公开(公告)号：US20210274616A1

公开(公告)日：2021-09-02

申请号：US17274669

申请日：2019-02-21

Applicant: ROHM CO., LTD.

Inventor： Ryosuke Kanemitsu ,  Koji Katsura

IPC: H05B45/3725 ,  H05B45/325 ,  H05B45/56 ,  H05B45/345 ,  H05B45/10 ,  B60Q3/18

Abstract: An LED driving device includes a DC/DC controller which controls an output stage for supplying an output voltage to an LED; and a current driver which generates an output current of the LED. The current driver performs PWM dimming by turning on the output current in accordance with an LED-current-on period of a PWM dimming signal and turning off the output current in accordance with an LED-current-off period of the PWM dimming signal. The DC/DC controller includes a feedback control unit which performs feedback control for outputting a switching pulse to the output stage so as to make a cathode voltage of the LED equal to a reference voltage. A pulse addition control unit performs pulse addition control for adding a predetermined pulse number of additional switching pulses at a time of switching between the LED-current-on period and the LED-current-off period.

公开(公告)号：US11864282B2

公开(公告)日：2024-01-02

申请号：US17891311

申请日：2022-08-19

Applicant: ROHM CO., LTD.

Inventor： Makoto Suyama ,  Koji Katsura ,  Toshiro Okubo

IPC: H05B45/14 ,  H05B45/345 ,  H05B45/50 ,  H05B45/46

CPC classification number: H05B45/14 ,  H05B45/345 ,  H05B45/46 ,  H05B45/50

Abstract: The present disclosure provides a light emitting element driving device. The light emitting element driving device includes a constant current circuit and a current detection unit. The constant current circuit includes: a first transistor including a first end, a second end and a control end connected to an external terminal; a current setting resistance connected to the second end of the first transistor; and a drive amplifier including a first input end connected to a first node to which the first transistor and the current setting resistance are connected, a second input end to which a current set voltage is applied, and an output end connected to the control end of the first transistor. The current detection unit generates a current detection signal based on a feedback voltage generated in the first node.

公开(公告)号：US20190387591A1

公开(公告)日：2019-12-19

申请号：US16480327

申请日：2018-01-31

Applicant: ROHM CO., LTD.

Inventor： Kenichi FUKUMOTO ,  Koji Katsura ,  Ryosuke Kanemitsu ,  Junichi ITAI ,  Nobuaki MATSUI ,  Seiji NAKASHIMA ,  Kouji Miyamoto

IPC: H05B33/08

Abstract: An LED drive circuit drives an LED module. The LED module has a light-emitting diode, and an identification unit having characteristic information relating to light-emitting characteristics of the light-emitting diode. The LED drive circuit includes a detection unit and a drive circuit. The detection unit is provided for detecting characteristic information, and generates a detection signal that corresponds to the characteristic information. The drive circuit generates drive current by a drive signal supplied according to the characteristic information based on the detection signal, and supplies the drive current to drive the light-emitting diode.

公开(公告)号：US09980331B2

公开(公告)日：2018-05-22

申请号：US15219618

申请日：2016-07-26

Applicant: ROHM CO., LTD.

Inventor： Koji Katsura ,  Toru Takuma ,  Yasunori Muramatsu

IPC: H05B33/08 ,  H03L7/00 ,  H03K7/08 ,  H03K3/0233 ,  H05B37/02

CPC classification number: H05B33/0815 ,  H03K3/02337 ,  H03K7/08 ,  H05B33/0845 ,  H05B33/0884 ,  H05B37/0281

Abstract: An oscillation circuit for generating a clock signal of a switching power supply circuit is provided. The oscillation circuit includes a circuit configured to perform frequency spreading control of the clock signal in synchronization with an output operation control signal for periodically turning on/off an output operation of the switching power supply circuit.

公开(公告)号：US09226350B2

公开(公告)日：2015-12-29

申请号：US14159493

申请日：2014-01-21

Applicant: Rohm Co., Ltd.

Inventor： Koji Katsura

IPC: H05B33/08 ,  H03B23/00 ,  B60Q1/00 ,  B60Q11/00 ,  H03K4/06 ,  H02M3/156

CPC classification number: H05B33/0815 ,  B60Q1/0094 ,  B60Q11/005 ,  H02M3/156 ,  H03B23/00 ,  H03K4/06 ,  H05B33/0818 ,  H05B33/0887 ,  H05B33/089

Abstract: An oscillation circuit includes: a ramp voltage generating unit configured to generate a ramp voltage; and a clock signal generating unit configured to generate a clock signal. The clock signal generating unit includes: a bias unit configured to apply one of the ramp voltage and a fixed voltage, as a bias voltage, to a resistor; and an oscillator configured to determine an oscillation frequency of the clock signal in response to a bias current flowing through the resistor.

Abstract translation: 振荡电路包括：斜坡电压产生单元，被配置为产生斜坡电压; 以及时钟信号生成单元，被配置为生成时钟信号。 时钟信号发生单元包括：偏置单元，被配置为将斜坡电压和固定电压中的一个作为偏置电压施加到电阻器; 以及振荡器，被配置为响应于流过所述电阻器的偏置电流来确定所述时钟信号的振荡频率。

公开(公告)号：US20250024573A1

公开(公告)日：2025-01-16

申请号：US18895847

申请日：2024-09-25

Applicant: ROHM CO., LTD.

Inventor： Keisuke Miura ,  Koji Katsura

IPC: H05B45/52 ,  G01R31/26

Abstract: For each channel, a light-emitting unit provided between a wire fed with a driving voltage and a connection terminal can be supplied with a driving current via the connection terminal. For each channel, a switch circuit is provided between the connection terminal and a voltage generation circuit. Based on the driving voltage, a first and a second voltage lower than the driving voltage are generated at a first and a second node. With each connection terminal cut off from the first and second nodes, the second voltage is lower than the first voltage. In a period in which each channel is not supplied with the driving current, the switch circuit operates to connect, of two adjacent connection terminals, one to the second node and the other to the first node. Based on the voltage at the one connection terminal, a resistance value abnormality between the two connection terminals is detected.

公开(公告)号：US12069783B2

公开(公告)日：2024-08-20

申请号：US18303871

申请日：2023-04-20

Applicant: Rohm Co., Ltd.

Inventor： Ryosuke Kanemitsu ,  Koji Katsura

IPC: H05B45/30 ,  B60Q3/18 ,  H05B45/10 ,  H05B45/325 ,  H05B45/345 ,  H05B45/3725 ,  H05B45/56

CPC classification number: H05B45/3725 ,  B60Q3/18 ,  H05B45/10 ,  H05B45/325 ,  H05B45/345 ,  H05B45/56

Abstract: This LED driving device comprises: a DC/DC controller which controls an output stage for supplying an output voltage to an LED; and a current driver which generates an output current of the LED, wherein the current driver performs PWM dimming by turning on the output current in accordance with an LED-current-on period of a PWM dimming signal and turning off the output current in accordance with an LED-current-off period of the PWM dimming signal, and the DC/DC controller includes a feedback control unit which performs feedback control for outputting a switching pulse to the output stage so as to make a cathode voltage of the LED equal to a reference voltage, and a pulse addition control unit which performs pulse addition control for adding a predetermined pulse number of additional switching pulses at a time of switching between the LED-current-on period and the LED-current-off period.

公开(公告)号：US20230254957A1

公开(公告)日：2023-08-10

申请号：US18303871

申请日：2023-04-20

Applicant: Rohm Co., Ltd.

Inventor： Ryosuke Kanemitsu ,  Koji Katsura

IPC: H05B45/3725 ,  B60Q3/18 ,  H05B45/345 ,  H05B45/56 ,  H05B45/325 ,  H05B45/10

CPC classification number: H05B45/3725 ,  B60Q3/18 ,  H05B45/345 ,  H05B45/56 ,  H05B45/325 ,  H05B45/10

Abstract: This LED driving device comprises: a DC/DC controller which controls an output stage for supplying an output voltage to an LED; and a current driver which generates an output current of the LED, wherein the current driver performs PWM dimming by turning on the output current in accordance with an LED-current-on period of a PWM dimming signal and turning off the output current in accordance with an LED-current-off period of the PWM dimming signal, and the DC/DC controller includes a feedback control unit which performs feedback control for outputting a switching pulse to the output stage so as to make a cathode voltage of the LED equal to a reference voltage, and a pulse addition control unit which performs pulse addition control for adding a predetermined pulse number of additional switching pulses at a time of switching between the LED-current-on period and the LED-current-off period.

公开(公告)号：US20220330403A1

公开(公告)日：2022-10-13

申请号：US17851369

申请日：2022-06-28

Applicant: Rohm Co., Ltd.

Inventor： Ryosuke Kanemitsu ,  Koji Katsura

IPC: H05B45/3725 ,  B60Q3/18 ,  H05B45/345 ,  H05B45/56 ,  H05B45/325 ,  H05B45/10

Abstract: This LED driving device comprises: a DC/DC controller which controls an output stage for supplying an output voltage to an LED; and a current driver which generates an output current of the LED, wherein the current driver performs PWM dimming by turning on the output current in accordance with an LED-current-on period of a PWM dimming signal and turning off the output current in accordance with an LED-current-off period of the PWM dimming signal, and the DC/DC controller includes a feedback control unit which performs feedback control for outputting a switching pulse to the output stage so as to make a cathode voltage of the LED equal to a reference voltage, and a pulse addition control unit which performs pulse addition control for adding a predetermined pulse number of additional switching pulses at a time of switching between the LED-current-on period and the LED-current-off period.

公开(公告)号：US10562438B2

公开(公告)日：2020-02-18

申请号：US15492102

申请日：2017-04-20

Applicant: Rohm Co., Ltd.

Inventor： Koji Katsura ,  Yasunori Muramatsu

IPC: H05B33/08 ,  B60Q1/00

Abstract: A light-emitting element driving semiconductor integrated circuit constitutes at least part of a light-emitting element driving device that is configured to drive a first and a second light source when the first light source is not short-circuited and drive the second light source when the first light source is short-circuited and that includes an output capacitor. The light-emitting element driving semiconductor integrated circuit has a controller configured to control the resistance value of a variable resistor connected in series with the first and second light sources according to the voltage across a resistor connected in series with the first and second light sources.