Constant current control circuit and method

Abstract

The application relates to the electrical technical field and discloses a constant current control circuit and method. The circuit comprises a load module, a plurality of parallel load units, a controller connected with each load unit and used for outputting a first voltage signal to the load unit, and a constant current control module connected with the controller and each load unit through at least one differential resistance, used for receiving the first voltage signal from the controller and generating a second voltage signal and a second voltage signal according to the first voltage signal and outputting to the load module. The technical scheme provided by the application can realize the opening or closing of the plurality of load units and the size of the current of the load unit through the cooperation of the controller and the constant current control module without increasing the number of constant current control related devices and redundant switching transistors in the control circuit, and the opening or closing of each individual load unit can be independently controlled.

Description

Technical Field

[0001] This invention relates to the field of electrical technology, and more specifically to a constant current control circuit and method. Background Technology

[0002] Semiconductor devices with sensitive characteristics and negative temperature characteristics (such as LEDs, light-emitting diodes) require stable operation and protection during applications, leading to the development of the concept of a driver. The main function of a constant current driver circuit is to convert AC voltage into a constant current power supply, while simultaneously matching the voltage and current to the load element according to its requirements. Figure 1 This schematically illustrates an existing constant current drive circuit, such as... Figure 1 The operational amplifier constant current drive circuit shown mainly utilizes the "voltage follower characteristic" of the operational amplifier, that is, the circuit characteristic that the voltages at the two input pins 2 and 3 of the operational amplifier are equal. When a stable power supply voltage (Vin) is input to resistor R7, the voltage across the current-limiting resistor R8 is also constant at Vin. Therefore, regardless of changes in the external circuit, the current flowing through the current-limiting resistor R8 remains constant. The load current is equal to the current through the current-limiting resistor R8, so even if the load power supply is a variable voltage power supply, the current through the load remains constant, achieving a constant current effect.

[0003] To enable independent control of multiple load components, existing constant current drive circuits typically use multiple digital-to-analog converter (DAC) signals for control. These DAC signals are output by a multi-channel control chip (or multiple ordinary control chips), requiring multiple operational amplifiers to process them, thus occupying a significant area on the PCB. Furthermore, to ensure no residual voltage remains on the load components when they are turned off (e.g., to prevent flickering when an LED is off), a PMOS transistor is needed to ensure complete power disconnection. Therefore, the entire constant current drive circuit uses numerous resources and lacks integration. Summary of the Invention

[0004] The purpose of this invention is to overcome the problem that existing constant current drive circuits use a lot of electrical components, occupy a large area on the PCB board, and are not well integrated, and to provide a constant current control circuit and method.

[0005] To achieve the above objectives, the first aspect of this application provides a constant current control circuit, the circuit comprising:

[0006] A load module, comprising multiple load units connected in parallel;

[0007] The controller, connected to each load unit, is used to output a first-level signal to the load unit;

[0008] The constant current control module is connected to the controller and also to each load unit through at least one differential voltage resistor. It is used to receive the first voltage signal sent by the controller and generate a second level signal and a second voltage signal based on the first voltage signal, which are then output to the load module.

[0009] In one embodiment of this application, the constant current control module includes an operational amplifier, the non-inverting input of which is connected to a controller, the inverting input of which is connected to a load module, and the output of which is connected to each load unit through at least one differential voltage resistor.

[0010] In one embodiment of this application, the load unit includes:

[0011] Load elements; and

[0012] A switching element is connected to the load element, the switching element is connected to the controller, and is connected to the constant current control module through at least one differential voltage resistor.

[0013] In one embodiment of this application, the switching element is an NMOS transistor, the controller is connected to the gate of the NMOS transistor, the constant current control module is connected to the gate of the NMOS transistor through a differential voltage resistor, the drain of the NMOS transistor is connected to the load element, and the source of the NMOS transistor is connected to the constant current control module.

[0014] In one embodiment of this application, the circuit further includes a filter capacitor, one end of which is connected to the constant current control module, and the other end is connected to a ground point through at least one filter resistor.

[0015] In one embodiment of this application, the circuit further includes a current-limiting resistor connected between the constant current control module and the grounding point.

[0016] In one embodiment of this application, the load element is an LED, the anode of the LED is connected to the power supply, and the cathode of the LED is connected to the switching element.

[0017] A second aspect of this application provides an electronic device including the constant current control circuit described above.

[0018] A third aspect of this application provides a constant current control method applied to the aforementioned constant current control circuit, the method comprising:

[0019] The controller outputs a first-level signal to the load unit to control the load unit to turn on or off.

[0020] The constant current control module receives the first voltage signal from the controller and generates a second level signal and a second voltage signal based on the first voltage signal, which are then output to the load module.

[0021] The second voltage signal is used to control the magnitude of the current passing through the load unit;

[0022] When the first voltage signal is a positive voltage, the second level signal is a high level signal.

[0023] In one embodiment of this application, a controller outputs a first-level signal to the load unit to control the load unit to turn on or off, including:

[0024] The load unit is turned on when both the first level signal and the second level signal are high.

[0025] The load unit is turned off if at least one of the first and second level signals is low.

[0026] The above technical solution eliminates the need to increase the number of constant current control components and redundant switching transistors in the circuit. The controller can work in conjunction with the constant current control module to control the on / off state of multiple load units and the magnitude of the current flowing through each load unit. Furthermore, the on / off state of each individual load unit can be independently controlled, resulting in a simpler circuit, fewer components, and high integration.

[0027] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0028] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0029] Figure 1 This schematically illustrates an existing constant current drive circuit;

[0030] Figure 2 The schematic diagram illustrates a circuit topology of a constant current control circuit according to an embodiment of this application;

[0031] Figure 3 The circuit topology of a constant current control circuit according to an embodiment of this application is illustrated schematically.

[0032] Figure 4 This schematically illustrates a circuit topology diagram of a constant current control circuit with added filter capacitors and filter resistors according to an embodiment of this application; and

[0033] Figure 5 A flowchart illustrating a constant current control method according to an embodiment of this application is shown schematically. Detailed Implementation

[0034] The specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this application.

[0035] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0036] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0037] Figure 2 A schematic diagram illustrating the circuit topology of a constant current control circuit according to an embodiment of this application is shown, such as... Figure 2 As shown, in one embodiment of this application, a constant current control circuit is provided, which may include:

[0038] The load module (100) includes multiple load units (110) connected in parallel;

[0039] The controller (200) is connected to each load unit (110) and is used to output a first level signal to the load unit (110);

[0040] The constant current control module (300) is connected to the controller (200) and also connected to each of the load units (110) through at least one differential voltage resistor (400). It is used to receive a first voltage signal issued by the controller (200) and generate a second level signal and a second voltage signal according to the first voltage signal and output them to the load module (100).

[0041] In one embodiment of this application, the load unit (110) includes:

[0042] Load elements; and

[0043] A switching element is connected to the load element, the switching element is connected to the controller (200), and is connected to the constant current control module (300) through at least one differential voltage resistor.

[0044] The controller (200) and the constant current control module (300) work together to control the opening or closing of multiple load units (110) and the magnitude of the current through the load unit (110). Because a differential voltage resistor (400) is provided in the circuit, the opening or closing of each individual load unit (110) can be independently controlled.

[0045] Figure 3 A circuit topology diagram of a constant current control circuit according to an embodiment of this application is illustrated schematically, such as... Figure 3 As shown, the load module (100) includes three load units (110) connected in parallel. Each load unit (110) includes a load element and a switching element connected to the load element. The load element can be... Figure 2 The LEDs (D1, D2, D3) shown in the examples have their anodes connected to the power supply and their cathodes connected to the switching elements. It is worth noting that the load element can also be any load requiring constant current control other than LEDs.

[0046] In one embodiment of this application, the controller is an MCU controller, also known as a single-chip microcomputer or microcontroller, which integrates a D / A converter (digital-to-analog converter). In practical electronic devices, the actual circuitry often mixes analog and digital signals. The internal signal output unit of the electronic device outputs a digital signal to the constant current control circuit of this embodiment. This digital signal is converted by the D / A converter within the MCU controller into an electrical signal that can be recognized and applied in the circuit, namely, a first voltage signal (DAC signal 1), which is then output to the constant current control module (300).

[0047] In one embodiment of this application, the MCU controller is connected to three parallel load units (110). The MCU controller includes multiple general-purpose pins and outputs three first-level signals (LED_SW_1, LED_SW_2, LED_SW_3) through the three general-purpose pins to control the opening and closing of the LEDs (D1, D2, D3) of a single load unit (110) respectively.

[0048] In one embodiment of this application, the constant current control module (300) includes an operational amplifier (U1), the non-inverting input terminal (pin 1) of the operational amplifier (U1) is connected to the controller, the inverting input terminal (pin 3) of the operational amplifier (U1) is connected to the load module (100), and the output terminal (OUT pin) of the operational amplifier (U1) is connected to each load unit (110) through at least one differential voltage resistor (R1, R2, R3).

[0049] The constant current control module (300) includes an operational amplifier (U1). An operational amplifier (op-amp) is a circuit unit with very high amplification; most op-amps exist as a single chip. Op-amps come in many types and are widely used in the electronics industry. The amplification factor A of an op-amp can be expressed as:

[0050]

[0051] Where u0 is the voltage output from the op-amp output terminal, u + u is the voltage at the non-inverting input terminal of the op-amp. - Let u be the voltage at the inverting input of the op-amp. An ideal operational amplifier can be considered to have infinite amplification, i.e., A→∞, hence u + -u _ =0, u + =u _ This means that the potential at the non-inverting input terminal of the op-amp is equal to the potential at the inverting input terminal; this is the "virtual short" characteristic of the op-amp.

[0052] The non-inverting input (pin 1) of the operational amplifier (U1) is connected to the MCU controller. For protection circuit or voltage drop control, a resistor (R4) can be placed between the MCU controller and the non-inverting input (pin 1). The negative power supply terminal (pin 2) of the operational amplifier (U1) is connected to the ground point, and the positive power supply terminal (pin 5) is connected to a 3.3V power supply. The output terminal (OUT pin) of the operational amplifier (U1) is connected to each load unit (110) through a differential voltage resistor (R1, R2, R3). After receiving the first voltage signal (DAC signal 1) through the non-inverting input terminal (pin 1), the operational amplifier (U1) outputs a level signal, namely the second level signal (LED_YF_OUT), through the output terminal (pin 4) of the operational amplifier (U1) based on the voltage carried by the first voltage signal (DAC signal 1). This signal is used to control the opening and closing of the LEDs (D1, D2, D3) in all the load units (110) included in the load module (100). Whether the second level signal (LED_YF_OUT) is a high level signal or a low level signal is determined by the voltage carried by the first voltage signal (DAC signal 1). When the voltage carried by the first voltage signal (DAC signal 1) is positive, the second level signal (LED_YF_OUT) is a high level signal.

[0053] After receiving the first voltage signal (DAC signal 1) through the non-inverting input terminal (pin 1), the operational amplifier (U1) generates a second voltage signal (LED_CUR_VRE) based on the voltage carried by the first voltage signal (DAC signal 1) and outputs it to the load module (100) to control the current through each load unit (110). Because the operational amplifier (U1) has the characteristic of "virtual short", that is, the potential of the non-inverting input terminal (pin 1) is equal to the potential of the inverting input terminal (pin 3), the information carried by this second voltage signal (LED_CUR_VRE) is "the voltage equal to the voltage carried by the first voltage signal (DAC signal 1)" or "the voltage equal to the voltage after the first voltage signal (DAC signal 1) is dropped by R4".

[0054] In one embodiment of this application, the constant current control circuit further includes a current-limiting resistor (R5), which is connected between the constant current control module (300) and the ground point.

[0055] The constant current control circuit also includes a current-limiting resistor (R5). The voltage carried by the second voltage signal (LED_CUR_VRE) forms a constant current across the current-limiting resistor (R5), which is the current passing through each load unit (110).

[0056] In one embodiment of this application, the switching element is an NMOS transistor (Q1, Q2, Q3), the controller (200) is connected to the gate (G) of the NMOS transistor (Q1, Q2, Q3), the constant current control module (300) is connected to the gate (G) of the NMOS transistor (Q1, Q2, Q3) through differential voltage resistors (R1, R2, R3), the drain (D) of the NMOS transistor (Q1, Q2, Q3) is connected to the load element, and the source (S) of the NMOS transistor is connected to the constant current control module (300).

[0057] The switching elements can be NMOS transistors (Q1, Q2, Q3), which are N-type metal-oxide-semiconductor field-effect transistors. The MCU controller is connected to the gate (G) of the NMOS transistors (Q1, Q2, Q3). The output terminal (pin 4) of the operational amplifier (U1) is connected to the gate (G) of the NMOS transistors (Q1, Q2, Q3) through differential voltage resistors (R1, R2, R3). The drain (D) of the NMOS transistors (Q1, Q2, Q3) is connected to the cathode of the LEDs (D1, D2, D3). The source (S) of the NMOS transistors is connected to the inverting input terminal (pin 3) of the operational amplifier (U1).

[0058] When the second level signal (LED_YF_OUT) is high, all LEDs (D1, D2, D3) in the load module (100) meet the necessary conditions to turn on. Because the second level signal (LED_YF_OUT) is high, the second voltage signal (LED_CUR_VRE) will carry the voltage determined by the first voltage signal (DAC signal 1) and output it to the current-limiting resistor (R5) to form a constant current.

[0059] When the second level signal (LED_YF_OUT) is high, and the first level signal (LED_SW_1) is high, NMOS transistor (Q1) is turned on, and LED (D1) is on; when the first level signal (LED_SW_2) is high, NMOS transistor (Q2) is turned on, and LED (D2) is on; when the first level signal (LED_SW_3) is high, NMOS transistor (Q3) is turned on, and LED (D3) is on. When the first level signal (LED_SW_1) is low, NMOS transistor (Q1) is turned off, and LED (D1) is off; when the first level signal (LED_SW_2) is low, NMOS transistor (Q2) is turned off, and LED (D2) is off; when the first level signal (LED_SW_3) is low, NMOS transistor (Q3) is turned off, and LED (D3) is off.

[0060] When the second level signal (LED_YF_OUT) is low, none of the LEDs (D1, D2, D3) in the load module (100) meet the necessary conditions to turn on. Because when the second level signal (LED_YF_OUT) is low, the first voltage signal (DAC signal 1) is 0, and the voltage output from the second voltage signal (LED_CUR_VRE) to the current-limiting resistor (R5) is also 0, a constant current cannot be generated. Therefore, even if the first level signal (LED_SW_1, LED_SW_2, LED_SW_3) is high, allowing the NMOS transistors (Q1, Q2, Q3) to conduct, the LEDs (D1, D2, D3) still cannot turn on without the constant current generated by the second voltage signal (LED_CUR_VRE).

[0061] That is, the specific on / off state of each LED (D1, D2, D3) is independently controlled by the first level signal (LED_SW_1, LED_SW_2, LED_SW_3) output by the MCU controller. The first level signal (LED_SW_1, LED_SW_2, LED_SW_3) controls the on / off state of the NMOS transistors (Q1, Q2, Q3) to control the circuit on / off state, ensuring that the LEDs (D1, D2, D3) will not flicker due to the drift of the operational amplifier (U1) output signal.

[0062] Since both the first level signal (LED_SW_1, LED_SW_2, LED_SW_3) and the second level signal (LED_YF_OUT) are level signals, in order to achieve independent control of each LED (D1, D2, D3), at least one differential voltage resistor (R1, R2, R3) needs to be set between the output terminal (OUT pin) of the operational amplifier (U1) and each load unit (110) so that the control information carried by the two level signals can be correctly received and implemented without interfering with each other.

[0063] The control flow of the constant current control circuit provided in this application embodiment, as described above, based on the signal transmission sequence, can be described as follows:

[0064] The MCU controller outputs a first voltage signal (DAC signal 1) to the non-inverting input (pin 1) of the operational amplifier (U1). The operational amplifier (U1) generates a second level signal (LED_YF_OUT) and a second voltage signal (LED_CUR_VRE) based on the voltage carried by the first voltage signal (DAC signal). Utilizing the "virtual short" characteristic of the operational amplifier (U1), the second voltage signal (LED_CUR_VRE) carries a voltage equal to that of the first voltage signal (DAC signal 1) (or the voltage after the voltage drop of DAC signal 1 through R4) to form a constant current in the current-limiting resistor (R5). This is the constant current through each LED (D1, D2, D3). Even if the power supply of the LEDs (D1, D2, D3) is a variable voltage source, the current through the LEDs (D1, D2, D3) remains constant.

[0065] The second-level signal (LED_YF_OUT) is transmitted to each NMOS transistor (Q1, Q2, Q3) through differential resistors (R1, R2, R3), fulfilling the necessary conditions for all LEDs (D1, D2, D3) to turn on. To independently control each LED (D1, D2, D3), the MCU controller sends three first-level signals (LED_SW_1, LED_SW_2, LED_SW_3) through ordinary pins. When the first-level signals (LED_SW_1, LED_SW_2, LED_SW_3) are high, the NMOS transistors (Q1, Q2, Q3) are turned on, and the LEDs (D1, D2, D3) are activated.

[0066] In another embodiment of this application, the switching element can also be a transistor. The base of the transistor is connected to the MCU controller and connected to the output of the operational amplifier through a differential voltage resistor. The collector of the transistor is connected to the cathode of the LED, and the emitter of the transistor is connected to the inverting input of the operational amplifier. The switching characteristics of the transistor are used to realize the opening and closing of the circuit.

[0067] In one embodiment of this application, the constant current control circuit further includes a filter capacitor, one end of which is connected to the constant current control module (300), and the other end is connected to a ground point through at least one filter resistor.

[0068] Figure 4 The schematic diagram illustrates a circuit topology of a constant current control circuit according to an embodiment of this application, incorporating a filter capacitor (C2) and a filter resistor (R6). Figure 4 As shown, the constant current control circuit also includes a filter capacitor (C2). One end of the filter capacitor (C2) is connected to the output terminal of the operational amplifier, and the other end is connected to a filter resistor (R6). It is also connected to the ground point through a current limiting resistor (R5) to prevent the LED from flickering due to noise interference from the first voltage signal.

[0069] Figure 5 A flowchart illustrating a constant current control method according to an embodiment of this application is shown, such as... Figure 5 As shown, in one embodiment of this application, a constant current control method is provided, applied to the constant current control circuit in the above embodiment. The method may include:

[0070] Step S101: The controller (200) outputs a first level signal to the load unit (110) to control the opening or closing of the load unit (110).

[0071] The MCU controller (200) outputs three first-level signals (LED_SW_1, LED_SW_2, LED_SW_3) through three ordinary pins to control the opening and closing of LEDs (D1, D2, D3) of a single load unit (110).

[0072] Step S102: The constant current control module (300) receives the first voltage signal sent by the controller (200), and generates a second level signal (LED_YF_OUT) and a second voltage signal (LED_CUR_VRE) according to the first voltage signal and outputs them to the load module (100).

[0073] After receiving the first voltage signal (DAC signal 1) through the non-inverting input terminal (pin 1), the operational amplifier (U1) outputs a level signal, namely the second level signal (LED_YF_OUT), through the output terminal (pin 4) of the operational amplifier (U1) based on the voltage carried by the first voltage signal (DAC signal 1). This signal is used to control the opening and closing of the LEDs (D1, D2, D3) in all the load units (110) included in the load module (100).

[0074] In one embodiment of this application, step S101 may include:

[0075] Step S001: When the first level signal (LED_SW_1, LED_SW_2, LED_SW_3) is a high level signal and the second level signal (LED_YF_OUT) is a high level signal, the load unit (110) is turned on;

[0076] When the second level signal (LED_YF_OUT) is high, all LEDs (D1, D2, D3) in the load module (100) meet the necessary conditions to turn on. When the second level signal (LED_YF_OUT) is high, and the first level signal (LED_SW_1) is high, the NMOS transistor (Q1) is turned on, and LED (D1) turns on.

[0077] When the first level signal (LED_SW_2) is high, the NMOS transistor (Q2) is turned on and the LED (D2) is turned on.

[0078] When the first level signal (LED_SW_3) is high, the NMOS transistor (Q3) is turned on and the LED (D3) is turned on.

[0079] Step S002: If at least one low-level signal exists in the first level signal (LED_SW_1, LED_SW_2, LED_SW_3) and the second on-hook control signal (LED_YF_OUT), the load unit (110) is turned off.

[0080] When the second level signal (LED_YF_OUT) is high and the first level signal (LED_SW_1) is low, the NMOS transistor (Q1) is turned off and the LED (D1) is turned off.

[0081] When the second level signal (LED_YF_OUT) is high and the first level signal (LED_SW_2) is low, the NMOS transistor (Q2) is turned off and the LED (D2) is turned off.

[0082] When the second level signal (LED_YF_OUT) is high and the first level signal (LED_SW_3) is low, the NMOS transistor (Q3) is turned off and the LED (D3) is turned off.

[0083] When the second level signal (LED_YF_OUT) is a low level signal, all LEDs (D1, D2, D3) in the load module (100) do not meet the necessary conditions to be turned on.

[0084] In one embodiment of this application, an electronic device is provided, including the constant current control circuit described in the above embodiments.

[0085] In a typical configuration, an electronic device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0086] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0087] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0088] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0089] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A constant current control circuit, characterized in that, The circuit includes: A load module, comprising multiple load units connected in parallel; A controller, connected to each of the load units, is used to output a first level signal to the load unit; A constant current control module is connected to the controller and also connected to each of the load units through at least one differential voltage resistor. It is used to receive a first voltage signal from the controller and generate a second level signal and a second voltage signal based on the first voltage signal, and output them to the load module. The controller is used to control the opening or closing of the load unit; Specifically, the load unit is turned on when both the first level signal and the second level signal are high. The load unit is turned off if at least one of the first level signal and the second level signal is low. The load unit includes: Load elements; and A switching element is connected to the load element, the switching element is connected to the controller, and is connected to the constant current control module through at least one differential voltage resistor, wherein the first level signal and the second level signal act together on the control terminal of the switching element.

2. The constant current control circuit according to claim 1, characterized in that, The constant current control module includes an operational amplifier. The non-inverting input of the operational amplifier is connected to the controller, the inverting input of the operational amplifier is connected to the load module, and the output of the operational amplifier is connected to each load unit through at least one differential voltage resistor.

3. The constant current control circuit according to claim 1, characterized in that, The switching element is an NMOS transistor, the controller is connected to the gate of the NMOS transistor, the constant current control module is connected to the gate of the NMOS transistor through the differential voltage resistor, the drain of the NMOS transistor is connected to the load element, and the source of the NMOS transistor is connected to the constant current control module.

4. The constant current control circuit according to claim 1, characterized in that, The circuit also includes a filter capacitor, one end of which is connected to the constant current control module, and the other end is connected to the ground point through at least one filter resistor.

5. The constant current control circuit according to claim 1, characterized in that, The circuit also includes a current-limiting resistor, which is connected between the constant current control module and the grounding point.

6. The constant current control circuit according to claim 1, characterized in that, The load element is an LED, the anode of the LED is connected to the power supply, and the cathode of the LED is connected to the switching element.

7. An electronic device, characterized in that, Includes the constant current control circuit as described in any one of claims 1-6.

8. A constant current control method, characterized in that, The method, applied to the constant current control circuit as described in any one of claims 1-6, comprises: The controller outputs the first level signal to the load unit to control the load unit to turn on or off. The constant current control module receives the first voltage signal from the controller and generates the second level signal and the second voltage signal based on the first voltage signal, which are then output to the load module. The second voltage signal is used to control the magnitude of the current passing through the load unit; When the first voltage signal is a positive voltage, the second level signal is a high level signal.

9. The constant current control method according to claim 8, characterized in that, The step of outputting the first level signal to the load unit through the controller to control the opening or closing of the load unit includes: When both the first level signal and the second level signal are high, the load unit is turned on. The load unit is turned off if at least one of the first level signal and the second level signal is low.

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