffer capacitors C1, C2, and C3 are connected in parallel and diodes D1, D2, and D3 are connected in a back-to-back configuration. After part of the energy stored in the smoothing reactor Ls and/or resonant reactors Lr1 and Lr2 draws charges in the buffer capacitor C3 and is stored in the resonant capacitor Cr, the energy is stored in the resonant reactors Lr1 and Lr2. The energy is used to draw charges in the buffer capacitors C1 and C2, achieving soft switching of IGBTs Q1, Q2, and Q3.

Abstract: The present invention includes a plurality of mounting portions on which a semiconductor element is mounted, a plurality of electrodes to which the semiconductor elements that are mounted on each of the mounting portions are electrically connected, a corner portion which connects the plurality of mounting portions and which has a hanging lead piece that supports the mounting portions and an electrode connection piece that connects the plurality of electrodes, and a half-blanking portion that has a concave portion formed in a thickness direction of the lead frame and a protrusion formed at a position corresponding to the concave portion, and which is covered with a sealing resin material that seals the semiconductor element. A stress-dispersing portion for dispersing stress that arises, when the half-blanking portion is formed, is provided in the corner portion.

Abstract: An optical semiconductor element 2 is mounted on a lead frame 1, the optical semiconductor element 2 is encapsulated with a mold resin portion 14 of a first layer that has light permeability, and the mold resin portion 14 of the first layer is encapsulated with a mold resin portion 15 of a second layer that has light permeability. Then, a coefficient of linear expansion of the mold resin portion 14 of the first layer is made smaller than a coefficient of linear expansion of the mold resin portion 15 of the second layer.

Abstract: An optical semiconductor device has an optical semiconductor element (2) such as an LED or PD, and a light-permeable resin (4) encapsulating the optical semiconductor element. The light-permeable resin contains a base resin and filler. The light-permeable resin (4) has a characteristic that its transmittance increases with a temperature rise within an operating temperature range (e.g., ?40° C.?+85° C.).

Abstract: A transmission power of a communication apparatus can be appropriately determined in accordance with different communication multiplicities between two or more communication channels. A mobile communication system in which a base station apparatus and a mobile station apparatus communicate with each other by using configuration channels (CCH) or random access channels (RACH) includes a transmission power control part for determining basic data of the transmission power in RACH of the mobile station apparatus in accordance with a communication status in CCH, and a transmission power determining part for determining the transmission power in RACH of the mobile station apparatus by changing the basic data at least in accordance with the communication multiplicity of RACH.

Abstract: A buck converter circuit and a boost converter circuit, which co-use a main inductor, are connected in series with each other between a DC power-supply and a DC load between output terminals a-b of a rectifier circuit. Moreover, utilizing energy accumulated into first and second auxiliary inductors which are loosely coupled to the main inductor magnetically, a current is flown through diodes during a short time-period including a point-in-time at which main switching elements of the buck and boost converter circuits are to be turned ON. Here, the diodes are connected in inversely parallel to the main switching elements.

Abstract: A photo-coupler semiconductor device includes first and second planar lead frames each having a main portion and a distal portion, a light emitting element and a light receiving element respectively mounted on upper surfaces of the distal portions of the first and second lead frames, a light-transmitting resin member which covers the light emitting element and the light receiving element, and supports the distal portions of the first and second lead frames in spaced opposed relation with the light emitting element and the light receiving element being mounted on the upper surfaces of the distal portions so that the main portions of the first and second lead frames are located in coplanar relation, and a opaque resin member which covers the light-transmitting resin member, and supports the main portions of the first and second lead frames. The light-transmitting resin member and the opaque resin member are each composed of an epoxy resin as a base resin.

Abstract: To provide a power supply apparatus having high control resolution of an output power. A PWM signal generating circuit includes: a non-inverting element 31, and an inverting element 32; and further includes a counter 11 for performing count operation in response to rising of a clock signal, a counter 12 for performing count operation in response to falling of the clock signal, comparison circuits 21, 22, and a multiplexer 20. These circuit elements are controlled by PWM control means 10. As another circuit element, the PWM signal generating circuit includes a logical sum element 33. The PWM signal generating circuit serves to arbitrarily change both period and logic “H” time of a PWM signal to be outputted at a time interval which is one half of the clock period. Thus, there is provided a power supply apparatus in which resolution of a PWM signal has been improved within a broad duty range, and fine control of an output power has been performed within a broad output power range.

Abstract: A unidirectional DC-DC converter which has a simple control circuit without using multiple insulated power supplies, uses an auxiliary inductor of a comparatively small capacitance, reduces the size and weight of the converter, and has a very great capacitance without switching of supply current. A unidirectional DC-DC converter equipped with main IGBT101 which supplies and shuts off current for first inductor 108a and diode 107 which discharges energy from main inductor 108a to an output, wherein the DC-DC converter is further equipped with auxiliary IGBT104 which applies current to back-to-back-connected diode 102 by using energy stored in auxiliary inductor 108b which is magnetically coupled with main inductor 108a. This applies current to the back-to-back-connected diode in a short period including a time period in which the first switching element is turned on and accomplishes ZVZCS.

Abstract: A semiconductor device capable of achieving downsizing without reducing the power supply efficiency and capable of reducing switching noises and a memory card using the same are disclosed. The device comprises a plurality of stages of voltage booster circuits for potentially raising a power supply voltage up to a final output voltage, a voltage control unit for controlling an output voltage at a nearby location of the final stage, and one or more internal elements to which the final output voltage is supplied. A primary voltage booster circuit at the first stage includes an inductance element, a switching element, a diode and a driver circuit. At a metal core part of the inductance element, a metal wiring line is used, which was formed by use of a fabrication process of semiconductor integrated circuits, while employing for its core part an inter-wiring layer dielectric film that was formed using the fabrication process.

Abstract: A manufacturing method of an optical coupling device includes, preparing an elongated lead frame on which a plurality of tie bars are placed between a pair of side rails that are mutually in parallel with each other so as to orthogonally cross the tie bars, with a plurality of lead terminals being placed in a staggered form in a manner so as to orthogonally cross the tie bars, and laterally cutting the elongated lead frame to prepare a plurality of strap-shaped lead frames, in such a manner that the length of protrusion of a cut end of each of the side rails from each of the tie bars is made longer than the length of protrusion of a lead terminal from each of the tie bars.

Abstract: The inventive bi-directional DC-DC converter addresses a problem of an insufficient step-up ratio during the step-up operation that is caused when a turns ratio of the transformer is determined to, for example, match the step-up operation and also address a contrary problem of an insufficient step-down ratio during the step-down operation that is caused when a turns ratio is determined to match the step-up operation. In the inventive bi-directional DC-DC converter that uses a transformer for both step-down and step-up operations, a switching frequency for operating a switching device is set separately for the step-down and step-up operations. For example, when the switching frequency during the step-up operation is lower than the switching frequency during the step-down operation, the range in which the duty ratio in PWM control can be controlled is widened, compensating for step-up ratio insufficiency.

Abstract: A package includes: a substrate having a ridged peripheral portion and a center portion defined by and lower in level than the ridged peripheral portion. A semiconductor chip is mounted on the center portion. A plurality of lead is electrically coupled to the semiconductor chip and penetrates the substrate outwardly from the center portion. The package also includes a cap defining a cavity space which accommodates the semiconductor chip. The cap has a cap bonding face bonded with a substrate bonding face of the ridged peripheral portion. The cap bonding face and the substrate bonding face are higher in level than the center portion.

Abstract: First and second signal processing units are each configured by an IC, so that the circuit space occupying in a receiver apparatus can be reduced. The signal path can be shortened from a BPF section inputting a program signal coming from a broadcasting station to a demodulation section compared with the related art. The transmission loss on the signal path can be thus reduced compared with the related art. The possible route for noise entering from the outside to the first and second signal processing units can be made as short as possible. This enables to reduce the noise entering from the outside, and prevents the signals coming over the signal path from being attenuated by the noise so that the signal reception sensitivity can be increased.

Abstract: The present invention relates to a soft switching DC-DC converter. A soft switching DC-DC converter comprises a first switching element having a first terminal connected to an input side and having a control terminal for controlling a main electric current; a first diode having a first terminal connected to a second terminal of this first switching element; a primary coil of a transformer having primary and secondary coils, connected to the second terminal of the first switching element; a second diode having a first terminal connected to the first terminal of the first switching element; a second switching element having a first terminal connected to the second terminal of this second diode; and the secondary coil of the transformer, having a first terminal connected to a second terminal of this second switching element, and having a second terminal connected to the second terminal of the first switching element.

Abstract: The DC-DC converter connects a first and a second switching circuit for converting power mutually between direct current and alternating current respectively to a first DC power source and a second DC power source and has a transformer between the AC terminals thereof. Here, between the AC terminals of the second switching circuit and the negative pole terminal of the DC power source, a voltage clamp circuit composed of a series unit of switching devices with a reverse parallel diode and a clamp condenser is connected. An isolated bidirectional DC-DC converter which prevents a reduction in a circulating current at time of buck and an occurrence of a surge voltage at time of voltage boost and realizes highly efficiency, low noise, and miniaturization is provided.