Rohm Co., Ltd.

Koichi Miyanaga

Isao Yamamoto

Jun Maede

Hiroyuki Ishikawa

Takeru Matsuki

Yutaka Shibata

Takahiro Ota

Akihito Ito

A semiconductor integrated circuit includes multiple termination circuits that correspond to multiple target pins. The multiple termination circuits each include a first resistor and a first transistor coupled in series between the corresponding target pin and the ground. A second resistor is provided between the corresponding target pin and the control electrode of the first transistor. The enable circuit is arranged such that its output node is coupled to the control electrode of the first transistor, and configured such that (i) when the enable pin is set to the first state, the current is sunk from the output node, and (ii) when the enable pin is set to the second state, the output node is set to the low level.

Semiconductor integrated circuit

A pulse generator includes a mode controller that detects a state in which there has been no transition of a pulse signal to the off level for a given cycle (period). When such a state is detected, the pulse generator transits to a skip mode. In the skip mode, the period is repeatedly switched between: (i) a first period in which the pulse signal is maintained at the on level over multiple cycles; and (ii) a second period in which the pulse signal is forcibly switched to the off level so as to charge the bootstrap capacitor by means of a bootstrap circuit.

Step-down DC/DC converter

A bootstrap power supply circuit generates a constant voltage Vfor charging a bootstrap capacitor. An output transistor is configured as an N-channel MOSFET arranged such that its drain is connected to an input line and such that its source is connected to an output line. A constant voltage circuit connected to the gate of the output transistor stabilizes the gate voltage Vto a constant value. A variable impedance circuit is arranged between the input line and the gate of the output transistor, in order to provide a variable impedance. An impedance controller controls the impedance of the variable impedance circuit according to the state of a step-down DC/DC converter.

A shunt circuit includes: a shunt resistor; a transistor connected in parallel to a storage element via the shunt resistor; a first OP amplifier configured to compare a battery voltage supplied to the storage element with a detection voltage; and a second OP amplifier configured to shunt a shunt current from a charging current supplied from a charging unit when the battery voltage reaches the detection voltage. The detection voltage is increased step by step, and the shunt current is increased whenever the battery voltage reaches the detection voltage.

Shunt circuit, charging system and integrated circuit

An electrical storage device monitoring circuit includes a 3-state buffer configured to switch between a high output state and a low output state based on a flag output delivered from a previous electrical storage device monitoring circuit at a front stage, and also configured to detect a disconnection between the current electrical storage device monitoring circuit and the previous electrical storage device monitoring circuit at the front stage; a detection circuit configured to monitor an electrical storage device to detect whether the electrical storage device is normal or abnormal; and an output circuit configured to deliver the flag output to a subsequent electrical storage device monitoring circuit at a next stage based on an input of the 3-state buffer and a detection result of the detection circuit.

Detecting disconnection fault in device monitoring circuit connected in multiple stages for battery cells connected in series

An energy harvesting apparatus includes: a capacitor configured to store energy generated by an energy harvesting element; and a switch connected to the capacitor and configured to switch energy supply from the capacitor to a load based on a capacitor voltage with which the capacitor is charged. An energy harvesting system includes: energy harvesting elements; energy harvesting apparatuses which are provided to respectively correspond to the energy harvesting elements; and a load as an energy supply destination connected to the energy harvesting apparatuses.

Energy harvesting apparatus and energy harvesting system

A battery module includes an anode terminal, a cathode terminal, and multiple capacitor cells. Multiple tap electrodes are each provided to a corresponding connection node that connects adjacent capacitor cells. An intermediate terminal is connected to one from among the multiple tap electrodes. A battery control circuit includes a cell balance circuit configured to stabilize each of the voltages at the multiple tap electrodes to a corresponding target voltage level. The voltage at the anode terminal is supplied to the power supply terminal of the cell balance circuit.

Battery control circuit

A first switch is arranged between a judgment unit and a signal line. The first switch is turned on during a period in which the judgment unit judges a device, after which the first switch is turned off. A second switch is turned off during a period in which the judgment unit judges the device, after which the second switch is turned on. The signal line connects a communication interface port, which allows various different kinds of devices to be connected, and a communication terminal of a processor configured to perform data communication with the device. The judgment unit monitors the electrical state of the signal line, and judges the device connected to the port.

Semiconductor apparatus having a controller arranged to turn on a first switch and turn off a second switch during a period in which a judgement unit judges a device type of a device

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.

Voltage comparison circuit

An external power source is connected to an adapter input terminal (first terminal). A battery is connected to a path input terminal (second terminal). A selection circuit (a first switch, a second switch, logic circuit compares the input voltage input from the external power supply with the battery voltage, and selects one of the two. The voltage thus selected by the selection circuit is output to an external load circuit via a system power supply terminal. A charging circuit charges the battery using the input voltage supplied from the external power supply.

Power management circuit

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.

Electronic equipment synchronously controlling light emission from light emitting devices and audio control

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.

Image pickup apparatus with light emission control adapted for light-receiving characteristics

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 Vof 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 Vof the first transistor and that of the second transistor match each other.

[object Object]

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.

Light-emission control circuit

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 unitcontrols 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.

Growing community of inventors

Kyoto, Japan

Koichi Miyanaga