Constant current source with temperature compensation and constant current source circuit

Abstract

The invention discloses a constant current source with temperature compensation and a constant current source circuit, a series-parallel resistance compensation circuit comprises a Wheatstone bridge, a first operational amplifier, a series resistor and a parallel resistor, the first operational amplifier, the series resistor and the parallel resistor are connected with the Wheatstone bridge, one end of the series resistor is connected with power supply voltage VCC, and the other end of the series resistor is connected with a first resistor. The other end of the first resistor is connected with the first operational amplifier and one end of the second resistor; one end of the third resistor is connected with the power supply voltage VCC, and the other end of the third resistor is connected with the first operational amplifier and one end of the fourth resistor; the other end of the second resistor is connected with the constant current source circuit; compensation is further carried out on the basis of improvement of a series-parallel bridge, the temperature characteristic of the voltage-regulator tube and the temperature characteristic of the pressure sensor are complementary, compensation of sensitivity drift is completed, the circuit is simpler, the cost is low, and the temperature compensation effect can be fully adjusted according to the environment temperature.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of constant current source, in particular to a constant current source with temperature compensation and a constant current source circuit. BACKGROUND

[0002] The constant current source is an important power supply circuit for providing stable current in the sensor circuit, which can ensure the stability and accuracy of the sensor output signal and reduce the measurement error caused by power supply fluctuation or load change. At the same time, the bridge type resistance sensor can eliminate the influence of the connecting wire resistance and the contact resistance when the constant current source is powered. Due to the characteristic of providing stable current, the constant current source is widely used in various sensor products.

[0003] The temperature compensation constant current source is a circuit that can maintain constant current output at different temperatures. Its main purpose is to solve the problem of unstable performance caused by the change of constant current output with temperature. The principle is that the output current of the constant current source usually changes with temperature. The temperature compensation constant current source measures the ambient temperature and adjusts the circuit parameters according to the measurement results to maintain the stability of the output current.

[0004] Hardware temperature compensation is a technology that offsets the influence of temperature change on device performance through physical circuit design. It mainly uses the temperature characteristics of components or changes the circuit parameters to compensate for the change of component temperature characteristics. Currently, a thermistor is connected to the circuit, and the change of resistance value causes the change of circuit parameters to achieve compensation. This method has low cost, is suitable for large-scale application, and the response time of the thermistor is very fast, which is suitable for fast response occasions. However, the nonlinearity of the thermistor is large, and linearization compensation needs to be performed on the circuit, the stability effect is general, there is an aging phenomenon, and the resistance value error of the same type of thermistor is large, the consistency is poor, and a lot of labor cost is needed when selecting. SUMMARY

[0005] In view of the above-mentioned deficiencies in the current constant current source technology field, the present application provides a constant current source with temperature compensation and a constant current source circuit, which connects a series resistance in a Wheatstone bridge and connects a parallel resistance in the Wheatstone bridge, further compensates on the basis of the improvement of the series-parallel bridge, complements the temperature characteristics of the voltage stabilizing tube and the temperature characteristics of the pressure sensor, completes the compensation of sensitivity drift, the circuit is simpler, the cost is low, and the effect of temperature compensation can be adjusted according to the environmental temperature.

[0006] To achieve the above-mentioned purpose, the embodiments of the present application adopt the following technical solutions:

[0007] The constant current source with temperature compensation comprises a constant current source circuit and a series-parallel resistance compensation circuit connected to the constant current source circuit, the series-parallel resistance compensation circuit comprises a Wheatstone bridge and a first operational amplifier connected to the Wheatstone bridge, and is connected to a power supply voltage VCC, the series-parallel resistance compensation circuit is further provided with a series resistance and a parallel resistance, the series resistance is connected in series in the Wheatstone bridge, the parallel resistance is connected in parallel in the Wheatstone bridge, the first operational amplifier outputs the voltage input by the Wheatstone bridge after amplification, the Wheatstone bridge comprises a first resistance, a second resistance, a third resistance and a fourth resistance, one end of the series resistance is connected to the power supply voltage VCC, the other end is connected to the first resistance, the other end of the first resistance is connected to the first operational amplifier and one end of the second resistance, one end of the third resistance is connected to the power supply voltage VCC, the other end is connected to the first operational amplifier and one end of the fourth resistance, the parallel resistance is connected in parallel with the third resistance, the other end of the second resistance is connected to the constant current source circuit, and the other end of the fourth resistance is connected to the constant current source circuit.

[0008] According to an aspect of the present application, the constant current source circuit comprises a second operational amplifier and a current control module, and is connected to an input voltage, the current control module comprises a transistor and a voltage stabilizing diode, a collector of the transistor is connected to the series-parallel resistance compensation circuit, a base is connected to an output end of the operational amplifier, an emitter is respectively connected to a fifth resistance and a sixth resistance, the other end of the fifth resistance is connected to a negative electrode of the second operational amplifier, the other end of the sixth resistance is connected to the ground, a positive electrode of the voltage stabilizing diode is connected to the ground, and a negative electrode is connected to a positive electrode of the second operational amplifier.

[0009] According to an aspect of the present application, the constant current source circuit controls the conduction state of the current control module by detecting the output current and comparing with a reference current, so as to maintain the stability of the output current.

[0010] According to an aspect of the present application, the constant current source circuit further comprises a voltage dividing resistance, the voltage dividing resistance comprises a seventh resistance and an eighth resistance, one end of the seventh resistance is connected to the input voltage, the other end is connected to the eighth resistance, and the other end of the eighth resistance is connected to the ground.

[0011] According to an aspect of the present application, the constant current source circuit further comprises a ninth resistance, one end of the ninth resistance is connected to a connection point of the seventh resistance and the eighth resistance, and the other end is connected to the negative electrode of the second operational amplifier.

[0012] According to an aspect of the present application, the constant current source circuit further comprises a tenth resistance, an eleventh resistance and a twelfth resistance, one end of the tenth resistance is connected to the input voltage, the other end is connected to the negative electrode of the voltage stabilizing diode, one end of the eleventh resistance is connected to the positive electrode of the second operational amplifier, the other end is connected to the negative electrode of the voltage stabilizing diode, and one end of the twelfth resistance is connected to the positive electrode of the second operational amplifier, and the other end is connected to the ground.

[0013] According to one aspect of the present application, the constant current source circuit further comprises a first capacitor and a second capacitor, one end of the first capacitor and the second capacitor being connected to the input voltage and the other end being connected to the ground.

[0014] According to one aspect of the present application, the constant current source circuit further comprises a thirteenth resistor, which is located between the second operational amplifier and the base of the transistor.

[0015] According to one aspect of the present application, the temperature characteristic of the voltage stabilizing diode in the constant current source circuit is between -2.7mV / ℃ and 1.2mV / ℃.

[0016] A constant current source circuit comprises a second operational amplifier and a current control module, the current control module comprising a transistor and a voltage stabilizing diode, the collector of the transistor being connected to a power supply voltage VCC, the base being connected to the output of the second operational amplifier, the emitter being connected to a fifth resistor and a sixth resistor respectively, the other end of the fifth resistor being connected to the negative pole of the second operational amplifier, the other end of the sixth resistor being connected to the ground, the positive pole of the voltage stabilizing diode being connected to the ground, and the negative pole being connected to the positive pole of the second operational amplifier.

[0017] The advantages of the present application are as follows: the series-parallel resistance compensation circuit comprises a Wheatstone bridge, a first operational amplifier connected to the Wheatstone bridge, a series resistance and a parallel resistance, one end of the series resistance being connected to a power supply voltage VCC, the other end being connected to a first resistance, the other end of the first resistance being connected to the first operational amplifier and one end of a second resistance; one end of a third resistance being connected to the power supply voltage VCC, the other end being connected to the first operational amplifier and one end of a fourth resistance, the parallel resistance being connected to the third resistance in parallel; the other end of the second resistance being connected to a constant current source circuit; and the other end of the fourth resistance being connected to the constant current source circuit. On the basis of the improvement of the series-parallel bridge, further compensation is made, the temperature characteristic of the voltage stabilizing tube is complementary to the temperature characteristic of the pressure sensor, the compensation of the sensitivity drift is completed, the circuit is simpler, the cost is lower, and the effect of the temperature compensation can be adjusted according to the environmental temperature. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description only represent some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0019] Figure 1 A constant current source circuit structure diagram of a constant current source with temperature compensation according to the present application;

[0020] Figure 2This is an overall circuit diagram of a constant current source with temperature compensation and a constant current source circuit according to the present invention;

[0021] Figure 3 This is a graph showing the voltage output results of a pressure sensor with a constant current source and a constant current source circuit with temperature compensation at 100 kPa according to the present invention;

[0022] Figure 4 This is a table showing the characteristics of a constant current source with temperature compensation and a voltage regulator tube of a constant current source circuit according to the present invention;

[0023] Figure 5 This is a diagram showing the influence of temperature on voltage regulation of a constant current source circuit and a voltage regulator tube with temperature compensation after testing according to the present invention. DETAILED DESCRIPTION

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] Example 1

[0026] like Figure 1 As shown, a constant current source circuit includes an operational amplifier , several resistors, transistors and Zener diodes , and connected to V10V voltage and power supply voltage VCC. The collector is connected to the power supply voltage VCC, and the base is connected to the operational amplifier The output end and emitter are connected to the resistor and resistors Phase connection, resistance The other end is connected to the operational amplifier The negative pole, the resistor The other end of the voltage stabilizing diode is grounded. The positive pole is grounded and the negative pole is connected to the resistor One end of the The other end of the operational amplifier The positive pole of the resistor is connected. One end is connected to the operational amplifier The positive terminal is connected to the ground.

[0027] The constant current source circuit further includes a voltage dividing resistor, the voltage dividing resistor including a resistor and resistors ,resistance one end of the resistor is connected to a V10V voltage, and the other end is connected to a resistor . The other end of the resistor is connected to ground. The connection point of the resistor and the resistor is also connected to a resistor . The other end of the resistor is connected to the negative electrode of the operational amplifier .

[0028] The constant current source circuit further comprises a resistor , one end of the resistor is connected to a V10V voltage, and the other end is connected to the negative electrode of a voltage stabilizing diode .

[0029] The constant current source circuit further comprises a resistor , one end of the resistor is connected to the output terminal of the operational amplifier , and the other end is connected to the base of a triode .

[0030] The constant current source circuit further comprises a capacitor and a capacitor , the capacitor and the capacitor are connected in parallel to each other, one end is connected to a V10V voltage, and the other end is connected to ground. The size of the capacitor is 10uF, and the size of the capacitor is 100nF.

[0031] When the input voltage or the load resistance changes, the current control module adjusts its conduction state to maintain the constant output current. The constant current source circuit designed in this embodiment utilizes the negative feedback principle, monitors the output current and compares it with the reference current, controls the working state of the current control module, and thus realizes stable constant output current. The principle is shown in Figure 1 .

[0032] The voltage at the negative end of the voltage stabilizing tube is , and the voltage at the positive end of the operational amplifier is :

[0033]

[0034] The voltage at the negative end of the operational amplifier is , and .

[0035] In this embodiment, = , , The voltage value of the upper end is , which now flows through Current value for:

[0036]

[0037] at this time Upper voltage value for:

[0038]

[0039] The transistor The output current and the current flowing through Sum of current for:

[0040]

[0041] In summary, when = When the constant current source output current value is mainly determined by Decide.

[0042] In this embodiment, the voltage stabilizing diode The model is BZT52C5V1. The voltage stabilizing diode is a diode made by taking advantage of the reverse breakdown state of the PN junction. The current through it can vary in a wide range while the voltage remains basically unchanged. Among them, the temperature characteristics of the 5.1V voltage stabilizing diode are different from those of other voltage ranges. Its characteristic data are as follows: Figure 4 The temperature characteristic of the BZT52C5V1 voltage regulator is between -2.7mV / ℃ and 1.2mV / ℃. After the system test of the voltage regulator, the curve of its temperature characteristic and voltage stabilization effect is as follows: Figure 5 shown.

[0043] The advantages of the present invention are as follows: the collector of the transistor is connected to the power supply voltage VCC, the base is connected to the output end of the operational amplifier, the emitter is connected to the first resistor and the second resistor respectively, the other end of the first resistor is connected to the negative electrode of the operational amplifier, the other end of the second resistor is grounded, the positive electrode of the voltage regulator diode is grounded, and the negative electrode is connected to the positive electrode of the operational amplifier. By utilizing the negative feedback principle, the output current is detected and compared with the reference current to control the working state of the current control module, thereby achieving a stable constant output current. The circuit is simpler and the cost is lower.

[0044] Example 2

[0045] like Figure 2 As shown, a constant current source with temperature compensation includes a constant current source circuit and a series-parallel resistance compensation circuit connected thereto.

[0046] The constant current source circuit includes an operational amplifier , operational amplifier , several resistors, transistors and Zener diodes , and access the V10V voltage and the power supply voltage VCC.

[0047] The series-parallel resistance compensation circuit includes four diffusion resistors of equal value. 、 、 and The Wheatstone bridge circuit is formed by One end is connected to the power supply voltage VCC, and the other end is connected to the operational amplifier The positive electrode and one end; One end is connected to the power supply voltage VCC, and the other end is connected to the operational amplifier The negative electrode and one end; The other end of the transistor The collector; The other end of the transistor In this embodiment, a parallel resistor is also provided. and series resistance ,in, and Series, One end of , the other end is connected to the power supply voltage VCC; and in parallel, One end is connected to the power supply voltage VCC, and the other end is connected to the operational amplifier The negative terminal of the operational amplifier The difference between the positive and negative voltages is amplified several times to output a 0-5V voltage. VOUT is the output voltage of the series-parallel resistor compensation circuit.

[0048] The transistor The base of the operational amplifier is connected to The output end and emitter are connected to the resistor and resistors Phase connection, resistance The other end is connected to the operational amplifier The negative pole, the resistor The other end of the voltage stabilizing diode is grounded. The positive pole is grounded and the negative pole is connected to the resistor One end of the The other end of the operational amplifier The positive pole of the resistor is connected. One end is connected to the operational amplifier The positive terminal is connected to the ground.

[0049] The constant current source circuit further includes a voltage dividing resistor, the voltage dividing resistor including a resistor and resistors ,resistance One end is connected to V10V voltage and the other end is connected to resistor ,resistance The other end of the resistor is grounded. and resistors The connection point is also connected to the resistor ,resistance The other end is connected to the operational amplifier of the negative electrode.

[0050] The constant current source circuit further includes a resistor ,resistance One end is connected to V10V voltage and the other end is connected to the voltage stabilizing diode of the negative electrode.

[0051] The constant current source circuit further includes a resistor ,resistance One end of the operational amplifier The output end of the transistor The base.

[0052] The constant current source circuit further includes a capacitor and capacitors ,capacitance and capacitors Connect them in parallel, with one end connected to V10V voltage and the other end grounded. The size of the capacitor is 10uF, The size is 100nF.

[0053] When the input voltage or load resistance changes, the current control module will adjust its conduction state to maintain a constant output current. The constant current source circuit designed in this embodiment uses the negative feedback principle to monitor the output current and compare it with the reference current to control the working state of the current control module, thereby achieving a stable constant output current. Figure 1 shown.

[0054] In the series-parallel resistance compensation circuit, the resistance 、 、 and is the bridge resistance. Theoretically, when there is no external pressure, = = = However, due to the differences in modern manufacturing processes and other technical factors, the resistance 、 、 and This will cause an offset when outputting a voltage signal. Therefore, in order to solve this problem, a series resistor is added in this embodiment. and parallel resistors The output voltage of the series-parallel resistance compensation circuit at 100kPa and different temperatures is tested as follows Figure 3 shown. Figure 3 In the figure, the horizontal axis is the temperature value and the vertical axis is the voltage output value. Figure 3 It can be observed that the output voltage is the lowest at room temperature. When the temperature changes, the deviation from room temperature is the greatest, and the higher the output voltage value is.

[0055] The negative terminal voltage of the Zener diode is , operational amplifier Positive terminal voltage for:

[0056]

[0057] Operational amplifier The negative terminal voltage is ,and .

[0058] In this embodiment, = , ,but The voltage value of the upper end is , which now flows through Current value for:

[0059]

[0060] at this time Upper voltage value for:

[0061]

[0062] Then the transistor The output current and the current flowing through Sum of current for:

[0063]

[0064] In summary, when = When the constant current source outputs the current value mainly determined by Decide.

[0065] In this embodiment, the voltage stabilizing diode is BZT52C5V1. The voltage stabilizing diode is a diode made by using the phenomenon that the voltage is basically unchanged while the current can vary in a large range in the reverse breakdown state of PN junction. The temperature characteristic of the 5.1V voltage stabilizing diode is different from other voltage ranges, and the characteristic data is shown in Table 1. Figure 4 The temperature characteristic of the BZT52C5V1 voltage stabilizing diode is between -2.7mV / °C and 1.2mV / °C. The curve of the temperature characteristic of the voltage stabilizing diode to the voltage stabilizing effect is shown in Figure 1. Figure 5

[0066] Figure 5 In the figure, the abscissa is the temperature value, and the ordinate is the voltage output value. It can be observed from the figure that the output voltage is the lowest at normal temperature, and the more the temperature deviates from the normal temperature, the lower the output voltage value. The analysis of the temperature compensation of the voltage stabilizing diode in the circuit is as follows:

[0067] 1. When the temperature is higher than the normal temperature, the output voltage VOUT of the series-parallel resistance compensation circuit is higher, and the output voltage of the voltage stabilizing diode is smaller. At this time, and are relatively unchanged, the positive voltage value of the operational amplifier is reduced, the negative voltage value of the operational amplifier is reduced, the voltage value at the upper end of the resistor is reduced, the current value flowing through is reduced, the current value flowing through is reduced, and the difference between the positive voltage and the negative voltage of is reduced, so that the output VOUT is finally reduced.

[0068] 2. When the temperature is lower than the normal temperature, the output voltage VOUT of the series-parallel resistance compensation circuit is lower, and the output voltage of the voltage stabilizing diode is higher. At this time, and are relatively unchanged, the positive voltage value of the operational amplifier is increased, the negative voltage value of the operational amplifier is increased, the voltage value at the upper end of the resistor is increased, the current value flowing through is increased, the current value flowing through is increased, and the difference between the positive voltage and the negative voltage of is increased, so that the output VOUT is finally increased.

[0069] ​Semiconductor strain gauge pressure sensor is also called pressure resistance pressure sensor, which uses single crystal silicon diaphragm as elastic diaphragm element. The sensor is composed of a shell, a silicon diaphragm and a lead, four equivalent diffusion resistors are manufactured, and a Wheatstone bridge is designed. When the solid is subjected to force, the resistivity changes, and the piezoresistive effect is generated. Since the piezoresistive coefficient alpha of the resistor changes with temperature T. When the temperature T rises, the piezoresistive coefficient alpha is small, and when the temperature T decreases, the piezoresistive coefficient alpha is large. If the resistance value of the resistor is , the resistance value of the sensor is , then the value is:

[0070]

[0071] The sensor output is affected by the temperature coefficient of resistance, and a certain temperature drift curve is generated. For this temperature drift, the bridge compensation method is used in the embodiment, and the compensation principle is mainly to adjust the zero drift of the sensor by series and parallel connection of the resistors in the bridge. Through series and parallel connection of the resistors and , the output curve of the sensor is shown in Figure 3 .

[0072] From Figure 5 and Figure 3 , it can be seen that the temperature characteristic curves are basically the same, which can prove that the 5.1V voltage stabilizing tube has a temperature characteristic compensation effect on the sensor circuit. However, since the curves are basically the same, the resistance ratio of and can be adjusted to change the current size and improve the compensation effect, so that the adjustment range of the voltage stabilizing tube and the output temperature characteristic of the sensor bridge are realized.

[0073] The advantages of the embodiment are: the collector of the triode is connected to the power voltage VCC, the base is connected to the output end of the operational amplifier, the emitter is connected to the first resistor and the second resistor respectively, the other end of the first resistor is connected to the negative electrode of the operational amplifier, the other end of the second resistor is connected to the ground, the positive electrode of the voltage stabilizing diode is connected to the ground, and the negative electrode is connected to the positive electrode of the operational amplifier; the series-parallel resistor compensation circuit is also provided with series resistors and parallel resistors, the series resistors are connected in series in the Wheatstone bridge, and the parallel resistors are connected in parallel in the Wheatstone bridge. On the basis of the improvement of the series-parallel bridge, the temperature characteristics of the voltage stabilizing tube and the pressure sensor are complementary, the sensitivity drift compensation is completed, the circuit is simpler, the cost is lower, and the temperature compensation effect can be adjusted according to the environmental temperature.

[0074] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of the changes or replacements within the technical scope disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A constant current source with temperature compensation, comprising a constant current source circuit and a series-parallel resistance compensation circuit connected thereto, wherein the series-parallel resistance compensation circuit comprises a Wheatstone bridge and a first operational amplifier connected thereto and is connected to a power supply voltage VCC, characterized in that: The series-parallel resistance compensation circuit is further provided with a series resistor and a parallel resistor. The series resistor is connected in series in the Wheatstone bridge, and the parallel resistor is connected in parallel in the Wheatstone bridge. The first operational amplifier amplifies the voltage input by the Wheatstone bridge and outputs it. The Wheatstone bridge includes a first resistor, a second resistor, a third resistor and a fourth resistor. One end of the series resistor is connected to the power supply voltage VCC, and the other end is connected to the first resistor. The other end of the first resistor is connected to the first operational amplifier and one end of the second resistor; one end of the third resistor is connected to the power supply voltage VCC, and the other end is connected to the first operational amplifier and one end of the fourth resistor. The parallel resistor is connected in parallel with the third resistor; the other end of the second resistor is connected to the constant current source circuit; and the other end of the fourth resistor is connected to the constant current source circuit.

2. The constant current source with temperature compensation according to claim 1, characterized in that: The constant current source circuit includes a second operational amplifier and a current control module, and is connected to the input voltage. The current control module includes a transistor and a voltage-stabilizing diode. The collector of the transistor is connected to the series-parallel resistance compensation circuit, the base is connected to the output end of the operational amplifier, and the emitter is connected to a fifth resistor and a sixth resistor respectively. The other end of the fifth resistor is connected to the negative electrode of the second operational amplifier, and the other end of the sixth resistor is grounded. The positive electrode of the voltage-stabilizing diode is grounded, and the negative electrode is connected to the positive electrode of the second operational amplifier.

3. The constant current source with temperature compensation according to claim 2, characterized in that: The constant current source circuit controls the conduction state of the current control module by detecting the output current and comparing it with the reference current, thereby maintaining the stability of the output current.

4. The constant current source with temperature compensation according to claim 3, characterized in that: The constant current source circuit further includes a voltage-dividing resistor, which includes a seventh resistor and an eighth resistor. One end of the seventh resistor is connected to the input voltage, and the other end is connected to the eighth resistor. The other end of the eighth resistor is grounded.

5. The constant current source with temperature compensation according to claim 4, characterized in that: The constant current source circuit further includes a ninth resistor, one end of the ninth resistor being connected to the connection point between the seventh resistor and the eighth resistor, and the other end of the ninth resistor being connected to the negative electrode of the second operational amplifier.

6. The constant current source with temperature compensation according to claim 5, characterized in that: The constant current source circuit also includes a tenth resistor, an eleventh resistor and a twelfth resistor, wherein one end of the tenth resistor is connected to the input voltage and the other end is connected to the cathode of the voltage-stabilizing diode; one end of the eleventh resistor is connected to the anode of the second operational amplifier and the other end is connected to the cathode of the voltage-stabilizing diode; one end of the twelfth resistor is connected to the anode of the second operational amplifier and the other end is grounded.

7. The constant current source with temperature compensation according to claim 2, characterized in that: The constant current source circuit further includes a first capacitor and a second capacitor, wherein one end of the first capacitor and the second capacitor are connected to the input voltage and the other end thereof are grounded.

8. The constant current source with temperature compensation according to claim 2, characterized in that: The constant current source circuit further includes a thirteenth resistor, and the thirteenth resistor is located between the second operational amplifier and the base of the transistor.

9. The constant current source with temperature compensation according to claim 2, characterized in that: The temperature characteristic of the voltage stabilizing diode in the constant current source circuit is between -2.7 mV / °C and 1.2 mV / °C.

10. A constant current source circuit, implemented based on the constant current source with temperature compensation according to claim 1, comprising a second operational amplifier and a current control module, characterized in that: The current control module includes a transistor and a voltage regulator diode. The collector of the transistor is connected to the power supply voltage VCC, the base is connected to the output end of the second operational amplifier, and the emitter is connected to a fifth resistor and a sixth resistor respectively. The other end of the fifth resistor is connected to the negative electrode of the second operational amplifier, and the other end of the sixth resistor is grounded. The positive electrode of the voltage regulator diode is grounded, and the negative electrode is connected to the positive electrode of the second operational amplifier.

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