KR102367335B1 - Light-emitting diode driving module, method of operating thereof, and lighting apparatus including the same - Google Patents

Abstract

The light emitting diode driving module according to an embodiment of the present invention drives the light emitting diodes receiving the rectified voltage through driving nodes, and driving the light emitting diodes configured to control the driving currents flowing through the driving nodes according to the voltage of the current setting node. Circuit; and a driving current controller configured to output a driving current control signal to control the voltage of the current setting node. The driving current controller includes: a control signal output circuit coupled to the dimming node for receiving a dimming signal provided when the rectified voltage is modulated, and configured to adjust the driving current control signal according to the dimming signal; a mode detector configured to receive a source voltage according to the rectified voltage, detect whether the rectified voltage is modulated, and enable a selection signal according to a detection result; and a power compensator configured to adjust the drive current control signal according to the source voltage when the select signal is enabled.

Description

A light emitting diode driving module for driving light emitting diodes, an operating method thereof, and a lighting device including the same

Embodiments of the present disclosure relate to electronic devices, and more particularly, to a light emitting diode driving module for driving light emitting diodes, an operating method thereof, and a lighting device including the same.

In order to drive light-emitting diodes (LEDs) using a rectified voltage, a lighting device including the light-emitting diodes converts an alternating current voltage into a rectified voltage and emits light according to the level of the rectified voltage. there is.

Recently, not only a lighting device providing a predetermined light output, but also a lighting device supporting a dimming function capable of providing various levels of light output according to a user's needs has been developed.

Users may or may not need this dimming function. A lighting device capable of adaptively covering both a case in which a user requires a dimming function and a case in which a dimming function is not required is required.

The above description is only for helping the understanding of the background for the technical ideas of the present invention, and therefore it cannot be understood as the content corresponding to the prior art known to those skilled in the art.

SUMMARY Embodiments of the present invention provide a light emitting diode driving module that adaptively covers a case in which a dimming function is used and a case in which the dimming function is not used, and an operating method thereof.

A light emitting diode driving module according to an embodiment of the present invention is a light emitting diode configured to drive the light emitting diodes receiving a rectified voltage through driving nodes, and to adjust driving currents flowing through the driving nodes according to the voltage of the current setting node. drive circuit; and a driving current controller configured to output a driving current control signal to control the voltage of the current setting node, wherein the driving current controller is a dimming node for receiving a dimming signal provided when the rectified voltage is modulated. a control signal output circuit connected to and configured to adjust the driving current control signal according to the dimming signal; a mode detector configured to receive a source voltage according to the rectified voltage, detect whether the rectified voltage is modulated, and enable a selection signal according to the detection result; and a power compensator configured to adjust the drive current control signal according to the source voltage when the selection signal is enabled.

The mode detector may be configured to enable the select signal when the rectified voltage is modulated and disable the select signal when the rectified voltage is not modulated.

The mode detector may be configured to detect whether the rectified voltage is modulated according to a change rate of the source voltage.

The mode detector may disable the selection signal when the rate of change of the source voltage is lower than a threshold value, and enable the selection signal when the rate of change of the source voltage is greater than or equal to the threshold value.

The power compensator may be configured to adjust the driving current control signal according to a peak value of the source voltage.

The power compensator may adjust the driving current control signal to decrease the voltage of the current setting node as the peak value increases.

When the peak value is higher than a reference value, the power compensator may adjust the driving current control signal to decrease the voltage of the current setting node as the peak value increases.

The power compensator may apply a control current that varies according to the peak value to the control signal output circuit, and the control signal output circuit may adjust the driving current control signal according to the level of the control current.

The dimming node may float when the rectified voltage is not modulated.

The light emitting diode driving module may further include a driving current setting circuit configured to control the voltage of the current setting node according to the voltage level of the driving current control signal.

The LED driving module may further include a DC power source configured to generate DC power using the rectified voltage. In this case, the driving current setting circuit may include a voltage regulator connected between the DC power source and the current setting node and configured to apply a current varying according to the voltage of the driving current control signal to the current setting node. can

The current setting node may be connected to a ground node through a resistor.

The light emitting diode driving circuit may include: a first transistor connected between a first driving node of the driving nodes and a first source node; a first comparator comprising a non-inverting terminal coupled to the current setting node, an inverting terminal coupled to the first source node, and an output terminal coupled to the gate of the first transistor; a second transistor coupled between a second driving node of the driving nodes and a second source node; and a second comparator including a non-inverting terminal connected to the current setting node, an inverting terminal connected to the second source node, and an output terminal connected to a gate of the second transistor. In this case, the first and second source nodes may be connected to the ground node through at least one resistor.

The light emitting diode driving module may further include a temperature sensor configured to sense a temperature in response to generation of a power-on reset signal, and configured to output a temperature detection signal when the temperature is higher than a threshold temperature. In this case, the driving current control signal may be adjusted according to the temperature sensing signal.

When the temperature sensing signal is enabled, the driving current control signal may be adjusted so that the voltage of the current setting node is maintained at a predetermined level.

The source voltage may be a divided voltage of the rectified voltage.

Another aspect of the present invention relates to a method of driving light emitting diodes operated using a rectified voltage but controlled through driving nodes. The method may include: receiving a source voltage according to the rectified voltage and determining whether the rectified voltage is modulated; adjusting currents of the driving nodes according to the source voltage when the determination result indicates that the rectified voltage is not modulated; and when the determination result indicates that the rectified voltage is modulated, the current of the driving nodes according to a dimming signal indicating a modulation degree of the rectified voltage without adjusting the currents of the driving nodes according to the source voltage including adjusting them.

When the rate of change of the source voltage is higher than a threshold value, the rectified voltage may be determined as a modulated voltage, and when the rate of change of the source voltage is lower than or equal to the threshold value, the rectified voltage may be determined as an unmodulated voltage.

One aspect of the present invention relates to a lighting device. A lighting device according to an embodiment of the present invention includes: a light emitting circuit that receives a rectified voltage and includes light emitting diodes and a capacitor connected to the light emitting diodes; and a light emitting diode driving module connected to the light emitting circuit through driving nodes. The light emitting diode driving module includes: a light emitting diode driver configured to adjust currents of the driving nodes according to the voltage of the current setting node; and a driving current controller configured to output a driving current control signal to control the voltage of the current setting node, wherein the driving current controller is a dimming node for receiving a dimming signal provided when the rectified voltage is modulated. a control signal output circuit connected to and configured to adjust the driving current control signal according to the dimming signal; a mode detector configured to receive a source voltage according to the rectified voltage, detect whether the rectified voltage is modulated, and enable a selection signal according to the detection result; and a power compensator configured to adjust the drive current control signal according to the source voltage when the selection signal is enabled.

The light emitting diode driver includes, during first periods of the rectified voltage, a first driving stage for applying a current from the rectified voltage to at least one of the light emitting diodes and the capacitor, and a current from the capacitor to emit the light performing a second driving stage of applying the at least one of the diodes, and performing the first driving stage without performing the second driving stage during a second period of the rectified voltage received before the first periods can do.

The light emitting diode driver further performs a third driving stage of applying a current from the rectified voltage to the light emitting diodes during first periods of the rectified voltage, and during the second period of the rectified voltage, the The first driving stage may be performed without performing the third driving stage.

According to embodiments of the present invention, a light emitting diode driving module that adaptively covers a case in which a dimming function is used and a case in which the dimming function is not used, and an operating method thereof are provided.

SUMMARY Embodiments of the present invention provide a light emitting diode driving module having constant power consumption and improved durability, and an operating method thereof.

1 is a block diagram showing a lighting device according to an embodiment of the present invention.
2A, 2B, 2C, and 2D are circuit diagrams illustrating exemplary embodiments of the light emitting diode group of FIG. 1 .
3 is a circuit diagram illustrating an exemplary embodiment of the voltage divider of FIG. 1 .
4 is a block diagram illustrating an embodiment of the driving current controller of FIG. 1 .
5A is a graph showing the voltage change signal of FIG. 4 when the rectified voltage is not modulated.
5B is a graph showing the voltage change signal of FIG. 4 when the rectified voltage is modulated.
6 is a circuit diagram illustrating an embodiment of the light emitting circuit, the light emitting diode driver, and the driving current setting circuit of FIG. 1 .
7 is a flowchart illustrating a method of driving light emitting diodes according to an embodiment of the present invention.
8 and 9 are graphs illustrating a relationship between a dimming level and a voltage of a current setting node when a light emitting circuit is driven in a dimming mode.
10 and 11 are graphs showing the relationship between the peak value of the rectified voltage and the voltage of the current setting node when the light emitting circuit is driven in the power compensation mode.
12 is a block diagram illustrating a lighting device according to another embodiment of the present invention.
13 is a flowchart illustrating a method of driving light emitting diodes according to an embodiment of the present invention.
14 is a block diagram illustrating a lighting device according to an embodiment of the present invention.
15 is a timing diagram illustrating a method of operating light emitting diodes according to an embodiment of the present invention.
16 to 18 are diagrams for explaining currents flowing in the light emitting circuit during first to third driving stages.

In the following description, for purposes of explanation, numerous specific details are set forth to aid in understanding various embodiments. It will be evident, however, that various embodiments may be practiced without these specific details or in one or more equivalent manners. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the various embodiments.

In the drawings, the size or relative size of layers, films, panels, regions, etc. may be exaggerated for purposes of clarity and description. Also, like reference numbers indicate like elements.

When it is stated that a certain element or layer is “connected” with another element or layer, this includes not only the case where it is directly connected, but also the case where it is indirectly connected with another element or layer interposed therebetween. . However, if it is stated that a part is "directly connected to" another part, it means that there is no other element between the part and the other part. “At least any one of X, Y, and Z” and “at least any one selected from the group consisting of X, Y, and Z” means one X, one Y, one Z, or two of X, Y, and Z or It can be interpreted as any combination of more (eg, XYZ, XYY, YZ, ZZ). Herein, “and/or” includes any combination of one or more of the components.

Although terms such as first, second, etc. may be used herein to describe various elements, configurations, regions, layers, and/or sections, such elements, configurations, regions, layers, and/or or sections are not limited to these terms. These terms are used to distinguish one element, configuration, region, layer, and/or section from another element, configuration, region, layer, and/or section. Accordingly, a first element, configuration, region, layer, and/or section in one embodiment may be referred to as a second element, configuration, region, layer, and/or section in another embodiment.

The terminology used herein is for the purpose of describing particular embodiments and not for the purpose of limitation. Throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated. Unless otherwise defined, terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

1 is a block diagram showing a lighting device 100 according to an embodiment of the present invention. 2A, 2B, 2C, and 2D are circuit diagrams illustrating exemplary embodiments of the light emitting diode group of FIG. 1 . 3 is a circuit diagram illustrating an exemplary embodiment of the voltage divider 160 of FIG. 1 .

Referring to Figure 1, the lighting device 100 is connected to the AC power source 110 to receive the AC voltage (Vac), a rectifier (120, Rectifier), a light emitting circuit (130, Light Emitting Circuit), a light emitting diode driver ( 140 (LED Driver), driving current setting circuit (150, Driving Current Setting Circuit), voltage divider (160, Voltage Divider), driving current controller (170, Driving Current Controller), and DC power source (180, DC Power Source) may include

The lighting apparatus 100 may further include a dimmer 115 according to a user's selection. The dimmer 115 may receive the AC voltage Vac from the AC power source 110 , modulate the AC voltage Vac to have a dimming level selected by a user, and output the modulated AC voltage.

As an embodiment, the dimmer 115 is a triac dimmer that cuts the phase of the AC voltage Vac using a TRIAC, a pulse width dimmer that modulates the pulse width of the AC voltage Vac, etc. this can be used

When the dimmer 115 is a triac dimmer, the dimmer 115 may output a modulated AC voltage by cutting a phase of the AC voltage Vac based on a dimming level selected by a user. When the dimmer 115 is a triac dimmer, control of the TRIAC trigger current may be required. To this end, the dimming apparatus 100 may further include a bleeder circuit (not shown) connected between the dimmer 115 and the rectifier 120 . The bleeder circuit may include, for example, a bleeder capacitor and a bleeder resistor.

In FIG. 1 , a dimmer 115 is illustrated as being provided as a component of a lighting device 100 . However, embodiments of the present invention are not limited thereto. The dimmer 115 may be disposed outside the lighting device 100 and may be electrically connected to the lighting device 100 .

The rectifier 120 rectifies the AC voltage Vac or the AC voltage modulated by the dimmer 115 to output the rectified voltage Vrct through the first power node VPND and the second power node VNND. is composed The rectified voltage Vrct is output to the light emitting circuit 130 and the voltage divider 160 .

In an embodiment, the lighting device 100 may further include a surge protection circuit (not shown, surge protection circuit) configured to protect internal components of the lighting device 100 from overvoltage and/or overcurrent. The surge protection circuit may be connected between the first and second power nodes VPND and VNND, for example.

The light emitting circuit 130 is connected between the first and second power nodes VPND and VNND. The light emitting circuit 130 operates under the control of the light emitting diode driver 140 . The light emitting circuit 130 may include a first light emitting diode group LED1 , a second light emitting diode group LED2 , and a capacitor Cp. In FIG. 1 , the light emitting circuit 130 is illustrated as including two light emitting diode groups LED1 and LED2 and a capacitor Cp, but embodiments of the present invention are not limited thereto, and the number of light emitting diode groups is not limited thereto. and the number of capacitors may be variously changed.

Each of the first and second light emitting diode groups LED1 and LED2 may include at least one light emitting diode. The number of light emitting diodes included in each light emitting diode group and a connection relationship between the light emitting diodes may be variously changed. Exemplary embodiments of each group of light emitting diodes are shown in FIGS. 2A-2D . Referring to FIG. 2A , each light emitting diode group may include a plurality of light emitting diodes connected in series. Referring to FIG. 2B , each light emitting diode group may include a plurality of light emitting diodes connected in parallel. Referring to FIG. 2C , each light emitting diode group may include subgroups connected in parallel to each other, and each subgroup may include series connected light emitting diodes. Referring to FIG. 2D , each light emitting diode group may include subgroups connected in series with each other, and each subgroup may include a plurality of light emitting diodes connected in parallel. According to these embodiments, the first light emitting diode group LED1 and the second light emitting diode group LED2 may have the same forward voltage or different forward voltages. The forward voltage is a threshold voltage capable of driving the corresponding light emitting diode group.

Referring back to FIG. 1 , the first and second light emitting diode groups LED1 and LED2 may be connected in series between the first power node VPND and the second driving node D2 . The capacitor Cp may be connected between the output terminal of the first light emitting diode group LED1 (or the input terminal of LED2 ) and the first driving node D1 . The capacitor Cp is charged and discharged according to the level of the rectified voltage Vrct, and may provide a current to at least one of the first and second light emitting diode groups LED1 and LED2 during discharging. Due to the capacitor Cp, the first and second light emitting diode groups LED1 and LED2 can emit light even when the level of the rectified voltage Vrct is lowered.

In an embodiment, the light emitting circuit 130 may further include first to fifth diodes DID1 to DID5 for preventing reverse flow. The first diode DID1 is connected between the first power node VPND and the first light emitting diode group LED1 and blocks the current flowing from the first light emitting diode group LED1 to the first power node VPND. . The second diode DID2 is connected between the output terminal of the first light emitting diode group LED1 (or the input terminal of LED2) and the capacitor Cp, from the capacitor Cp to the output terminal of the first light emitting diode group LED1. Block the current flowing. The third diode DID3 is connected to the capacitor Cp and the input terminal of the first light emitting diode group LED1 , and blocks a current flowing from the input terminal of the first light emitting diode group LED1 to the capacitor Cp. The fourth and fifth diodes DID4 and DID5 are connected between the ground node (ie, VNND) and the first driving node D1, and the branch node between the fourth and fifth diodes DID4 and DID5 is It is connected to the capacitor Cp. The fourth diode DID4 blocks the current flowing from the corresponding branch node to the ground node, and the fifth diode DID5 blocks the current flowing from the first driving node D1 to the corresponding branch node.

The light emitting diode driver 140 is connected to the light emitting circuit 130 through the first and second driving nodes D1 and D2. The light emitting diode driver 140 is configured to drive the light emitting circuit 130 by applying first and second driving currents DI1 and DI2 to the first and second driving nodes D1 and D2, respectively. As the level of each driving current increases, the amount of light of the light emitting diode group through which the corresponding driving current flows increases.

The light emitting diode driver 140 adjusts the level of each of the first and second driving currents DI1 and DI2 according to the voltage of the current setting node DISND. When the voltage of the current setting node DISND increases, the light emitting diode driver 140 may increase the levels of the first and second driving currents DI1 and DI2 . When the voltage of the current setting node DISND decreases, the light emitting diode driver 140 may decrease the levels of the first and second driving currents DI1 and DI2 .

The driving current setting circuit 150 adjusts the voltage of the current setting node DISND according to the driving current control signal DICS. The voltage of the current setting node DISND may be a DC voltage. As an embodiment, the driving current setting circuit 150 may include at least one setting resistor for allowing the voltage of the current setting node DISND to fall within a desired voltage range.

It is understood that the relationship between the voltage level of the driving current control signal DICS and the voltage level of the current setting node DISND may be changed according to internal components of the driving current setting circuit 150 . For example, the driving current setting circuit 150 may decrease the voltage of the current setting node DISND as the voltage of the driving current control signal DICS decreases. As another example, the driving current setting circuit 150 may decrease the voltage of the current setting node DISND as the voltage of the driving current control signal DICS increases. Hereinafter, for convenience of description, it is assumed that the driving current setting circuit 150 is configured to decrease the voltage of the current setting node DISND as the voltage of the driving current control signal DICS decreases.

The voltage divider 160 is connected between the first power node VPND and the ground node (ie, VNND). The voltage divider 160 is configured to divide the rectified voltage Vrct of the first power node VPND to output the source voltage Vsrc to the source voltage node SVND. By using the voltage divider 160 , a relatively low voltage may be applied to the driving current controller 170 .

Referring to FIG. 3 , the voltage divider 160 includes a first divider resistor DR1 connected between the first power node VPND and the source voltage node SVND, and connected between the source voltage node SVND and the ground node. and a second division resistor DR2. The voltage divider 160 is connected between the source voltage node SVND and the ground node, and may further include a first capacitor C1 for removing noise of the source voltage Vsrc.

Referring back to FIG. 1 , the driving current controller 170 is connected to the source voltage node SVND and the dimming node ADIMND. The driving current controller 170 is configured to adjust the driving current control signal DICS based on the source voltage Vsrc of the source voltage node SVND and the dimming signal of the dimming node ADIMND.

The driving current controller 170 includes a mode detector 171 , a power compensator 172 , a switch SW, and a control signal output circuit 173 .

The mode detector 171 is connected to the source voltage node SVND. The mode detector 171 receives the source voltage Vsrc, detects whether the rectified voltage Vrct is modulated according to the source voltage Vsrc, and according to the detection result, the power compensator 172 and the control signal output circuit 173 ) can be electrically connected. The mode detector 171 may enable the selection signal SEL when it is determined that the rectified voltage Vrct is not modulated. The mode detector 171 may disable the selection signal SEL when it is determined that the rectified voltage Vrct has been modulated. When the selection signal SEL is enabled, the switch SW is turned on to electrically connect the power compensator 172 to the control signal output circuit 173 . When the selection signal SEL is disabled, the switch SW is turned off.

When the rectified voltage Vrct is modulated, the source voltage Vsrc may have a high variation rate. The mode detector 171 may detect whether the rectified voltage Vrct is modulated according to a change rate of the source voltage Vsrc. For example, the mode detector 171 may include a differential circuit.

The power compensator 172 is connected between the source voltage node SVND and the switch SW. The power compensator 172 supplies the control current CI based on the source voltage Vsrc when the switch SW is turned on so that the control signal output circuit 173 adjusts the driving current control signal DICS. . That is, the power compensator 172 may control the voltage of the driving current setting node DISND by adjusting the driving current control signal DICS according to the source voltage Vsrc. Accordingly, even if the peak or amplitude of the source voltage Vsrc is unstable, the power compensator 172 may cause the light emitting diode groups LED1 and LED2 to consume relatively constant power.

The control signal output circuit 173 is connected to the dimming node ADIMND. The control signal output circuit 173 may output the driving current control signal DICS according to the dimming signal received through the dimming node ADIMND. The dimming signal may indicate a degree of modulation of the rectified voltage Vrct. The driving current control signal DICS may have a DC voltage.

As an embodiment, the dimming signal may be a DC voltage indicating a dimming level. As another embodiment, the dimming signal may be a pulse width modulation signal indicating a dimming level. In this case, the control signal output circuit 173 may include a component such as an integrating circuit for converting a pulse width into a voltage level.

In an embodiment, the dimming signal may be provided by the dimmer 115 . As another embodiment, the lighting apparatus 100 may further include a dimming level detector (not shown) configured to convert the rectified voltage Vrct or the source voltage Vsrc into a dimming signal. For example, the dimming level detector may be an RC integrator circuit.

The dimming signal may be received when the rectified voltage Vrct is modulated. For example, the modulated rectified voltage Vrct may be provided by using the dimmer 115 , and the dimming signal may be provided from the dimmer 115 through the dimming node ADIMND. When the dimming signal is not received, the dimming node ADIMND may float. When the dimming signal is not received, the control signal output circuit 173 may adjust the driving current control signal DICS to have a default voltage. When the dimming signal is received, the control signal output circuit 173 may change the voltage of the driving current control signal DICS from the default voltage according to the dimming signal.

The control signal output circuit 173 is configured to adjust the driving current control signal DICS according to the control current CI when the control current CI is received from the power compensator 172 . The mode detector 171 detects whether the rectified voltage Vrct is modulated and electrically connects the control signal output circuit 173 to the power compensator 172, so that the control current CI is provided when the dimming signal is not provided. can be On the other hand, when the dimming signal is provided, the control current CI may not be supplied to the control signal output circuit 173 .

The power compensator 172 increases the source voltage Vsrc so that the voltage of the driving current setting node DISND decreases (in this embodiment, the voltage of the driving current control signal DICS also decreases). can be printed out. In an embodiment, the power compensator 172 may detect the peak value of the source voltage Vsrc and output the control current CI. As another embodiment, the power compensator 172 may detect an average value of the source voltage Vsrc and output the control current CI.

It will be understood that the relationship between the level of the control current CI and the voltage level of the driving current control signal DICS may be changed according to internal components of the control signal output circuit 173 . For example, the control signal output circuit 173 may be configured such that the voltage level of the driving current control signal DICS decreases as the level of the control current CI increases. As another example, as the level of the control current CI decreases, the control signal output circuit 173 may be configured such that the voltage level of the driving current control signal DICS decreases.

As described above, the driving current controller 170 according to the embodiment of the present invention receives the source voltage Vsrc according to the rectified voltage Vrct, and determines whether the rectified voltage Vrct is modulated according to the source voltage Vsrc. do. When it is determined that the rectified voltage Vrct is modulated (ie, it is determined that the dimming function is used), the driving current controller 170 operates in the dimming mode. The driving current controller 170 adjusts the voltage of the driving current setting node DISND according to the dimming signal. When it is determined that the rectified voltage Vrct is not modulated (ie, it is determined that the dimming function is not used), the driving current controller 170 operates in the power compensation mode. The driving current controller 170 decreases the voltage of the driving current setting node DISND as the source voltage Vsrc increases in the power compensation mode. This means that the first and second driving currents DI1 and DI2 decrease.

The lighting device 100 may receive the rectified voltage Vrct and determine whether to modulate it, thereby adaptively covering a case in which a dimming function is used and a case in which the dimming function is not used. Furthermore, when the dimming function is not used, the lighting device 100 reduces the first and second driving currents DI1 and DI2 depending on whether the rectified voltage Vrct is relatively large, so that the light emitting circuit 130 is Relatively constant power consumption can be achieved. Accordingly, heat generated from the light emitting circuit 130 may be reduced. Therefore, deterioration of the first and second light emitting diode groups LED1 and LED2 can be prevented or at least reduced.

The DC power source 180 is connected between the first power node VPND and the second power node VNND, and is configured to generate the DC voltage VCC using the rectified voltage Vrct. In an embodiment, the DC power source 180 may be a band gap reference circuit. The DC voltage VCC may be provided as an operating voltage of the light emitting diode driver 140 , the driving current setting circuit 150 , and the driving current controller 170 .

4 is a block diagram illustrating an embodiment 200 of the driving current controller 170 of FIG. 1 . 5A is a graph showing the voltage change signal VCS of FIG. 4 when the rectified voltage Vrct is not modulated. FIG. 5B is a graph showing the voltage change signal VCS of FIG. 4 when the rectified voltage Vrct is modulated. 5A and 5B , the horizontal axis represents time, and the vertical axis represents voltage.

Referring first to FIG. 4 , the driving current controller 200 may include a mode detector 210 , a power compensator 220 , a switch SW, and a control signal output circuit 230 .

The mode detector 210 includes a variation rate detection circuit 211 and a mode selection circuit 212 .

The rate-of-change detection circuit 211 may detect a rate of change of the source voltage Vsrc received through the source voltage node SVND and output the voltage change signal VCS. In an embodiment, the rate-of-change detection circuit 211 may be a differential circuit.

The mode selection circuit 212 is configured to enable the selection signal SEL according to the voltage change signal VCS. The mode selection circuit 212 enables the selection signal SEL when the voltage level of the voltage change signal VCS is lower than the threshold value, and selects when the voltage level of the voltage change signal VCS is higher than or equal to the threshold value The signal SEL may be disabled.

Referring to FIG. 5A , three periods of the rectified voltage Vrct are shown. The rectified voltage Vrct is divided to provide a source voltage Vsrc. In addition, the voltage of the voltage change signal VCS may indicate a rate of change of the source voltage Vsrc. The voltage of the voltage change signal VCS is lower than the threshold value THV. Accordingly, the selection signal SEL is enabled. Referring to FIG. 5B , the rectified voltages Vrct of the three poles are phase-cut. The voltage change signal VCS is output according to the source voltage Vsrc that is the divided voltage of the rectified voltage Vrct. At the first time t1 , the second time t2 , and the third time t3 , the voltage of the voltage change signal VCS is higher than the threshold value THV due to the modulation of the rectified voltage Vrct. Accordingly, the selection signal SEL is disabled. According to this method, it may be determined whether the rectified voltage Vrct is modulated.

Referring back to FIG. 4 , the power compensator 220 may include a voltage level detection circuit 221 and a control current generating circuit 222 .

The voltage level detection circuit 221 may detect a peak value of the source voltage Vsrc received through the source voltage node SVND and output the detection result to the control current generation circuit 222 . The voltage level detection circuit 221 may detect the peak or amplitude of the source voltage Vsrc.

The control current generation circuit 222 generates a control current CI according to the detection result of the voltage level detection circuit 221 . It is assumed that the control signal output circuit 230 is configured such that the voltage of the driving current control signal DICS decreases as the level of the control current CI increases. As the peak value of the source voltage Vsrc increases, the control current generation circuit 222 may decrease the voltage of the driving current control signal DICS by increasing the level of the control current CI. This may mean that the levels of the driving currents DI1 and DI2 of FIG. 1 are decreased. As the peak value of the source voltage Vsrc decreases, the control current generation circuit 222 may increase the voltage of the driving current control signal DICS by decreasing the level of the control current CI. This may mean that the levels of the driving currents DI1 and DI2 of FIG. 1 are increased. As another embodiment, when the control signal output circuit 230 decreases the voltage of the driving current control signal DICS as the level of the control current CI decreases, the control current generation circuit 222 may generate the source voltage Vsrc. As the peak value of , the level of the control current CI may be decreased.

6 is a circuit diagram illustrating an embodiment of the light emitting circuit 130 , the light emitting diode driver 140 , and the driving current setting circuit 150 of FIG. 1 .

6, the light emitting diode driver 140 is connected to the light emitting circuit 130 through the first and second driving nodes D1 and D2, and the driving current setting circuit ( It may include a light emitting diode driving circuit 141 connected to 150 , and a resistor circuit 142 connected to the light emitting diode driving circuit 141 through first and second source nodes S1 and S2 .

The light emitting diode driving circuit 141 includes a first transistor TR1 and a first comparator OP1 for controlling the first driving node D1 , and a second transistor TR2 for controlling the second driving node D2 . ) and a second comparator OP2.

The first transistor TR1 is connected between the first driving node D1 and the first source node S1 . The first comparator OP1 has an output terminal connected to the gate of the first transistor TR1 and an inverting terminal connected to the first source node S1 . The second transistor TR2 is connected between the second driving node D2 and the second source node S2 . The second comparator OP2 has an output terminal connected to the gate of the second transistor TR2 and an inverting terminal connected to the second source node S2 . Non-inverting terminals of the first and second comparators OP1 and OP2 may be commonly connected to the current setting node DISND. The first and second transistors TR1 and TR2 may be PMOS and/or NMOS transistors.

When the voltage of the first source node S1 is lower than the voltage of the current setting node DISND, the first transistor TR1 may be turned on by the output of the first comparator OP1 . When the voltage of the first source node S1 is higher than the voltage of the current setting node DISND by the rectified voltage Vrct, the first transistor TR1 may be turned off by the output of the first comparator OP1. there is. In this way, the first transistor TR1 may be repeatedly turned on and off. Accordingly, the voltage of the current setting node DISND may be reflected in the voltage of the first source node S1 . Similarly, the voltage of the current setting node DISND may be reflected in the voltage of the second source node S2 .

The first source resistor Rs1 is connected between the first source node S1 and the ground node. Therefore, the level of the first driving current DI1 may be determined according to the voltage of the first source node S1 and the first source resistor Rs1 . The second source resistor Rs2 is connected between the second source node S2 and the first source node S1 . Therefore, the level of the second driving current DI2 may be determined according to the sum of the voltage of the second source node S2 and the first and second source resistors Rs1 and Rs2 . For example, the level of the second driving current DI2 may be lower than the level of the first driving current DI1 .

As such, the levels of the first and second driving currents DI1 and DI2 may be respectively controlled according to the voltage of the current setting node DISND.

The driving current setting circuit 150 may include a voltage regulator 151 and a setting resistor Rset.

The setting resistor Rset is connected between the current setting node DISND and the ground node. To remove voltage noise of the current setting node DISND, a setting capacitor Cset connected in parallel with the setting resistor Rset may be further provided.

The voltage regulator 151 applies a voltage to the driving current setting node DISND according to the driving current control signal DICS. The voltage regulator 151 may include a variable current source that generates a variable current according to the driving current control signal DICS.

7 is a flowchart illustrating a method of driving light emitting diodes according to an embodiment of the present invention. 8 and 9 are graphs illustrating the relationship between the dimming level and the voltage of the current setting node DISND when the light emitting circuit 130 is driven in the dimming mode. 10 and 11 are graphs showing the relationship between the peak value of the rectified voltage Vrct and the voltage of the current setting node DISND when the light emitting circuit 130 is driven in the power compensation mode.

1 and 7 , in step S110 , the source voltage Vsrc according to the rectified voltage Vrct is received and monitored. According to an embodiment of the present invention, a rate of change of the source voltage Vsrc may be sensed.

As another embodiment, the rectified voltage Vrct may be monitored.

In step S120, it is determined whether the rectified voltage Vrct is modulated according to the result monitored in step S110. When the rate of change of the rectified voltage Vrct is higher than the threshold value, the rectified voltage Vrct may be determined as a modulated voltage. When the rate of change of the rectified voltage Vrct is less than or equal to the threshold value, the rectified voltage Vrct may be determined as an unmodulated voltage. When the rectified voltage Vrct is modulated, step S130 is performed. When the rectified voltage Vrct is not modulated, step S140 is performed.

In step S130, the light emitting circuit 130 is driven in the dimming mode. At this time, a dimming signal indicating a modulation degree of the rectified voltage Vrct is received. The currents of the driving nodes D1 and D2 are adjusted according to the dimming signal without adjusting the currents of the driving nodes D1 and D2 according to the source voltage Vsrc.

As an embodiment, as shown in FIG. 8 , as the dimming level increases, the voltage of the current setting node DISND may be increased. As another embodiment, as shown in FIG. 9 , when the dimming level is lower than the first reference dimming level DLrf1, the voltage of the current setting node DISND is controlled to the first voltage V1, and the dimming level is the second When it is higher than the second reference dimming level DLrf2, the voltage of the current setting node DISND is controlled to a second voltage V2 higher than the first voltage V1, and the dimming level is at the first and second reference dimming levels ( Between DLrf1 and DLrf2 , the voltage of the current setting node DISND may be increased between the first and second voltages V1 and V2 as the dimming level increases.

Referring back to FIGS. 1 and 7 , in step S140 , the light emitting circuit 130 is driven in the power compensation mode. At this time, the dimming signal is not received. For example, the dimming node ADIMND may be floating. In this case, currents of the driving nodes D1 and D2 are adjusted according to the source voltage Vsrc.

As an embodiment, as shown in FIG. 10 , as the peak value of the source voltage Vsrc increases, the voltage of the current setting node DISND may be decreased. As another embodiment, as shown in FIG. 11 , when the peak value is lower than the first reference peak value PVrf1, the voltage of the current setting node DISND is controlled as the third voltage V3, and the peak value is the second When it is higher than the second reference peak value PVrf2, the voltage of the current setting node DISND is controlled to a fourth voltage V4 lower than the third voltage V3, and the peak value is the first and second reference peak values ( Between PVrf1 and PVrf2), the voltage of the current setting node DISND may be decreased as the peak value between the third and fourth voltages V3 and V4 increases.

According to an embodiment of the present invention, it is possible to adaptively cover a case in which a dimming function is used and a case in which the dimming function is not used by determining whether the rectified voltage Vrct is modulated. Furthermore, when the dimming function is not used, the light emitting circuit 130 is driven in the power compensation mode, so that the light emitting circuit 130 consumes relatively constant power.

12 is a block diagram illustrating a lighting device 500 according to another embodiment of the present invention.

The lighting device 500 includes a rectifier 520 , a light emitting circuit 530 , a light emitting diode driver 540 , a driving current setting circuit 550 , a voltage divider 560 , a driving current controller 570 , and a DC power source 580 . ), a power-on reset circuit 590, and a temperature sensor 600 .

The rectifier 520 , the light emitting circuit 530 , the light emitting diode driver 540 , the driving current setting circuit 550 , the voltage divider 560 , and the DC power source 580 are the rectifier 120 described with reference to FIG. 1 . ), the light emitting circuit 130 , the light emitting diode driver 140 , the driving current setting circuit 150 , the voltage divider 160 , and the DC power source 180 , respectively. Hereinafter, overlapping descriptions will be omitted.

The driving current controller 570 includes a mode detector 571 , a power compensator 572 , a switch SW, and a control signal output circuit 573 . The mode detector 571 , the power compensator 572 , and the switch SW are configured similarly to the mode detector 171 , the power compensator 172 , and the switch SW described with reference to FIG. 1 , respectively. The control signal output circuit 573 may further receive the temperature detection signal TS as compared to the control signal output circuit 173 of FIG. 1 .

The power-on reset circuit 590 is configured to sense the rectified voltage Vrct and/or the DC voltage VCC to generate the power-on reset signal POR. For example, the power-on reset circuit 590 may enable the power-on reset signal POR after a predetermined time has elapsed from when the rectified voltage Vrct starts to be applied.

The temperature sensor 600 is configured to sense a temperature in response to the power on reset signal POR. The temperature sensor 600 may output a temperature detection signal TS when the current temperature is higher than a temperature limit.

The control signal output circuit 573 controls the driving current control signal DICS according to the temperature sensing signal TS. According to an embodiment of the present invention, the control signal output circuit 573 may output a predetermined voltage as the driving current control signal DICS in response to the temperature sensing signal TS. This predetermined voltage controls the driving currents DI1 and DI2 to be set and fixed to predetermined fixed levels. For example, the predetermined voltage may be selected so that the light emitting diode groups LED1 and LED2 emit half of a set maximum amount of light.

The control signal output circuit 573 may maintain the driving current control signal DICS at the predetermined voltage until a power source (eg, Vac and/or Vrct) is turned off. In an embodiment, the control signal output circuit 573 may receive the power-on reset signal POR as shown in FIG. 12 . In this case, the control signal output circuit 573 may fix the driving current control signal DICS to a predetermined voltage as long as the power-on reset signal POR is not disabled. Accordingly, until the power is cut off, the light emitting diode groups LED1 and LED2 may emit fixed amounts of light.

13 is a flowchart illustrating a method of driving light emitting diodes according to an embodiment of the present invention.

12 and 13 , in step S510 , power is started to be applied, and a power-on reset signal POR is generated.

In step S520 , after the power-on reset signal POR is generated, the current temperature is sensed. In step S530, it is determined whether the sensed temperature is higher than the limit temperature. If so, step S540 is performed.

In step S540 , the driving currents DI1 and DI2 are set and fixed to predetermined levels. Until the power is turned off, the driving currents DI1 and DI2 may be fixed at predetermined levels.

According to an embodiment of the present invention, it is possible to control the light emitting diode groups LED1 and LED2 to emit predetermined amounts of light when the current temperature is higher than the threshold temperature. Accordingly, the user can easily identify that the lighting device 500 is overheated. On the other hand, when the lighting device 500 is deteriorated, it may be easily overheated. According to an embodiment of the present invention, unless the power is cut off, by controlling the light emitting diode groups (LED1, LED2) to maintain fixed amounts of light, the user controls the light emitting diode groups (LED1, LED2), the light emitting circuit 530 , and/or the need for replacement of the lighting device 500 can be easily identified.

14 is a block diagram illustrating a lighting apparatus 1000 according to an embodiment of the present invention.

Referring to FIG. 14 , the lighting device 1000 is connected to an AC power source 1100 . The lighting device 1000 includes a rectifier 1200 , a light emitting circuit 1300 , a light emitting diode driving circuit 1410 , a voltage regulator 1510 , a voltage divider 1600 , a driving current controller 1700 , and a DC power source 1800 . , a power-on reset circuit 1900 , a temperature sensor 2000 , a setting resistor Rset, a setting capacitor Cset, and first and second source resistors Rs1 and Rs2 .

The lighting apparatus 1000 further includes a dimmer 1150 according to a user's selection. According to an embodiment of the present invention, the lighting device 1000 determines whether the rectified voltage Vrct is modulated based on the rectified voltage Vrct, and operates in a dimming mode or a power compensation mode according to the determination result. do.

The lighting device 1000 may further include a fuse 1160 . The fuse 1160 may electrically cut off the lighting device 1000 from the AC power supply 1100 when, for example, an unintended high voltage is applied from the AC power source 1100 .

The light emitting diode driving circuit 1410 , the voltage regulator 1510 , the driving current controller 1700 , the DC power source 1800 , the power-on reset circuit 1900 , and the temperature sensor 2000 are one semiconductor chip (CHP) can be mounted on At this time, the light emitting diode driving circuit 1410 and the voltage regulator 1510 may be configured similarly to the light emitting diode driving circuit 141 and the voltage regulator 151 described with reference to FIG. 6 , respectively, and the driving current controller 1700 . and the DC power source 1800 may be configured similarly to the driving current controller 170 and the DC power source 180 described with reference to FIG. 1 , and the power-on reset circuit 1900 and the temperature sensor 2000 are illustrated in FIG. It may be configured similarly to the power-on reset circuit 590 and the temperature sensor 600 described with reference to 12 .

The semiconductor chip CHP may further include a bleeder circuit 2100 . The bleeder circuit 2100 may control the triac firing current between the first and second bleeder nodes BLDR1 and BLDR2 . The bleeder circuit 2100 may be connected to suitable nodes according to the characteristics of the dimmer 1150 , the location of the dimmer 1150 in the lighting apparatus 1000 , etc. according to embodiments of the lighting apparatus 1000 . In an embodiment, the first and second bleeder nodes BLDR1 and BLDR2 may be respectively connected to the first and second nodes ND1 and ND2. As another embodiment, the first and second bleeder nodes BLDR1 and BLDR2 may be respectively connected to the third and fourth nodes ND3 and ND4 .

The voltage divider 1600 is connected to the driving current controller 1700 through the source voltage node SVND, and may be configured similarly to the voltage divider 160 described with reference to FIGS. 1 and 3 . The setting resistor Rset and the setting capacitor Cset are connected to the voltage regulator 1510 through the driving current setting node DISND, and similarly to the setting resistor Rset and the setting capacitor Cset described with reference to FIG. 6 . can be configured. The first and second source resistors Rs1 and Rs2 are connected to the light emitting diode driving circuit 1410 through the first and second source nodes S1 and S2, respectively, and the first and the second source resistors Rs1 and Rs2.

The voltage divider 1600 , the setting resistor Rset, the setting capacitor Cset, and the first and second source resistors Rs1 and Rs2 may be disposed outside the semiconductor chip CHP. In this case, the impedances of the dividing resistors DR1 and DR2 and the capacitor C1, the setting resistor Rset, the setting capacitor Cset, and the source resistors Rs1 and Rs2 of the voltage divider 1600 are determined by the user's requirements. may be appropriately selected according to

15 is a timing diagram illustrating a method of operating light emitting diodes according to an embodiment of the present invention. 16 to 18 are diagrams for explaining currents flowing in the light emitting circuit 130 during first to third driving stages. 16 to 18 , only the light emitting circuit 130 and the light emitting diode driver 140 of FIG. 6 are shown for convenience of explanation.

15 to 18 , a rectified voltage Vrct is received. In FIG. 15 , an unmodulated rectified voltage Vrct is illustrated, but embodiments of the present invention are not limited thereto. It is clear that the embodiments of the present invention can be applied to the modulated rectified voltage Vrct as well within the range that can be learned from the description below. Hereinafter, for convenience of description, it is assumed that an unmodulated rectified voltage Vrct is received.

At a first time t1 , the rectified voltage Vrct of the first period PRD1 increases to reach the first voltage Vf1 . The first voltage Vf1 may be a forward voltage of the first light emitting diode group LED1 . Meanwhile, when the rectified voltage Vrct starts to be applied, the capacitor Cp is not charged with electric charges. For example, in the initial operation, the voltage across the capacitor Cp may be 0V. In this case, as in the current path (a) shown in FIG. 16 , the current I1 input to the light emitting circuit 130 is the first light emitting diode group LED1 , the capacitor Cp, and the first driving node ( D1) can flow through. The first light emitting diode group LED1 emits light by the current I3 flowing through the first light emitting diode group LED1 . The capacitor Cp is charged by the current I2 flowing through the capacitor Cp. When the capacitor Cp is charged, the current and voltage across the capacitor Cp may gradually increase. An operation of emitting light of the first light emitting diode group LED1 using the input current I1 and charging the capacitor Cp may be defined as a first driving stage.

At the second time t2 , the rectified voltage Vrct of the first period PRD1 may be lower than the sum of the forward voltage of the first light emitting diode group LED1 and the voltage across the capacitor Cp. The current path (a) of FIG. 16 may be blocked so that the first driving stage may be stopped. In this case, the sum of the forward voltage of the first light emitting diode group LED1 and the voltage across the capacitor Cp may be between the first voltage Vf1 and the second voltage Vf2 as shown in FIG. 15 . . The second voltage Vf2 may be the sum of forward voltages of the first and second light emitting diode groups LED1 and LED2 .

At the third time t3 , the rectified voltage Vrct of the second period PRD2 may be higher than the sum of the forward voltage of the first light emitting diode group LED1 and the voltage across the capacitor Cp. The input current I1 may flow through the current path (a) of FIG. 16 to perform the first driving stage. The first light emitting diode group LED1 emits light, and the capacitor Cp is charged.

At the fourth time t4 , the rectified voltage Vrct of the second period PRD2 may be lower than the sum of the forward voltage of the first light emitting diode group LED1 and the voltage across the capacitor Cp. The current path (a) of FIG. 16 may be blocked so that the first driving stage may be stopped.

In this way, the first driving stage may operate using the rectified voltage Vrct of a plurality of periods, and the capacitor Cp may be charged. While the rectified voltage Vrct of a plurality of periods is received, the voltage across the capacitor Cp may be higher than the second voltage Vf2 and the third voltage Vf3. In this case, the third voltage Vf3 may be the sum of the voltage across the capacitor Cp charged by the intended amount of charge and the forward voltage of the first light emitting diode group LED1 .

At the fifth time t5 , the rectified voltage Vrct of the third period PRD3 increases to reach the second voltage Vf2 . As mentioned above, the second voltage Vf2 may be the sum of forward voltages of the first and second light emitting diode groups LED1 and LED2 . As shown in the current path (b) of FIG. 17 , the input current I1 may flow through the first and second light emitting diode groups LED1 and LED2 and the second driving node D2 . The first light emitting diode group LED1 may emit light by the current I3 flowing through the first light emitting diode group LED1 . The second light emitting diode group LED2 may emit light by the current I4 flowing through the second light emitting diode group LED2 . The operation of emitting light of the first and second light emitting diode groups LED1 and LED2 using the input current I1 may be defined as a second driving stage.

At the sixth time t6 , the rectified voltage Vrct of the third period PRD3 becomes higher than the third voltage Vf3 . The input current I1 may flow through the current path (a) of FIG. 16 to perform the first driving stage.

On the other hand, the sum of the resistors Rs1 and Rs2 connected to the second driving node D2 through the second transistor TR2 is the resistor connected to the first driving node D1 through the first transistor TR1 ( TR1 ). higher than Rs1). In addition, the input current I1 may flow through the resistor Rs1 as in the current path (a) of FIG. 16 . Accordingly, the current path b of FIG. 17 flowing through the second driving node D2 may be gradually cut off. Accordingly, the second driving stage can be stopped.

The resistance Rs1 in the current path (a) of FIG. 16 is lower than the resistances (Rs1, Rs2) in the current path (b) of FIG. 17 . Accordingly, the current flowing through the first light emitting diode group LED1 in the second driving stage may be higher than the current flowing through the first and second light emitting diode groups LED1 and LED2 in the first driving stage.

At the seventh time t7 , the rectified voltage Vrct of the third period PRD3 is lower than the third voltage Vf3 . The current path (a) of FIG. 16 is cut off to stop the first driving stage. Meanwhile, at the seventh time t7 , the rectified voltage Vrct of the third period PRD3 is higher than the second voltage Vf2 . The input current I1 may flow through the current path b of FIG. 17 to perform the second driving stage.

At the eighth time t8 , the rectified voltage Vrct of the third period PRD3 is further decreased to be lower than the second voltage Vf2 . The current path (b) of FIG. 17 is blocked so that the second driving stage can be stopped. On the other hand, the voltage across the charged capacitor Cp may be higher than the second voltage Vf2. In this case, the charges charged in the capacitor Cp are the capacitor Cp, the first and second light emitting diode groups LED1 and LED2, and the second driving, as in the current path c shown in FIG. 18 . It can flow through node D2. The operation of emitting light of the first and second light emitting diode groups LED1 and LED2 using the capacitor Cp may be defined as a third driving stage.

By performing the third driving stage, the first and second light emitting diode groups LED1 and LED2 may emit light even though the rectified voltage Vrct is lower than the second voltage Vf2 . The capacitance of the capacitor Cp may be selected so that the capacitor Cp may be charged higher than the second voltage Vf2.

The ninth time t9, the tenth time t10, the eleventh time t11, and the twelfth time t12 are the fifth time t5, the sixth time t6, the seventh time t7, and the description of the eighth time t8, respectively. At the ninth time t9, the input current I1 flows through the current path b of FIG. 17 to operate the second driving stage. At the tenth time t10, the input current I1 flows through the current path a of FIG. 16 to operate the first driving stage and stop the second driving stage. At the eleventh time t11, the input current I1 flows through the current path b of FIG. 17 to operate the second driving stage, and the first driving stage to stop. At the twelfth time t12 , the electric charges charged in the capacitor Cp flow through the current path c of FIG. 18 to operate the third driving stage, and the second driving stage to stop.

According to an embodiment of the present invention, while the rectified voltage Vrct of at least one cycle (eg, PRD1 and PRD2) is input, the first driving stage operates without the second and third driving stages to operate the capacitor Cp ) can be charged. When the rectified voltage Vrct of subsequent periods (eg, PRD3 and PRD4) is input, the first driving stage, the second driving stage, and the third driving stage are selectively performed according to the level of the rectified voltage Vrct. can work

As described above, in the present invention, specific matters such as specific components, etc., and limited embodiments and drawings have been described, but these are only provided to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments. , various modifications and variations are possible from these descriptions by those of ordinary skill in the art to which the present invention pertains.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and not only the claims to be described later, but also all those with equivalent or equivalent modifications to the claims will be said to belong to the scope of the spirit of the present invention. .

100: lighting device
130: light emitting circuit
140: light emitting diode driver
141: light emitting diode driving circuit
150: drive current setting circuit
151: voltage regulator
160: voltage divider
170: drive current controller

Claims (21)

a light emitting diode driving circuit configured to drive the light emitting diodes receiving the rectified voltage through driving nodes, and to adjust driving currents flowing through the driving nodes according to the voltage of the current setting node; and
a driving current controller configured to output a driving current control signal to control the voltage of the current setting node;
The driving current controller is
a control signal output circuit coupled to a dimming node for receiving a dimming signal provided when the rectified voltage is modulated, the control signal output circuit configured to adjust the drive current control signal according to the dimming signal;
a mode detector configured to receive a source voltage according to the rectified voltage, detect whether the rectified voltage is modulated, and enable a selection signal according to the detection result; and
a power compensator configured to adjust the drive current control signal according to the source voltage when the selection signal is enabled;
The power compensator is configured to adjust the driving current control signal to decrease the voltage of the current setting node as the peak value of the source voltage increases. The method of claim 1,
wherein the mode detector disables the selection signal when the rectified voltage is modulated, and enables the selection signal when the rectified voltage is not modulated. The method of claim 1,
The mode detector is a light emitting diode driving module configured to detect whether the rectified voltage is modulated according to a change rate of the source voltage. 4. The method of claim 3,
The mode detector is
enabling the selection signal when the rate of change of the source voltage is lower than a threshold value;
and disabling the selection signal when the rate of change of the source voltage is greater than or equal to the threshold value. delete delete The method of claim 1,
When the peak value is higher than a reference value, the power compensator adjusts the driving current control signal to decrease the voltage at the current setting node as the peak value increases. The method of claim 1,
The power compensator applies a control current that varies according to the peak value to the control signal output circuit,
The control signal output circuit is a light emitting diode driving module for adjusting the driving current control signal according to the level of the control current. The method of claim 1,
The dimming node floats when the rectified voltage is not modulated. The method of claim 1,
The light emitting diode driving module further comprising a driving current setting circuit configured to control the voltage of the current setting node according to the voltage level of the driving current control signal. 11. The method of claim 10,
Further comprising a DC power source configured to generate DC power using the rectified voltage,
The driving current setting circuit is
and a voltage regulator connected between the DC power source and the current setting node and configured to apply a current varying according to a voltage of the driving current control signal to the current setting node. 12. The method of claim 11,
The current setting node is a light emitting diode driving module connected to a ground node through a resistor. The method of claim 1,
The light emitting diode driving circuit,
a first transistor coupled between a first driving node of the driving nodes and a first source node;
a first comparator comprising a non-inverting terminal coupled to the current setting node, an inverting terminal coupled to the first source node, and an output terminal coupled to the gate of the first transistor;
a second transistor coupled between a second driving node of the driving nodes and a second source node; and
a second comparator comprising a non-inverting terminal coupled to the current setting node, an inverting terminal coupled to the second source node, and an output terminal coupled to the gate of the second transistor;
The first and second source nodes are connected to a ground node through at least one resistor. The method of claim 1,
a temperature sensor configured to sense a temperature in response to generating a power-on reset signal, wherein the temperature sensor is configured to output a temperature sensing signal when the temperature is above a threshold temperature;
A light emitting diode driving module in which the driving current control signal is adjusted according to the temperature sensing signal. 15. The method of claim 14,
A light emitting diode driving module in which the driving current control signal is adjusted so that the voltage of the current setting node is maintained at a predetermined level when the temperature sensing signal is enabled. The method of claim 1,
The source voltage is a divided voltage of the rectified voltage. A method of driving light emitting diodes operated using a rectified voltage and controlled through driving nodes, comprising:
determining whether the rectified voltage is modulated by receiving a source voltage according to the rectified voltage;
adjusting currents of the driving nodes according to the source voltage when the determination result indicates that the rectified voltage is not modulated; and
When the determination result indicates that the rectified voltage is modulated, the currents of the driving nodes are adjusted according to a dimming signal indicating the degree of modulation of the rectified voltage without adjusting the currents of the driving nodes according to the source voltage. comprising the step of regulating,
The adjusting the currents of the driving nodes according to the source voltage includes decreasing the currents of the driving nodes as the peak value of the source voltage increases. 18. The method of claim 17,
When the rate of change of the source voltage is higher than a threshold value, the rectified voltage is determined as a modulated voltage,
The rectified voltage is determined to be an unmodulated voltage when the rate of change of the source voltage is less than or equal to a threshold value. a light emitting circuit that receives a rectified voltage and includes light emitting diodes and a capacitor connected to the light emitting diodes; and
A light emitting diode driving module connected to the light emitting circuit through driving nodes,
The light emitting diode driving module,
a light emitting diode driver configured to adjust currents of the driving nodes according to the voltage of the current setting node; and
a driving current controller configured to output a driving current control signal to control the voltage of the current setting node;
The driving current controller is
a control signal output circuit coupled to a dimming node for receiving a dimming signal provided when the rectified voltage is modulated, the control signal output circuit configured to adjust the drive current control signal according to the dimming signal;
a mode detector configured to receive a source voltage according to the rectified voltage, detect whether the rectified voltage is modulated, and enable a selection signal according to the detection result; and
a power compensator configured to adjust the drive current control signal according to the source voltage when the selection signal is enabled;
The power compensator is configured to adjust the driving current control signal so that the voltage of the current setting node decreases as the peak value of the source voltage increases. 20. The method of claim 19,
The light emitting diode driver,
During first periods of the rectified voltage, a first driving stage that applies a current from the rectified voltage to at least one of the light emitting diodes and the capacitor, and a current from the capacitor to the at least one of the light emitting diodes performing a second driving stage applied to
and during a second period of the rectified voltage received before the first periods, the first driving stage is performed without performing the second driving stage. 21. The method of claim 20,
The light emitting diode driver,
During the first periods of the rectified voltage, a third driving stage of applying a current from the rectified voltage to the light emitting diodes is further performed;
and during the second period of the rectified voltage, the first driving stage is performed without performing the third driving stage.

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