JP5376249B2 - Lighting device and lighting device - Google Patents

Description

The present invention is lit device, and a lighting device.

  It is known that an LED lighting device with high circuit efficiency can be obtained by lighting a light emitting diode using a DC-DC converter (see, for example, Patent Document 1). The DC-DC converter described in Patent Document 1 includes a step-down chopper, and a secondary winding that is magnetically coupled thereto when an increasing current flows through an inductor (first inductor) via an on-state switch element. The voltage induced in the (second inductor) is fed back to continue the ON operation of the switch element. In addition, a resistance element R6 is inserted in series with the switching element for detecting the increased current, and a control circuit is added to turn off the switching element when the voltage drop of the resistance element R6 exceeds a preset threshold value. Yes.

  Then, when the switching element is turned off when the increasing current exceeds a predetermined value, the electromagnetic energy accumulated in the first inductor is released, and the decreasing current passes through the diode 15 and the capacitor 9 at the output end. Then flow. When the decreasing current becomes zero, the switch element is turned on by the counter electromotive force generated in the secondary winding of the inductor. By repeating the above circuit operation, DC-DC conversion is performed by self-excited constant current control, and the light emitting diode is turned on.

  On the other hand, a wide gap semiconductor is a semiconductor having a large band gap. Wide bandgap semiconductor elements using semiconductors such as SiC (silicon carbide), GaN (gallium nitride), and diamond as semiconductor substrates are attracting attention as semiconductors that have the potential to significantly break the performance limits of Si power devices. In the field of high-frequency power devices, expectations for wide gap semiconductors are high. These wide band gap semiconductor elements generally have normally-on characteristics in which current flows when the gate voltage is zero (see, for example, Patent Document 2).

  Further, as representative semiconductor elements using wide band gap semiconductors, JFET (junction FET), SIT (electrostatic induction transistor), MESFET (metal-semiconductor-field-effect-transistor), HFET ( There are Heterojunction Field Effect Transistors), HEMTs (High Electron Mobility Transistors), and storage FETs. In order to reliably turn off a semiconductor element having normally-on characteristics (hereinafter referred to as a normally-on switch), a drive circuit for a negative gate voltage is required.

  Since the wide band gap semiconductor element has excellent characteristics as described above, a wide-gap semiconductor is used for the switching element of the LED lighting device, and the device can be significantly reduced in size by operating at a high frequency of 10 MHz or more. Can be expected.

Japanese Patent No. 4123886 JP 2007-006658 A

  However, when the LED lighting device of the prior art is inserted in series with the switch element and impedance means such as a resistance element for detecting an increasing current flowing through the inductor, and the voltage drop of the impedance means reaches a preset threshold value In addition, a current feedback type feedback circuit composed of a control circuit for turning off the switching element is required. For this reason, there is a problem that not only the circuit configuration becomes complicated, but also there is a difficulty in miniaturization.

The present invention increases the current flowing through the inductor and to provide a point light apparatus that is turned off in a simple means of switching elements when it reaches a predetermined value, and a lighting device.

  In order to solve the above-described problems, the lighting device of the present invention has an input terminal, a switching element connected to the input terminal, a constant current means connected to the switching element, and at least a current when the switching element is on. A chopper having a flowing inductor, at least a diode through which a current flows when the switching element is turned off, a drive winding magnetically coupled to the inductor and connected to a control terminal of the switching element, and connected to the chopper and emitting light And an output terminal connected to the diode.

  In the present invention, the “chopper” is a concept including various choppers such as a step-down chopper, a step-up chopper, and a step-up / step-down chopper. The step-up / step-down chopper is obtained by sequentially connecting a step-up chopper and a step-down chopper. In each of the above choppers, an increase current flows from the DC power source to the inductor by turning on the switching element, and a decrease current flows through the diode by the electromagnetic energy accumulated in the inductor by turning off the switching element. Is common in that the DC power supply voltage is DC-DC converted and output to the output terminal.

  The switching element may be either a normally-on switch or a normally-off switch. When a wide bandgap semiconductor such as GaN-HEMT is used as the switching element, the switching characteristics at high frequency of MHz or higher, for example, 10 MHz or higher are remarkably improved, the switching loss is reduced, and the inductor is also downsized. Can be greatly reduced in size.

In addition, in the case of a switching element using a wide band gap semiconductor, a device having a normally-on characteristic is easier to obtain and lower in cost, but a device having a normally-off characteristic is also possible. Also good. Also, normally the switching element, the threshold of the switching used as a negative, is suitable because off control is facilitated using a magnetically coupled drive windings in the inductor.

The constant current means is a circuit means having a constant current characteristic. For example, various constant current circuits using a constant current diode, a junction FET, a three-terminal regulator, and a transistor can be used. The constant current circuit using a transistor is allowed to be a known constant current circuit using a monolithic or bilithic transistor. Moreover, GaN-HEMT which is a kind of junction FET can be used as a constant current means. Since the switching element as the constant current means is excellent in switching characteristics at a high frequency of 10 MHz or more, it is convenient for performing high-speed switching.

  The constant current means is interposed in series with the switching element in the first circuit in which current flows through the inductor when the switching element is on. The constant current means is also interposed in the drive circuit for the switch element including the drive winding for driving the switching element. By having these configurations, the increasing current flowing through the constant current means reaches a constant current value, and when further increasing, the voltage of the constant current means rapidly increases. Due to the rise in voltage, the potential of the main terminal (eg, source) incorporated in the switching element drive circuit can be made relatively higher than the potential of the control terminal (eg, gate). As a result, since the potential of the control terminal becomes lower than the threshold value of the switching element, the switching element can be turned off. This circuit operation becomes easier and more reliable when the switching element is a normally-on switch and the threshold value is negative, but it is also effective for a normally-off switch.

  When implementing the present invention, it is allowed to directly connect the switching element and the constant current means in series. In this case, the switching element and the constant current means are integrated on a common semiconductor chip, for example, a GaN-based chip. It becomes easy to integrate. In this case, one main terminal of the switching element, for example, the drain, two terminals of the power system consisting of the main terminal on the other end side with respect to the switching element of the constant current means, and control of each of the switching element and the constant current means The switching element and the constant current means can be constituted by an IC module having a terminal structure, for example, two control system terminals composed of gates, so that the single component can be further miniaturized. be able to.

  The inductor stores electromagnetic energy inside when an increasing current flows from the DC power source to the first circuit via the switching element and the constant current means. Further, since the inductor releases the electromagnetic energy stored when the switching element is turned off, a current that decreases at that time flows to the second circuit.

  Further, when the chopper is operated at a high frequency of 10 MHz or higher, the inductor and the drive winding magnetically coupled to the inductor have a planar coil structure, and the capacitor has a planar structure, which is convenient for the integrated circuit of the chopper, Highly reliable operation can be obtained. In other words, a planar coil inductor and drive winding, a planar capacitor, a switching element, a constant current means, and a semiconductor chip on which semiconductor components such as a diode to be described later are stacked are integrated to be integrated as a whole. A circuit module can be constructed. As a result, the LED lighting device can be significantly reduced in size. Along with this, the distance between the drive coil and the switch is minimized, so that the generation of parasitic inductance and capacitance that are unnecessary and harmful to noise generation can be minimized, and the chopper operation. Improves stability and reliability.

  The diode provides a second circuit that is a path through which a decreasing current flows out of the inductor. When a wide bandgap semiconductor, for example, a GaN-based diode is used as the diode, even higher speed switching is possible. In this case, it becomes easy to configure the diode as an integrated circuit of the semiconductor element together with the switching element and the constant current means. This integrated circuit has three main terminals of a power system comprising a main terminal at one end, a main terminal at the other end, and a main terminal at an intermediate connection point in a series connection body of a switching element, a constant current means and a diode. And it has a structure provided with five external terminals for convenience with two control terminals for controlling the switching element and the constant current means, respectively.

  When the chopper is configured using the integrated circuit, the whole is further reduced in size and it becomes easy to perform high-speed switching.

  The drive winding is a winding magnetically coupled to the inductor and controls the switching element. That is, when the increasing current flowing in the inductor when the switching element is on reaches the constant current value of the constant current means and the switching element is turned off, a large voltage is generated, so the main terminal (source) of the switching element is controlled. Since it becomes higher than the terminal and the control terminal becomes relatively negative and falls below the threshold value, the switching element is maintained in the OFF state.

According to the present invention, the lighting device includes an input end, a switching element connected to the input end, a constant current means connected to the switching element, an inductor through which current flows at least when the switching element is turned on, and at least the A chopper comprising a diode through which a current flows when the switching element is turned off, a drive winding magnetically coupled to the inductor and connected to a control terminal of the switching element, and an output terminal connected to the chopper and connected to the light emitting diode And. Therefore, it is possible to provide a point lamp device having an easy chopper integration and miniaturization with a simple circuit configuration.

Further, it is possible to obtain a point light device can be used normally switches, and a lighting device to the switching element.

  Furthermore, the inductor and the drive winding have a planar coil structure, and an integrated circuit in which at least the switching element and the diode are stacked on at least one surface of the planar coil structure is configured. Since the generation of parasitic inductance and parasitic capacitance that are unnecessary and harmful to noise generation can be minimized, the stability and reliability of the chopper operation is improved.

  Furthermore, if the switching element, the constant current means, and the diode are configured as an integrated circuit having five external terminals, the entire chopper can be further miniaturized and high-speed switching can be easily performed.

Is a circuit diagram in a first mode for carrying out the lit device of the present invention. Is a circuit diagram in a second mode for carrying out the lit device of the present invention. Similarly, it is the electric current and voltage waveform figure of each part. Is a circuit diagram of the third mode for carrying out the lit device of the present invention. Is a circuit diagram in a fourth mode for carrying out the lit device of the present invention. It is a schematic view of an integrated circuit module in a fifth mode for carrying out the lit device of the present invention. FIG. 2 is a schematic partially enlarged and partially sectional perspective view of the planar coil structure.

  Hereinafter, embodiments of the present invention will be described in detail.

  (First embodiment) will be described.

A first embodiment is shown in FIG. The lighting device (LED lighting device) includes a DC power source DC, a chopper CH, and a load circuit LC.

  The DC power source DC is means for inputting a DC voltage before conversion to a chopper CH described later. Any configuration may be used as long as it outputs a DC voltage. For example, a rectifier circuit DB is mainly used, and a smoothing circuit including a smoothing capacitor can be provided as desired. In this embodiment, the rectifier circuit DB is preferably a bridge-type rectifier circuit, and full-wave rectifies the AC voltage of an AC power supply AC, for example, a commercial AC power supply, to obtain a DC voltage.

  In this embodiment, the chopper CH includes DC input terminals t1 and t2 and DC output terminals t3 and t4, and the inside is configured by any of various known choppers such as a step-down chopper, a step-up chopper, and a step-up / step-down chopper. The chopper CH includes the switching element Q1, the constant current means CCM, the inductor L1, the diode D1, and the drive winding DW as common essential components in any of the above configurations.

The switching element Q1 may be any of the normally-off switch and a node on Marion switch. The constant current means CCM may be of a type in which the constant current value is fixedly set in advance or may be variable. One end of the inductor L1 is connected to the drive winding DW. The drive winding DW is magnetically coupled to the inductor L1, induces a voltage proportional to the terminal voltage of the inductor L1, and drives the switching element Q1 by applying it to the control terminal of the switching element Q1.

  The chopper CH has a pair of input terminals t1 and t2 and a pair of output terminals t3 and t4, and the internal circuit can be divided into a first circuit and a second circuit in terms of circuit operation. The first circuit is a circuit that accumulates electromagnetic energy in the inductor L1 by flowing an increasing current from the DC power source DC. In the case of a step-down chopper, the switching element Q1, the constant current means, the inductor L1, and the load circuit LC are connected. The series circuit including is provided with the structure connected to DC power supply DC. When the switching element Q1 is turned on, an increasing current flows from the DC power source DC, and electromagnetic energy is accumulated in the inductor L1.

  The second circuit is a circuit that discharges electromagnetic energy accumulated in the inductor L1 and flows a current that decreases. In the case of a step-down chopper, a series circuit including a diode D1 and a load circuit LC described later is connected to the inductor L1. A current that decreases from the inductor L1 flows when the switching element Q1 is turned off.

  In the case of the step-up chopper, the chopper CH is a first circuit in which a series circuit of the inductor L1, the switching element Q1, and the constant current means CCM is connected to the DC power source DC, and a series circuit of the inductor L1, the diode D1, and the load circuit LC. Can be configured with a second circuit connected to the DC power source DC. The step-up / down chopper is as described above.

  The load circuit LC includes an output capacitor that includes a light emitting diode as a load and bypasses a high frequency component. In the case of a step-down chopper, the load circuit LC is located at a position on the circuit where both an increasing current and a decreasing current flow. It is connected. In the case of the step-up type, it is connected to a position on the circuit through which a decreasing current flows. The light-emitting diode LED is composed of a single forward current or a plurality of serially connected currents flowing through the output end of the chopper.

  Hereinafter, second to fifth embodiments for carrying out the present invention will be described with reference to FIGS. In addition, in each figure, the same code | symbol is attached | subjected about the part same as FIG. 1, and description is abbreviate | omitted.

  (Second embodiment) will be described.

  A second form is shown in FIG. In this embodiment, a GaN-HEMT is used for the switching element Q1, a constant current diode is used for the constant current means CCM, and an inductor L1 is connected between the constant current means CCM and the load circuit LC. In the figure, the same parts as those in FIG. Reference numeral C1 denotes a high frequency bypass capacitor connected between the input ends t1 and t2 of the chopper CH. Reference numeral C2 is a coupling capacitor inserted between the drive winding DW and the control terminal of the switching element Q1. Reference numeral A is a first circuit, and reference numeral B is a second circuit. Reference symbol LED of the load circuit LC is a light emitting diode, and C3 is an output capacitor.

  Next, the circuit operation in the second embodiment will be described with reference to FIG. 2 and FIG.

When the DC power source DC is turned on, since the switching element Q1 of the chopper CH is turned on, a current flows from the DC power source DC through the switching element Q1 and the constant current means CCM in the first circuit A. Increases linearly. As a result, electromagnetic energy is accumulated in the inductor L1. Note that the gate-source voltage V _GS of the switching element Q1 is 0 during the period in which the switching element Q1 is on. When the increasing current reaches the constant current value of the constant current means CCM, the increasing tendency of the current is stopped and held at the constant current. Note that while the increasing current flows through the inductor L1, the terminal voltage of the inductor L1 is positive as shown in FIG.

When the increasing current reaches the constant current value of the constant current means CCM, the current flowing through the inductor L1 tends to increase further, so that the voltage V _CCM of the constant current means CCM is pulsed as shown in FIG. Become bigger. Along with this, the source potential of the switching element Q1 becomes higher than the potential of the control terminal (gate), and as a result, the control terminal becomes relatively clearly a negative potential, so that the switching element Q1 is turned off. Therefore, current I _U to increase flowing into the inductor L1 is blocked by the switching element Q1 is off as shown in (b) of FIG.

As soon as the switching element Q1 is turned off, the electromagnetic energy stored in the inductor L1 starts to be released, and a current that decreases as shown in FIG. Note that while the current decline is flowing, the voltage polarity of the inductor L1 becomes inverted to negative polarity as shown in FIG. 3 (e), the control terminal of the switching element Q1 is in the driving winding DW is negative Since a voltage that becomes a potential is induced and a negative voltage is applied between the gate and source of the switching element Q1 via the constant current means CCM as shown in FIG. 3F, the switching element Q1 is maintained in the OFF state. Is done.

  When the decreasing current flowing through the second circuit becomes 0, the negative voltage applied to the control terminal of the switching element Q1 is not induced, and at the same time, the control terminal is shown in FIG. Since a positive voltage is induced in the drive winding DW, the switching element Q1 is turned on again, and thereafter the same circuit operation as described above is repeated.

As is apparent from the above circuit operation, the chopper CH performs a step-down chopper operation, and an output current I _{O in} which an increasing current and a decreasing current alternately flow in the load circuit LC connected between the output terminals t3 and t4. Is formed as shown in FIG. 3 (d), and the light emitting diode LED is lit with these DC components, and the output capacitor C4 bypasses the high frequency component.

  (Third embodiment) will be described.

  A third embodiment is shown in FIG. In this embodiment, the constant current means CCM is a GaN-HEMT, and the inductor L1 is connected to a position where the load circuit LC is interposed between the constant current means CCM.

Further, the constant current means CCM makes the constant current value variable by making the gate potential variable by using the adjustable potential source E. In the figure, a symbol ZD1 is a diode for clamping so that the gate-source voltage V _GS of the switching element Q1 does not exceed 0.6V.

  Further, in this embodiment, the switching element Q1, the constant current means CCM, and the diode D1 forming the series connection body are configured as an integrated circuit IC. The integrated circuit IC includes first to fifth external terminals P1 to P5. The first external terminal P1 is derived from the drain of the switching element Q1. The second external terminal P2 is derived from the cathode of the diode D1. The third external terminal P3 is derived from the connection point between the source of the constant current means CCM and the anode of the diode D1. The fourth external terminal P4 is derived from the gate of the switching element Q1. The fifth external terminal P5 is derived from the gate of the constant current means CCM.

  That is, in the integrated circuit IC, the first and second main terminals are derived from the main terminals of the semiconductor elements located at both ends of the series connection body composed of the three power semiconductor elements of the chopper, and the middle of the series connection body. The third external terminal is led out from the main terminal of the connection portion, and the fourth and fifth external terminals are led out from the control terminal of the switching element Q1 and the constant current means CCM. Therefore, the first to third external terminals are power systems, and the fourth and fifth external terminals are control systems.

  Thus, in the third embodiment, since the constant current means CCM is composed of a GaN-HEMT like the switching element Q1, the high-speed switching characteristic at a high frequency of 10 MHz or more is further improved. However, if the diode D1 is also formed of a GaN substrate if desired, an integrated integrated circuit can be configured using a GaN substrate, and extremely high-speed switching can be achieved and a downsized chopper can be configured. Becomes easier.

  Further, since the constant current value is variable by using the adjustable potential source E1, it becomes easy to set a desired load current, and if the adjustable potential source E1 is feedback-controlled with respect to power supply voltage fluctuations. In addition, fluctuations in the light output of the light emitting diode with respect to fluctuations in the power supply voltage can be suppressed. Further, the voltage drop of the constant current means CCM and the load circuit LC is added to the negative voltage of the drive winding DW applied to the control terminal of the switching element Q1.

  (4th form) is demonstrated.

  A fourth embodiment is shown in FIG. Note that the same parts as those in FIG. In this embodiment, the constant current means CCM is constituted by a current mirror constant current circuit using transistors Q2 and Q3. In the current mirror constant current circuit, the series circuit of the transistor Q2 and the resistor R1 is inserted in series with the switching element Q1, the base of the transistor Q3 is connected to the base of the transistor Q2, and the reverse bias power supply E2 is reverse polarity to the emitter. A DC power supply E3 is connected to a series circuit of a collector and a bias power supply E2. Further, the collector and base of the transistor Q3 are directly connected by a conductor.

In addition, a pair of Zener diodes ZD1 and ZD2 are connected in parallel with opposite polarities between the control terminal of the switching element Q1 and the position across the constant current means CCM to form a clamp circuit. The Zener voltage of the Zener diode ZD1 is −12V, and the Zener voltage of the Zener diode ZD2 is + 0.7V, so that an excessive V _GS is not applied to the switching element Q1.

  Thus, according to the fourth embodiment, the constant current value flowing through the transistor Q2 can be controlled as desired by the DC voltage connected to the transistor Q3, and the voltage generated when the constant current value is reached increases. It is no longer necessary to use the voltage of the light emitting diode LED. Further, since the DC power source E2 is used to control the constant current means CCM constant current value, a transistor capable of high speed control is not required. Furthermore, if the constant current means CCM is turned off in synchronization when turning off the switching element Q1, the switching element Q1 can be substantially normally off. Furthermore, the semiconductor component parts of the switching element Q1, the constant current means CCM, and the diode D1 can be integrated on a GaN-based chip as desired.

  (5th form) is demonstrated.

  A fifth embodiment is shown in FIGS. In this embodiment, in one or more of the first to fourth embodiments of the present invention, an IC is formed by integrating a semiconductor component, a coil component, a capacitor component, and an external terminal of the LED lighting device. That is, the remaining circuit components excluding the light emitting diode LED of the LED lighting device are composed of a planar coil structure L, a planar capacitor structure C, a GaN chip G, a wiring formation body W, a terminal formation body T, and a substrate structure B. Each planar structure is divided and formed, these planar structures are laminated together, and the structures are connected using means such as through holes to form an integrated circuit module IC ′. The integrated circuit module IC of the illustrated example is configured by the following planar structures.

As shown in FIG. 7, the planar coil structure L includes an inductor L1 and a drive winding DW.
Each of the flat coil wires is formed by winding in a plane to form a spiral shape, and is held so that they are in an appropriate separated state, and the inside and the periphery are covered with the magnetic layer M, and as a whole It is configured in a planar shape. One end of the inductor L1 and the drive winding DW is located at the center of the coil and constitutes a terminal portion t. Then, a through hole h is formed at the center of the terminal portion t, one terminal conductor of a constant current means portion of a GaN chip G described later is inserted into the through hole h, and a conductor is injected into the inside, The inductor L1, the drive winding DW, and the connection conductor of the GaN chip G are connected together. The magnetic layer M is made of, for example, ceramics or plastics in which ferrite fine particles are dispersed, as shown in a cross-sectional view in which a part of FIG.

  The planar capacitor structure C is a planar structure in which a plurality of capacitors each including a pair of electrode bodies each sandwiching a thin dielectric film is assembled.

  The GaN chip G is a planar structure in which a switching element Q1, a constant current means CCM, and a diode D1 are formed on a GaN-based semiconductor substrate.

  The wiring formation body W is a planar structure that connects the planar coil structure L, the planar capacitor structure C, and the GaN chip G to the terminal formation body T described later as required.

  The terminal forming body T is interposed between the wiring forming body W and a substrate structure B to be described later to connect the two.

The board structure B includes an external terminal _TE and an external mounting means (not shown), and integrally supports the planar structures described above to form a module. The external terminal _TE is an output terminal for connecting the input terminal of the LED lighting device and the light emitting diode LED.

Then, this embodiment is suitable for LED lighting devices operating at high frequencies above 10 MHz, the external terminal T _E which is arranged in the board structure B is a direct either the DC input and output only Therefore, the operation is stable and a remarkable downsizing can be realized. For this reason, it becomes possible to arrange | position an LED lighting device between the light emitting diodes of an illuminating device, and it contributes to remarkable miniaturization of an illuminating device.
In addition, the claims at the beginning of the filing of the present application are appended below.
[1]
DC power supply;
A first circuit comprising a switching element, a constant current means, an inductor, a diode and a drive winding of the switching element magnetically coupled to the inductor, and a current flows from the DC power source to the inductor via the constant current means when the switching element is turned on; A second circuit in which a current flows from the inductor via a diode when the switching element is turned off, and a chopper including a switching element drive circuit including a control terminal of the switching element, a constant current means, and a drive winding;
A load circuit comprising a parallel circuit of a light emitting diode and an output capacitor and connected to the output end of the chopper;
The LED lighting device characterized by comprising.
[2]
The LED lighting device according to [1], wherein the switching element is a normally-on switch.
[3]
The inductor and the drive winding are configured by a planar coil structure, and at least the switching element and the diode are stacked on at least one surface of the planar coil structure, and the planar coil structure and at least the switching element and the diode form an integrated circuit. The LED lighting device according to [1] or [2], which is configured.
[4]
A switching element, a constant current means, and a series connection body of diodes are provided, and the series connection body includes first and second external terminals derived from a pair of main terminals located at both ends thereof, and a series connection body. An integrated circuit comprising a third external terminal derived from the main terminal located at the intermediate connection portion and fourth and fifth external terminals derived from the control terminals of the switching element and the constant current means is configured. The LED lighting device according to any one of [1] to [3].

  A ... first circuit, B ... second circuit, C1 ... high frequency bypass capacitor, C2 coupling capacitor, C3 ... output capacitor, CCM ... constant current means, CH ... chopper, D1 ... diode, DB ... rectifier circuit, DC ... DC power supply, DW ... drive winding, IC ... integrated circuit, L1 ... inductor, LC ... load circuit, LED ... light emitting diode, Q1 ... switching element, t1, t2 ... DC input terminal, t3, t4 ... DC output terminal

Claims (6)

With the input end ;
A switching element connected to said input terminal, a constant current means for connecting to the switching element, an inductor current flows during on of at least the switching element, and at least the switching element diode current flows at the time of off, the inductor a chopper and a driving winding connected to the control terminal of the switching element as well as the magnetic coupling;
An output end connected to the chopper and connected to a light emitting diode;
The lighting device characterized by comprising. 2. The LED lighting device according to claim 1 , wherein at least one of the switching element , the constant current means, and the diode uses GaN (gallium nitride) . Together with the inductor and the driving winding is constituted by a planar coil structure, at least the switching element and the diode provided on at least one side of the planar coil structure, the planar coil structure and at least the switching element and the lighting apparatus according to claim 1 or 2, wherein said diode is characterized in that it is integrated. The chopper, the switching element, wherein the provided with a series connection of the current regulating means and said diode connected in series, the series connection body, derived from a pair of main terminals located on both end sides of the series connection body first and second external terminals is, the switching element, the current regulating means and the third external terminal of which is derived from at least one two connection points of the diode, the switching element and the constant current means 4. The lighting device according to claim 1, further comprising an integrated circuit including fourth and fifth external terminals derived from the control terminal. 5. When the current flowing through the constant current means reaches a predetermined current value, the switching element of the chopper has a potential at a connection point between the switching element and the constant current means than a potential of the control terminal of the switching element. The lighting device according to claim 1, wherein the lighting device is turned off when the height is increased. A lighting device according to any one of claims 1 to 5;
A light emitting diode connected to an output end of the lighting device;
An illumination device comprising:

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