Renesas Technology Corp.

Hitachi, Ltd.

Hitachi Information Systems, Ltd.

Shinichi Yoshida

Takashi Sase

Tomohiro Tazawa

Kouji Tateno

Akihiko Kanouda

Koji Tateno

Yasumasa Matsuda

Tsukasa Hasegawa

Katsunori Hayashi

Akira Naito

Yasuhiko Kasai

Hajime Asuma

Tomoko Tsuchiya

Ryotaro Kudo

Kenichi Onda

Kyoichi Hosokawa

Yoichi Uehara

Mitsuaki Maeta

Eiji Yamagata

Hachio Tsuchida

Shigeo Onda

A switching power supply circuit in which a series circuit comprising a resistive element and a capacitive element is provided in a parallel configuration with an inductor which supplies a load current to a load circuit, a voltage comparator having first and second threshold voltages discriminates a voltage obtained from a mutual connecting point of the series circuit therefrom and controls a switch element for supplying a current to the inductor, thereby varying the current supplied to the inductor in accordance with a variation in the load current is combined with a series power supply circuit which shares the load current of the load circuit.

Switching power supply in an integrated circuit having a comparator with two threshold values, a synchronization input and output, voltage feedback and efficient current sensing

A semiconductor integrated circuit for controlling power supply which has a function of preventing a reverse current flowing in a coil under a light load condition and ensures good response of output voltage to load variation. In a synchronous rectification switching regulator having a reverse current detection circuit which can detect a reverse current flowing in an inductor (coil) and a reverse current prevention function, when a prescribed time has elapsed after detection of a reverse current based on a detection signal from the reverse current detection circuit or after the number of times of reverse current detection has reached a prescribed value, the reverse current prevention function is activated to turn Off a synchronous rectification switching device.

Semiconductor integrated circuit for controlling power supply, an electronic component and a power supply device

It is aimed at decreasing losses not only in a synchronous rectifier circuit provided at a secondary side of a DC-DC converter, but also in a full-bridge switching circuit provided at a primary side thereof. The DC-DC converter comprises a transformer for voltage conversion, a synchronous rectifier circuit at the secondary side, and a full-bridge switching circuit at the primary side. The DC-DC converter performs synchronous rectifier control which uses switch transistors to change paths of currents flowing through the secondary coil in synchronization with switching operations at the primary side. The DC-DC converter detects currents flowing through a load at the secondary side, primary-side currents varying with the load currents, or primary-side input voltages to dynamically control off-timings of a synchronous rectification transistor at the secondary side. In addition, the DC-DC converter detects primary-side input voltages and currents flowing through the secondary-side load to dynamically control on-timings of a transistor in the primary-side switching circuit.

Switching power supply device and the semiconductor integrated circuit for power supply control

There is provided a switching power supply device of hysteresis current mode control system which assures excellent response characteristic for change of output current and reduction of power consumption. In a switching regulator of hysteresis current mode control system, a sense resistor connected in series to a coil is eliminated, a serially connected resistor and a capacitor are connected in parallel to a coil in place of such sense resistor. Thereby, a potential of a connection node of these resistor and capacitor is inputted to a comparator circuit having the hysteresis characteristic for comparison with the reference voltage. Accordingly, a switch may be controlled for ON and OFF states.

Switching power supply device and switching power supply system

A step down type DC-DC power-supply device implements both the stabilization of the control loop and the responsibility at the same time. In the power-supply device, an output power signal is fed back to an error amplifier after having passed through a CR smoothing filter provided independently of a power LC smoothing filter. Also, independently of the duty controls over Power MOSFETs, i.e., upper-side/lower-side semiconductor switching components in the steady state, an output from the power LC smoothing filter is added to an upper and lower limit-mode-equipped control circuit, thereby, at the transient state, forcefully setting the duty &#x3b1; at either 0% or 100%.

Power-supply device

A step-down type DC&mdash;DC power-supply device implements both the stabilization of the control loop and the responsibility at the same time. In the power-supply device, an output power signal is fed back to an error amplifier after having passed through a CR smoothing filter provided independently of a power LC smoothing filter. Also, independently of the duty controls over Power MOSFETs, i.e., upper-side/lower-side semiconductor switching components in the steady state, an output from the power LC smoothing filter is added to an upper and lower limit-mode-equipped control circuit, thereby, at the transient state, forcefully setting the duty &agr; at either 0% or 100%.

The icon menu display method and apparatus according to the invention displays a perspective view of a work room over an entire screen as a background against which a plurality of icons are displayed. The icons are arranged against the background image at locations which are functionally related to the functions associated with each icon.

Icon menu display apparatus and icon menu display method

Menu picture display method and apparatus for a data processor

A dot printer device is disclosed, in which in order to print a horizontal ruled line, paper feed data for placing the head pin of a printing head at a predetermined position on a printing paper, dot pin data indicative of a dot pin specified on the basis of a predetermined rotation of dot pins for printing the horizontal ruled line, and paper feed data indicative of how much the printing paper is to be moved in accordance with the predetermined rotation of dot pins after the horizontal ruled line has been printed by the specified dot pin, are sent from a control unit to a printing unit.

Dot printer device having a control unit to print horizontal lines

Growing community of inventors

Takasaki, Japan

Shinichi Yoshida