公开(公告)号：US09265101B2

公开(公告)日：2016-02-16

申请号：US13829607

申请日：2013-03-14

Applicant: ANALOG DEVICES, INC.

Inventor： Jonathan Kraft

IPC: H05B37/00 ,  H05B33/08 ,  H05B37/02

CPC classification number: H05B33/0851 ,  H05B33/0809 ,  H05B33/0812 ,  H05B33/0815 ,  H05B33/0827 ,  H05B33/0884 ,  H05B37/02 ,  Y02B20/341 ,  Y02B20/347

Abstract: A LED drive system for controlling an off-chip power supply enables the power supply function to be located ‘off-chip’—i.e., on an IC which is separate from the IC containing the other LED drive system components. The off-chip supply provides a common line voltage for LED strings connected in series with respective current sink circuits at respective junctions, in response to a signal applied to a control input. The system includes a ‘minimum’ circuit which outputs the least of the voltages at the junctions, and an I/O pin which receives a signal that varies with the output of the minimum circuit. When the external supply's control input is coupled to the system's I/O pin, the present system controls the output of the external power supply as needed to provide a desired common line voltage.

Abstract translation: 用于控制芯片外电源的LED驱动系统使得电源功能能够位于“芯片外”，即在与包含其它LED驱动系统部件的IC分开的IC上。 响应于施加到控制输入的信号，片外电源为在相应结处的相应电流吸收电路串联连接的LED串提供公共线路电压。 该系统包括输出结点处最小电压的“最小”电路，以及接收随着最小电路的输出而变化的信号的I / O引脚。 当外部电源的控制输入耦合到系统的I / O引脚时，本系统根据需要控制外部电源的输出以提供所需的公共电压。

公开(公告)号：US20140015427A1

公开(公告)日：2014-01-16

申请号：US13919371

申请日：2013-06-17

Applicant: ANALOG DEVICES, INC.

Inventor： Eric Sagen ,  Jonathan Kraft ,  Kenneth G. Richardson

IPC: H05B33/08

CPC classification number: H05B33/083 ,  H05B33/0815 ,  H05B33/0827 ,  Y02B20/347

Abstract: A drive system for multiple LED strings powered by a common line voltage. Current control circuits are connected in series with respective LED strings; each current control circuit includes a drive transistor (typically a FET) which causes a desired LED string current to be conducted. In one embodiment, the current conducted by a selected one of the LED strings is controlled by the line voltage regulation loop, while the currents conducted by the remaining LED strings are controlled by respective local current loops, thus avoiding conflicts between the local current and line voltage regulation loops. The LED string to be current regulated by the line voltage regulation loop can be determined by a variety of criteria, such as the current control circuit having the maximum FET gate voltage, the minimum FET source voltage, the minimum FET drain voltage, the maximum FET gate-source voltage, or the minimum FET drain-source voltage.

Abstract translation: 用于由公共线路电压供电的多个LED串的驱动系统。 电流控制电路与相应的LED串串联; 每个电流控制电路包括导致期望的LED串电流的驱动晶体管（通常为FET）。 在一个实施例中，由所选择的一个LED串所传导的电流由线路电压调节回路控制，而由剩余LED串传导的电流由各自的局部电流回路控制，从而避免局部电流和线路之间的冲突 电压调节回路。 由电压调节回路调节的LED串可以通过各种标准来确定，例如具有最大FET栅极电压，最小FET源电压，最小FET漏极电压，最大FET的电流控制电路 栅源电压或最小FET漏源电压。

公开(公告)号：US08907573B2

公开(公告)日：2014-12-09

申请号：US13777045

申请日：2013-02-26

Applicant: Analog Devices, Inc.

Inventor： Jonathan Kraft

IPC: H05B37/02 ,  H05B33/08

CPC classification number: H05B33/0851 ,  H05B33/0809 ,  H05B33/0812 ,  H05B33/0815 ,  H05B33/0827 ,  H05B33/0884 ,  H05B37/02 ,  Y02B20/341 ,  Y02B20/347

Abstract: A LED current control system for use with an LED drive system which includes LED strings connected in series with respective current sink circuits, each of which causes a current to be conducted by the LED string to which it is connected. The drive system includes 3 or more ‘dimming’ inputs with which the LED string currents can be adjusted. The LED current control system comprises at least one minimum circuit which receives two or more dimming inputs and produces an output which is proportional to the lesser of the inputs, a multiplier circuit which receives the outputs of the minimum circuits and at least one other dimming input and produces an output ILED which is proportional to the product of the received signals, and a sink control circuit which receives ILED and controls the current sink circuits such that the string currents vary with ILED.

Abstract translation: 一种与LED驱动系统一起使用的LED电流控制系统，其包括与各个电流吸收电路串联连接的LED串，每个电流引起电流由与其连接的LED串导通。 驱动系统包括3个或更多个“调光”输入，可以调节LED串电流。 LED电流控制系统包括至少一个最小电路，其接收两个或多个调光输入并产生与较小输入成比例的输出;接收最小电路的输出和至少一个其它调光输入的乘法器电路 并产生与接收信号的乘积成比例的输出ILED，以及接收ILED并控制电流吸收电路的吸收控制电路，使得串电流随着ILED而变化。

公开(公告)号：US08890421B2

公开(公告)日：2014-11-18

申请号：US13760881

申请日：2013-02-06

Applicant: Analog Devices, Inc.

Inventor： Jonathan Kraft

IPC: H05B37/00 ,  H05B39/00 ,  H05B41/00 ,  H01J7/44 ,  H01J13/46 ,  H01J17/34 ,  H01J19/78 ,  H01J23/16 ,  H05B33/08 ,  H05B37/02

CPC classification number: H05B33/0851 ,  H05B33/0809 ,  H05B33/0812 ,  H05B33/0815 ,  H05B33/0827 ,  H05B33/0884 ,  H05B37/02 ,  Y02B20/341 ,  Y02B20/347

Abstract: A line voltage control circuit for use with a multi-string LED drive system which provides a common line voltage for multiple LED strings that are connected to respective current sink circuits at respective junctions. An error amplifier receives the minimum junction voltage and a reference ‘desired junction voltage’ at respective inputs, and a voltage regulator outputs the line voltage in response to a voltage applied to a feedback input. A comparator toggles an output when the maximum junction voltage (Vmax) exceeds a reference limit (Vlimit). A multiplexer receives the error amplifier output and a fixed voltage at respective inputs and provides one of the signals to the regulator's feedback input in response to the comparator output. When Vmax>Vlimit, the fixed voltage is provided to the feedback input and the line voltage is reduced, thereby protecting low voltage current sinks from potentially damaging high voltages.

Abstract translation: 一种用于多串LED驱动系统的线路电压控制电路，其为在各个连接处连接到相应的电流吸收电路的多个LED串提供公共线路电压。 误差放大器在相应的输入处接收最小结电压和参考“期望的结电压”，并且电压调节器响应于施加到反馈输入的电压而输出线电压。 当最大结电压（Vmax）超过参考极限（Vlimit）时，比较器切换输出。 多路复用器在相应的输入处接收误差放大器输出和固定电压，并响应于比较器输出将一个信号提供给调节器的反馈输入。 当Vmax> Vlimit时，固定电压被提供给反馈输入并且线路电压降低，从而保护低电压电流吸收器免受潜在的破坏性高电压。

公开(公告)号：US09363858B2

公开(公告)日：2016-06-07

申请号：US13919371

申请日：2013-06-17

Applicant: ANALOG DEVICES, INC.

Inventor： Eric Sagen ,  Jonathan Kraft ,  Kenneth G. Richardson

IPC: H05B37/00 ,  H05B39/00 ,  H05B41/00 ,  H05B33/08

CPC classification number: H05B33/083 ,  H05B33/0815 ,  H05B33/0827 ,  Y02B20/347

Abstract: A drive system for multiple LED strings powered by a common line voltage. Current control circuits are connected in series with respective LED strings; each current control circuit includes a drive transistor (typically a FET) which causes a desired LED string current to be conducted. In one embodiment, the current conducted by a selected one of the LED strings is controlled by the line voltage regulation loop, while the currents conducted by the remaining LED strings are controlled by respective local current loops, thus avoiding conflicts between the local current and line voltage regulation loops. The LED string to be current regulated by the line voltage regulation loop can be determined by a variety of criteria, such as the current control circuit having the maximum FET gate voltage, the minimum FET source voltage, the minimum FET drain voltage, the maximum FET gate-source voltage, or the minimum FET drain-source voltage.

Abstract translation: 用于由公共线路电压供电的多个LED串的驱动系统。 电流控制电路与相应的LED串串联; 每个电流控制电路包括导致期望的LED串电流的驱动晶体管（通常为FET）。 在一个实施例中，由所选择的一个LED串所传导的电流由线路电压调节回路控制，而由剩余LED串所传导的电流由各自的局部电流回路控制，从而避免局部电流和线路之间的冲突 电压调节回路。 由电压调节回路调节的LED串可以通过各种标准来确定，例如具有最大FET栅极电压，最小FET源电压，最小FET漏极电压，最大FET的电流控制电路 栅源电压或最小FET漏源电压。

公开(公告)号：US20160088705A1

公开(公告)日：2016-03-24

申请号：US14957339

申请日：2015-12-02

Applicant: Analog Devices Inc.

Inventor： Jonathan Kraft

IPC: H05B33/08

CPC classification number: H05B33/0851 ,  H05B33/0809 ,  H05B33/0812 ,  H05B33/0815 ,  H05B33/0827 ,  H05B33/0884 ,  H05B37/02 ,  Y02B20/341 ,  Y02B20/347

Abstract: A LED drive system for controlling an off-chip power supply enables the power supply function to be located ‘off-chip’—i.e., on an IC which is separate from the IC containing the other LED drive system components. The off-chip supply provides a common line voltage for LED strings connected in series with respective current sink circuits at respective junctions, in response to a signal applied to a control input. The system includes a ‘minimum’ circuit which outputs the least of the voltages at the junctions, and an I/O pin which receives a signal that varies with the output of the minimum circuit. When the external supply's control input is coupled to the system's I/O pin, the present system controls the output of the external power supply as needed to provide a desired common line voltage.

Abstract translation: 用于控制芯片外电源的LED驱动系统使得电源功能能够位于“芯片外”，即在与包含其它LED驱动系统部件的IC分开的IC上。 响应于施加到控制输入的信号，片外电源为在相应结处的相应电流吸收电路串联连接的LED串提供公共线路电压。 该系统包括输出结点处最小电压的“最小”电路，以及接收随着最小电路的输出而变化的信号的I / O引脚。 当外部电源的控制输入耦合到系统的I / O引脚时，本系统根据需要控制外部电源的输出以提供所需的公共电压。

公开(公告)号：US08901853B2

公开(公告)日：2014-12-02

申请号：US13742770

申请日：2013-01-16

Applicant: Analog Devices, Inc.

Inventor： Jonathan Kraft

IPC: G05F1/00

CPC classification number: H05B33/0851 ,  H05B33/0809 ,  H05B33/0812 ,  H05B33/0815 ,  H05B33/0827 ,  H05B33/0884 ,  H05B37/02 ,  Y02B20/341 ,  Y02B20/347

Abstract: A multi-string LED drive system for multiple LED strings powered by a common line voltage. A plurality of current control circuits are connected in series with respective LED strings, each of which includes a transistor which causes a desired LED string current to be conducted when a sufficient voltage is applied to the transistor's gate. A “maximum” circuit receives each of the gate voltages at respective inputs and outputs a voltage which is proportional to the greatest of the received voltages. A line regulator circuit receives the output of the maximum circuit and a signal which represents a target gate voltage at respective inputs and generates the common line voltage such that the highest of the gate voltages is approximately equal to the target gate voltage, such that system power efficiency is optimized in cases of imbalance between LED string voltage drops and/or sink device characteristics.

Abstract translation: 多串LED驱动系统，用于由公共线电压供电的多个LED串。 多个电流控制电路与相应的LED串串联连接，每个LED串包括晶体管，当晶体管的栅极施加足够的电压时，该晶体管导致所需的LED串电流。 “最大”电路在各个输入端接收每个栅极电压，并输出与最大接收电压成比例的电压。 线路稳压器电路接收最大电路的输出和表示各个输入端的目标栅极电压的信号，并产生公共线路电压，使得栅极电压的最高值近似等于目标栅极电压，使得系统功率 在LED串电压降和/或吸收器件特性之间的不平衡的情况下，效率被优化。