LED device and lighting device comprising the same

Abstract

A light emitting diode (LED) apparatus is provided. The LED apparatus includes a first LED string configured to emit light having a first color temperature, a second LED string connected in parallel to the first LED string and configured to emit light having a second color temperature different from the first color temperature, a controller configured to generate a control signal based on a control command received from an external controller, a switching circuit configured to control a luminance of any one or any combination of the first LED string and the second LED string based on the control signal, and a power supply configured to generate an internal power voltage for operations of the controller and the switching circuit.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2020-0157649, filed with the Korean Intellectual Property Office on November 23, 2020, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The methods, apparatus, and systems consistent with the example embodiments relate to LED devices and lighting devices including the LED devices. Background Technology

[0004] Light-emitting diodes (LEDs) have advantages such as low power consumption and relatively long lifespan, and are rapidly replacing fluorescent and incandescent lamps. Recently, various types of lighting devices using LEDs as light sources have been developed and marketed, and research is actively underway on lighting devices with various functions beyond simple illumination. For example, functions that can control the color temperature and / or brightness of light, or monitor the operating status of the LEDs installed as light sources, can be applied to lighting devices. Summary of the Invention

[0005] One or more example embodiments provide LED devices that can provide a variety of functions while significantly reducing the replacement and / or upgrading of components included in a lighting device, and lighting devices that include the LED device.

[0006] According to one aspect of an example embodiment, an LED device includes: a first LED string configured to emit light having a first color temperature; a second LED string connected in parallel to the first LED string and configured to emit light having a second color temperature different from the first color temperature; a controller configured to generate a control signal based on a control command received from an external controller; a switching circuit configured to control the brightness of either the first LED string or any combination of the second LED string based on the control signal; and a power supply configured to generate an internal power supply voltage for operation of the controller and the switching circuit.

[0007] According to one aspect of an example embodiment, a lighting device includes: an LED driver configured to generate drive power using alternating current (AC) power and output the drive power through a first drive node and a second drive node; a plurality of LED strings including a first LED string connected between the first drive node and a first LED output node, and a second LED string connected between the first drive node and the second LED output node, the first LED string being configured to emit light having a first color temperature, and the second LED string being configured to emit light having a second color temperature; and a controller connected between the LED driver and the plurality of LED strings to the first drive node, the second drive node, the first LED output node, and the second LED output node. The controller includes a switching circuit connected to the first LED output node, the second LED output node, and the second drive node, and is configured to adjust the brightness of any one of the first LED string and the second LED string, or any combination of the first LED string and the second LED string.

[0008] According to one aspect of an example embodiment, an LED device includes: a plurality of LEDs directly connected to at least a portion of a plurality of output terminals of an output harness of an LED driver; a power supply connected to a first output terminal of the plurality of output terminals and configured to generate a first internal power supply voltage and a second internal power supply voltage using drive power received from the LED driver via the first output terminal; a controller configured to operate using the first internal power supply voltage and generate a PWM control signal based on a control command received from an external controller; and a switching circuit connected between one of the plurality of LEDs and a second output terminal of the plurality of output terminals and configured to operate using the second internal power supply voltage and adjust the brightness of a portion of the plurality of LEDs based on the PWM control signal. Attached Figure Description

[0009] The above and other aspects, features, and advantages will become more apparent from the following description of exemplary embodiments, taken in conjunction with the accompanying drawings, in which:

[0010] Figure 1 This is a block diagram schematically illustrating a lighting device according to an example embodiment;

[0011] Figure 2 This is a block diagram schematically illustrating an LED device according to an example embodiment;

[0012] Figures 3 to 6 This is a diagram illustrating the operation of an LED device according to an example embodiment.

[0013] Figure 7This is a schematic diagram of an LED device according to an example embodiment;

[0014] Figure 8 This is a block diagram schematically illustrating an LED driver included in a lighting device according to an example embodiment;

[0015] Figure 9 This is a schematic diagram illustrating the converter circuit of the LED driver included in a lighting device according to an example embodiment;

[0016] Figure 10 This is a schematic diagram illustrating an LED device according to an example embodiment;

[0017] Figure 11 and Figure 12 This is a schematic diagram illustrating a lighting device according to an example embodiment.

[0018] Figure 13 This is a diagram illustrating the dimming function of an LED device according to an example embodiment;

[0019] Figure 14 and Figure 15 This is a diagram illustrating a connection method between an LED device and an LED driver according to an example embodiment; and

[0020] Figure 16 and Figure 17 This is a schematic diagram illustrating an LED device according to an example embodiment. Detailed Implementation

[0021] The following is a detailed description of an example embodiment in conjunction with the accompanying drawings.

[0022] Figure 1 This is a block diagram schematically illustrating a lighting device according to an example embodiment.

[0023] Reference Figure 1 According to an example embodiment, the lighting device 10 may include an LED driver 20 and an LED device 30 connected to a power supply 1. The LED device 30 may be connected to the LED driver 20 via a first drive node 21 and a second drive node 22, and the LED device 30 may be driven by a drive power V output from the LED driver 20. DRV To function. For example, LED driver 20 can output an LED current I to drive the LED. LED As a constant current.

[0024] LED driver 20 may include AC power V output from power supply 1. AC A rectifier circuit that converts DC power to DC power, using the rectified DC power to generate drive power V. DRVThe converter circuit, etc. According to the example embodiment, an electromagnetic interference (EMI) filter, etc., can also be connected between the power supply 1 and the rectifier circuit. The structure and operation of the LED driver 20 will be described later.

[0025] The LED device 30 may include an LED string 31, an intelligent controller 32, etc. The LED string 31 includes multiple LEDs that function as a light source and can be driven by a power supply V. DRV Connect multiple LEDs.

[0026] For example, the multiple LEDs included in LED string 31 can constitute a first LED string and a second LED string. The first LED string can emit light of a first color temperature, and the second LED string can emit light of a second color temperature. The first color temperature and the second color temperature can be different from each other. For example, the LEDs included in the first LED string can output cool white light, and the LEDs included in the second LED string can output warm white light. The first LED string and the second LED string can be connected in parallel with each other. Furthermore, the number of LED strings included in LED string 31 is not necessarily limited to two, and LED string 31 can include three or more LED strings.

[0027] The intelligent controller 32 may include a controller, a switching circuit, a power supply, etc. The controller can be connected to an external controller, etc., and can operate to generate predetermined control signals, and the switching circuit can operate according to the control signals. For example, the switching circuit can be directly connected to the LED string 31 and can control multiple LEDs included in the LED string 31 according to the control signals. The power supply can use drive power V. DRV This generates the internal power supply voltage required for the operation controller and switching circuits.

[0028] Figure 2 This is a block diagram schematically illustrating an LED device according to an example embodiment.

[0029] Reference Figure 2 The LED device 100 according to the example embodiment may include an LED string 110, an intelligent controller 120, etc. The LED string 110 includes a first LED string 111 and a second LED string 112, and as described above, the first LED string 111 and the second LED string 112 can be connected in parallel with each other and can emit light of different color temperatures.

[0030] The intelligent controller 120 may include a power supply 121, a controller 122, a switching circuit 123, etc. The power supply 121 can use drive power V. DRV To generate the internal power supply voltage V for the operation of controller 122 and switching circuit 123. INT1 and V INT2According to the example embodiment, the operating voltage of the controller 122 and the operating voltage of the switching circuit 123 may be different from each other, and the power supply 121 may provide a first internal power supply voltage V to the controller 122. INT1 And it provides a second internal power supply voltage V to the switching circuit 123. INT2 The power supply 121 may include generating a first internal power supply voltage V. INT1 The first regulator and the generator of the second internal power supply voltage V INT2 The second regulator.

[0031] Controller 122 can receive a first internal power supply voltage V INT1 The controller 122 can operate and generate a control signal CTR for the control switching circuit 123. For example, the control signal CTR can be a pulse width modulation (PWM) signal. The controller 122 can adjust the duty cycle of the control signal CTR according to control commands received from an external controller.

[0032] According to an example embodiment, controller 122 can be connected to an external controller via wired or wireless communication to receive control commands. For example, controller 122 may include a wireless communication interface and can be connected to an external controller via wireless communication such as BLUETOOTH™, ZIGBEE™, Wi-Fi, Li-Fi, and infrared communication. Alternatively, controller 122 may include a wired communication interface and can be connected to an external controller via wired communication such as a Digital Addressable Lighting Interface (DALI) or Digital Multiplexing (DMX). Controller 122 may include a microcontroller unit (MCU), communication circuitry, an antenna, an oscillator, etc., to operate by connecting to an external controller via various wired and wireless communications.

[0033] The microcontroller unit of controller 122 can generate a control signal CTR using control commands received from an external controller via a communication circuit. As described above, the duty cycle of the control signal CTR can vary according to the control command.

[0034] Switching circuit 123 may be connected to a first LED string 111 and a second LED string 112. In an example embodiment, switching circuit 123 may include a switching device connected to at least one of the first LED string 111 and the second LED string 112, and a switch driver for controlling the on / off switching of the switching device. According to the example embodiment, the number of each of the switching device and the switch driver included in switching circuit 123 may vary. Referring later... Figures 3 to 6 Describe the detailed configuration of the switching circuit 123.

[0035] Reference Figure 2 The first LED string 111 can be connected to the first LED input node N. IN1and the first LED output node N OUT1 Between, and the second LED string 112 can be connected to the second LED input node N. IN2 Second LED output node N OUT2 Between. First LED input node N IN1 Second LED input node N IN2 It is possible Figure 2 The LEDs are interconnected as shown and can be directly connected to an external LED driver via the first drive node 101. First LED output node N OUT1 Second LED output node N OUT2 They can be separated from each other and can be connected to the second drive node 102 via the switching circuit 123. The switching device included in the switching circuit 123 can be connected to the first LED output node N. OUT1 Second LED output node N OUT2 At least one of them.

[0036] By using the first LED output node N OUT1 Second LED output node N OUT2 Separate from each other, and output the first LED node N. OUT1 Second LED output node N OUT2 Connected to the switching circuit 123, the output of at least one of the first LED string 111 and the second LED string 112 can be adjusted independently. (Refer to...) Figures 3 to 6 The operation of switch circuit 123 is described in more detail.

[0037] According to an example embodiment, the LED string 110 and the smart controller 120 can be implemented on a single package substrate. As an example, the first LED string 111 and the second LED string 112 can be mounted on the front surface of the package substrate, and the power supply 121, controller 122, switching circuit 123, etc., can be mounted on the rear surface of the package substrate. As described above, by implementing both the LED string 110 and the smart controller 120 on a single package substrate, the LED device 100 can be manufactured in a form compatible with existing LED modules connected to an LED driver.

[0038] However, the example embodiment is not limited to this, and the smart controller 120 can also be implemented separately from the LED string 110. As an example, the first LED string 111 and the second LED string 112 of the LED string 110 can be implemented using multiple LEDs mounted on a predetermined package substrate, and the smart controller 120 can be implemented using an IC and devices mounted on a different package substrate than the LED string 110. When the smart controller 120 is implemented in a separate package different from the LED string 110 as described above, an antenna or the like, included in the controller 122 of the smart controller 120 and communicating with an external controller, can be provided in the light-emitting direction of the LED string 110. Therefore, the wireless communication performance between the external controller and the smart controller 120 can be improved.

[0039] Figures 3 to 6 This is a diagram illustrating the operation of an LED device according to an example embodiment.

[0040] like Figures 3 to 6 As shown, LED string 110 may include a first LED string 111 and a second LED string 112 connected in parallel with each other. The first LED string 111 may include a first LED (LED1), and the second LED string 112 may include a second LED (LED2). The first LED string 111 is connected to the first LED input node N. IN1 and the first LED output node N OUT1 Between, and the second LED string 112 is connected to the second LED input node N. IN2 Second LED output node N OUT2 Between, and the first LED input node N IN1 Second LED input node N IN2 They can be connected to each other. First LED input node N IN1 Second LED input node N IN2 Connected to the first drive node 101, and can receive drive power V DRV .

[0041] like Figure 3 As shown, the switching circuit 123 may include a switching device SW and a switching driver SDV. The switching device SW may be connected to the second LED output node N. OUT2 Between the second drive node 102 and the switch driver SDV. The switch driver SDV operates via the control signal CTR, and the control signal CTR can be a PWM signal generated by the controller, as referred above. Figure 2For example, the switch driver SDV can control the switch device SW to turn on and off according to the control signal CTR. For example, the switch circuit 123 can control the duty cycle of the second LED string 112 according to the control signal CTR. For example, the switch circuit 123 can control the color temperature of the light emitted by the LED string 110 by controlling the duty cycle of the second LED string 112.

[0042] exist Figure 3 In the example embodiment shown, the switching circuit 123 cannot control the first LED string 111, and can only adjust the duty cycle of the control signal CTR used to control the second LED string 112. Therefore, although the control range of the color temperature of the light emitted by the LED string 110 may be relatively small, the production cost and power consumption can be reduced because the switching circuit 123 is only equipped with one switching device SW and one switching driver SDV.

[0043] like Figure 4 As shown, the switching circuit 123A may include a first switching device SW1, a second switching device SW2, and a switch driver SDV. The first switching device SW1 can be connected to the first LED output node N of the first LED string 111. OUT1 Between the second drive node 102 and the second switch device SW2, the second LED output node N can be connected. OUT2 Between the second driving node 102 and the second driving node.

[0044] exist Figure 4 In the illustrated example embodiment, the first switching device SW1 may include a PMOS transistor, and the second switching device SW2 may include an NMOS transistor. Therefore, a single switch driver SDV can be used to control the first LED string 111 and the second LED string 112. For example, the switch driver SDV can control the first switching device SW1 and the second switching device SW2 to be turned on and off according to the control signal CTR. For example, the first switching device SW1 and the second switching device SW2 can operate in opposite states according to the control signal CTR. For example, the switch circuit 123A can control the duty cycle of the first LED string 111 and the second LED string 112 according to the control signal CTR. For example, the switch circuit 123A can control the color temperature of the light emitted by the LED string 110 by controlling the duty cycle of the first LED string 111 and the second LED string 112. However, since the first switching device SW1 and the second switching device SW2 are turned on and off by the same control signal CTR, it may be difficult to control the first LED string 111 and the second LED string 112 independently, and therefore, the color temperature control range of the light emitted by the LED string 110 may be limited.

[0045] Reference Figure 5The switching circuit 123B may include a first switching device SW1, a second switching device SW2, a first switch driver SDV1, and a second switch driver SDV2. For example, the first switching device SW1 and the second switching device SW2 may each include a PMOS transistor or each include an NMOS transistor. The first switch driver SDV1 can control the first switching device SW1 using a complementary signal of the control signal CTR received from the controller, and the second switch driver SDV2 can control the second switching device SW2 using the control signal CTR. For example, the first switching device SW1 and the second switching device SW2 can operate in opposite states according to the control signal CTR. For example, the switching circuit 123B can control the duty cycle of the first LED string 111 and the second LED string 112 according to the control signal CTR. For example, the switching circuit 123B can control the color temperature of the light emitted by the LED string 110 by controlling the duty cycle of the first LED string 111 and the second LED string 112.

[0046] In respectively Figure 4 and Figure 5 The operation of the switching circuits 123A and 123B shown can be similar to each other. For example, refer to Figure 5 When the duty cycle of the control signal CTR is 25%, the first switching device SW1 is controlled by a signal with a duty cycle of 75%, while the second switching device SW2 can be controlled by a signal with a duty cycle of 25%. Conversely, when the duty cycle of the control signal CTR is 75%, the first switching device SW1 is turned on / off by a signal with a duty cycle of 25%, while the second switching device SW2 can be turned on / off by a signal with a duty cycle of 75%.

[0047] Reference Figure 6 The switching circuit 123C may include a first switching device SW1, a second switching device SW2, a first switch driver SDV1, and a second switch driver SDV2. Figure 6 In the example embodiment shown, the first switch driver SDV1 and the second switch driver SDV2 can control the switching devices SW1 and SW2 through different control signals. The first switch driver SDV1 can control the first switching device SW1 through the first control signal CTR1, and the second switch driver SDV2 can control the second switching device SW2 through the second control signal CTR2.

[0048] The first control signal CTR1 and the second control signal CTR2 are signals generated by a controller included in the intelligent controller along with the switching circuit 123C, and the duty cycle of the first control signal CTR1 and the duty cycle of the second control signal CTR2 can be determined independently of each other. Specifically, the duty cycle of the first control signal CTR1 can be determined independently of the duty cycle of the second control signal CTR2. For example, the switching circuit 123C can control the duty cycle of the first LED string 111 according to the first control signal CTR1, and control the duty cycle of the second LED string 112 according to the second control signal CTR2. For example, the switching circuit 123C can control the color temperature of the light emitted by the LED string 110 by independently controlling the duty cycles of the first LED string 111 and the second LED string 112. Therefore, compared with the reference... Figures 3 to 5 Compared to the described example embodiments, the control range of the color temperature of the light emitted by the LED string 110 can be increased, and the brightness of the light emitted by the LED string 110 can also be adjusted.

[0049] In the example embodiment, the first LED string 111 can emit cool white light, and the second LED string 112 can emit warm white light. As an example, assume that the first color temperature of the light emitted by the first LED string 111 is approximately 6000K (cool white series), and the second color temperature of the light emitted by the second LED string 112 is approximately 2700K (warm white series). Therefore, the color temperature (CCT) of the light emitted by the LED string 110 can be determined based on the duty cycle of the first control signal CTR1 used to determine the on / off switching of the first switching device SW1 and the duty cycle of the second control signal CTR2 used to determine the on / off switching of the second switching device SW2, as shown in Table 1.

[0050] [Table 1]

[0051] Duty cycle of the first control signal Duty cycle of the second control signal Color temperature of light 100％ 0％ 6000K 75％ 25％ 5175K 50％ 50％ 4350K 25％ 75％ 3525K 0％ 100％ 2700K

[0052] The combination of the duty cycles of the first control signal CTR1 and the second control signal CTR2, as described in the example in Table 1, can also be based on... Figure 4 and Figure 5 The example embodiments of the switching circuits 123A and 123B shown are implemented. However, as described above, in the case of switching circuit 123C, according to... Figure 6 In the example embodiment shown, because the first switching device SW1 and the second switching device SW2 are controlled by the first control signal CTR1 and the second control signal CTR2 generated by the controller respectively, the color temperature of the light emitted by the LED string 110 can be changed to have various values.

[0053] Figure 7 This is a schematic diagram of an LED device according to an example embodiment.

[0054] Reference Figure 7 The LED device 200 according to an example embodiment may include an LED string 210, a power supply 220, a controller 230, and a switching circuit 240. The LED device 200 can be connected to an external LED driver via a first driving node 201 and a second driving node 202. Figure 7 In the example embodiment shown, the configuration of the LED string 210 and the switching circuit 240 can be similar to that described in the reference. Figure 6 The configuration of the LED string and switching circuit is described.

[0055] For example, LED string 210 may include a first LED string 211 and a second LED string 212. The first LED string 211 includes a first LED (LED1) that emits light of a first color temperature, and the second LED string 212 includes a second LED (LED2) that emits light of a second color temperature. Switching circuit 240 may include a first switching device SW1 connected to the first LED string 211, a second switching device SW2 connected to the second LED string 212, and switch drivers SDV1 and SDV2. The on / off switching of the first switching device SW1 may be controlled by the first switch driver SDV1 according to a first control signal CTR1, and the on / off switching of the second switching device SW2 may be controlled by the second switch driver SDV2 according to a second control signal CTR2.

[0056] The power supply 220 may include a first regulator 221 and a second regulator 222. Each of the first regulator 221 and the second regulator 222 may include an input terminal IN, an output terminal OUT, a resistor terminal ADJ connected to a resistor, etc.

[0057] The input terminals IN of the first regulator 221 and the second regulator 222 can each be connected to the node between the first diode D1 and the first capacitor C1, and the first diode D1 can be connected to the first drive node 201. Therefore, drive power V can be input through the input terminal IN. DRV The output terminal OUT can be connected to either the second capacitor C2 or the third capacitor C3, which serves as the output capacitor. Furthermore, the first resistor R1 and the second resistor R2 can be connected to the output terminal OUT in the first regulator 221. The node between the first resistor R1 and the second resistor R2 is connected to the resistance terminal ADJ of the first regulator 221, and the first internal power supply voltage V can be determined based on the resistance value of each of the first resistor R1 and the second resistor R2. INT1 The magnitude of the voltage. Similarly, the second internal power supply voltage V can be determined based on the resistance values ​​of each of the third resistor R3 and the fourth resistor R4. INT2 Size.

[0058] In the example embodiment, the first internal power supply voltage V INT1 This is the power supply voltage used for the operation of controller 230, the second internal power supply voltage V. INT2 This is the power supply voltage used for the operation of the switching circuit 240, and the first internal power supply voltage V INT1 The size can be smaller than the second internal power supply voltage V. INT2 The size. However, the example embodiment is not limited to this, and the first internal power supply voltage V INT1 Second internal power supply voltage V INT2 The sizes of each can vary depending on the example embodiment.

[0059] The controller 230 can generate a first control signal CTR1 and a second control signal CTR2 as PWM signals. The first control signal CTR1 can be input to the first switch driver SDV1 to control the first switching device SW1, and the second control signal CTR2 can be input to the second switch driver SDV2 to control the second switching device SW2. Figure 7 In the example embodiment shown, the first switching device SW1 and the second switching device SW2 are independently controlled by the first control signal CTR1 and the second control signal CTR2, respectively, and the color temperature and / or brightness of the light emitted by the LED string 210 can be adjusted in various ways.

[0060] The controller 230 can be connected to the external controller 250 via various wired / wireless communication methods. For example, the external controller 250 can be a mobile device such as a smartphone or tablet, or it can be a lighting controller that is fixedly installed in a space close to the LED device 200.

[0061] The user can monitor the supply of drive power V to the LED device 200 via an external controller 250. DRV The LED device 200 monitors the state of the LED driver and the state of the LED strings 210 included in the LED device 200. For example, when at least one of the first LEDs, LED1, fails, the voltage applied to the entire first LED string 211 can be changed. The LED device 200 monitors the voltage and current of each LED string 211 and 212 to monitor whether LEDs LED1 and LED2 are faulty and to monitor power consumption.

[0062] Provide drive power V to LED device 200 DRVThe power consumption of an LED driver is determined by the maximum value of its rated voltage and rated current, and is described in the LED driver's specifications. However, if the forward voltage of the LEDs (LED1 and LED2) included in the LED string 210 corresponds to a relatively low voltage within the rated voltage range of the LED driver, a difference may arise between the power consumption described in the LED driver's specifications and the actual power consumed by the LED string 210. In an example embodiment, the LED device 200 may include a voltage / current sensing circuit connected to the LED string 210. By including the voltage / current sensing circuit, the controller 230 can calculate the actual power consumption of the LED string 210 and send the calculated power consumption to an external controller 250 to notify the user.

[0063] Furthermore, the LED device 200 according to the example embodiment can determine whether flickering occurs in the LED string 210. As described above, the LED device 200 may include a voltage / current detection circuit that detects the voltage / current of the LED string 210 and sends the detected voltage / current to the controller 230. In this case, the controller 230 can use the ripple component included in the current detected from the LED string 210 to determine whether flickering has occurred and sends the determination result to an external controller 250. Alternatively, a separate optical sensor for detecting the light emitted by the LED string 210 can be added to the LED device 200, and the controller 230 can use the output of the optical sensor to calculate an accurate flicker index. The flicker index is determined to be a value between 0 and 1, and the flicker index may have a higher value (i.e., closer to 1) as the severity of flicker increases.

[0064] Figure 8 This is a block diagram schematically illustrating an LED driver included in a lighting device according to an example embodiment.

[0065] Reference Figure 8 The LED driver 300 according to the example embodiment may include an EMI filter 310, a rectifier circuit 320, a converter circuit 330, etc. The EMI filter 310 can receive AC power V. AC And it can filter AC power V AC The electromagnetic waves included. Rectifier circuit 320 can convert AC power V filtered by EMI filter 310 into AC power V. AC It is converted to DC power. In an example embodiment, rectifier circuit 320 may include a diode bridge.

[0066] Converter circuit 330 provides drive power V to multiple LEDs DRVThe converter circuit 330 can be configured in various ways according to example embodiments. For example, the converter circuit 330 may include a power factor correction (PFC) converter and a DC-DC converter that improves the power factor and increases the voltage. The converter circuit 330 can use the rectifier circuit 320 to convert AC power V AC The rectified power V generated by rectification REC To generate the driving power V for driving multiple LEDs DRV The drive power V can be determined by the characteristics of the multiple LEDs connected to the output terminals of the converter circuit 330 (e.g., the forward voltage of each LED). DRV The voltage level. In an example embodiment, the LED driver 300 can transmit the LED current I used to drive the LED. LED The output is a constant current.

[0067] Figure 9 This is a schematic diagram illustrating the converter circuit of the LED driver included in a lighting device according to an example embodiment.

[0068] For example, Figure 9 The converter circuit shown can be Figure 8 The LED driver 300 shown in the example embodiment includes a converter circuit 330. (Refer to...) Figure 9 The converter circuit 330 may include a PFC converter 331, a DC-DC converter 332, a controller 333, etc. The PFC converter 331 can be used to process rectified power V... REC The boost converter circuit operates and may include a first inductor L1, a first diode D1, a first capacitor C1, a first converter switch Q1, etc.

[0069] The first converter switch Q1 can be controlled by a signal output from the first output terminal CON1 of the controller 333, and the second converter switch Q2 can be controlled by a signal output from the second output terminal CON2 of the controller 333. When the first converter switch Q1 is turned on by the controller 333, the rectified power V REC The resulting current flows to the switching resistor R S This allows the first inductor L1 to be charged. Conversely, when the controller 333 opens the first converter switch Q1, the current charging in the first inductor L1 can be discharged, generating a current greater than the rectified power V input to the PFC converter 331. REC The voltage. In this case, the high-frequency components can be removed by connecting the first capacitor C1 connected to the first diode D1.

[0070] The DC-DC converter 332, connected in series with the PFC converter 331, can operate as a buck converter circuit and may include a second inductor L2, a second diode D2, a second capacitor C2, and a second converter switch Q2. Similar to the first converter switch Q1, the second converter switch Q2 can be controlled by the controller 333.

[0071] When the controller 333 turns on the second converter switch Q2, it can charge the second inductor L2 while current flows to it. Conversely, when the controller 333 turns off the second converter switch Q2, the current flowing in the second inductor L2 due to the energy being charged can output drive power V. DRV When the second converter switch Q2 is off, the second diode D2 provides a path for current to flow, and the second capacitor C2 can be used as a rectifier capacitor.

[0072] LED driver 300 outputs LED current I to multiple LEDs through converter circuit 330. LED It can have a fixed value. Furthermore, the LED driver 300 can have a rated voltage within a predetermined range, and can be controlled by the maximum value of the rated voltage and the LED current I. LED To determine the power consumption of LED driver 300. The LED current I of LED driver 300 can be provided. LED Rated voltage and power consumption are specified as LED driver 300.

[0073] However, if the sum of the forward voltages of the multiple LEDs connected to the LED driver 300 corresponds to the middle or lower part of the rated voltage range due to reasons such as the failure of at least some of the LEDs connected to the LED driver 300, the power consumption of the multiple LEDs connected to the LED driver 300 as a load can be reduced. Therefore, there may be a difference between the power consumption described in the specification of the LED driver 300 and the power actually consumed by the LED driver 300 in operation.

[0074] In an example embodiment, the aforementioned problems can be prevented using a smart controller included in the LED device along with the plurality of LEDs connected to the LED driver 300. The smart controller can monitor the actual power consumed by the LED driver 300 by detecting the voltage applied to the plurality of LEDs and the current flowing through them. For example, when a relatively low voltage is detected applied to one of the LEDs in an LED string consisting of the plurality of LEDs, it can be determined that a portion of the LEDs in that LED string has failed. The LED driver 300 can generate a signal indicating that a portion of the LEDs has failed. Therefore, the state of the LED string connected to the LED driver 300 and the power consumption of the LED driver 300 can be monitored.

[0075] As described above, the intelligent controller can be connected to an external controller via wired or wireless communication. The external controller can be a device such as a smartphone and can receive indications, for example, that a portion of the LEDs has failed via wireless notification from the LED driver 300. Therefore, users can use an application with an external controller interlocked with the intelligent controller to check the status of the LED driver 300 and the LED string.

[0076] Figure 10 This is a schematic diagram illustrating an LED device according to an example embodiment.

[0077] like Figure 10 As shown, the LED device 400 according to the example embodiment may include a main device 400A and multiple slave devices 400B and 400C. The main device 400A may include an LED string 410 and an intelligent controller 420. The intelligent controller 420 includes a power supply 421, a controller 422, a switching circuit 423, etc., and the operation of each component can be similar to that described above. Figure 2 The operation of the various components in the described example embodiments.

[0078] According to Figure 10 In the LED device 400 of the illustrated example embodiment, a plurality of slave devices 400B and 400C may be further connected to a master device 400A. In the example embodiment, each of the plurality of slave devices 400B and 400C may include only a plurality of LEDs. (Refer to...) Figure 10 The first slave device 400B may include a first LED string 403 and a second LED string 404, and the second slave device 400C may include a first LED string 406 and a second LED string 407. Specifically, the intelligent controller 420 may not be included in each of the plurality of slave devices 400B and 400C.

[0079] The first LED strings 403, 406, and 411, including those in the main device 400A and multiple slave devices 400B and 400C, can be connected in series with each other, and the second LED strings 404, 407, and 412 can also be connected in series with each other. Therefore, when the switching device in the switching circuit 423 is switched on / off with a predetermined duty cycle via the control signal CTR output by the controller 422 of the intelligent controller 420, the brightness of the first LED strings 403, 406, and 411 can be adjusted simultaneously, and the brightness of the second LED strings 404, 407, and 412 can also be adjusted simultaneously. In this way, the intelligent controller 420, which is provided only in one of the multiple devices 400A, 400B, and 400C (the main device 400A), can simultaneously control multiple devices 400A, 400B, and 400C, each including multiple LEDs.

[0080] Figure 11 and Figure 12 This is a schematic diagram illustrating a lighting device according to an example embodiment.

[0081] Figure 11 and Figure 12 The diagram is provided to illustrate lighting devices 500 and 600 that provide dimming functionality. (See diagram for reference.) Figure 11 As shown, the lighting device 500 may include an LED string 510, an intelligent controller 520, an LED driver 530, etc. The LED driver 530 can receive AC power V. AC And generate driving power V DRV According to an example embodiment, the LED string 510 and the smart controller 520 can be included in a single package and the LED device can be implemented, and can be driven by power V. DRV The first LED string 511 and the second LED string 512 are used to operate the LED string 510. The LED string 510 and the intelligent controller 520 are connected to the LED driver 530 through the first driver node 501 and the second driver node 502, and can be packaged together to configure the LED device.

[0082] exist Figure 11 In the example embodiment shown, the intelligent controller 520 may include a power supply 521, a controller 522, a switching circuit 523, a dimming controller 524, etc. The power supply 521 outputs a first internal power supply voltage V. INT1 Second internal power supply voltage V INT2 and the third internal power supply voltage V INT3 And the controller 522 can be powered by the first internal power supply voltage V. INT1 The switching circuit 523 can operate via the second internal power supply voltage V. INT2 The controller 522 outputs a control signal CTR for controlling the switching circuit 523 and a dimming control signal CTR for controlling the dimming controller 524. DIM In the example embodiment, the control signal CTR and the dimming control signal CTR DIM It can be a PWM signal. Refer to the above example embodiments to understand the detailed operation of the power supply 521, controller 522, and switching circuit 523.

[0083] The dimming controller 524 operates via a third internal power supply voltage V. INT3 It works and can be controlled by the dimming control signal CTR. DIM Generates dimming control voltage. Figure 11 In the example embodiment shown, the LED driver 530 can provide dimming functionality and therefore may include, for example, Figure 11 The dimming control terminals DIM+ and DIM- are shown. The dimming controller 524 can adjust the dimming control signal CTR according to the dimming control signal.DIM The generated dimming control voltage is output to the dimming control terminals DIM+ and DIM-.

[0084] For example, the dimming control signal CTR DIM It can be a PWM signal, and the dimming controller 524 can adjust the dimming control signal CTR accordingly. DIM The duty cycle determines the level of the dimming control voltage. For example, assuming the dimming control voltage for maximum output brightness is 3V, then when the dimming control signal CTR... DIM When the duty cycle is 50%, the dimming control voltage can be 1.5V. Additionally, when the dimming control signal CTR... DIM When the duty cycle is 30%, the dimming control voltage can be 0.9V, and when the dimming control signal CTR... DIM When the duty cycle is 80%, the dimming control voltage can be 2.4V. The LED current I output by the LED driver 530 is... LED The size of the light emitted by the LED string 510 changes depending on the magnitude of the dimming control voltage, and therefore the brightness of the light emitted by the LED string 510 can be adjusted.

[0085] Next, refer to Figure 12 The lighting device 600 may include an LED string 610, an intelligent controller 620, an LED driver 630, etc. The intelligent controller 620 may include a power supply 621, a controller 622, a switching circuit 623, a dimming controller 624, etc.

[0086] and Figure 11 Compared to the example embodiments shown, Figure 12 The LED driver 630 in the example embodiment shown does not provide dimming functionality and may not include dimming control terminals. Therefore, it is not necessary to refer to... Figure 11 The dimming controller 624 operates according to the dimming control signal CTR. DIM The dimming function is achieved by determining the magnitude of the dimming control voltage through the duty cycle.

[0087] To achieve dimming functionality when connected to an LED driver 630 that does not provide dimming capabilities, a dimming controller 624 can be connected to the first LED string 611 and the second LED string 612 of the LED string 610. For example, the dimming controller 624 can adjust the dimming control signal CTR according to the dimming control signal. DIM The duty cycle is used to adjust the number of LEDs actually emitting light in each of the first LED string 611 and the second LED string 612. Therefore, in Figure 12 In the example embodiment shown, although the LED current I output by the LED driver 630 LED The size remains unchanged, but the intensity of the light emitted by the LED string 610 can be changed, as will be shown below. Figure 13To describe in more detail.

[0088] Figure 13 This is a diagram illustrating the dimming function of an LED device according to an example embodiment.

[0089] Figure 13 The operation of a dimming controller included in an LED device connected to an LED driver that does not provide dimming functionality is illustrated. (Refer to...) Figure 13 The LED device 700 may include an LED string 710, a switching circuit 720, a dimming controller 730, etc. The switching circuit 720 can control the on / off switching of the first switching device SW1 and the second switching device SW2 through the first control signal CTR1 and the second control signal CTR2 transmitted from the controller.

[0090] The dimming controller 730 includes a switching unit 731 and a switching control circuit (dim switch controller) 732, and the switching unit 731 may include multiple dimming control switches DSW1 to DSW3. The multiple dimming control switches DSW1 to DSW3 can be connected to a first LED string 711 and a second LED string 712. Figure 13 As shown, each of the multiple dimming control switches DSW1 to DSW3 can be connected to the node between the first LED LED1 and the node between the second LED LED2.

[0091] The switch control circuit 732 can adjust the dimming control signal CTR transmitted from the controller. DIM This controls the on / off switching of multiple dimming control switches DSW1 to DSW3. For example, the dimming control signal CTR DIM It can be a PWM signal, and the switching control circuit 732 can adjust the signal according to the dimming control signal CTR. DIM The duty cycle of the dimming control signal CTR turns each of the multiple dimming control switches DSW1 to DSW3 on or off. For example, when the dimming control signal CTR is active, the duty cycle of the switch is active. DIM When the duty cycle is 50%, the switch control circuit 732 can turn on the second dimming control switch DSW2 and turn off the first dimming control switch DSW1 and the third dimming control switch DSW3. Similarly, when the dimming control signal CTR... DIM When the duty cycle is 25%, the switch control circuit 732 can turn on the first dimming control switch DSW1 and turn off the second dimming control switch DSW2 and the third dimming control switch DSW3. In the example embodiment, when the dimming control signal CTR... DIM When the duty cycle is greater than 25% and less than 50%, it can be adjusted according to the dimming control signal CTR. DIM When the duty cycle is 50%, multiple dimming control switches DSW1 to DSW3 are turned on or off in the same way.

[0092] exist Figure 13 In the example embodiment shown, dimming functionality can be achieved even without a dimming control terminal on the LED driver. However, when one of the multiple dimming control switches DSW1 to DSW3 is turned on, the current input to the LED string 710 cannot flow through the switching circuit 720. Therefore, when the dimming function is activated, the color temperature of the light output from the LED string 710 may not be adjustable.

[0093] Figure 14 and Figure 15 This is a diagram illustrating a connection method between an LED device and an LED driver according to an example embodiment.

[0094] Figure 14 This diagram illustrates the connection method between the LED driver 810, which provides dimming functionality, and the LED device 820. (Refer to...) Figure 14 The LED driver 810 can be connected to an input harness 811 and an output harness 815. The input harness 811 may include multiple input terminals 812 to 814 for receiving AC power, and the output harness 815 may include multiple output terminals 816 to 819 for transmitting drive power generated by the LED driver to the LEDs. For example, a first input terminal is provided as a live terminal, a second input terminal is provided as a protective earth (PE) terminal, and a third input terminal is provided as a neutral terminal. Among the multiple output terminals, the first output terminal 816 (LED+) and the second output terminal 817 (LED-) may be terminals for outputting drive power. For example, the voltage output to the first output terminal 816 may be greater than the voltage output to the second output terminal 817.

[0095] The LED driver 810 can generate drive power using AC power received through the input wiring harness 811. The LED driver 810 may include an EMI filter, a rectifier circuit, a converter circuit, a controller, etc. The rectifier circuit converts AC power to DC power, and the converter circuit can use the DC power to generate drive power. Depending on the application of the lighting device 800, the LED driver 810 may have waterproof and dustproof properties. In an example embodiment, the LED driver 810 can be sealed with a seal capable of preventing moisture and dust penetration.

[0096] In an example embodiment, the LED driver 810 can output a constant current to drive an LED connected to the output harness 815, and the magnitude of the constant current can be determined by a controller. The controller can provide a dimming function that adjusts the magnitude of the constant current output by the LED driver 810 within a rated current range. The controller can adjust the magnitude of the constant current based on dimming control signals input through the dimming control terminals DIM+ and DIM-.

[0097] Reference Figure 14 The LED device 820 may include an LED string 821 and an intelligent controller 822. The intelligent controller 822 may include a power supply 823, a controller 824, a switching circuit 825, a dimming controller 826, etc. When the controller 824 receives a control command from an external controller via wired or wireless communication to change the brightness of the light emitted by the LED string 821, the controller 824 can convert the control command into a dimming control signal as a PWM signal and send the converted signal to the dimming controller 826. The dimming controller 826 can determine the dimming control voltage based on the duty cycle of the dimming control signal and can output the dimming control voltage to the dimming control terminals DIM+ and DIM-. Based on the magnitude of the dimming control voltage received through the dimming control terminals DIM+ and DIM-, the magnitude of the constant current output by the LED driver 810 can be increased or decreased.

[0098] Figure 15 This diagram illustrates the connection method between an LED driver 910 (which does not provide dimming functionality) and an LED device 920. (Refer to...) Figure 15 The LED driver 910 can be connected to an input harness 911 and an output harness 915. The input harness 911 may include multiple input terminals 912 to 914 for receiving AC power, and the output harness 915 may include multiple output terminals 916 (LED+) and 917 (LED-) for transmitting drive power generated by the LED driver to the LEDs. For example, a first input terminal may be provided as a live terminal, a second input terminal may be provided as a protective earth (PE) terminal, and a third input terminal may be provided as a non-live terminal.

[0099] exist Figure 15 In the example embodiment shown, the LED driver 910 does not provide dimming functionality, and therefore, there is no separate dimming control terminal in the LED driver 910. Therefore, in Figure 15 In the example embodiment shown, the dimming controller 926 of the LED device 920 includes dimming control switches connected to nodes between the LEDs of the LED string 921, and the dimming function can be implemented in a manner that changes the number of LEDs actually emitting light by turning each of the dimming control switches on or off. As an example, it can be compared with reference to... Figure 13 The dimming function is implemented in the same way as described.

[0100] Figure 16 and Figure 17 This is a schematic diagram illustrating an LED device according to an example embodiment.

[0101] according to Figure 16 and Figure 17 In the illustrated example embodiments, LED devices 1000 and 1100 may include thermoelectric circuits 1030 and 1130. Thermoelectric circuits 1030 and 1130 each include thermoelectric elements for converting heat into electrical energy. (Refer to...) Figure 16 The LED device 1000 may include an LED string 1010, a smart controller 1020, and a thermoelectric circuit 1030. The thermoelectric circuit 1030 includes a thermoelectric element and is attached to the LED string 1010 to convert heat generated during operation of the LED string 1010 into electrical energy. In an example embodiment, the thermoelectric element may be a device using the Seebeck effect, where electrical energy is generated through a temperature difference occurring between different metals or semiconductors.

[0102] Immediately after the LED string 1010 begins to emit light in the LED device 1000, almost no heat is generated in the LED string 1010. Therefore, in the initial stage of operation of the LED device 1000, as described above, the power supply 1021 can use the driving power V. DRV Generate internal power supply voltage V INT1 and V INT2 When the temperature of the LED string 1010 rises after a certain period of time and generates electrical energy in the thermoelectric circuit 1030, the electrical energy of the thermoelectric circuit 1030 can be supplied to the power supply 1021.

[0103] For example, power supply 1021 may include a capacitor that is charged using electrical energy supplied by thermoelectric circuit 1030. When the capacitor is charged, an internal power supply voltage V for the operation of controller 1022 and switching circuit 1023 can be generated from the capacitor. INT1 and V INT2 Therefore, the controller 1022 and the switching circuit 1023 can operate based on the power supplied by the capacitor, and the intelligent controller 1020 can operate with a significantly reduced impact on the LED driver connected to the LED device 1000 via drive nodes 1001 and 1002.

[0104] Next, in Figure 17 In the example embodiment shown, the smart controller 1120 may include a battery 1124. For example, the battery 1124 may include a lithium-ion battery, a charging circuit, etc.

[0105] When initially driving the LED device 1100, the battery 1124 can be in a discharged state. Therefore, the power supply 1121 can use the driving power V generated by the LED driver connected through drive nodes 1101 and 1102. DRV To generate internal power supply voltage V INT1 and V INT2 .

[0106] After a predetermined time has elapsed since the LED string 1110 began operation, the thermoelectric circuit 1130 outputs electrical energy generated from the heat produced by the LED string 1110, thereby charging the battery 1124. When the charge level of the battery 1124 exceeds a predetermined threshold, the power supply 1121 can use the output power of the battery 1124 instead of the driving power V. DRV To generate internal power supply voltage V INT1 and V INT2 Therefore, the controller 1122 and the switching circuit 1123 can operate based on the power provided by the battery 1124, and the impact of the smart controller 1120 on the LED driver connected to the LED device 1100 via drive nodes 1101 and 1102 can be significantly reduced.

[0107] As described above, according to the example embodiment, functions such as communicating with an external controller, monitoring operational status, and adjusting brightness and / or color temperature can be achieved by simply replacing the light source, which includes LEDs, without replacing or upgrading the LED drivers included in the existing lighting device. Therefore, a lighting device can be realized that significantly increases user convenience while significantly reducing the waste of previously installed equipment.

[0108] Although exemplary embodiments have been described above with reference to the accompanying drawings, it will be apparent to those skilled in the art that modifications and changes can be made without departing from the scope of this disclosure.

Claims

1. A light-emitting diode device, comprising: A first light-emitting diode string, comprising a plurality of first light-emitting diodes emitting light having a first color temperature; A second string of light-emitting diodes is connected in parallel to the first string of light-emitting diodes and includes a plurality of second light-emitting diodes that emit light with a second color temperature different from the first color temperature; An intelligent controller includes a controller, a switching circuit, a power supply, and a dimming controller. The controller is configured to generate a control signal based on a control command received from an external controller. The switching circuit is configured to control the brightness of any one of the first and second LED strings or any combination of the first and second LED strings based on the control signal. The power supply is configured to generate an internal power supply voltage for the operation of the controller and the switching circuit. The dimming controller includes a dimming control switch connected to a node between the plurality of first LEDs and a node between the plurality of second LEDs.

2. The light-emitting diode device according to claim 1, wherein the switching circuit comprises: A switch connected in series with the second string of light-emitting diodes, and a switch driver configured to control the switch based on the control signal.

3. The light-emitting diode device according to claim 1, wherein the switching circuit comprises: A first switch connected in series to the first string of light-emitting diodes, a second switch connected in series to the second string of light-emitting diodes, and a switch driver configured to control the first switch and the second switch based on the control signal.

4. The light-emitting diode device according to claim 3, wherein, The switch driver is configured to control the first switch based on the pulse width modulation signal and to control the second switch based on the pulse width modulation signal.

5. The light-emitting diode device according to claim 3, wherein, The switch driver is configured to provide a first pulse width modulation signal to the first switch and a second pulse width modulation signal to the second switch, and Wherein, the first phase of the first pulse width modulation signal is opposite to the second phase of the second pulse width modulation signal.

6. The light-emitting diode device according to claim 3, wherein, The switch driver is configured to provide a first pulse width modulation signal to the first switch and a second pulse width modulation signal to the second switch, and The first pulse width modulation signal is different from the second pulse width modulation signal.

7. The light-emitting diode device according to claim 1, wherein, The controller is configured to provide the external controller with information indicating the state of the first LED string and the second LED string.

8. The light-emitting diode device according to claim 1, wherein, The power supply includes a first regulator configured to generate a first internal power supply voltage for the operation of the controller and a second regulator configured to generate a second internal power supply voltage for the operation of the switching circuit. The first magnitude of the first internal power supply voltage is different from the second magnitude of the second internal power supply voltage.

9. The light-emitting diode device according to claim 8, wherein, The first size is smaller than the second size.

10. The light-emitting diode device according to claim 1, wherein, The intelligent controller is located on a separate module, separate from the first LED string and the second LED string.

11. The light-emitting diode device according to claim 1, wherein, The first LED is connected in series between the first input node and the first output node, and the second LED is connected in series between the second input node and the second output node. The first input node and the second input node are electrically connected to each other, and the first output node is isolated from the second output node.

12. The light-emitting diode device according to claim 1, wherein, The dimming controller is configured to provide a dimming control voltage to the dimming control terminal of the controller. The dimming controller is configured to generate the dimming control voltage based on a pulse width modulation signal provided by the controller based on the control command.

13. The light-emitting diode device according to claim 1, in, The dimming controller is configured to control the dimming control switch according to the duty cycle of a pulse width modulation signal generated by the controller based on the control command.

14. A lighting device, comprising: A light-emitting diode driver configured to generate drive power using AC power and output the drive power through a first drive node and a second drive node; Multiple light-emitting diode strings, including a first light-emitting diode string connected between the first driving node and the first light-emitting diode output node, and a second light-emitting diode string connected between the first driving node and the second light-emitting diode output node, wherein the first light-emitting diode string includes multiple first light-emitting diodes emitting light with a first color temperature, and the second light-emitting diode string includes multiple second light-emitting diodes emitting light with a second color temperature; and An intelligent controller is connected between the LED driver and the plurality of LED strings to the first driver node, the second driver node, the first LED output node, and the second LED output node. The intelligent controller includes a switching circuit connected to the first LED output node, the second LED output node, and the second driver node, and is configured to adjust the brightness of any one of the first LED string and the second LED string, or any combination of the first LED string and the second LED string. The intelligent controller further includes a dimming controller, which includes a dimming control switch connected to a node between the plurality of first light-emitting diodes and a node between the plurality of second light-emitting diodes.

15. The lighting device according to claim 14, wherein, The LED driver includes a rectifier circuit and a converter circuit, the rectifier circuit being configured to rectify the AC power and the converter circuit being configured to generate the drive power using the output of the rectifier circuit.

16. The lighting device according to claim 14, wherein, The first string of light-emitting diodes is configured to emit white light having the first color temperature, and the second string of light-emitting diodes is configured to emit white light having the second color temperature. The second color temperature is higher than the first color temperature.

17. The lighting device of claim 14, further comprising a thermoelectric circuit attached to the plurality of light-emitting diode strings and including a thermoelectric element configured to convert heat dissipated from the plurality of light-emitting diode strings into electrical energy.

18. The lighting device according to claim 17, wherein, The intelligent controller also includes a power supply connected to the first drive node and the output node of the thermoelectric circuit, and configured to use the drive power and the output power of the thermoelectric circuit to generate an internal power supply voltage for at least one component of the controller.

19. The lighting device according to claim 17, wherein, The intelligent controller also includes: a battery connected to the output node of the thermoelectric circuit, and a power source configured to use the output power of the battery to generate an internal power supply voltage.

20. A light-emitting diode device, comprising: A plurality of light-emitting diodes (LEDs) are directly connected to at least a portion of a plurality of output terminals of an output harness of an LED driver. The plurality of LEDs include a first LED string and a second LED string connected in parallel. The first LED string includes a plurality of first LEDs, and the second LED string includes a plurality of second LEDs. A power supply, which is connected to a first output terminal of the plurality of output terminals, is configured to use drive power received from the light-emitting diode driver via the first output terminal to generate a first internal power supply voltage and a second internal power supply voltage. The controller is configured to operate using the first internal power supply voltage and generate pulse width modulation control signals based on control commands received from an external controller. A switching circuit is connected between one of the plurality of light-emitting diodes and a second output terminal of the plurality of output terminals, and is configured to operate using the second internal power supply voltage and adjust the brightness of a portion of the plurality of light-emitting diodes based on the pulse width modulation control signal; and A dimming controller includes a dimming control switch connected to a node between the plurality of first light-emitting diodes and a node between the plurality of second light-emitting diodes.

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