Constant current source circuit

Abstract

The invention provides a constant current source circuit, and relates to the technical field of electronic circuits. The constant current source circuit comprises a constant current source body circuit and an open circuit detection circuit electrically connected with the constant current source body circuit. The constant current source body circuit comprises a load resistor which is electrically connected with the open circuit detection circuit. The open circuit detection circuit comprises a first triode and a second triode, the constant current source body circuit and an emitter of the first triode are electrically connected with a base of the first triode, and a collector of the first triode, an emitter of the second triode and a grounding electrode are electrically connected with a base of the second triode. When the load is closed, the collector of the second triode outputs high level; when the load is disconnected, the collector of the second triode becomes low level. The circuit break detection function is directly integrated into the constant current source body circuit, and the traditional complex detection circuit is replaced by the linkage control of the two triodes, so that the circuit break detection function is realized, and meanwhile, the complexity of the circuit break detection circuit is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and in particular to a constant current source circuit. Background Art

[0002] A constant current source is an electronic circuit used to provide a constant current to a load. However, in actual use, the load may become disconnected due to poor connections, disconnected wires, or component failure, causing the constant current source to malfunction. Therefore, detecting whether the load has experienced a disconnection is crucial in constant current source applications.

[0003] Conventional constant current source disconnect detection typically relies on adding additional detection circuitry, such as voltage or current sensing circuits, to the circuit. These circuits monitor changes in voltage or current across the load to determine if a disconnect has occurred. When the load disconnects, the current drops to zero, and the voltage or current sensing circuit detects the abnormal change. At this point, the detection circuit triggers a control mechanism, sounding an alarm.

[0004] However, existing technologies suffer from the high complexity of circuit break detection. Implementing circuit break detection often requires complex circuit designs to meet specific detection and control requirements. While this approach can achieve the desired functionality, the multiple components and complex connections involved increase circuit complexity, making design and maintenance more difficult. Summary of the Invention

[0005] The embodiments of the present application provide a constant current source circuit to solve the problem of high complexity of the open circuit detection circuit in the prior art.

[0006] In a first aspect, an embodiment of the present application provides a constant current source circuit, comprising: a constant current source main circuit, and a circuit breaker detection circuit electrically connected to the constant current source main circuit;

[0007] The constant current source main circuit includes a load resistor, and the load resistor is electrically connected to the circuit breaker detection circuit;

[0008] The disconnection detection circuit includes a first transistor and a second transistor, the constant current source body circuit and the emitter of the first transistor are electrically connected to the base of the first transistor, and the collector of the first transistor, the emitter of the second transistor and the ground electrode are electrically connected to the base of the second transistor;

[0009] The constant current source main circuit is used to maintain a constant current in the load resistor. The first transistor is used to turn on when the load resistor is connected to control the second transistor to be cut off, so that the collector of the second transistor presents a high level. The collector of the second transistor presents a high level to indicate that the load resistor is connected. The first transistor is used to turn off when the load resistor is disconnected to control the second transistor to be turned on, so that the collector of the second transistor presents a low level. The collector of the second transistor presents a low level to indicate that the load resistor is disconnected.

[0010] In one possible design, the constant current source circuit further includes: a voltage reference circuit;

[0011] The voltage reference circuit includes a voltage reference chip, a first diode, a first resistor and a second resistor. The first input end of the voltage reference chip is electrically connected to the positive electrode of the first power supply. The first resistor is electrically connected to the ground electrode, the second input end of the voltage reference chip, the third input end of the voltage reference chip and the constant current source main circuit respectively. The second resistor is electrically connected to the positive electrode of the first power supply, the cathode of the first diode, the first output end of the voltage reference chip, the second output end of the voltage reference chip and the constant current source main circuit respectively. The anode of the first diode is electrically connected to the ground electrode.

[0012] In one possible design, the disconnection detection circuit further includes a third resistor and a fourth resistor;

[0013] The collector of the first transistor, the base of the second transistor and the grounding electrode are all electrically connected to the third resistor, and the fourth resistor is electrically connected to the positive electrode of the first power supply and the collector of the second transistor respectively.

[0014] In one possible design, the second input terminal of the voltage reference chip is electrically connected to the third input terminal of the voltage reference chip, and the first output terminal of the voltage reference chip is electrically connected to the second output terminal of the voltage reference chip.

[0015] In one possible design, the constant current source main circuit further includes a fifth resistor, an operational amplifier, a transistor, and a sixth resistor;

[0016] The fifth resistor is electrically connected to the first output terminal of the voltage reference chip, the second output terminal of the voltage reference chip, the second resistor, the cathode of the first diode, the in-phase input terminal of the operational amplifier and the load resistor, respectively; the out-of-phase input terminal of the operational amplifier is electrically connected to the first resistor, the first input terminal of the voltage reference chip and the second input terminal of the voltage reference chip, respectively; the output terminal of the operational amplifier is electrically connected to the gate of the transistor; the sixth resistor is electrically connected to the source of the transistor and the negative electrode of the second power supply, respectively; and the drain of the transistor is electrically connected to the load resistor; wherein, the transistor is a field effect transistor that uses a negative semiconductor material to form a conductive channel.

[0017] In one possible design, the positive power supply terminal of the operational amplifier is electrically connected to the positive electrode of the second power supply, and the negative power supply terminal of the operational amplifier is electrically connected to the negative electrode of the second power supply.

[0018] In a possible design, the constant current source main circuit further includes a second diode, an anode of the second diode is electrically connected to the load resistor, and a cathode of the second diode is electrically connected to the drain of the transistor.

[0019] In one possible design, the voltage reference circuit further includes a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, and a fifth capacitor;

[0020] The first capacitor is electrically connected to the positive electrode of the first power supply, the second capacitor, the third capacitor, the first resistor, the first input terminal of the voltage reference chip, the second input terminal of the voltage reference chip, the third input terminal of the voltage reference chip, and the out-of-phase input terminal of the operational amplifier respectively;

[0021] The second capacitor is electrically connected to the third capacitor, the ground electrode, the first resistor, the second input terminal of the voltage reference chip, the third input terminal of the voltage reference chip, and the out-of-phase input terminal of the operational amplifier respectively;

[0022] The third capacitor is electrically connected to the fourth input terminal of the voltage reference chip, the first resistor, the second input terminal of the voltage reference chip, the third input terminal of the voltage reference chip and the out-of-phase input terminal of the operational amplifier respectively;

[0023] The fourth capacitor is electrically connected to the ground electrode, the first output terminal of the voltage reference chip, the second output terminal of the voltage reference chip, the second resistor, the cathode of the first diode, the fifth capacitor and the fifth resistor respectively;

[0024] The fifth capacitor is electrically connected to the ground electrode, the second resistor, the cathode of the first diode, the fifth resistor, the first output end of the voltage reference chip, and the second output end of the voltage reference chip respectively.

[0025] In one possible design, the constant current source main circuit further includes a seventh resistor, an eighth resistor, and a ninth resistor;

[0026] The seventh resistor is electrically connected to the non-inverting input terminal of the operational amplifier and the fifth resistor respectively;

[0027] The eighth resistor is electrically connected to the out-of-phase input terminal of the operational amplifier, the first capacitor, the second capacitor, the third capacitor, the first resistor, the second input terminal of the voltage reference chip, and the third input terminal of the voltage reference chip respectively;

[0028] The ninth resistor is electrically connected to the output terminal of the operational amplifier, the gate of the transistor and the base of the first triode respectively.

[0029] In one possible design, the first diode is a voltage regulator diode, which is used to stabilize the output voltage of the voltage reference chip.

[0030] The present application provides a constant current source circuit, the constant current source circuit comprising: a constant current source main circuit, and a circuit break detection circuit electrically connected to the constant current source main circuit; the constant current source main circuit comprising a load resistor, the load resistor being electrically connected to the circuit break detection circuit; the circuit break detection circuit comprising a first transistor and a second transistor, the emitter of the constant current source main circuit and the first transistor being electrically connected to the base of the first transistor, the collector of the first transistor, the emitter of the second transistor, and the ground electrode being electrically connected to the base of the second transistor; the constant current source main circuit being configured to maintain a constant current in the load resistor, the first transistor being configured to be turned on when the load resistor is connected to control the second transistor to be turned off, so that the collector of the second transistor presents a high level, the collector of the second transistor presenting a high level being used to indicate that the load resistor is connected, the first transistor being configured to be turned off when the load resistor is disconnected to control the second transistor to be turned on, so that the collector of the second transistor presents a low level, the collector of the second transistor presenting a low level being used to indicate that the load resistor is disconnected. The constant current source circuit of the present application integrates a circuit break detection function into the circuit, utilizing the coordinated control of two transistors to replace the traditional complex detection circuit, thus reducing the complexity of the circuit break detection circuit. When the load is open, the first transistor turns on, causing the second transistor to turn off, and its collector outputs a high level. When the load is open, the constant current source output voltage increases, causing the first transistor to turn off, the second transistor to turn on, and the collector to become a low level. By monitoring the high and low level changes of the collector of the second transistor, it is possible to determine whether the load is open, without the need for an additional complex detection circuit. This achieves the circuit break detection function while reducing the complexity of the circuit break detection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0032] Figure 1 Schematic diagram of the structure of the constant current source circuit provided in the embodiment of the present application Figure 1 ;

[0033] Figure 2 Schematic diagram of the structure of the constant current source circuit provided in the embodiment of the present application Figure 2 .

[0034] Description of reference numerals:

[0035] 100-constant current source body circuit;

[0036] 101- load resistor;

[0037] 102-fifth resistor;

[0038] 103- Operational amplifier;

[0039] 104-transistor;

[0040] 105-sixth resistor;

[0041] 106 - second diode;

[0042] 107-seventh resistor;

[0043] 108-eighth resistor;

[0044] 109-9th resistor;

[0045] 200-circuit break detection circuit;

[0046] 201-first transistor;

[0047] 202-second transistor;

[0048] 203- third resistor;

[0049] 204- fourth resistor;

[0050] 300-voltage reference circuit;

[0051] 301- voltage reference chip;

[0052] 302-first diode;

[0053] 303 - first resistor;

[0054] 304 - second resistor;

[0055] 305-first capacitor;

[0056] 306 - second capacitor;

[0057] 307-third capacitor;

[0058] 308- fourth capacitor;

[0059] 309-Fifth capacitor.

[0060] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0061] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0062] In the embodiments of the present application, words such as "first" and "second" are used to distinguish between identical or similar items with substantially the same functions and effects. Those skilled in the art will understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit differences. It should be noted that in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described in this application as "exemplary" or "for example" should not be interpreted as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way. In the embodiments of the present application, "at least one" refers to one or more, and "more" refers to two or more.

[0063] It should be noted that the term "at..." in the embodiments of the present application can refer to the instant when a certain situation occurs or a period of time after the situation occurs, and the embodiments of the present application do not specifically limit this. In addition, the constant current source circuit provided in the embodiments of the present application is only an example, and a constant current source circuit may also include more or less content.

[0064] To facilitate a clear description of the technical solutions of the embodiments of the present application, some of the terms and technologies involved in the embodiments of the present application are briefly introduced below:

[0065] A voltage reference chip is an electronic component used to provide a stable and accurate reference voltage. It is commonly used in circuits that require a high-precision voltage reference, such as data converters, amplifiers, and power management systems, to ensure overall circuit performance.

[0066] A transistor is a semiconductor device widely used to amplify and switch electronic signals. Made of semiconductor material, it typically has three terminals: source, gate, and drain. By controlling the current or voltage at the base or gate, the transistor regulates the flow of current through the other two terminals, thereby amplifying or switching signals. Transistors are fundamental building blocks of modern electronic devices and are used in a wide variety of circuits.

[0067] Exemplary embodiments will be described in detail herein, examples of which are illustrated in the accompanying drawings. In the following description, when referring to the drawings, like numbers in different figures represent like or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present invention, as detailed in the appended claims.

[0068] The technical solution of the present invention is described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present invention will be described below with reference to the accompanying drawings.

[0069] To clearly understand the technical solution of this application, we first provide a detailed introduction to the prior art solutions. A constant current source is an electronic circuit used to provide a constant current to a load. However, in actual use, the load may experience a short circuit due to poor connection, disconnected circuit, or component failure, causing the constant current source to malfunction. Therefore, in the application of a constant current source, it is crucial to detect whether the load has experienced a short circuit.

[0070] In the prior art, the circuit break detection of a constant current source usually relies on adding additional detection circuits to the circuit, such as voltage or current sensing circuits. These circuits determine whether a circuit break occurs by monitoring the voltage or current changes across the load. When the load is disconnected, the current will drop sharply to zero, and the voltage or current sensing circuit will detect the abnormal change. At this time, the detection circuit will trigger the control mechanism and sound an alarm. However, when implementing circuit break detection in the prior art, it is often necessary to introduce complex circuit designs to meet specific detection and control requirements. Although this method can achieve the intended function, it involves multiple components and complex connections, which increases the complexity of the circuit and increases the difficulty of design and maintenance. Therefore, the prior art has the problem of high complexity of the circuit break detection circuit.

[0071] To address the high complexity of existing circuit break detection circuits, research has found that circuit break detection can be simplified by using fewer components or integrated solutions, thereby reducing circuit complexity: ① Dedicated integrated circuits can be used to implement the break detection function. These ICs typically integrate the necessary detection and signal processing circuitry, reducing the number of external components and circuit design complexity. ② A modular design can be adopted, designing the break detection function as a standalone module that can be easily integrated into different circuit systems. This modular design simplifies the development process and improves the circuit's maintainability and scalability. ③ A self-triggering switching circuit can be designed to automatically detect and respond by monitoring changes in the constant current source's characteristics when the load is broken, such as an increase in output voltage or an abnormality in the feedback loop. This circuit can use a comparator or voltage detector to monitor these changes in real time and automatically trigger an alarm or indicator light upon detecting an anomaly.

[0072] Specifically, the key operating parameters of the constant current source circuit can be monitored in real time, and the nonlinear characteristics of the analog circuit can be used to establish a dynamic threshold judgment window. When it is detected that the parameters abnormally deviate from the normal operating range, the built-in state transition circuit is automatically triggered to output a standardized fault indication signal.

[0073] A constant current source circuit in an embodiment of the present application integrates a circuit break detection function into the constant current source circuit and utilizes the linkage control of two transistors to replace the traditional complex detection circuit, thereby reducing the complexity of the circuit break detection circuit. When the load is open, the first transistor is turned on, causing the second transistor to be turned off, and its collector outputs a high level. When the load is open, the constant current source output voltage increases, causing the first transistor to be turned off, the second transistor to be turned on, and the collector to become a low level. By monitoring the high and low level changes of the collector of the second transistor, it is possible to determine whether the load is open, without the need for an additional complex detection circuit. This reduces the complexity of the circuit break detection circuit while achieving the circuit break detection function.

[0074] Based on the above creative findings, the technical solution of the present application is proposed.

[0075] Figure 1 Schematic diagram of the structure of the constant current source circuit provided in the embodiment of the present application Figure 1 , Figure 2 Schematic diagram of the structure of the constant current source circuit provided in the embodiment of the present application Figure 2 .like Figure 1 and Figure 2 As shown, in this embodiment, the constant current source circuit includes: a constant current source main circuit 100 and a disconnection detection circuit 200 electrically connected to the constant current source main circuit 100 .

[0076] Specifically, by combining the constant current source circuit 100 with the disconnection detection circuit 200, real-time monitoring of the load status is achieved. The constant current source circuit 100 is responsible for maintaining a stable output current, while the disconnection detection circuit 200 connected to it continuously monitors the operating status of the load circuit. It remains silent when the load is operating normally, and immediately triggers an alarm signal if a load disconnection fault is detected.

[0077] The constant current source main circuit 100 includes a load resistor 101 , which is electrically connected to the disconnection detection circuit 200 .

[0078] Specifically, one end of the load resistor 101 can be connected to the circuit break detection circuit 200, and the other end can be connected to the constant current source main circuit 100, using the voltage change across the load resistor as the detection signal source. This connection method enables the circuit break detection circuit 200 to sense the current on / off state of the load resistor 101 in real time. When the load resistor 101 is operating normally, the current generates a normal voltage drop across the load resistor 101; when a circuit break occurs, this voltage drop disappears or increases abnormally, thereby triggering the circuit break detection circuit 200 to output a state change signal.

[0079] The circuit breaker detection circuit 200 includes a first transistor 201 and a second transistor 202. The emitter of the constant current source main circuit 100 and the first transistor 201 are electrically connected to the base of the first transistor 201. The collector of the first transistor 201, the emitter of the second transistor 202 and the ground electrode are electrically connected to the base of the second transistor 202.

[0080] Specifically, the emitter of the constant current source main circuit 100 and the first transistor 201 are electrically connected to the base of the first transistor 201, which allows the output current of the constant current source main circuit 100 to enter the base of the first transistor 201, thereby controlling its conduction state. In addition, the collector of the first transistor 201, the emitter of the second transistor 202 and the ground electrode are all electrically connected to the base of the second transistor 202, which indicates that the conduction state of the first transistor 201 will directly affect the base voltage of the second transistor 202, thereby controlling its conduction state. This connection relationship is used to detect the state of the load resistor 101: different states of the load resistor 101 will cause the collector of the second transistor 202 to present different levels, and the on-off state of the load resistor 101 can be obtained by detecting the level of the collector of the second transistor 202.

[0081] The constant current source main circuit 100 is used to maintain a constant current in the load resistor 101. The first transistor 201 is used to turn on when the load resistor 101 is connected to control the second transistor 202 to be cut off, so that the collector of the second transistor 202 is at a high level. The collector of the second transistor 202 is at a high level to indicate that the load resistor 101 is connected. The first transistor 201 is used to turn off when the load resistor 101 is disconnected to control the second transistor 202 to be turned on, so that the collector of the second transistor 202 is at a low level. The collector of the second transistor 202 is at a low level to indicate that the load resistor 101 is disconnected.

[0082] Specifically, the constant current source main circuit 100 provides a constant current to the load resistor 101. When the load is connected, the current flows through the load resistor 101 and forms a voltage between the base and emitter of the first transistor 201, turning it on, thereby lowering the base voltage of the second transistor 202 to turn it off, causing the collector of the second transistor 202 to output a high level. When the load is disconnected, the first transistor 201 is cut off due to the loss of base current, and the base of the second transistor 202 is pulled down through the ground electrode and turned on, causing its collector to output a low level. This connection relationship is used to convert the on-off state of the load resistor 101 into a logic level signal, which is convenient for detecting whether the load resistor 101 is connected or disconnected.

[0083] This embodiment provides a constant current source circuit, including a constant current source main circuit and a circuit break detection circuit electrically connected to the constant current source main circuit; the constant current source main circuit includes a load resistor, which is electrically connected to the circuit break detection circuit; the circuit break detection circuit includes a first transistor and a second transistor, the emitter of the constant current source main circuit and the first transistor are both electrically connected to the base of the first transistor, and the collector of the first transistor, the emitter of the second transistor, and the ground electrode are all electrically connected to the base of the second transistor; the constant current source main circuit is used to maintain a constant current in the load resistor, the first transistor is used to turn on when the load resistor is connected to control the second transistor to turn off, so that the collector of the second transistor presents a high level, and the collector of the second transistor presents a high level to indicate that the load resistor is connected, and the first transistor is used to turn off when the load resistor is disconnected to control the second transistor to turn on, so that the collector of the second transistor presents a low level, and the collector of the second transistor presents a low level to indicate that the load resistor is disconnected. A constant current source circuit achieves the following technical effects: By integrating a circuit break detection function into the constant current source circuit and replacing traditional complex detection circuits with linked control of two transistors, the complexity of the circuit break detection circuit is reduced. When the load is open, the first transistor turns on, causing the second transistor to turn off, and its collector outputs a high level. When the load is open, the constant current source output voltage increases, causing the first transistor to turn off, the second transistor to turn on, and the collector to go low. By monitoring the high and low level changes of the second transistor's collector, it is possible to determine whether the load is open, without the need for additional complex detection circuits. This achieves the circuit break detection function while reducing the complexity of the circuit break detection circuit.

[0084] In one possible design, the constant current source circuit further includes: a voltage reference circuit 300 .

[0085] Specifically, the output end of the voltage reference circuit 300 can be connected to the constant current source main circuit 100 through a wire. This connection relationship is used to provide a stable reference voltage for the constant current source main circuit 100 to ensure the accuracy and stability of the output of the constant current source main circuit 100.

[0086] The voltage reference circuit 300 includes a voltage reference chip 301, a first diode 302, a first resistor 303 and a second resistor 304. The first input terminal of the voltage reference chip 301 is electrically connected to the positive electrode of the first power supply. The first resistor 303 is electrically connected to the ground electrode, the second input terminal of the voltage reference chip 301, the third input terminal of the voltage reference chip 301 and the constant current source main circuit 100 respectively. The second resistor 304 is electrically connected to the positive electrode of the first power supply, the cathode of the first diode 302, the first output terminal of the voltage reference chip 301, the second output terminal of the voltage reference chip 301 and the constant current source main circuit 100 respectively. The anode of the first diode 302 is electrically connected to the ground electrode.

[0087] Specifically, wires can be used to connect the various components according to the circuit design. The first input terminal of the voltage reference chip 301 is connected to the positive pole of the first power supply via a wire to ensure that the voltage reference chip 301 obtains the required operating voltage. The first resistor 303 is connected to the ground electrode via a wire, and is also connected to the second and third input terminals of the voltage reference chip 301, as well as the constant current source main circuit 100, to provide voltage division and stable operating conditions. The second resistor 304 is connected to the positive pole of the first power supply via a wire, and is connected to the cathode of the first diode 302, the first and second output terminals of the voltage reference chip 301, and the constant current source main circuit 100 to further stabilize the voltage output. The anode of the first diode 302 is connected to the ground electrode via a wire to provide voltage protection. This connection relationship is used to provide a stable voltage reference in the constant current source circuit, ensuring the stability of the current output under different load conditions. The stable voltage output by the voltage reference chip 301 is combined with the peripheral components to increase the common terminal voltage. After the common terminal voltage is increased, the load operating range of the constant current source main circuit 100 is also improved.

[0088] For example, the calculation formula for the operating range of the load resistor 101 can be expressed as:

[0089]

[0090] Wherein, RL is the maximum resistance value of the load allowed for normal operation of the constant current source circuit, COM is the common terminal voltage, VD2 is the voltage of the second diode 106, Rds(on) is the resistance when the transistor is fully turned on, I d is the current of the constant current source circuit 100. By increasing the common terminal voltage COM, the maximum load resistance RL allowed for normal operation of the circuit is also increased, so that the constant current source circuit 100 can adapt to a wider range of load conditions.

[0091] The current I of the constant current source main circuit 100 d The calculation formula is:

[0092]

[0093] Among them, I 102 is the current of the fifth resistor 102, R 102 Refers to the resistance of the fifth resistor 102, V1 refers to the voltage value of the first output terminal of the voltage reference chip 301, COM is the common terminal voltage, V1-COM is the voltage value between the first output terminal of the voltage reference chip 301 and the ground electrode, which is a fixed value, so I d It is a value that has nothing to do with the load resistance, which means that constant current is achieved.

[0094] Among them, the first input terminal of the voltage reference chip 301 can be a chip input terminal (Input, IN), the second input terminal can be a ground level (Ground, GND), the third input terminal can be a ground detection terminal (Ground Sense, GNDS), the first output terminal can be a chip output terminal (Output, OUT), and the second output terminal can be an output detection terminal (Output Sense, OUTS).

[0095] The technical effect of this embodiment is that, by adding a voltage reference circuit and utilizing the synergistic effect of the voltage reference chip and the first diode, a voltage boost mechanism is established in the constant current source circuit. This mechanism uses the stable voltage output by the reference chip and the peripheral components to increase the common terminal voltage. This increase in common terminal voltage also increases the load operating range of the constant current source circuit, enabling the constant current source circuit to adapt to a wider range of load conditions and expanding its applicability.

[0096] In a possible design, the disconnection detection circuit 200 further includes a third resistor 203 and a fourth resistor 204 .

[0097] Specifically, third resistor 203 provides current to second transistor 202 and sets its conduction threshold, ensuring reliable conduction when the load is disconnected. Fourth resistor 204 acts as a pull-up resistor for the collector of second transistor 202, limiting the operating current and performing level conversion, converting the transistor's switching state into detectable high and low-level signals. These two resistors together optimize the detection circuit's switching characteristics, enhancing the reliability of disconnection detection and the stability of the signal output.

[0098] The collector of the first transistor 201 , the base and the ground of the second transistor 202 are all electrically connected to the third resistor 203 , and the fourth resistor 204 is electrically connected to the positive electrode of the first power supply and the collector of the second transistor 202 , respectively.

[0099] Specifically, a wire can be used to connect the third resistor 203 to the collector of the first transistor 201, the base of the second transistor 202, and the ground to form a current path, ensuring that the voltage and current conditions between these nodes can meet the normal operation of the transistor. The fourth resistor 204 can be connected to the positive electrode of the first power supply and the collector of the second transistor 202 via a wire to limit the current flowing through the second transistor 202, preventing excessive current from damaging the second transistor 202, and enabling the second transistor 202 to correctly switch its on and off states when the state of the load resistor 101 changes. The function of the third resistor 203 is to regulate and stabilize the operating voltage of the transistor to ensure the sensitivity and responsiveness of the circuit, while the fourth resistor 204 provides the necessary protection measures so that the circuit can accurately indicate its state when the load resistor 101 is connected or disconnected.

[0100] The technical effect of this embodiment is: by adding a current-limiting resistor to the transistor base circuit, the stability of the transistor operating point is ensured, and the impact of overcurrent on the detection circuit is prevented. At the same time, together with the load resistor of the collector circuit, a reliable signal conversion network is formed. This design improves the sensitivity and anti-interference ability of circuit break detection.

[0101] In one possible design, the second input terminal of the voltage reference chip 301 is electrically connected to the third input terminal of the voltage reference chip 301 , and the first output terminal of the voltage reference chip 301 is electrically connected to the second output terminal of the voltage reference chip 301 .

[0102] Specifically, a wire can be used to directly connect the second input terminal and the third input terminal of the voltage reference chip 301 to ensure that the two input terminals receive the same voltage signal, thereby stabilizing the internal reference voltage of the chip. The first output terminal and the second output terminal of the voltage reference chip 301 can be connected together by a wire to provide a consistent output voltage signal to the constant current source body circuit 100. This connection relationship is used to ensure that the voltage reference chip has voltage consistency between the input and output terminals when providing a stable reference voltage, thereby improving the overall accuracy and stability of the constant current source circuit.

[0103] The technical effect of this embodiment is that by connecting the input and output terminals of the voltage reference chip separately, the stability and driving capability of the reference voltage are improved. This symmetrical connection reduces the impact of internal chip parameter drift on the output voltage, ensuring that the reference voltage remains stable under various load conditions. This design provides a precise reference voltage for the subsequent constant current source, improving circuit stability.

[0104] In a possible design, the constant current source main circuit 100 further includes a fifth resistor 102 , an operational amplifier 103 , a transistor 104 and a sixth resistor 105 .

[0105] Specifically, the fifth resistor 102, the operational amplifier 103, the transistor 104 and the sixth resistor 105 work together to achieve precise current control. The fifth resistor 102 is used to provide a feedback voltage to help the operational amplifier 103 adjust the output signal. The operational amplifier 103 receives signals from the voltage reference chip 301 and the fifth resistor 102, amplifies the error and outputs a control signal to the transistor 104. The transistor 104 acts as a variable resistor to adjust the current passing through the load resistor 101 to maintain a constant current. The sixth resistor 105 is used to stabilize the operating state of the transistor 104 and ensure its normal operation under different load conditions. Through the synergistic effect of these components, the circuit can achieve a stable constant current output.

[0106] The fifth resistor 102 is electrically connected to the first output terminal of the voltage reference chip 301, the second output terminal of the voltage reference chip 301, the second resistor 304, the cathode of the first diode 302, the non-inverting input terminal of the operational amplifier 103 and the load resistor 101 respectively. The out-of-phase input terminal of the operational amplifier 103 is electrically connected to the first resistor 303, the first input terminal of the voltage reference chip 301 and the second input terminal of the voltage reference chip 301 respectively. The output terminal of the operational amplifier 103 is electrically connected to the gate of the transistor 104. The sixth resistor 105 is electrically connected to the source of the transistor 104 and the negative electrode of the second power supply respectively. The drain of the transistor 104 is electrically connected to the load resistor 101; wherein, the transistor 104 is a field effect transistor that uses a negative semiconductor material to form a conductive channel.

[0107] Specifically, the fifth resistor 102 can be connected via wires to the output of the voltage reference chip 301, the second resistor 304, the cathode of the first diode 302, the non-inverting input of the operational amplifier 103, and the load resistor 101 to form a feedback loop, ensuring that the operational amplifier 103 receives an accurate feedback signal. The non-inverting input of the operational amplifier 103 can be connected via wires to the first resistor 303 and the input of the voltage reference chip 301 to receive a reference voltage signal. The output of the operational amplifier 103 is connected via wires to the gate of the transistor 104 to control its conduction state. The sixth resistor 105 is connected via wires to the source of the transistor 104 and the negative electrode of the second power supply, providing a stable current path. The drain of the transistor 104 is connected to the load resistor 101 to regulate the current passing through the load. This connection relationship is used to achieve precise current control. The conduction state of the transistor 104 is adjusted by the operational amplifier 103 to ensure that the current in the load resistor 101 remains constant, thereby improving the stability and performance of the circuit.

[0108] The technical effect of this embodiment is: a high-precision constant current output is achieved through a closed-loop control system composed of an operational amplifier and a field-effect transistor. The design uses an operational amplifier to monitor and adjust the conduction state of the field-effect transistor in real time, so that the load current strictly follows the reference voltage changes, ensuring that the output current is not affected by load impedance fluctuations. The negative feedback mechanism automatically compensates for line voltage drops and device parameter drifts, thereby improving current stability and expanding the load adaptation range. When the load increases abnormally, the circuit can automatically limit the current output to protect the safety of circuit components. This structure not only achieves precise constant current control, but also enhances the reliability and adaptability of the circuit through an intelligent adjustment mechanism, providing a stable circuit foundation for subsequent circuit break detection.

[0109] In one possible design, the positive power supply terminal of the operational amplifier 103 is electrically connected to the positive electrode of the second power supply, and the negative power supply terminal of the operational amplifier 103 is electrically connected to the negative electrode of the second power supply.

[0110] Specifically, the positive power supply terminal of operational amplifier 103 can be connected to the positive terminal of a second power supply via a wire, and the negative power supply terminal can be connected to the negative terminal of the second power supply. This connection relationship is used to provide the necessary operating voltage for operational amplifier 103, enabling it to properly amplify the input signal. Through this power supply method, operational amplifier 103 can effectively process the input signal within its linear operating region, perform accurate voltage comparison and amplification, thereby controlling the operation of subsequent circuit components such as transistors and ensuring the stability of the constant current source circuit.

[0111] The technical effect of this embodiment is that by configuring an independent power supply architecture for the operational amplifier, the stability and dynamic response performance of the constant current control circuit are improved. This design makes the operating voltage range of the operational amplifier completely independent of the reference voltage circuit, effectively eliminating power supply coupling interference. The dual power supply not only expands the output signal swing range, but also improves the response speed to sudden load changes, making constant current regulation more accurate and rapid, providing a reliable power supply guarantee for constant current output, and ensuring that the entire constant current source circuit remains stable under complex operating conditions.

[0112] In a possible design, the constant current source main circuit 100 further includes a second diode 106 , an anode of the second diode 106 is electrically connected to the load resistor 101 , and a cathode of the second diode 106 is electrically connected to the drain of the transistor 104 .

[0113] Specifically, the anode of the second diode 106 can be connected to one end of the load resistor 101 via a wire, and its cathode can be connected to the drain of the transistor 104. This connection relationship is used to provide reverse current protection in the circuit to prevent the reverse flow of current caused by a fault in the load resistor 101 or other circuit components. Through this configuration, the second diode 106 is non-conductive under normal circumstances, but can quickly turn on when reverse current occurs, thereby protecting the transistor 104 and other sensitive components from damage, ensuring the reliability and stability of the constant current source circuit.

[0114] The technical effect of this embodiment is that by adding a protection diode to the load circuit, the reliability and safety of the constant current source circuit are improved. This diode is in a reverse cutoff state when the load is operating normally, without affecting the circuit function. When an abnormal reverse voltage appears, it immediately turns on to form a protection path, preventing high-voltage shocks from damaging the core components. This design not only provides reliable voltage clamping protection for the transistor, preventing overvoltage breakdown between the gate and source, but also suppresses the reverse electromotive force generated by sudden load changes, enhancing the circuit's anti-interference ability and fault tolerance.

[0115] In one possible design, the voltage reference circuit 300 further includes a first capacitor 305 , a second capacitor 306 , a third capacitor 307 , a fourth capacitor 308 , and a fifth capacitor 309 .

[0116] Specifically, these capacitors form a multi-stage filtering network. First capacitor 305 acts as a high-frequency decoupling capacitor at the power input, suppressing power supply ripple. Second capacitor 306 and third capacitor 307 form a low-pass filter for the reference voltage, improving reference stability. Fourth capacitor 308 and fifth capacitor 309 form a multi-stage filter at the output, filtering out noise interference at different frequency bands. These capacitors work together to provide a clean operating environment for voltage reference chip 301, effectively suppressing power supply noise, reference fluctuations, and output interference, ensuring the accuracy and stability of the reference voltage.

[0117] The first capacitor 305 is electrically connected to the positive electrode of the first power supply, the second capacitor 306, the third capacitor 307, the first resistor 303, the first input terminal of the voltage reference chip 301, the second input terminal of the voltage reference chip 301, the third input terminal of the voltage reference chip 301 and the out-of-phase input terminal of the operational amplifier 103 respectively.

[0118] Specifically, first capacitor 305 serves as the main filter capacitor at the power input stage, primarily used to filter out high-frequency noise and transient interference introduced by the positive terminal of the first power supply, thereby providing a stable DC power supply for the entire voltage reference circuit 300. By being connected to the positive terminal of the power supply, it effectively suppresses ripple and spike interference on the power line.

[0119] The second capacitor 306 is electrically connected to the third capacitor 307 , the ground, the first resistor 303 , the second input terminal of the voltage reference chip 301 , the third input terminal of the voltage reference chip 301 , and the out-of-phase input terminal of the operational amplifier 103 , respectively.

[0120] Specifically, the second capacitor 306 serves as a low-frequency filter capacitor for the reference voltage, and is used to filter out medium and low-frequency noise in the reference voltage. It cooperates with the third capacitor 307 to form a multi-stage filtering network to ensure the voltage stability of the reference chip input end and prevent the reference signal from being affected by low-frequency fluctuations.

[0121] The third capacitor 307 is electrically connected to the fourth input terminal of the voltage reference chip 301 , the first resistor 303 , the second input terminal of the voltage reference chip 301 , the third input terminal of the voltage reference chip 301 and the out-of-phase input terminal of the operational amplifier 103 , respectively.

[0122] Specifically, the third capacitor 307 serves as a bypass capacitor at the input end of the reference chip, used to further suppress high-frequency noise, forming a complementary filter with the second capacitor 306, covering a wider frequency band, ensuring the purity of the input voltage of the voltage reference chip 301, and improving the accuracy and anti-interference ability of the reference voltage.

[0123] The fourth input terminal of the voltage reference chip 301 may be a noise reduction terminal (NR).

[0124] The fourth capacitor 308 is electrically connected to the ground, the first output terminal of the voltage reference chip 301 , the second output terminal of the voltage reference chip 301 , the second resistor 304 , the cathode of the first diode 302 , the fifth capacitor 309 and the fifth resistor 102 , respectively.

[0125] Specifically, the fourth capacitor 308 serves as a high-frequency filter capacitor at the reference voltage output end, and is mainly used to filter out high-frequency noise at the output end of the reference chip, prevent the output signal from being affected by switching noise or high-frequency interference, and ensure that the reference voltage output to the constant current source main circuit 100 is stable and reliable.

[0126] The fifth capacitor 309 is electrically connected to the ground, the second resistor 304 , the cathode of the first diode 302 , the fifth resistor 102 , the first output terminal of the voltage reference chip 301 , and the second output terminal of the voltage reference chip 301 , respectively.

[0127] Specifically, the fifth capacitor 309 serves as an auxiliary filter capacitor of the output stage and works in conjunction with the fourth capacitor 308 to further smooth the reference voltage output, suppress medium and low frequency noise, and ensure that the reference voltage remains stable when transmitted to subsequent circuits.

[0128] The technical effect of this embodiment is that by configuring multiple capacitors at key nodes in the voltage reference circuit, a hierarchical power supply purification network is constructed. These capacitors are placed at key locations such as the power input, reference voltage output, and feedback loop, forming a full-spectrum noise filtering system for high, medium, and low frequencies. This design effectively suppresses the effects of power supply ripple, ground noise, and high-frequency interference, provides a stable voltage for the constant current source circuit, and enhances the reliability of the entire circuit, enabling it to maintain stable output in various electrical environments.

[0129] In a possible design, the constant current source main circuit 100 further includes a seventh resistor 107 , an eighth resistor 108 , and a ninth resistor 109 .

[0130] Specifically, seventh resistor 107, eighth resistor 108, and ninth resistor 109 work together in the control loop of operational amplifier 103 and transistor 104, ensuring that the circuit accurately maintains a constant current output. These resistors adjust the response characteristics of operational amplifier 103 by setting its gain and input / output conditions, enabling it to accurately compare input signals and appropriately drive the gate voltage of transistor 104.

[0131] The seventh resistor 107 is electrically connected to the non-inverting input terminal of the operational amplifier 103 and the fifth resistor 102 respectively.

[0132] Specifically, one end of the seventh resistor 107 can be connected to the non-inverting input of the operational amplifier 103 via a wire, and the other end can be connected to the fifth resistor 102. This connection is used to regulate and stabilize the input signal of the operational amplifier 103, enabling it to accurately receive the reference voltage from the voltage reference circuit 300. Through this configuration, the circuit can better maintain the constancy of the output current, ensuring that the operational amplifier 103 can provide a stable amplification effect under different operating conditions.

[0133] The eighth resistor 108 is electrically connected to the out-of-phase input terminal of the operational amplifier 103, the first capacitor 305, the second capacitor 306, the third capacitor 307, the first resistor 303, the second input terminal of the voltage reference chip 301, and the third input terminal of the voltage reference chip 301 respectively.

[0134] Specifically, one end of the eighth resistor 108 can be connected to the out-of-phase input terminal of the operational amplifier 103 via a wire, and the other end can be connected to the first capacitor 305, the second capacitor 306, the third capacitor 307, the first resistor 303, and the second and third input terminals of the voltage reference chip 301. This connection relationship is used to set the input conditions and gain of the operational amplifier 103 to ensure that it can accurately process and compare input signals. Through this configuration, the circuit can effectively filter out noise and interference, providing a stable input signal to the operational amplifier 103.

[0135] The ninth resistor 109 is electrically connected to the output terminal of the operational amplifier 103 , the gate of the transistor 104 , and the base of the first transistor 201 , respectively.

[0136] Specifically, one end of the ninth resistor 109 can be connected to the output of the operational amplifier 103 via a wire, and the other end can be connected to the gate of the transistor 104 and the base of the first triode 201. This connection relationship is used to transmit the output signal of the operational amplifier 103 to the transistor 104 and the first triode 201 to control their conduction state. Through this configuration, the circuit can effectively adjust the conductivity of the transistor 104, thereby accurately controlling the load current and quickly responding to changes in the load resistance 101, ensuring the stability and reliability of the constant current source circuit.

[0137] The technical effect of this embodiment is as follows: the seventh resistor is connected in series with the fifth resistor and connected to the positive input terminal of the operational amplifier to divide the voltage and adjust the voltage level of the input signal so that the operational amplifier can accurately process the input signal. The eighth resistor is set between the common terminal and the negative input terminal of the operational amplifier to play a voltage divider role, ensuring that the input voltage of the operational amplifier is within the appropriate range, thereby achieving precise current control. The ninth resistor is used to regulate and stabilize the current flow in the circuit, ensuring that the circuit can maintain a constant current output under different load conditions. The reasonable configuration of these resistors collectively improves the reliability of the circuit.

[0138] In a possible design, the first diode 302 is a Zener diode, which is used to stabilize the output voltage of the voltage reference chip 301 .

[0139] Specifically, first diode 302 can be defined as a voltage-stabilizing diode. When the output voltage of voltage reference chip 301 fluctuates or exceeds a preset range, the voltage-stabilizing diode can limit the voltage rise through its breakdown characteristics, ensuring that the output voltage remains at a stable level. In this way, the voltage-stabilizing diode can effectively protect voltage reference chip 301 from excessive voltage, preventing circuit performance degradation or damage.

[0140] The technical effect of this embodiment is that the first diode is designed as a voltage-stabilizing diode. The addition of the voltage-stabilizing diode effectively resists the effects of voltage fluctuations and external interference on the circuit, ensuring that the voltage reference chip can provide a constant voltage output. This design improves the reliability of the constant current source circuit, enabling it to maintain stable performance under different operating conditions, thereby enhancing circuit stability.

[0141] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the scope of protection of the present application is obviously not limited to these specific embodiments. The above embodiments are only used to illustrate the technical solution of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solution to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A constant current source circuit, characterized in that: include: A constant current source main body circuit (100), and a disconnection detection circuit (200) electrically connected to the constant current source main body circuit (100); The constant current source main circuit (100) comprises a load resistor (101), and the load resistor (101) is electrically connected to the disconnection detection circuit (200); The disconnection detection circuit (200) comprises a first triode (201) and a second triode (202); the emitter of the constant current source main circuit (100) and the first triode (201) are electrically connected to the base of the first triode (201); the collector of the first triode (201), the emitter of the second triode (202) and the ground electrode are electrically connected to the base of the second triode (202); The constant current source main circuit (100) is used to maintain a constant current of the load resistor (101); the first transistor (201) is used to be turned on when the load resistor (101) is connected, so as to control the second transistor (202) to be turned off, so that the collector of the second transistor (202) presents a high level; the collector of the second transistor (202) presents a high level to indicate that the load resistor (101) is connected; the first transistor (201) is used to be turned off when the load resistor (101) is disconnected, so as to control the second transistor (202) to be turned on, so that the collector of the second transistor (202) presents a low level; the collector of the second transistor (202) presents a low level to indicate that the load resistor (101) is disconnected.

2. The constant current source circuit according to claim 1, characterized in that: Also includes: voltage reference circuit (300); The voltage reference circuit (300) comprises a voltage reference chip (301), a first diode (302), a first resistor (303) and a second resistor (304); the first input terminal of the voltage reference chip (301) is electrically connected to the positive electrode of the first power supply; the first resistor (303) is electrically connected to the ground electrode, the second input terminal of the voltage reference chip (301), the third input terminal of the voltage reference chip (301) and the constant current source main circuit (100); the second resistor (304) is electrically connected to the positive electrode of the first power supply, the cathode of the first diode (302), the first output terminal of the voltage reference chip (301), the second output terminal of the voltage reference chip (301) and the constant current source main circuit (100); and the anode of the first diode (302) is electrically connected to the ground electrode.

3. The constant current source circuit according to claim 2, characterized in that: The disconnection detection circuit (200) further includes a third resistor (203) and a fourth resistor (204); The collector of the first triode (201), the base of the second triode (202) and the grounding electrode are all electrically connected to the third resistor (203), and the fourth resistor (204) is electrically connected to the positive electrode of the first power supply and the collector of the second triode (202), respectively.

4. The constant current source circuit according to claim 2, characterized in that: The second input terminal of the voltage reference chip (301) is electrically connected to the third input terminal of the voltage reference chip (301), and the first output terminal of the voltage reference chip (301) is electrically connected to the second output terminal of the voltage reference chip (301).

5. The constant current source circuit according to claim 2, characterized in that: The constant current source main body circuit (100) further includes a fifth resistor (102), an operational amplifier (103), a transistor (104) and a sixth resistor (105); The fifth resistor (102) is electrically connected to the first output terminal of the voltage reference chip (301), the second output terminal of the voltage reference chip (301), the second resistor (304), the cathode of the first diode (302), the in-phase input terminal of the operational amplifier (103) and the load resistor (101), respectively; the out-of-phase input terminal of the operational amplifier (103) is electrically connected to the first resistor (303), the first input terminal of the voltage reference chip (301) and the second input terminal of the voltage reference chip (301), respectively; the output terminal of the operational amplifier (103) is electrically connected to the gate of the transistor (104); the sixth resistor (105) is electrically connected to the source of the transistor (104) and the negative electrode of the second power supply, respectively; the drain of the transistor (104) is electrically connected to the load resistor (101); wherein, the transistor (104) is a field effect transistor using a negative semiconductor material to form a conductive channel.

6. The constant current source circuit according to claim 5, characterized in that: The positive power supply terminal of the operational amplifier (103) is electrically connected to the positive electrode of the second power supply, and the negative power supply terminal of the operational amplifier (103) is electrically connected to the negative electrode of the second power supply.

7. The constant current source circuit according to claim 5, characterized in that: The constant current source main circuit (100) further includes a second diode (106), an anode of the second diode (106) is electrically connected to the load resistor (101), and a cathode of the second diode (106) is electrically connected to the drain of the transistor (104).

8. The constant current source circuit according to claim 5, characterized in that: The voltage reference circuit (300) further includes a first capacitor (305), a second capacitor (306), a third capacitor (307), a fourth capacitor (308) and a fifth capacitor (309); The first capacitor (305) is electrically connected to the positive electrode of the first power supply, the second capacitor (306), the third capacitor (307), the first resistor (303), the first input terminal of the voltage reference chip (301), the second input terminal of the voltage reference chip (301), the third input terminal of the voltage reference chip (301), and the out-of-phase input terminal of the operational amplifier (103); The second capacitor (306) is electrically connected to the third capacitor (307), the ground electrode, the first resistor (303), the second input terminal of the voltage reference chip (301), the third input terminal of the voltage reference chip (301), and the out-of-phase input terminal of the operational amplifier (103), respectively; The third capacitor (307) is electrically connected to the fourth input terminal of the voltage reference chip (301), the first resistor (303), the second input terminal of the voltage reference chip (301), the third input terminal of the voltage reference chip (301), and the out-of-phase input terminal of the operational amplifier (103), respectively; The fourth capacitor (308) is electrically connected to the ground electrode, the first output end of the voltage reference chip (301), the second output end of the voltage reference chip (301), the second resistor (304), the cathode of the first diode (302), the fifth capacitor (309), and the fifth resistor (102), respectively; The fifth capacitor (309) is electrically connected to the ground electrode, the second resistor (304), the cathode of the first diode (302), the fifth resistor (102), the first output end of the voltage reference chip (301), and the second output end of the voltage reference chip (301), respectively.

9. The constant current source circuit according to claim 8, characterized in that: The constant current source main circuit (100) further includes a seventh resistor (107), an eighth resistor (108) and a ninth resistor (109); The seventh resistor (107) is electrically connected to the non-inverting input terminal of the operational amplifier (103) and the fifth resistor (102) respectively; The eighth resistor (108) is electrically connected to the out-of-phase input terminal of the operational amplifier (103), the first capacitor (305), the second capacitor (306), the third capacitor (307), the first resistor (303), the second input terminal of the voltage reference chip (301), and the third input terminal of the voltage reference chip (301), respectively; The ninth resistor (109) is electrically connected to the output end of the operational amplifier (103), the gate of the transistor (104), and the base of the first triode (201), respectively.

10. The constant current source circuit according to claim 7, characterized in that: The first diode (302) is a voltage stabilizing diode, and the voltage stabilizing diode is used to stabilize the output voltage of the voltage reference chip (301).

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