Rohm Co., Ltd.

Honda Motor Co., Ltd.

Masaaki Nakayama

Ryosuke Kanemitsu

Noboru Takizawa

Akira Aoki

Krishnachandran Krishnan Nair

Mathew George

Toru Takahashi

Shinsuke Takagimoto

Ryo Takagi

Yosuke Tsuchiya

Kei Nagao

Yoshiyuki Nakatani

Kouji Miyamoto

Koji Okamoto

Tomoya Saito

Yoshito Nishigami

Masaharu Ando

Vishwajit Babasaheb Bugade

A light-emitting element driving device () includes: a first external terminal (SET terminal) connectable to a first setting resistor (Rset); a second external terminal (SET_TH terminal) connectable to a first thermistor (TH) with a negative coefficient arranged beside a light-emitting element light source (); a current setter () that generates a setting current (Iset) based on the resistance value of the first setting resistor; a current adder () that generates an addition current (Iadd) with a negative coefficient to the resistance value of the first thermistor; and a current driver () that generates an output current (Iout) that passes through the light-emitting element light source connected between an application terminal for a supply voltage (Vin) and a ground terminal based on a reference current (Iref) which is the sum of the setting current and the addition current.

Light-emitting element driving device, lighting device, and vehicle

In a normal mode in which light emission control of the light emitting element is performed by a dimming controller (), if no communication signal from an external microprocessor () is recognized beyond a first predetermined period, the control logic circuit () shifts from the normal mode to a first limp home mode (limp homemode). In the first limp home mode, the dimming controller sets a light emitting element current set value based on a terminal current set value commensurate with a resistance value of a setting resistor (Rextiset) and a DC dimming set value for each of the channel set in the register (A), controls the current driver () so as to generate a current of the set light emitting element set value, and turns on and off the current driver based on a PWM on-duty for each of the channels set in the register.

Light emitting element driving device

A semiconductor device, and an electronic module including the semiconductor device, are described. In an example, the semiconductor device includes a first voltage side terminal arranged to be connected to an external first voltage, a second voltage side terminal arranged to be connected to an external second voltage different from the external first voltage, and a terminal which is adjacent to the first voltage side terminal and is arranged to be connected to one terminal of an external resistor. A current distributor is configured to distribute a current to a direct path to the first voltage side terminal and to a loss path to the terminal. A current driver is configured to perform current control of a current including a current between the first voltage side terminal and the second voltage side terminal.

Load drive device

A light-emitting element driving circuit () includes: a first buffer () provided between the transmission terminal (B) and the communication circuit (), with the output side of the first buffer connected to the transmission terminal and the input side of the first buffer connected to the communication circuit; and a determination circuit () configured to determine whether the controller () is connected or not based on a first signal (S) at the output terminal of the first buffer and a second signal (S) at the input terminal of the first buffer. If the determination circuit determines that the controller is not connected, the communication circuit is disabled from processing the signal received via the reception terminal (A), and the dimming signal generator () generates the dimming signal (Spwm) based on a pulse signal (Sp) fed to the reception terminal or the transmission terminal.

Light-emitting element driving circuit

A semiconductor device comprises: a package having a rectangular shape when viewed in plan and including a first side, a second side parallel to the first side, a third side orthogonal to the first side and the second side, and a fourth side parallel to the third side and orthogonal to the first side and the second side; a power supply terminal provided on the first side; a power ground terminal provided on the second side; a switch output terminal provided on the second side; an upper switch connected between the power supply terminal and the switch output terminal; and a lower switchL connected between the switch output terminal and the power ground terminal.

Semiconductor device with arrangement for terminals connected to multiple switches

A lamp control device includes: an output; a comparator; and a first setter configured to set the voltage fed to a first input terminal of the comparator to a second voltage that depends on a first voltage or to a third voltage that depends on a first current, in which the output terminal is connected to a second input terminal of the comparator, the output terminal is configured to be connectable to the lamp via a switch, the output terminal is configured to be connectable to a second setter including the switch, when the first setter sets the voltage fed to the first input terminal of the comparator to the second voltage, and the second setter is configured to set the voltage fed to the output terminal to a fourth voltage that depends on the first voltage and the resistance value of the switch.

Lamp control device

A lamp control device comprises a first input terminal, a second input terminal, an output terminal that is configured to be connectable to a lamp via an external switch and outputs a drive current for the lamp, an internal switch provided on a first path connecting the first input terminal and the output terminal, a constant current section provided on a second path connecting the second input terminal and the output terminal, a voltage monitoring section that monitors a voltage applied to the output terminal, and a control section that controls the internal switch on the basis of a monitoring result from the voltage monitoring section.

A light emitting element drive device includes a driving circuit that supplies a variable drive current to a light emitting unit having one or more light emitting elements so that the light emitting unit can emit light, a drive reference voltage generation circuit that generates a drive reference voltage defining the upper limit value of the drive current and supplies the same to the driving circuit, and a specific external terminal capable of connecting to an external resistor. The drive reference voltage generation circuit operates selectively in a first mode to generate the drive reference voltage regardless of the state of the specific external terminal, or a second mode to generate the drive reference voltage in accordance with a second mode current through the specific external terminal.

Light emitting element drive device and light emitting system

Provided is a load drive device comprising: a first input terminal for accepting an input of a first input current from a power source; a second input terminal for accepting an input of a second input current from the power source via an external resistor; an output terminal for outputting an output current to a load; a current distribution unit for summing the first input current and second input current at a prescribed distribution ratio and generating the output current and a control unit for controlling the distribution ratio. As one example, it would be appropriate for the control unit to control the distribution ratio according to the difference between a first terminal voltage present in the second input terminal and a second terminal voltage present in the output terminal.

A light-emitting element driving device includes a setter and first to nth constant current sources. An ith series circuit is a series circuit of an ith light-emitting element string and the ith constant current source. The ith constant current source is turned on and off with a delay from an ith dimming signal indicating either lighting or extinction of the ith light-emitting element string. The setter has a mode in which it sets the target value of an output voltage fed to the respective anodes of the first to nth series circuits at a value at which the jth light-emitting element string can be lit during the period from a first time point that a jth dimming signal switches from indicating extinction of the jth light-emitting element string to indicating its lighting to a second time point that the jth constant current source switches from off to on.

Light-emitting element driving device

A lighting device includes light emitting element groups (HSB) including a light emitting element group (HS) that emits light when being applied with a voltage at a light emission reference voltage (VH), and a light emitting element group (HS) that emits light when being applied with a light emission reference voltage (VH) higher than the light emission reference voltage (VH), the light emitting element groups (HSB) emitting light when being applied with a voltage equal to or higher than a light emission reference voltage (VHa); a semiconductor chip (IC) including a light emission control unit (HC) arranged to perform light emission control to cause light emission of a light emitting element group (HS) if a drive voltage (Vk) is higher than the light emission reference voltage (VHa), and to perform light emission stop control to stop the light emission if the drive voltage (Vk) is lower than the same; and a semiconductor chip (IC) including a light emission control unit (HC) arranged to perform light emission control to cause light emission of a light emitting element group (HSa) if the drive voltage (Vk) is higher than the light emission reference voltage (VHa), and to perform light emission stop control to turn off the emitting element group (HSa) if the drive voltage (Vk) is lower than the same.

Lighting device

A light emitting element drive device generates a single output current while switching a target current value for each of a plurality of light emitting elements, and supplies the single output current to the plurality of light emitting elements in a time division manner.

Light emitting element drive device

A driving device includes, for example: an output terminal; a transistor configured to generate an output current to the output terminal; a logic circuit configured to perform on/off control of the transistor at a predetermined period; and a current sense circuit configured to sense the output current. The current sense circuit is configured to be enabled during an on-period of the transistor. The logic circuit is configured to suspend the on/off control and reset the period when the output current becomes lower than a first threshold value during the on-period.

Driving device

A light-emitting element driving device includes: a first amplifier configured, with respect to each of a plurality of light-emitting element strings, to control a first transistor connected in series with the light-emitting element string based on the current passing through the light-emitting element string; and a second amplifier configured, with respect to each of at least part of the plurality of light-emitting element strings, a second transistor, which is included in a series circuit composed of the second transistor and a first resistor and connected in parallel with the first transistor, based on the current passing through the light-emitting element string and the current passing through the second transistor.

Growing community of inventors

Kyoto, Japan

Masaaki Nakayama