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: An over-current detection circuit using the ON-voltage of a main MOSFET is provided, which is resistant to process variations of a main MOSFET and is not easily influenced by switching noise. Separately from a main MOSFET (Q1), a sense MOSFET (Q3) whose size is 1/m of the main MOSFET is provided and it is caused to be normally on. A DC ON-voltage generated when a current that is 1/m of an over-current value is caused to flow through the sense MOSFET is obtained as a reference voltage for over-current setting. The ON-voltage when the main MOSFET is on is sampled and held, and it is obtained as a DC voltage. These DC voltages are compared in a comparator (COMP).

Abstract: A reliable uninterruptible DC power supply device. The DC backup power supply device includes an AC/DC converter, a DC/DC converter, voltage step-up/down choppers and a battery connected to a DC path of a main circuit connected with a load via a switch, and a microcomputer. In the device, under control of the microcomputer, the voltage step-up/down choppers are first operated under a condition that the MOS FET was turned OFF for self diagnosis of the backup power supply device. Next, the switch is turned ON to execute the remaining self diagnosis. The DC backup power supply device can execute its self diagnosis with a reduced likelihood of danger of exerting an adverse effect on the main circuit and also can exhibit a reliable uninterruptible power supply function.

Abstract: A power-supply device comprising such marginal check voltage setting circuit that is easily adaptable to downsizing of the device and to configuration using ICs. The power-supply device of this invention comprises a marginal check voltage setting circuit that accepts input of a reference voltage and sets a desired marginal check voltage, an error amplifier that accepts input of the marginal check voltage and also the output voltage of the power-supply device and delivers output of an error signal, that is, the difference between the two inputs, a pulse width modulation oscillator that modulates the pulse width of the output from the error amplifier, a driver circuit that generates driving signal from the pulse signal originating from the pulse width modulation oscillator, and a pair of power semiconductor switching devices that work to step down the input voltage and generate an output voltage based on the driving signal.

Abstract: A power supply apparatus has a fuel cell unit as a source of input power. A control device limits the output of the fuel cell unit within an operating range of up to a maximum power point, even if a load power is not lower than the maximum power of said fuel cell unit. In addition to the fuel cell, a charge storing device is provided at the output side of the power supply apparatus. The charge storing device is capable of making up a shortage of power of the fuel cell.

Abstract: Fuel concentration near a power generator of a DMFC is adjusted by decreasing current taken from the DMFC when the concentration near the power generator of the DMFC is higher than an optimum value and increasing the current taken from the DMFC when the concentration near the power generator of the DMFC is lower than the optimum value. Since the fuel does not come into direct contact with the power generator in the DMFC in a portion from a cartridge to the power generator in the DMFC, drying of the fuel is suppressed. By providing an auxiliary tank capable of storing fuel, concentration of methanol supplied near the power generator of the DMFC is lowered upon activation after long-time storage.

Abstract: An object of the invention is to provide a small and low-cost switching power supply unit with a backup function in which a proper circuit construction can be selected by simple method when it is necessary to compensate for the instantaneous drop or power failure and a disk array system having the switching power supply unit. To accomplish the object, a backup unit which can insert and pull out its hot line into a switching power supply unit casing and has a secondary battery and its state monitoring/control unit is built in the unit, and proper charge/discharge management of the secondary battery can be made. When the backup unit is unnecessary, a backup unit formed by a plurality of capacitors whose hot lines can be similarly inserted and pulled out can be built in an enclosing space of the backup unit.

Abstract: The object of the invention is to compensate an effect of a voltage drop emerging in output voltage by the equivalent series resistance of a power output filter in a power-supply device. To achieve the object, a power-supply device wherein the power output filter that passes output power and first and second filters provided separately from the power output filter are provided, the first filter provided separately and one input terminal of an error amplifier are connected, new reference voltage acquired by adding differential voltage between the output of the second filter provided separately and the output of the power output filter to reference voltage is input to the other input terminal of the error amplifier and an output signal is fed back to the error amplifier is provided. According to the power-supply device, a voltage drop by equivalent series resistance emerging the output voltage of the power-supply device can be compensated.

Abstract: The present invention reduces the capacity of the AC-DC converter for the peak load and realizes low price and reduction in the volume of the power unit. The apparatus built-in backup power supply has the peak cut function for sharing a part of the load current at the time of peak load from the secondary battery. The two-way DC-DC converter 5 and the secondary battery 4 are installed on the DC output side of the AC-DC converter 3 and a current larger than a predetermined peak cut level is discharged from the secondary battery 4 at the time of peak load. Further, when the load is less than the predetermined cut level, the secondary battery 4 is charged from the AC-DC converter 3 via the two-way DC-DC converter 5. Furthermore, a most suitable peak cut level according to the SOC of the secondary battery and load pattern is automatically set and dynamically changed.

Abstract: An uninterruptible power system for inputting an AC power, converting the AC power into a desired power, supplying the desired power to a load, and upon occurrence of an AC failure, converting a DC power from energy accumulation means into the desired power and supplying the desired power to the load, wherein the DC power from said energy accumulation means is passed through two serially connected boost means, and thereafter the power is converted into the desired power to be supplied to the load, wherein first boost means of the two serially connected boost means, which is nearer to the energy accumulation means, raises the DC electric power from said energy accumulation means to supply second boost means of the two serially connected boost means when supply of electric power is interrupted, and lowers inputted electric power for charging the electric accumulation means during an ordinary operation.

Abstract: A power supply driver circuit with low power losses and desired response characteristics with respect to changes in output and its miniaturization is provided. In a driver IC constituting a switched-mode power supply equipment controlling the switching, by pulse width modulation, of first and second power transistors passing a current in a coil, and outputting a voltage bucked or boosted from an input voltage, current sensing with desired responsiveness is enabled by providing a switching transistor between an inverted input terminal and a non-inverted input terminal of an operational amplifier, preventing, while the second power transistor is ON, the generation of a potential which is undefined when first power transistor is ON, i.e. when the second power transistor is OFF, and maintaining a node potential in a state in which the potential is well defined.

Abstract: A detection voltage, which is obtained by dividing the voltage of a fuel cell 1 by resistors, is compared with a first reference voltage Vref1 by a differential amplifier. The differential voltage is input to a control section. The control section performs PWM control for the circuit section according to the difference. The first reference voltage Vref1 is set according to the dividing ratio of the resistors, based on the output voltage when the fuel cell generates power at the maximum power point. To determine the output voltage for maximum power generation, a characteristic curve representing a current-voltage characteristic is approximated by an approximating line within a range excluding an area in which the output voltage changes abruptly when the output current is nearly zero, and an extrapolated voltage is obtained on the extension line of the approximating line at an output current of zero.

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: A resonant converter which can realize its easy design, eliminate the need for its adjustment, realize reliable soft switching operation, and increase an efficiency. A driver DRV of a main switching device uses a PLL circuit PLL to apply frequency tracking control in such a manner that a driving frequency fsw is made to track a resonant frequency fr (or 1/N thereof, N being an odd number) and that the phase of the driving frequency fsw leads the current zero phase of the resonant frequency fr always by a desired time. As a result, such an optimum condition can be kept that the main switching device is triggered immediately before the zero-cross point of a resonant current. Thus the resonant converter which can always satisfy the optimum operational conditions, realize soft switching operation, and increase an efficiency can be realized with an easy design and a manufacturing adjustment-free arrangement.

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.

Abstract: A power supply driver circuit with low power losses and desired response characteristics with respect to changes in output and its miniaturization is provided. In a driver IC constituting a switched-mode power supply equipment controlling the switching, by pulse width modulation, of first and second power transistors passing a current in a coil, and outputting a voltage bucked or boosted from an input voltage, current sensing with desired responsiveness is enabled by providing a switching transistor between an inverted input terminal and a non-inverted input terminal of an operational amplifier, preventing, while the second power transistor is ON, the generation of a potential which is undefined when first power transistor is ON, i.e. when the second power transistor is OFF, and maintaining a node potential in a state in which the potential is well defined.

Abstract: A boost circuit is connected to a rechargeable battery and a switch is connected between a rectification circuit and a power factor correction converter. In the power failure state, the switch is turned on to activate the boost circuit and energy of the rechargeable battery is supplied to a load by rasing the voltage at two steps in the path from the boost circuit, switch, and to power factor correction converter. Since the voltage of the battery can be lowered, the number of serially connected cells can be made small. The volume of UPS can be reduced and a low cost can be realized. Since the number of serially connected cells is reduced, the reliability against failure of battery cells can be improved.

Abstract: When the mobile type information terminal is transferred between an operating state and a standby state, self diagnosis is performed. The fuel cell charges the secondary cells with a normal current of fixed value I1, and when the output voltage of the boost DC/DC converter (when PG=L), the charge current is reduced to the fixed value and aging is performed. After aging is performed for 60 seconds, charging is performed once again performed at the normal fixed value I1. This type of operation is repeated 30 times. During aging, when the output voltage from the boost DC/DC converter is reduced (when PG=L), aging is stopped and after 20 seconds aging is performed again, and this operation is done 10 times. The mobile type information terminal can perform self diagnosis and retrial of regeneration without the user being aware, in which secondary batteries and a fuel cell are loaded.

Abstract: A method of controlling an electric power source apparatus, which comprises supplying electric power to an electronic device on which a secondary battery is mounted from a power source apparatus having a fuel cell and an auxiliary power source. Electric power is supplied intermittently to a charging terminal of the electronic device by means of a switch for controlling conduction and interruption of an output terminal of the power source apparatus.

Abstract: A method of controlling an electric power source apparatus, which comprises supplying electric power to an electronic device on which a secondary battery is mounted from a power source apparatus having a fuel cell and an auxiliary power source. Electric power is supplied intermittently to a charging terminal of the electronic device by means of a switch for controlling conduction and interruption of an output terminal of the power source apparatus.