LED segment code screen driving circuit

Abstract

An LED segment code screen driving circuit comprises a power supply access circuit used for accessing an input power supply; the input end of the direct-current step-down circuit is connected with the power supply access circuit, and the direct-current step-down circuit is used for reducing first voltage of an input power supply to second voltage and outputting the second voltage; the LDO circuit is connected with the output end of the direct-current step-down circuit and used for reducing the second voltage to third voltage and outputting the third voltage and accelerating power consumption; and the LED driving circuit is connected with the output end of the LDO circuit and is used for driving the LED segment code screen to work. According to the LED segment code screen driving circuit provided by the embodiment of the utility model, when the whole photographic studio lamp is powered off, the load is increased to accelerate the power consumption, the large capacitor storage power discharge in the built-in power supply module of the photographic studio lamp is accelerated, and the discharge time is reduced, so that the normal display and rapid closing of the LED segment code screen on the control panel are ensured; and abnormal conditions such as flicker, smear and the like of the LED segment code screen are reduced.

Description

Technical Field

[0001] The utility model relates to the field of electronic circuits, in particular to an LED segment code screen driving circuit. Background Art

[0002] The built-in power modules of always-on OLED studio lights are often different according to the power output of different specifications. Some modules output one voltage, some output two or three voltages. In order to maximize the switching power supply character ratio, 100W studio lights often use +36V built-in power modules. The control panel of the studio light is powered by the built-in power module of the studio light. When the whole light switches from the working state to the shutdown state, the power supply of the control panel is also cut off. Since there is a large-capacity capacitor in the built-in power module of the studio light, this capacitor has a discharge time after power failure, and when the whole light outputs at the maximum power, the discharge time is short, and when the whole light outputs at a lower power, the discharge time is long. The long discharge time will cause abnormal conditions such as flickering and smearing on the LED segment code screen on the control panel. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model proposes an LED segment code screen driving circuit, which can achieve that when the whole studio light is powered off, its control panel will no longer have abnormal conditions such as flickering and smearing.

[0004] According to the LED segment screen driving circuit of the first embodiment of the utility model, it includes a power supply access circuit, a DC step-down circuit, an LDO circuit and an LED driving circuit;

[0005] A power supply access circuit, used for accessing input power;

[0006] A DC step-down circuit, whose input end is connected to the power supply access circuit, is used to reduce the first voltage of the input power supply to a second voltage and output it;

[0007] An LDO circuit is connected to the output end of the DC step-down circuit, and is used to reduce the second voltage to a third voltage and output it, and to accelerate power consumption;

[0008] The LED driving circuit is connected to the output end of the LDO circuit and is used to drive the LED segment code screen to work.

[0009] The LED segment screen driving circuit according to the embodiment of the utility model has at least the following gain effects:

[0010] The power supply access circuit can access the input power supply by connecting the built-in power module of the OLED studio light; the DC step-down circuit can realize the first step-down; the LDO circuit can realize the second step-down and increase the load to accelerate the power consumption; the LED driving circuit is used to directly drive the LED segment code screen of the studio light control panel to work. The LED segment code screen driving circuit of the embodiment of the utility model can realize that when the whole studio light is powered off, the load is increased to accelerate the power consumption, accelerate the discharge of the large capacitor stored in the built-in power module of the studio light, and reduce the discharge time, thereby ensuring that the LED segment code screen on the control panel is displayed normally and turned off quickly, and reducing abnormal conditions such as flickering and smearing on the LED segment code screen.

[0011] According to some embodiments of the present utility model, the LDO circuit includes:

[0012] A first step-down unit, wherein an input end of the first step-down unit is connected to an output end of the DC step-down circuit, and an output end of the first step-down unit is used to connect to the LED driving circuit;

[0013] The loss unit is connected between the output end of the first step-down unit and the ground line, and is used to accelerate the power consumption by increasing the load.

[0014] According to some embodiments of the present invention, the first buck unit includes an AMS1117 chip.

[0015] According to some embodiments of the present invention, the loss unit is a discharge resistor, and the discharge resistor is connected between the output end of the first voltage reduction unit and the ground line.

[0016] According to some embodiments of the present utility model, the power access circuit includes:

[0017] An input switch integrated port, which has a power supply access terminal and a first ground terminal, the first ground terminal is connected to a ground wire, and the power supply access terminal is used to access the input power supply;

[0018] A first inductor, a first end of which is connected to the power supply access end, and a second end of which is connected to the input end of the DC step-down circuit;

[0019] A first capacitor connected between the power supply input terminal and the first ground terminal;

[0020] A second capacitor connected between the second end of the first inductor and the ground line;

[0021] The third capacitor is connected between the second end of the first inductor and the ground line.

[0022] According to some embodiments of the present utility model, the DC step-down circuit includes a first diode and a second step-down unit, the anode of the first diode is used to connect to the power access circuit, the cathode of the first diode is connected to the input end of the second step-down unit, and the output end of the second step-down unit is used to connect to the LDO circuit.

[0023] According to some embodiments of the present invention, the second buck unit includes an ECP2459 chip.

[0024] According to some embodiments of the present invention, the DC step-down circuit further includes an output filter unit, and the output filter unit is connected between the output end of the second step-down unit and a ground line.

[0025] According to some embodiments of the present utility model, the output filtering unit includes:

[0026] a fourth capacitor connected between the output end of the second step-down unit and the ground line;

[0027] a fifth capacitor connected between the output end of the second step-down unit and the ground line;

[0028] A sixth capacitor is connected between the output end of the second voltage-reducing unit and the ground line.

[0029] According to some embodiments of the present invention, the LED driving circuit includes a TM1640 chip.

[0030] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0032] Figure 1 The present invention is a circuit diagram of a power supply access circuit in an LED segment code screen driving circuit according to an embodiment of the present invention.

[0033] Figure 2 The present invention is a circuit diagram of a DC step-down circuit in an LED segment code screen driving circuit according to an embodiment of the present invention.

[0034] Figure 3 The circuit diagram of the LDO circuit in the LED segment code screen driving circuit of the embodiment of the utility model is shown in FIG.

[0035] Figure 4 The circuit diagram of the LED driving circuit in the LED segment code screen driving circuit of the embodiment of the utility model.

[0036] Figure 5 It is a segment code screen connected to the LED driving circuit in the LED segment code screen driving circuit of the embodiment of the utility model.

[0037] Reference numerals:

[0038] Power supply access circuit 100,

[0039] DC step-down circuit 200, second step-down unit 210,

[0040] LDO circuit 300, first buck unit 310, loss unit 320,

[0041] LED driving circuit 400. DETAILED DESCRIPTION

[0042] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0043] In the description of the present utility model, if there is a description of first, second, etc., it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0044] In the description of the present invention, it should be understood that the descriptions involving orientation, such as the orientation or positional relationship indicated as up, down, etc., are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0045] In the description of the present utility model, it should be noted that, unless otherwise clearly stated, terms such as limitation, setting, installation, connection, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present utility model based on the specific content of the technical solution.

[0046] The technical solution of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described below are only part of the embodiments of the present utility model, not all of the embodiments.

[0047] See also Figures 1 to 5 As shown, Figure 1 1 is a circuit diagram of a power supply access circuit 100 in a LED segment code screen driving circuit according to an embodiment of the utility model. Figure 2 2 is a circuit diagram of a DC step-down circuit 200 in a LED segment screen driving circuit according to an embodiment of the present utility model. Figure 3 : is a circuit diagram of the LDO circuit 300 in the LED segment screen driving circuit of the embodiment of the utility model, Figure 4 4 is a circuit diagram of an LED driving circuit 400 in an LED segment code screen driving circuit according to an embodiment of the present utility model. Figure 5 The LED segment code screen driving circuit of the embodiment of the utility model is connected to the LED driving circuit 400, and the LED segment code screen driving circuit includes a power supply access circuit 100, a DC buck circuit 200, an LDO circuit 300 and an LED driving circuit 400;

[0048] A power supply access circuit 100 is used to access an input power supply;

[0049] A DC step-down circuit 200, whose input end is connected to the power supply access circuit 100, is used to reduce the first voltage of the input power supply to a second voltage and output it;

[0050] The LDO circuit 300 is connected to the output end of the DC step-down circuit 200 and is used to reduce the second voltage to a third voltage and output it, and to speed up power consumption;

[0051] The LED driving circuit 400 is connected to the output end of the LDO circuit 300 and is used to drive the LED segment screen to work.

[0052] The power access circuit 100 is connected to the input power supply and the DC step-down circuit 200 respectively; the DC step-down circuit 200 is connected to the power access circuit 100 and the LDO circuit 300 respectively; the LDO circuit 300 is connected to the DC step-down circuit 200 and the LED driving circuit 400 respectively; the LED driving circuit 400 is connected to the LDO circuit 300 and the driven LED segment code screen respectively.

[0053] When the OLED studio light is working normally, its built-in power module normally supplies power to the control panel of the studio light, and the power access circuit 100 is connected to the input power provided by the built-in power module; the DC step-down circuit 200 can achieve the first step-down, and can reduce the first voltage of the input power supply to the second voltage and output it to the LDO circuit 300; the LDO circuit 300 can achieve the second step-down and stabilize the output, and can reduce the second voltage to the third voltage and stably output it to the LED drive circuit 400. The third voltage is stabilized at a suitable voltage value output to provide a suitable operating voltage for the LED drive circuit 400, further ensuring the stable and normal operation of the LED segment code screen, that is, the normal operation of the control panel display screen, avoiding adverse conditions such as the screen being too dark; the LED drive circuit 400 is directly connected to the LED segment code screen and drives it to work.

[0054] When the OLED studio light stops working and the entire light switches from working state to shutdown state, the power supply of the control panel is also cut off. This is often due to the presence of large-capacity capacitors in the built-in power module of the studio light. This capacitor has a discharge time after power failure, especially when the entire light outputs at a lower power. The electricity stored in the large capacitor in the built-in power module cannot be discharged immediately through the OLED lamp beads, and the discharge is a smooth downward process. At the moment of input power cut off, the DC buck circuit 200 still stably outputs the second voltage to the LDO circuit 300. When the second voltage reaches the start-up voltage of the LDO circuit 300, the LDO circuit 300 can still stably output the third voltage to the LED drive circuit 400, so that the LED segment code screen can work normally. At the same time, the LDO circuit 300 can increase the load to accelerate the discharge process; until the second voltage output by the DC buck circuit 200 is lower than the start-up voltage of the LDO circuit 300 during the discharge, the output of the LDO circuit 300 is quickly pulled down, and the subsequent circuit operation can be turned off. The third voltage output by the LDO circuit 300 will also be lower than the working voltage of the LED drive circuit 400, and the LED drive circuit 400 will stop working, and the LED segment code screen will also stop working, that is, the control panel display screen is turned off. Because the LDO circuit 300 increases the load, the discharge process of the large capacitor stored electricity is accelerated, and the discharge voltage of the large capacitor stored electricity in the later stage is quickly turned off, reducing the discharge time, thereby avoiding abnormal conditions such as flickering and smearing of the LED segment code screen on the control panel caused by a long discharge time.

[0055] The power supply access circuit 100 can access the input power supply by connecting to the built-in power module of the OLED studio light; the DC step-down circuit 200 can realize the first step-down; the LDO circuit 300 can realize the second step-down and increase the load to accelerate the power consumption; the LED driving circuit 400 is used to directly drive the LED segment code screen of the studio light control panel to work. The LED segment code screen driving circuit of the embodiment of the utility model can realize that when the entire studio light is powered off, the load is increased to accelerate the power consumption, accelerate the discharge of the large capacitor stored in the built-in power module of the studio light, and reduce the discharge time, thereby ensuring that the LED segment code screen on the control panel is displayed normally and turned off quickly, and reducing abnormal conditions such as flickering and smearing on the LED segment code screen.

[0056] In some embodiments, the LDO circuit 300 includes a first step-down unit 310 and a loss unit 320;

[0057] A first buck unit 310, wherein an input end of the first buck unit 310 is connected to an output end of the DC buck circuit 200, and an output end of the first buck unit 310 is used to connect to an LED driving circuit 400;

[0058] The loss unit 320 is connected between the output end of the first step-down unit 310 and the ground line, and is used to accelerate the power consumption by increasing the load.

[0059] The first step-down unit 310 includes a magnetic bead and an LDO voltage regulator chip and its peripheral circuit, wherein the LDO voltage regulator chip has an input terminal, an output terminal and a ground terminal. One end of the magnetic bead is used to access the second voltage output by the DC step-down circuit 200, and the other end of the magnetic bead is connected to the input terminal of the LDO voltage regulator chip. The magnetic bead is specifically used to suppress high-frequency noise and spike interference on the signal line and the power line, and has the ability to absorb electrostatic pulses, which can reduce the noise at the input terminal, improve the stability and anti-interference ability of the LDO voltage regulator chip, and can also limit the transient overload current of the input voltage, prevent the voltage peak from being too high and causing the LDO voltage regulator chip to fail or be damaged, and play the role of current limitation and overcurrent protection. The ground terminal of the LDO voltage regulator chip is connected to the ground wire, and the output terminal of the LDO voltage regulator chip outputs the third voltage as the output terminal of the LDO circuit 300. The input terminal and the output terminal of the LDO voltage regulator chip are both connected to multiple grounding capacitors, and the interference can be grounded through the capacitor, thereby improving the stability and anti-interference ability of the LDO voltage regulator chip.

[0060] According to the working principle of the LDO voltage regulator chip, a certain starting voltage difference must be reached between its input and output ends to achieve a regulated output of a fixed third voltage. When the input voltage is too low to meet the starting voltage difference, the LDO voltage regulator chip will not work properly, and the voltage output by its output end will be rapidly lowered, which is equivalent to being cut off, thereby affecting the subsequent LED drive circuit 400 and causing the LED segment code screen to stop working.

[0061] In some embodiments, when the studio light is working normally and at the moment of power failure, the DC step-down circuit 200 outputs 6.2V to the LDO circuit 300, and the LDO circuit 300 steps down the 6.2V to a 5V regulated output. After a period of smooth discharge after power failure, the DC step-down circuit 200 outputs a voltage lower than 6.2V to the LDO circuit 300, and the LDO circuit 300 will no longer work normally, and the voltage output at its output end will be rapidly pulled down, which is equivalent to being cut off, thereby affecting the subsequent LED drive circuit 400 and causing the LED segment code screen to stop working.

[0062] In some embodiments, the first step-down unit 310 includes an AMS1117 chip. The AMS1117 chip is a high-performance low-dropout linear regulator with advantages such as a wide input voltage range, small temperature drift, and good linearity. It is suitable for power management in various electronic devices, especially for applications with strict requirements on input voltage fluctuations, and is widely used in electronic devices.

[0063] In some embodiments, the loss unit 320 is a discharge resistor, which is connected between the output end and the ground of the first step-down unit 310. That is, the discharge resistor is connected between the output end and the ground of the LDO circuit 300, which can be used to increase the load, thereby accelerating the discharge process of the large capacitor stored electricity in the overall circuit of the studio lamp and reducing the discharge time.

[0064] In some embodiments, the power access circuit 100 includes an input switch integrated port, a first inductor, a first capacitor, a second capacitor, and a third capacitor;

[0065] An input switch integrated port, which has a power supply access terminal and a first ground terminal, the first ground terminal is connected to the ground wire, and the power supply access terminal is used to access the input power supply;

[0066] A first inductor, a first end of which is connected to the power supply access terminal, and a second end of which is connected to the input terminal of the DC step-down circuit 200;

[0067] A first capacitor is connected between a power supply input terminal and a first ground terminal;

[0068] A second capacitor connected between the second end of the first inductor and the ground line;

[0069] The third capacitor is connected between the second end of the first inductor and the ground line.

[0070] The built-in power module of the studio light is connected through the power access circuit 100 to supply power to the control panel of the studio light.

[0071] In some embodiments, the DC voltage-reducing circuit 200 includes a first diode and a second voltage-reducing unit 210, wherein the anode of the first diode is connected to the power supply access circuit 100, the cathode of the first diode is connected to the input end of the second voltage-reducing unit 210, and the output end of the second voltage-reducing unit 210 is connected to the LDO circuit 300. The DC voltage-stabilizing circuit can realize the first voltage reduction, and can reduce the first voltage of the input power supply to the second voltage that meets the working conditions of the LDO circuit 300 when working normally.

[0072] In some embodiments, a 100W studio light uses a 36V built-in power supply module. When the studio light is working normally, the built-in power supply module provides a 36V input power supply for the LED segment code screen driving circuit of the present application, which is connected through the power access circuit 100. The power access circuit 100 outputs 36V to the DC step-down circuit 200. The DC step-down circuit 200 performs the first step-down from 36V to 6.2V and outputs it to the LDO circuit 300.

[0073] In some embodiments, the second buck unit 210 includes an ECP2459 chip. The second buck unit 210 is composed of an ECP2459 chip and its peripheral circuits. ECP2459 is a current mode DC-DC asynchronous buck converter chip with built-in MOSFET to improve high power conversion efficiency. It also has a built-in compensation circuit to provide stable loop compensation and has excellent dynamic response and system stability under wide voltage input conditions.

[0074] In some embodiments, the DC step-down circuit 200 further includes an output filter unit, which is connected between the output terminal of the second step-down unit 210 and the ground line. The output filter unit can isolate the influence of various external interference signals on the internal circuit, thereby improving the anti-interference ability of the DC step-down circuit 200 and the stability of the circuit.

[0075] In some embodiments, the output filter unit includes a fourth capacitor, a fifth capacitor, and a sixth capacitor;

[0076] A fourth capacitor connected between the output terminal of the second step-down unit 210 and the ground line;

[0077] a fifth capacitor connected between the output terminal of the second step-down unit 210 and the ground;

[0078] The sixth capacitor is connected between the output terminal of the second step-down unit 210 and the ground line.

[0079] Using three filter capacitors can filter out high-frequency noises in different frequency bands at the output end of the DC step-down circuit 200, and has a better filtering and noise reduction effect.

[0080] In some embodiments, the DC step-down circuit 200 further includes an input filter unit, which is connected between the anode of the first diode and the ground line. The input filter unit can isolate the influence of various external interference signals on the internal circuit, and improve the anti-interference ability and circuit stability of the DC step-down circuit 200. The input filter unit includes a grounding capacitor, which can filter out the noise at the input end of the DC step-down circuit 200.

[0081] In some embodiments, adding a filter circuit structure to the input and output ends of a circuit is a common noise reduction method, and the internal component composition and device parameters of the filter circuit structure can be reasonably adjusted according to the specific situation of the circuit.

[0082] In some embodiments, the LED driving circuit 400 includes a TM1640 chip, which is a cost-effective, easy-to-use, and powerful LED driving chip that is widely used in various electronic circuits.

[0083] In some embodiments, when the studio light is working normally, the LDO circuit 300 stably outputs 5V to the LED driving circuit 400, which can make the LED driving circuit 400 work normally, and then the LED segment code screen works stably and normally, that is, the control panel display screen works normally, avoiding adverse conditions such as the screen being too dark.

[0084] In some embodiments, a 100W studio light adopts a 36V built-in power module. When the studio light is working normally, the built-in power module provides a 36V input power supply for the LED segment code screen driving circuit of the present application, which is connected through the power access circuit 100. The power access circuit 100 outputs 36V to the DC step-down circuit 200. The DC step-down circuit 200 performs the first step-down from 36V to 6.2V and outputs it to the LDO circuit 300. The LDO circuit 300 performs the second step-down and outputs 5V to the LED driving circuit 400 in a stable manner. The LED driving circuit 400 drives the LED segment code screen to work stably and normally. When the studio light is powered off, the DC step-down circuit 200 performs the first step-down from 36V to 6.2V and outputs it to the LDO circuit 300. The LDO circuit 300 performs the second step-down and outputs 5V in a stable manner to the LED driving circuit 400. The LED driving circuit 400 drives the LED segment code screen to work stably and normally. The DC buck circuit 200 still outputs 6.2V to the LDO circuit 300, and the LDO circuit 300 bucks the 6.2V to a 5V regulated output, and the LED segment code screen displays normally. At the same time, the discharge resistor in the LDO circuit 300 will increase the load, thereby accelerating the discharge process of the large capacitor stored electricity in the overall circuit of the studio light and reducing the discharge time; when the studio light is powered off and after a period of smooth down discharge, the output of the DC buck circuit 200 is lower than 6.2V, and the LDO circuit 300 will no longer work normally. The voltage output at its output end will be rapidly lowered, and the output is lower than the normal working voltage of the LED drive circuit 400, so that the LED segment code screen is quickly turned off. Therefore, after the studio light is powered off, the abnormal situation of flickering and trailing on the LED segment code screen caused by the discharge process of the large capacitor stored electricity in the overall circuit is reduced, thereby ensuring that the LED segment code screen on the control panel is displayed normally and turned off quickly.

[0085] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0086] Although the embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, the present invention is not limited to the above embodiments. Those skilled in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and purpose of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. An LED segment screen driving circuit, characterized in that: include: A power supply access circuit, used for accessing input power; A DC step-down circuit, whose input end is connected to the power supply access circuit, is used to reduce the first voltage of the input power supply to a second voltage and output it; An LDO circuit is connected to the output end of the DC step-down circuit, and is used to reduce the second voltage to a third voltage and output it, and to accelerate power consumption; The LED driving circuit is connected to the output end of the LDO circuit and is used to drive the LED segment code screen to work.

2. The LED segment screen driving circuit according to claim 1, characterized in that: The LDO circuit comprises: A first step-down unit, wherein an input end of the first step-down unit is connected to an output end of the DC step-down circuit, and an output end of the first step-down unit is used to connect to the LED driving circuit; The loss unit is connected between the output end of the first step-down unit and the ground line, and is used to accelerate the power consumption by increasing the load.

3. The LED segment screen driving circuit according to claim 2, characterized in that: The first step-down unit includes an AMS1117 chip.

4. The LED segment screen driving circuit according to claim 2, characterized in that: The loss unit is a discharge resistor, and the discharge resistor is connected between the output end of the first voltage reduction unit and the ground line.

5. The LED segment screen driving circuit according to claim 1, characterized in that: The power access circuit comprises: An input switch integrated port, which has a power supply access terminal and a first ground terminal, the first ground terminal is connected to a ground wire, and the power supply access terminal is used to access the input power supply; A first inductor, a first end of which is connected to the power supply access end, and a second end of which is connected to the input end of the DC step-down circuit; A first capacitor connected between the power supply input terminal and the first ground terminal; A second capacitor connected between the second end of the first inductor and the ground line; The third capacitor is connected between the second end of the first inductor and the ground line.

6. The LED segment screen driving circuit according to claim 1, characterized in that: The DC step-down circuit includes a first diode and a second step-down unit, wherein the anode of the first diode is used to connect to the power supply access circuit, the cathode of the first diode is connected to the input end of the second step-down unit, and the output end of the second step-down unit is used to connect to the LDO circuit.

7. The LED segment screen driving circuit according to claim 6, characterized in that: The second step-down unit includes an ECP2459 chip.

8. The LED segment screen driving circuit according to claim 6, characterized in that: The DC step-down circuit further includes an output filter unit, and the output filter unit is connected between the output end of the second step-down unit and a ground line.

9. The LED segment screen driving circuit according to claim 8, characterized in that: The output filtering unit comprises: a fourth capacitor connected between the output end of the second step-down unit and the ground line; a fifth capacitor connected between the output end of the second step-down unit and the ground line; A sixth capacitor is connected between the output end of the second voltage-reducing unit and the ground line.

10. The LED segment screen driving circuit according to claim 1, characterized in that: The LED driving circuit includes a TM1640 chip.

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