Abstract: Electronic equipment includes a processing unit which controls light emission from LEDs by referring to music data described in a music file such as a MIDI file. The processing unit controls light emission from the LEDs by detecting the occurrence of sound described in the music file. Light emission from the LEDs may be controlled in accordance with tone data and/or a track number included in the music file. Alternatively, light emission from the LEDs may be controlled in accordance with volume data.

Abstract: A first transistor and a second transistor are disposed in series between a first terminal and a ground terminal. A diode is disposed in parallel with the first transistor in a direction such that the cathode thereof will be on the first terminal side. An inductor is disposed between a connection point and a second terminal. A first capacitor is disposed between the first terminal and the ground terminal, and a second capacitor is disposed between the second terminal and the ground terminal. In a first mode, a control unit allows the first transistor and the second transistor to be alternately subjected to a switching operation, so as to lower the voltage of an external voltage Vext of the first terminal and to output the lowered voltage to the second terminal.

Abstract: An electronic flash light is emitted from a camera by causing light-emitting diodes corresponding to red, green and blue simultaneously. Light emission of the light-emitting diodes corresponding to respective colors is controlled in accordance with the light-receiving characteristics of the light-receiving elements. For example, by adjusting the on and off duration ratio of switches in accordance with the light-receiving characteristics, the quantity of light emitted by the light-emitting diodes is adjusted.

Abstract: A voltage comparison circuit makes a comparison between a first voltage and a second voltage. A resistor and a constant current source are provided in series between the first voltage and the ground voltage. A comparator receives the second voltage via one input terminal (non-inverting input terminal), and the voltage at a connection node between the aforementioned resistor and the constant current source via the other input terminal (inverting terminal). The first voltage is preferably used as the power supply voltage for the comparator.

Abstract: A light-emission control circuit may include n light-emitting devices, where n is an integer equal to or greater than 2; a light guide plate which causes light emitted by the n light-emitting devices to reach the entirety of the back of a liquid crystal panel; a measuring unit for measuring a luminance of the entirety of the n light-emitting devices operating in the liquid crystal panel; and a control unit for comparing the measured luminance with a predetermined value and controlling the luminance of the n light-emitting devices, based on a result of comparison, wherein the n light-emitting devices are attached to a side of the light guide plate, and the measuring unit is attached to an opposite side of the light guide plate.

Abstract: A first transistor is provided in a first route and a second transistor is provided in a second route, the first route and the second route constituting a current mirror circuit. The sources of the transistors are grounded. In order to match VDS of the first transistor and that of the second transistor match each other, there are provided an operational amplifier receiving the drain voltages of the transistors, and a third transistor having a gate thereof connected to the output of the operational amplifier. The third transistor is provided in the first route. As a result, the current fed to the third transistor is controlled so that VDS of the first transistor and that of the second transistor match each other.

Abstract: Light-emitting parts are attached to a light guide plate of a backlight unit so as to be illuminated by the backlight. A measuring unit formed by light-receiving parts is provided on the opposite side of the light guide plate. The measuring unit detects the luminance or color tone of light inside the light guide plate. A control unit subjects the luminance or color tone to feedback control in accordance with a result of measurement.

Abstract: A first transistor is provided in a first route and a second transistor is provided in a second route, the first route and the second route constituting a current mirror circuit. The sources of the transistors are grounded. In order to match VDS of the first transistor and that of the second transistor match each other, there are provided an operational amplifier receiving the drain voltages of the transistors, and a third transistor having a gate thereof connected to the output of the operational amplifier. The third transistor is provided in the first route. As a result, the current fed to the third transistor is controlled so that VDS of the first transistor and that of the second transistor match each other.

Abstract: A booster converter outputs a boosted voltage. A plurality of LEDs emit light of respective colors. The transistors establish or shut connection between the LEDs and a main driving circuit. A variable current circuit feeds a current to drive the LEDs. A PWM control unit effects control to cause the LEDs to emit light with respective tones of color. A PWM circuit executes PWM modulation in accordance with an instruction from the PWM control unit. A setting control unit 138 controls the magnitude of the driving current fed by the variable current circuit in accordance with an instruction from a second light emission control unit. In an image pickup mode, an additional driving circuit feeds a driving current to the LEDs so that the LEDs operate as an electronic flash.

Abstract: The image shooting apparatus 10 provided not only with the image shooting function but also the communications function is, for example, a camera portable telephone. The apparatus includes a call incoming notifying section, a camera section and an LCD monitor. LEDs in the call incoming notifying section emit a normal light for notifying a user of call incoming when an incoming call is detected and emit a high-luminance electronic flash light when the camera section is operated to take a photograph.

Abstract: A first transistor is provided in a first route and a second transistor is provided in a second route, the first route and the second route constituting a current mirror circuit. The sources of the transistors are grounded. In order to match VDS of the first transistor and that of the second transistor match each other, there are provided an operational amplifier receiving the drain voltages of the transistors, and a third transistor having a gate thereof connected to the output of the operational amplifier. The third transistor is provided in the first route. As a result, the current fed to the third transistor is controlled so that VDS of the first transistor and that of the second transistor match each other.

Abstract: An IC chip has a series regulator built therein. A battery voltage is applied to an input pin. An output of a transistor constituting the series regulator occurs at an output pin via an output pad. A feedback signal derived from an output voltage occurs at an end of a voltage division resistor via a feedback pad. Diodes connect the output pad and the feedback pad.

Abstract: A first transistor is provided in a first route and a second transistor is provided in a second route, the first route and the second route constituting a current mirror circuit. The sources of the transistors are grounded. In order to match VDS of the first transistor and that of the second transistor match each other, there are provided an operational amplifier receiving the drain voltages of the transistors, and a third transistor having a gate thereof connected to the output of the operational amplifier. The third transistor is provided in the first route. As a result, the current fed to the third transistor is controlled so that VDS of the first transistor and that of the second transistor match each other.

Abstract: A first transistor is provided in a first route and a second transistor is provided in a second route, the first route and the second route constituting a current mirror circuit. The sources of the transistors are grounded. In order to match VDS of the first transistor and that of the second transistor match each other, there are provided an operational amplifier receiving the drain voltages of the transistors, and a third transistor having a gate thereof connected to the output of the operational amplifier. The third transistor is provided in the first route. As a result, the current fed to the third transistor is controlled so that VDS of the first transistor and that of the second transistor match each other.

Abstract: Using the leakage current of the base resistance of the bipolar transistor, semiconductor integrated circuit device which detects an overheat condition of the elements protected from overheat, is realized. The overheat detection circuit and the elements or the circuits which might be protected from overheat, are formed on the same substrate. The said overheat detection circuit is comprised of a bipolar transistor, its base resistance, and a constant-voltage source. The constant-voltage source provides a certain voltage to isolate the elements. The joint base resistance is located close to elements or circuits which might be protected from overheat and located far from the constant-voltage source.

Abstract: Electronic equipment includes a processing unit which controls light emission from LEDs by referring to music data described in a music file such as a MIDI file. The processing unit controls light emission from the LEDs by detecting the occurrence of sound described in the music file. Light emission from the LEDs may be controlled in accordance with tone data and/or a track number included in the music file. Alternatively, light emission from the LEDs may be controlled in accordance with volume data.

Abstract: A first transistor is provided in a first route and a second transistor is provided in a second route, the first route and the second route constituting a current mirror circuit. The sources of the transistors are grounded. In order to match VDS of the first transistor and that of the second transistor match each other, there are provided an operational amplifier receiving the drain voltages of the transistors, and a third transistor having a gate thereof connected to the output of the operational amplifier. The third transistor is provided in the first route. As a result, the current fed to the third transistor is controlled so that VDS of the first transistor and that of the second transistor match each other.

Abstract: In a stabilized power supply unit having a current limiting function, the unit is designed to have a steep over-current dropping characteristic. This minimizes the over-current region, prevents oscillation during a startup, and limits inrush current during a start up within a predetermined range. The output voltage of the power supply unit provides a constant output voltage by controlling an output transistor by means of a differential amplifier amplifying the difference between a reference voltage and an output feedback voltage. The power supply unit has a first high-gain, slow-response type current limiting circuit that outputs a first current limiting signal when the output current of the power supply unit exceeds a predetermined level, and a second low-gain, quick-response type current limiting circuit that outputs a second current limiting signal when the outputs exceeds the predetermined level.

Abstract: The image shooting apparatus 10 provided not only with the image shooting function but also the communications function is, for example, a camera portable telephone. The apparatus includes a call incoming notifying section, a camera section and an LCD monitor. LEDs in the call incoming notifying section emit a normal light for notifying a user of call incoming when an incoming call is detected and emit a high-luminance electronic flash light when the camera section is operated to take a photograph.

Abstract: A booster converter outputs a boosted voltage. A plurality of LEDs emit light of respective colors. The transistors establish or shut connection between the LEDs and a main driving circuit. A variable current circuit feeds a current to drive the LEDs. A PWM control unit effects control to cause the LEDs to emit light with respective tones of color. A PWM circuit executes PWM modulation in accordance with an instruction from the PWM control unit. A setting control unit 138 controls the magnitude of the driving current fed by the variable current circuit in accordance with an instruction from a second light emission control unit. In an image pickup mode, an additional driving circuit feeds a driving current to the LEDs so that the LEDs operate as an electronic flash.