LED driving current regulating circuit with two-stage regulation

Abstract

The utility model relates to the technical field of switching power supplies, in particular to an LED driving current regulating circuit with two-stage regulation, which comprises a controller unit, a wireless communication unit, a multi-gear switch unit and an LED driving unit. The wireless communication unit is used for externally connecting a first driving current signal and transmitting the first driving current signal to the controller unit; the multi-gear switch unit is used for generating a gear signal and transmitting the gear signal to the controller unit; the controller unit is used for adjusting the first driving current signal according to the gear signal, generating a second driving current signal and transmitting the second driving current signal to the LED driving unit; the LED driving unit is used for dimming the LED according to the second driving current signal; therefore, the debugging efficiency is improved, and the problems that the dimming diversity of the switching power supply is limited and the accuracy of the LED driving current cannot be calibrated after leaving a factory are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of switching power supplies, in particular to an LED drive current regulation circuit with two-stage regulation. Background Art

[0002] As a new type of lighting source, LED has the advantages of high efficiency, energy saving, long life, environmental protection, etc., and is gradually replacing traditional lighting sources. However, the normal operation of LED requires stable DC voltage and current, while the commercial power supply is usually alternating current with unstable voltage and frequency. Directly connecting to the LED will cause it to malfunction or even be damaged. Therefore, LED lighting devices require a power supply that can convert alternating current into stable direct current, which is the switching power supply.

[0003] However, at present, for each switching power supply before leaving the factory, the LED drive current of the switching power supply is set and debugged using a debugging plug-in one by one before leaving the factory.

[0004] First of all, such a method is troublesome to debug and has low debugging efficiency, which also results in the inability to modify the LED drive current after the switching power supply leaves the factory, restricting the diversity of switching power supply dimming; secondly, it also leads to the inability to make fine adjustment to ensure the accuracy of the LED drive current after leaving the factory if there is an error during debugging. Summary of the Utility Model

[0005] Aiming at the above defects, the purpose of the utility model is to propose an LED drive current regulation circuit with two-stage regulation. The first-stage regulation solves the problem of low debugging efficiency, and the second-stage regulation solves the problems of limited diversity of switching power supply dimming and inability to calibrate the accuracy of the LED drive current after leaving the factory.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] An LED drive current regulation circuit with two-stage regulation includes a controller unit, a wireless communication unit, a multi-gear switch unit, and an LED drive unit; the first data terminal of the controller unit is electrically connected to the data terminal of the wireless communication unit, the second data terminal of the controller unit is electrically connected to the data terminal of the multi-gear switch unit, the output terminal of the controller unit is electrically connected to the drive terminal of the LED drive unit, and the output terminal of the LED drive unit is electrically connected to the LED;

[0008] The wireless communication unit is used to externally connect a first drive current signal and transmit it to the controller unit for storage;

[0009] The multi-gear switch unit is used to generate a gear signal and transmit it to the controller unit;

[0010] The controller unit is configured to adjust the first drive current signal according to the gear signal, generate a second drive current signal and transmit it to the LED drive unit;

[0011] The LED drive unit is configured to adjust the brightness of the LED according to the second drive current signal.

[0012] Further, the multi-gear switch unit is a multi-slice DIP switch, and each slice of the DIP switch represents a binary bit.

[0013] Further, the gear signal is an analog signal.

[0014] Further, the multi-gear switch unit includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8 and a four-slice DIP switch K1; one end of the resistor R3 and one end of the resistor R7 are both used as the data terminals of the multi-gear switch unit;

[0015] One side of the pins of the four-slice DIP switch K1 is grounded, and the other side of the pins of the four-slice DIP switch K1 is sequentially electrically connected to one end of the resistor R1, one end of the resistor R2, one end of the resistor R5 and one end of the resistor R6. The other ends of the resistor R1, the resistor R2 and the resistor R3 are all electrically connected to one end of the resistor R4. The other end of the resistor R4 is connected to a 3.3V power supply. The other ends of the resistor R5, the resistor R6 and the resistor R7 are all electrically connected to one end of the resistor R8. The other end of the resistor R8 is connected to a 3.3V power supply.

[0016] Further, the communication mode of the wireless communication unit is NFC communication.

[0017] Further, the wireless communication unit includes an antenna L12, a capacitor C43, a capacitor C42, a capacitor C46, a capacitor C47, a capacitor C40, a capacitor C41, a resistor R92, a resistor R91, a resistor R90 and an NFC chip U4; the GPO terminal, the SCL terminal and the SDA terminal of the NFC chip U4 are all used as the data terminals of the wireless communication unit;

[0018] The GPO terminal, SCL terminal, and SDA terminal of the NFC chip U4 are electrically connected to one end of the resistor R92, one end of the resistor R91, and one end of the resistor R90 respectively. The other end of the resistor R92, the other end of the resistor R91, the other end of the resistor R90, one end of the capacitor C41, and the VCC terminal of the NFC chip U4 are all connected to the 3.3V power supply. The other end of the capacitor C41 and the VSS terminal of the NFC chip U4 are both grounded. One end of the antenna L12, one end of the capacitor C43, one end of the capacitor C42, and one end of the capacitor C46 are all electrically connected to the AC0 terminal of the NFC chip U4. The other end of the antenna L12, the other end of the capacitor C43, the other end of the capacitor C42, and one end of the capacitor C47 are all electrically connected to the AC1 terminal of the NFC chip U4. The other end of the capacitor C47 and the other end of the capacitor C46 are both grounded. The V_EH terminal of the NFC chip U4 is electrically connected to one end of the capacitor C40, and the other end of the capacitor C40 is grounded.

[0019] Further, the LED driving unit includes a resistor R10, a capacitor C13, a diode D3, a diode D4, an inductor L3, a capacitor CB2, a common-mode inductor LF3, a resistor R33, a resistor R23, a resistor R25, a resistor R16, a resistor R24, a resistor R38, a resistor R39, a resistor R40, a capacitor C4, a MOS transistor Q4, and a dimming driving chip U2. The DIM1 terminal and DIM2 terminal of the dimming driving chip U2 are both used as data terminals of the LED driving unit. One end and the other end of the resistor R33 are both used as output terminals of the LED driving unit.

[0020] The VCC terminal of the dimming drive chip U2 is electrically connected to one end of the capacitor C13, the other end of the capacitor C13 is grounded, the VIN terminal of the dimming drive chip U2 is electrically connected to one end of the resistor R10, the other end of the resistor R10, the cathode of the diode D3, the cathode of the diode D4, one end of the capacitor CB2 and the 4-pin of the common mode inductor LF3 are all connected to the VBUS power supply, the anode of the diode D3, the anode of the diode D4, and one end of the inductor L3 are all electrically connected to the drain of the MOS transistor Q4, the other end of the capacitor CB2, the other end of the inductor L3 and the 1-pin of the common mode inductor LF3 are all grounded, the 3-pin of the common mode inductor LF3 is electrically connected to one end of the resistor R33, the 2-pin of the common mode inductor LF3 is electrically connected to the other end of the resistor R33, one end of the resistor R23 is electrically connected to the OUT terminal of the dimming drive chip U2, the other end of the resistor R23 and one end of the resistor R25 are both electrically connected to the gate of the MOS transistor Q4, one end of the resistor R16 and one end of the capacitor C4 are both electrically connected to the ISNS terminal of the dimming drive chip U2, the other end of the resistor R16, the other end of the resistor R25, one end of the resistor R38, one end of the resistor R39, and one end of the resistor R40 are all electrically connected to the gate of the MOS transistor Q4, the other end of the resistor R38, the other end of the resistor R39, and the other end of the resistor R40 are all grounded, the other end of the capacitor C4, one end of the resistor R24 and the GND terminal of the dimming drive chip U2 are all grounded, and the other end of the resistor R24 is electrically connected to the CFG terminal of the dimming drive chip U2.

[0021] The technical solution provided by the present invention may include the following beneficial effects: The circuit is arranged behind the switching power supply, and the wireless communication unit is used as the first-stage drive current regulation. During factory production, the switching power supplies are batch-connected through wireless communication to set and debug the drive current of the LEDs, thereby improving the debugging efficiency of the switching power supply; on this basis, the multi-gear switch unit is used as the second-stage drive current regulation. When the first-stage drive current regulation accuracy is insufficient, manual operation can be performed through the multi-gear switch, and the first drive current signal after the first-stage drive current regulation is further fine-tuned by using different gear signals to obtain the second drive current signal. Finally, the controller unit (such as the MCU) transmits the second drive current signal as the drive signal to the LED drive unit in the main circuit of the switching power supply, and the LED drive unit dims the LEDs; thus, when individual switching power supplies have errors, whether before or after leaving the factory, manual fine-tuning can be performed to ensure the accuracy of the LED drive current, and the diversity of later dimming is expanded. Description of the Drawings

[0022] Figure 1It is the schematic diagram of an LED drive current regulation circuit with two - stage regulation, which is one of the embodiments of the present utility model.

[0023] Figure 2 It is as Figure 1 shown in the circuit diagram of the multi - gear switch unit.

[0024] Figure 3 It is as Figure 1 shown in the circuit diagram of the wireless communication unit.

[0025] Figure 4 It is as Figure 1 shown in the circuit diagram of the LED drive unit.

[0026] Among them: controller unit 1, wireless communication unit 2, multi - gear switch unit 3, LED drive unit 4, resistor R1, resistor R2, resistor R3, resistor R4, resistor R5, resistor R6, resistor R7, resistor R8, four - dial switch K1, antenna L12, capacitor C43, capacitor C42, capacitor C46, capacitor C47, capacitor C40, capacitor C41, resistor R92, resistor R91, resistor R90, NFC chip U4, resistor R10, capacitor C13, diode D3, diode D4, inductor L3, capacitor CB2, common - mode inductor LF3, resistor R33, resistor R23, resistor R25, resistor R16, resistor R24, resistor R38, resistor R39, resistor R40, capacitor C4, MOS transistor Q4, dimming drive chip U2. Detailed implementation mode

[0027] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present utility model and should not be construed as a limitation of the present utility model.

[0028] In the description of the embodiments of the present utility model, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the embodiments of the present utility model, "a plurality of" means two or more unless otherwise specifically defined.

[0029] In the description of the embodiments of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0030] The following will describe a two-stage adjustable LED drive current regulation circuit according to an embodiment of the present invention in conjunction with Figures 1 to 4 , a two-stage adjustable LED drive current regulation circuit according to an embodiment of the present invention.

[0031] A two-stage adjustable LED drive current regulation circuit includes a controller unit 1, a wireless communication unit 2, a multi-gear switch unit 3, and an LED drive unit 4; the first data terminal of the controller unit 1 is electrically connected to the data terminal of the wireless communication unit 2, the second data terminal of the controller unit 1 is electrically connected to the data terminal of the multi-gear switch unit 3, the output terminal of the controller unit 1 is electrically connected to the drive terminal of the LED drive unit 4, and the output terminal of the LED drive unit 4 is electrically connected to the LED;

[0032] The wireless communication unit 2 is used to externally connect a first drive current signal and transmit it to the controller unit 1 for storage;

[0033] The multi-gear switch unit 3 is used to generate a gear signal and transmit it to the controller unit 1;

[0034] The controller unit 1 is used to adjust the first drive current signal according to the gear signal and generate a second drive current signal to transmit to the LED drive unit 4;

[0035] The LED drive unit 4 is used to adjust the light of the LED according to the second drive current signal.

[0036] In a preferred embodiment of a two-stage adjustable LED drive current regulation circuit proposed by the present invention, as Figure 1As shown, this circuit is arranged after the switching power supply. The wireless communication unit 2 is used as the first-stage drive current regulator. During factory production, it is batch-connected to the switching power supply through wireless communication to set and debug the drive current of the LED, thereby improving the debugging efficiency of the switching power supply. On this basis, the multi-gear switch unit 3 is used as the second-stage drive current regulator. When the accuracy of the first-stage drive current regulation is insufficient, manual operation can be performed through the multi-gear switch, and the first drive current signal after the first-stage drive current regulation is further fine-tuned using different gear signals to obtain the second drive current signal. Finally, the controller unit 1 (such as an MCU) transmits the second drive current signal as the drive signal to the LED drive unit 4 in the main circuit of the switching power supply, and the LED drive unit 4 dims the LED. Thus, when individual switching power supplies have errors, whether before or after factory production, manual fine-tuning can be performed to ensure the accuracy of the LED drive current and expand the diversity of later dimming.

[0037] Specifically, the two-stage regulation process is as follows: For example, the drive current range of this switching power supply is from 1000 mA to 500 mA. After wirelessly communicating with the host computer through the wireless communication unit 2, first, the host computer is adjusted to 700 mA (that is, the externally connected first drive current signal is -700 mA and saved to the control unit 1). Then, through the multi-gear switch unit 3 (for example, the read gear is 90%), the single-chip microcomputer will calculate the current value that needs to be output now, 700 mA * 90%, and finally calculate 630 mA (the second drive current signal).

[0038] Furthermore, the multi-gear switch unit 3 is a multi-slice DIP switch, and each slice of the DIP switch represents a binary bit.

[0039] In this embodiment, the multi-gear switch unit 3 is preferably a multi-slice DIP switch. Each slice represents a binary bit, where on represents 1 and off represents 0. According to the binary rule, with n slices, there can be 2 n gear positions, so that a rich set of adjustment gears can be obtained to diversely fine-tune the first drive current signal.

[0040] Furthermore, the gear signal is an analog signal.

[0041] In this embodiment, based on the case that the multi-gear switch unit 3 is a multi-slice DIP switch, if the gear signal is transmitted to the controller unit 1 in the form of a digital signal, then for each additional slice, one more input port of the controller unit 1 (such as the I / O port of the MCU) needs to be configured. When there are too many slices, the input ports of the controller unit 1 will not be sufficient, or a more advanced controller with more input ports needs to be replaced, resulting in a higher cost. Therefore, using an analog signal as the gear signal can greatly reduce the number of input port configurations of the controller unit 1.

[0042] Further, the multi - gear switch unit 3 includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, and a four - slide - switch K1; one end of the resistor R3 and one end of the resistor R7 are both used as the data terminals of the multi - gear switch unit 3;

[0043] One - side pins of the four - slide - switch K1 are all grounded, and the other - side pins of the four - slide - switch K1 are electrically connected to one end of the resistor R1, one end of the resistor R2, one end of the resistor R5, and one end of the resistor R6 in sequence. The other end of the resistor R1, the other end of the resistor R2, and the other end of the resistor R3 are all electrically connected to one end of the resistor R4. The other end of the resistor R4 is connected to a 3.3V power supply. The other end of the resistor R5, the other end of the resistor R6, and the other end of the resistor R7 are all electrically connected to one end of the resistor R8. The other end of the resistor R8 is connected to a 3.3V power supply.

[0044] In this embodiment, as Figure 2 shown, since the multi - gear switch unit 3 belongs to micro - adjustment and the adjustment range is not very large, it is preferably a four - slide - switch K1 that can generate sixteen gear signals, which can meet the requirements. A current - regulating circuit is composed of the four - slide - switch K1 and resistors. Among them, each combination of two slides generates an analog signal of 0 - 3.3V. Two analog signals are combined for the controller unit 1 to perform analog - to - digital conversion (ADC) to obtain the digital signal corresponding to the analog signal at this time, and then the percentage of the adjustment of the first drive current signal is obtained according to the data signal. It should be noted that the circuit structure of the multi - gear switch unit 3 is not limited to the four - slide - switch K1. According to this principle, the circuit structures of more slide - switches can also be expanded, which will not be listed one by one here.

[0045] Further, the communication mode of the wireless communication unit 2 is NFC communication.

[0046] In this embodiment, when the switch power supply sets and debugs the drive current before leaving the factory, usually the host computer is not far from the switch power supply. The communication mode of the wireless communication unit 2 is preferably NFC communication (i.e., near - field communication), which is more convenient and fast to connect to the switch power supply and is convenient for improving the adjustment efficiency of the first - stage drive current.

[0047] Further, the wireless communication unit 2 includes an antenna L12, a capacitor C43, a capacitor C42, a capacitor C46, a capacitor C47, a capacitor C40, a capacitor C41, a resistor R92, a resistor R91, a resistor R90, and an NFC chip U4; the GPO terminal, SCL terminal, and SDA terminal of the NFC chip U4 are all used as the data terminals of the wireless communication unit 2;

[0048] The GPO terminal, SCL terminal, and SDA terminal of the NFC chip U4 are electrically connected to one end of the resistor R92, one end of the resistor R91, and one end of the resistor R90 respectively. The other end of the resistor R92, the other end of the resistor R91, the other end of the resistor R90, one end of the capacitor C41, and the VCC terminal of the NFC chip U4 are all connected to the 3.3V power supply. The other end of the capacitor C41 and the VSS terminal of the NFC chip U4 are both grounded. One end of the antenna L12, one end of the capacitor C43, one end of the capacitor C42, and one end of the capacitor C46 are all electrically connected to the AC0 terminal of the NFC chip U4. The other end of the antenna L12, the other end of the capacitor C43, the other end of the capacitor C42, and one end of the capacitor C47 are all electrically connected to the AC1 terminal of the NFC chip U4. The other end of the capacitor C47 and the other end of the capacitor C46 are both grounded. The V_EH terminal of the NFC chip U4 is electrically connected to one end of the capacitor C40, and the other end of the capacitor C40 is grounded.

[0049] In this embodiment, since the communication method of the wireless communication unit 2 is NFC communication, the circuit structure of the wireless communication unit 2 is as Figure 3 shown and can implement the near-field communication function.

[0050] Furthermore, the LED driving unit 4 includes a resistor R10, a capacitor C13, a diode D3, a diode D4, an inductor L3, a capacitor CB2, a common-mode inductor LF3, a resistor R33, a resistor R23, a resistor R25, a resistor R16, a resistor R24, a resistor R38, a resistor R39, a resistor R40, a capacitor C4, a MOS transistor Q4, and a dimming driving chip U2. Both the DIM1 terminal and the DIM2 terminal of the dimming driving chip U2 are used as the data terminals of the LED driving unit 4, and one end and the other end of the resistor R33 are both used as the output terminals of the LED driving unit 4;

[0051] The VCC terminal of the dimming drive chip U2 is electrically connected to one end of the capacitor C13, the other end of the capacitor C13 is grounded, the VIN terminal of the dimming drive chip U2 is electrically connected to one end of the resistor R10, the other end of the resistor R10, the cathode of the diode D3, the cathode of the diode D4, one end of the capacitor CB2 and the 4-pin of the common-mode inductor LF3 are all connected to the VBUS power supply, the anode of the diode D3, the anode of the diode D4, and one end of the inductor L3 are all electrically connected to the drain of the MOS transistor Q4, the other end of the capacitor CB2, the other end of the inductor L3 and the 1-pin of the common-mode inductor LF3 are all grounded, the 3-pin of the common-mode inductor LF3 is electrically connected to one end of the resistor R33, the 2-pin of the common-mode inductor LF3 is electrically connected to the other end of the resistor R33, one end of the resistor R23 is electrically connected to the OUT terminal of the dimming drive chip U2, the other end of the resistor R23 and one end of the resistor R25 are both electrically connected to the gate of the MOS transistor Q4, one end of the resistor R16 and one end of the capacitor C4 are both electrically connected to the ISNS terminal of the dimming drive chip U2, the other end of the resistor R16, the other end of the resistor R25, one end of the resistor R38, one end of the resistor R39, and one end of the resistor R40 are all electrically connected to the gate of the MOS transistor Q4, the other end of the resistor R38, the other end of the resistor R39, and the other end of the resistor R40 are all grounded, the other end of the capacitor C4, one end of the resistor R24 and the GND terminal of the dimming drive chip U2 are all grounded, and the other end of the resistor R24 is electrically connected to the CFG terminal of the dimming drive chip U2.

[0052] In this embodiment, the circuit structure of the LED driving unit 4 is as Figure 4 shown. The dimming drive chip U2 (such as XP2116) can receive the second drive current signal from the controller unit 1 and accordingly dim the LED.

[0053] For those of ordinary skill in the art, other components and operations of an LED drive current regulation circuit with two-stage regulation according to an embodiment of the present invention are known, and will not be described in detail here.

[0054] In the description of this specification, the descriptions with reference to the terms "embodiment", "example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0055] Although embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present utility model. The scope of the present utility model is defined by the claims and their equivalents.

Claims

1. An LED drive current regulation circuit with two - stage regulation, characterized in that: It includes a controller unit, a wireless communication unit, a multi - gear switch unit, and an LED driving unit; the first data terminal of the controller unit is electrically connected to the data terminal of the wireless communication unit, the second data terminal of the controller unit is electrically connected to the data terminal of the multi - gear switch unit, the output terminal of the controller unit is electrically connected to the driving terminal of the LED driving unit, and the output terminal of the LED driving unit is electrically connected to the LED; The wireless communication unit is used to externally connect a first driving current signal and transmit it to the controller unit for storage; The multi - gear switch unit is used to generate a gear signal and transmit it to the controller unit; The controller unit is used to adjust the first driving current signal according to the gear signal and generate a second driving current signal to transmit to the LED driving unit; The LED driving unit is used to dim the LED according to the second driving current signal.

2. The LED drive current regulation circuit with two-stage regulation according to claim 1, characterized in that: The multi - gear switch unit is a multi - slide DIP switch, and each slide of the DIP switch represents a binary bit.

3. The LED drive current regulation circuit with two-stage regulation according to claim 1, wherein: The gear signal is an analog signal.

4. A LED drive current regulation circuit with two-stage regulation according to claim 1, characterized in that: The multi - gear switch unit includes resistor R1, resistor R2, resistor R3, resistor R4, resistor R5, resistor R6, resistor R7, resistor R8, and a four - slide DIP switch K1; one end of resistor R3 and one end of resistor R7 are both used as the data terminal of the multi - gear switch unit; One - side pins of the four - slide DIP switch K1 are all grounded, the other - side pins of the four - slide DIP switch K1 are sequentially and respectively electrically connected to one end of resistor R1, one end of resistor R2, one end of resistor R5, and one end of resistor R6, the other ends of resistor R1, resistor R2, and resistor R3 are all electrically connected to one end of resistor R4, the other end of resistor R4 is connected to a 3.3V power supply, the other ends of resistor R5, resistor R6, and resistor R7 are all electrically connected to one end of resistor R8, and the other end of resistor R8 is connected to a 3.3V power supply.

5. A LED drive current regulation circuit with two - stage regulation according to claim 1, characterized in that: The communication method of the wireless communication unit is NFC communication.

6. The LED drive current regulation circuit with two-stage regulation according to claim 1, wherein: The wireless communication unit includes antenna L12, capacitor C43, capacitor C42, capacitor C46, capacitor C47, capacitor C40, capacitor C41, resistor R92, resistor R91, resistor R90, and NFC chip U4; the GPO terminal, SCL terminal, and SDA terminal of the NFC chip U4 are all used as the data terminal of the wireless communication unit; The GPO terminal, SCL terminal, and SDA terminal of the NFC chip U4 are respectively electrically connected to one end of the resistor R92, one end of the resistor R91, and one end of the resistor R90. The other end of the resistor R92, the other end of the resistor R91, the other end of the resistor R90, one end of the capacitor C41, and the VCC terminal of the NFC chip U4 are all connected to the 3.3V power supply. The other end of the capacitor C41 and the VSS terminal of the NFC chip U4 are both grounded. One end of the antenna L12, one end of the capacitor C43, one end of the capacitor C42, and one end of the capacitor C46 are all electrically connected to the AC0 terminal of the NFC chip U4. The other end of the antenna L12, the other end of the capacitor C43, the other end of the capacitor C42, and one end of the capacitor C47 are all electrically connected to the AC1 terminal of the NFC chip U4. The other end of the capacitor C47 and the other end of the capacitor C46 are both grounded. The V_EH terminal of the NFC chip U4 is electrically connected to one end of the capacitor C40, and the other end of the capacitor C40 is grounded.

7. A LED drive current regulation circuit with two - stage regulation according to claim 1, characterized in that: The LED driving unit includes a resistor R10, a capacitor C13, a diode D3, a diode D4, an inductor L3, a capacitor CB2, a common mode inductor LF3, a resistor R33, a resistor R23, a resistor R25, a resistor R16, a resistor R24, a resistor R38, a resistor R39, a resistor R40, a capacitor C4, a MOS transistor Q4, and a dimming driving chip U2. The DIM1 terminal and the DIM2 terminal of the dimming driving chip U2 are both used as data terminals of the LED driving unit. One end and the other end of the resistor R33 are both used as output terminals of the LED driving unit. The VCC terminal of the dimming drive chip U2 is electrically connected to one end of the capacitor C13, the other end of the capacitor C13 is grounded, the VIN terminal of the dimming drive chip U2 is electrically connected to one end of the resistor R10, the other end of the resistor R10, the cathode of the diode D3, the cathode of the diode D4, one end of the capacitor CB2 and the 4-pin of the common mode inductor LF3 are all connected to the VBUS power supply. The anode of the diode D3, the anode of the diode D4, and one end of the inductor L3 are all electrically connected to the drain of the MOS transistor Q4. The other end of the capacitor CB2, the other end of the inductor L3 and the 1-pin of the common mode inductor LF3 are all grounded. The 3-pin of the common mode inductor LF3 is electrically connected to one end of the resistor R33, the 2-pin of the common mode inductor LF3 is electrically connected to the other end of the resistor R33. One end of the resistor R23 is electrically connected to the OUT terminal of the dimming drive chip U2, the other end of the resistor R23 and one end of the resistor R25 are both electrically connected to the gate of the MOS transistor Q4. One end of the resistor R16 and one end of the capacitor C4 are both electrically connected to the ISNS terminal of the dimming drive chip U2. The other end of the resistor R16, the other end of the resistor R25, one end of the resistor R38, one end of the resistor R39, and one end of the resistor R40 are all electrically connected to the gate of the MOS transistor Q4. The other end of the resistor R38, the other end of the resistor R39, and the other end of the resistor R40 are all grounded. The other end of the capacitor C4, one end of the resistor R24, and the GND terminal of the dimming drive chip U2 are all grounded. The other end of the resistor R24 is electrically connected to the CFG terminal of the dimming drive chip U2.

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