A high-precision current output adjustable circuit

Abstract

The present application discloses a high-precision current output adjustable circuit, which relates to the field of current output technology, including: a filter module, a first conversion module, a second conversion module, a first resistor, one end of the first resistor is connected to the second node, and the other end of the first resistor is grounded; a second resistor, one end of the second resistor is connected to the third node, and the other end of the second resistor is connected to the second signal input terminal; a third resistor, one end of the third resistor is connected to the second signal input terminal, and the other end of the third resistor is connected to the fourth node; a protection module; an output module, and the output module includes a transient suppression diode and a fuse. The present application utilizes the first conversion module and the second conversion module to achieve 0mA / 4mA‑20mA current output, and transmits the output current to the output module after passing through the protection module, protects the current output circuit, avoids the problem of high-voltage crosstalk, thereby avoiding the problem of burning the circuit and ensuring reliable output of current.

Description

Technical Field

[0001] The present application relates to the technical field of current output, and in particular to a high-precision current output adjustable circuit. Background Art

[0002] At present, 0mA / 4mA-20mA current output signals are commonly used in the instrument industry. However, most existing current output circuits have low accuracy, poor stability, and cannot effectively suppress noise, resulting in poor reliability in actual use and unable to meet the high-precision, high-quality and reliable operation requirements of instruments. Summary of the invention

[0003] In view of this, the present application provides a high-precision current output adjustable circuit, which uses a first conversion module and a second conversion module to achieve a current output of 0mA / 4mA-20mA, and transmits the output current to the output module after passing through a protection module, thereby protecting the current output circuit and avoiding the problem of high-voltage crosstalk, thereby avoiding the problem of circuit burning and ensuring reliable current output.

[0004] In order to solve the above technical problems, this application adopts the following technical solutions:

[0005] The present application provides a high-precision current output adjustable circuit, comprising:

[0006] A first signal input terminal, a second signal input terminal and a current signal output terminal;

[0007] A filtering module, wherein a first end of the filtering module is connected to the first signal input end, and a second end of the filtering module is connected to a first node;

[0008] a first conversion module, wherein a first end of the first conversion module is connected to the first node, a second end of the first conversion module is connected to the second node, and a third end of the first conversion module is connected to a third node;

[0009] a first resistor, one end of the first resistor being connected to the second node, and the other end of the first resistor being grounded;

[0010] a second resistor, one end of the second resistor being connected to the third node, and the other end of the second resistor being connected to the second signal input end;

[0011] a third resistor, one end of the third resistor being connected to the second signal input end, and the other end of the third resistor being connected to a fourth node;

[0012] a second conversion module, wherein a first end of the second conversion module is connected to the third node, a second end of the second conversion module is connected to the fourth node, and a third end of the second conversion module is connected to the fifth node;

[0013] a protection module, wherein a first end of the protection module is connected to the fifth node, and a second end of the protection module is connected to the fourth node;

[0014] The output module includes a transient suppression diode and a fuse; one end of the transient suppression diode and one end of the fuse are connected to the protection module, the other end of the transient suppression diode is grounded, and the other end of the fuse is connected to the current signal output end.

[0015] Optionally, where:

[0016] The filtering module includes a fourth resistor and a first capacitor;

[0017] One end of the fourth resistor is connected to the first signal input end, and the other end of the fourth resistor is connected to the first node;

[0018] One end of the first capacitor is connected to the first node, and the other end of the first capacitor is grounded.

[0019] Optionally, where:

[0020] It also includes a third signal input terminal; the first conversion module includes a first operational amplifier, a second capacitor, a first current limiting resistor and a first MOS tube;

[0021] The first channel positive input pin of the first operational amplifier is connected to the first node, the first channel negative input pin of the first operational amplifier is connected to the second node, the power input positive pin of the first operational amplifier is connected to the third signal input terminal, and the power input negative pin of the first operational amplifier is grounded; the first channel output pin of the first operational amplifier is connected to the gate of the first MOS tube through the first current limiting resistor, the source of the first MOS tube is connected to the second node, and the drain of the first MOS tube is connected to the third node; one end of the second capacitor is connected to the second node, and the other end of the second capacitor is connected to the first channel output pin of the first operational amplifier UA.

[0022] Optionally, where:

[0023] The first conversion module also includes a magnetic bead, a third capacitor and a first voltage regulator; one end of the magnetic bead is connected to the third signal input end, and the other end of the magnetic bead is connected to the positive power input pin of the first operational amplifier; one end of the third capacitor is connected to the positive power input pin of the first operational amplifier, and the other end of the third capacitor is grounded; one end of the first voltage regulator is connected to the gate of the first MOS tube, and the other end of the first voltage regulator is grounded.

[0024] Optionally, where:

[0025] The second conversion module includes a second operational amplifier, a second channel positive input pin of the second operational amplifier is connected to the third node, a second channel negative input pin of the second operational amplifier is connected to the fourth node, and a second channel output pin of the second operational amplifier is connected to the fifth node.

[0026] Optionally, where:

[0027] The protection module includes a second MOS tube, a second current limiting resistor, and a fourth capacitor;

[0028] One end of the second current limiting resistor is connected to the second channel output pin of the second operational amplifier, and the other end of the second current limiting resistor is connected to the gate of the second MOS tube; the drain of the second MOS tube is connected to the fourth node, and the source of the second MOS tube is grounded through the fourth capacitor.

[0029] Optionally, where:

[0030] The protection module also includes a second voltage regulator tube and a third voltage regulator tube, one end of the second voltage regulator tube is connected to the gate of the second MOS tube, and the other end of the second voltage regulator tube is grounded; one end of the third voltage regulator tube is connected to the gate of the second MOS tube, and the other end of the second voltage regulator tube is connected to the third signal input end.

[0031] Optionally, where:

[0032] The protection module also includes a fifth resistor, a sixth resistor and a transistor; one end of the sixth resistor is connected to the fourth node, and the other end of the sixth resistor is connected to the drain of the second MOS tube; the emitter of the transistor is connected to the drain of the second MOS tube, the base of the transistor is connected to the fourth node, and the collector of the transistor is grounded through the fifth resistor.

[0033] Compared with the prior art, the current output circuit provided by the present application achieves at least the following beneficial effects:

[0034] The current output circuit provided in the present application filters the input signal through a filtering module and then performs signal conversion, which can reduce interference in the input signal and improve signal stability; the first conversion module and the second conversion module are used to achieve 0mA / 4mA-20mA current output, and the output current is transmitted to the output module after passing through the protection module, so as to protect the current output circuit and avoid the problem of high-voltage crosstalk, thereby avoiding the problem of circuit burning and ensuring reliable current output. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0036] Figure 1 Shown is a structural schematic diagram of a current output adjustable circuit provided in an embodiment of the present application;

[0037] Figure 2 FIG. 2 is another structural schematic diagram of the current output adjustable circuit provided in an embodiment of the present application;

[0038] Figure 3 FIG. 1 is another structural schematic diagram of the current output adjustable circuit provided in an embodiment of the present application;

[0039] Figure 4 Shown is a structural schematic diagram of a first conversion module provided in an embodiment of the present application;

[0040] Figure 5 Another structural schematic diagram of the first conversion module provided in an embodiment of the present application is shown;

[0041] Figure 6 FIG. 1 is another structural schematic diagram of the current output adjustable circuit provided in the embodiment of the present application;

[0042] Figure 7 Shown is a structural schematic diagram of a protection module provided in an embodiment of the present application;

[0043] Figure 8 Shown is another structural schematic diagram of the protection module provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. For example, "including" mentioned throughout the specification and claims is an open term, so it should be interpreted as "including but not limited to". "Substantially" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and basically achieve the technical effect. In addition, the term "coupled" includes any direct and indirect electrical coupling means. Therefore, if the text describes that a first device is coupled to a second device, it means that the first device can be directly electrically coupled to the second device, or indirectly electrically coupled to the second device through other devices or coupling means. The subsequent description of the specification is a preferred embodiment of implementing the present application, but the description is for the purpose of illustrating the general principles of the present application, and is not used to limit the scope of the present application. The scope of protection of the present application shall be subject to the definition of the attached claims. Among them, the similarities between the various embodiments are not repeated one by one.

[0045] The following is a detailed description with reference to the accompanying drawings and specific embodiments.

[0046] Figure 1 FIG. 1 is a schematic diagram of a framework structure of a current output adjustable circuit 100 provided in an embodiment of the present application. Please refer to FIG. Figure 1 The present application provides a high-precision current output adjustable circuit 100, comprising:

[0047] A first signal input terminal V1, a second signal input terminal V2 and a current signal output terminal Iout;

[0048] A filter module 10, wherein a first end of the filter module 10 is connected to a first signal input end V1, and a second end of the filter module 10 is connected to a first node N1;

[0049] A first conversion module 20, wherein a first end of the first conversion module 20 is connected to a first node N1, a second end of the first conversion module 20 is connected to a second node N2, and a third end of the first conversion module 20 is connected to a third node N3;

[0050] A first resistor R1, one end of the first resistor R1 is connected to the second node N2, and the other end of the first resistor R1 is grounded;

[0051] A second resistor R2, one end of the second resistor R2 is connected to the third node N3, and the other end of the second resistor R2 is connected to the second signal input terminal V2;

[0052] a third resistor R3, one end of the third resistor R3 is connected to the second signal input terminal V2, and the other end of the third resistor R3 is connected to the fourth node N4;

[0053] A second conversion module 30, wherein a first end of the second conversion module 30 is connected to a third node N3, a second end of the second conversion module 30 is connected to a fourth node N4, and a third end of the second conversion module 30 is connected to a fifth node N5;

[0054] A protection module 40, wherein a first end of the protection module 40 is connected to a fifth node N5, and a second end of the protection module 40 is connected to a fourth node N4;

[0055] The output module 50 includes a transient suppression diode 51 and a fuse 52; one end of the transient suppression diode 51 and one end of the fuse 52 are connected to the protection module 40, the other end of the transient suppression diode 51 is grounded, and the other end of the fuse 52 is connected to the current signal output terminal Iout.

[0056] It should be noted that Figure 1 Only one frame structure of the current output adjustable circuit 100 in the present application is shown. In some other embodiments of the present application, the frame structure of the current output adjustable circuit 100 may also be embodied in other forms, which is not specifically limited in the present application.

[0057] Specifically, please refer to Figure 1 The high-precision current output adjustable circuit 100 provided in the embodiment of the present application includes a filter module 10, a first conversion module 20, a first resistor R1, a second resistor R2, and a second conversion module 30, wherein the first end of the filter module 10 is connected to the first signal input terminal V1, and the second end of the filter module 10 is connected to the first node N1. When the first signal input terminal V1 provides an input voltage signal to the first node N1, the input voltage signal is first filtered by the filter module 10 to reduce interference in the input signal and improve signal stability. The first conversion module 20 receives the filtered voltage signal and transmits it to the second node N2 and the third node N3 respectively, and makes the voltage signal of the second node N2 equal to the voltage signal of the first node N1. The voltage signal of the second node N2 flows to the ground terminal through the first resistor R1, and the current of the first resistor R1 is One end of the second resistor R2 is connected to the third node N3, and the other end is connected to the second signal input terminal V2. Figure 1 , the second resistor R2 and the first resistor R1 are connected in series through the second node N2 and the third node N3, so that the current flowing through the first resistor R1 and the second resistor R2 is equal, that is, The voltage signal of the third node N3 is transmitted to the fourth node N4 and the fifth node N5 respectively through the second conversion module 30, and the voltage signal of the fourth node N4 is equal to the voltage signal of the third node N3. The two ends of the third resistor R3 are connected to the second signal input terminal V2 and the fourth node N4 respectively. Then the current of the third resistor R3 is Achieve 0mA / 4mA-20mA current output.

[0058] Please continue to refer to Figure 1 , the current output circuit 100 provided in the embodiment of the present application also includes a protection module 40 and an output module 50. The current I3 of the third resistor R3 is transmitted to the output module 50 through the protection module 40, wherein the output module 50 includes a transient suppression diode 51 and a fuse 52; one end of the transient suppression diode 51 and one end of the fuse 52 are connected to the protection module 40, the other end of the transient suppression diode 51 is grounded, and the other end of the fuse 52 is connected to the current signal output terminal Iout. The transient suppression diode 51 can be used to protect the current output circuit 100. When a wiring error occurs and the external high voltage is mistakenly connected, the transient suppression diode is turned on, and the current flowing through the fuse 52 changes, and the fuse 52 will be quickly disconnected, thereby preventing the high-voltage crosstalk problem caused by the misconnection of the route, and then avoiding the problem of burning the circuit, and ensuring the reliable output of the current.

[0059] Optionally, Figure 2 FIG. 1 is another structural diagram of the current output adjustable circuit 100 provided in the embodiment of the present application. Figure 2 The filtering module 10 includes a fourth resistor R4 and a first capacitor C1; one end of the fourth resistor R4 is connected to the first signal input terminal V1, and the other end of the fourth resistor R4 is connected to the first node N1; one end of the first capacitor C1 is connected to the first node N1, and the other end of the first capacitor C1 is grounded.

[0060] Specifically, please refer to Figure 2 The filtering module 10 includes a fourth resistor R4 and a first capacitor C1, wherein one end of the fourth resistor R4 is connected to the first signal input terminal V1, and the other end is connected to the first node N1, one end of the first capacitor C1 is connected to the first node N1, and the other end is grounded. A filtering circuit is formed by the capacitor and the resistor, and the voltage signal input from the first signal input terminal V1 is filtered and transmitted to the first node N1, which can reduce interference in the input signal and improve signal stability, thereby ensuring the stability of the voltage signal transmitted to the first node N1, and further ensuring the reliable operation of subsequent circuits.

[0061] Optionally, Figure 3 FIG. 1 is another structural diagram of the current output adjustable circuit 100 provided in an embodiment of the present application. Figure 4FIG. 2 is a schematic diagram of a structure of the first conversion module 20 provided in an embodiment of the present application. Figure 3 and Figure 4 The current output adjustable circuit 100 provided in this embodiment also includes a third signal input terminal V3; the first conversion module 20 includes a first operational amplifier UA, a second capacitor C2, a first current limiting resistor R11 and a first MOS tube Q1; the first channel positive input pin 3 of the first operational amplifier UA is connected to the first node N1, the first channel negative input pin 2 of the first operational amplifier UA is connected to the second node N2, the power input positive pin 8 of the first operational amplifier UA is connected to the third signal input terminal V3, and the power input negative pin 44 of the first operational amplifier UA is grounded; the first channel output pin 1 of the first operational amplifier UA is connected to the gate of the first MOS tube Q1 through the first current limiting resistor R11, the source of the first MOS tube Q1 is connected to the second node N2, and the drain of the first MOS tube Q1 is connected to the third node N3; one end of the second capacitor C2 is connected to the second node N2, and the other end of the second capacitor C2 is connected to the first channel output pin 1 of the first operational amplifier UA.

[0062] Specifically, please refer to Figure 3 and Figure 4 In this embodiment, the first conversion module 20 includes a first operational amplifier UA, a first current limiting resistor R11 and a first MOS tube Q1, wherein the first operational amplifier UA receives the voltage signal provided by the third signal input terminal V3 through the power input positive pin 8, is grounded through the power input negative pin 4, and its first channel negative input pin 2 and first channel positive input pin 3 are respectively connected to the second node N2 and the first node N1. In the working state, the first channel negative input pin 2 and the first channel positive input pin 3 of the first operational amplifier UA are virtually shorted, so the voltage of the second node N2 is equal to the voltage of the first node N1. The input signal is processed by the first operational amplifier UA and transmitted to the first current limiting resistor R11, flows through the first current limiting resistor R11 and is transmitted to the gate of the first MOS tube Q1, controls the on-off of the first MOS tube Q1, and thus controls the on-off between the second node N2 and the third node N3, and realizes reliable signal transmission. In addition, the first conversion module 20 also includes a second capacitor C2, and the two ends of the second capacitor C2 are respectively connected to the first channel output pin 1 and the first channel negative input pin 2 of the first operational amplifier UA. By connecting the second capacitor C2 between the first channel output pin 1 and the first channel negative input pin 2, reliable transmission of the voltage signal is ensured.

[0063] Optionally, Figure 5 FIG. 2 is another schematic diagram of the structure of the first conversion module 20 provided in the embodiment of the present application. Figure 5The first conversion module 20 also includes a magnetic bead R0, a third capacitor C3 and a first voltage regulator D1, one end of the magnetic bead R0 is connected to the third signal input terminal V3, and the other end of the magnetic bead R0 is connected to the power input positive pin 8 of the first operational amplifier UA; one end of the third capacitor C3 is connected to the power input positive pin 8 of the first operational amplifier UA, and the other end of the third capacitor C3 is grounded; one end of the first voltage regulator D1 is connected to the gate of the first MOS tube Q1, and the other end of the first voltage regulator D1 is grounded.

[0064] Specifically, please refer to Figure 5 , the first conversion module 20 in this embodiment also includes a magnetic bead R0 and a third capacitor C3. The third signal input terminal V3 transmits the voltage signal to the power input positive pin 8 of the operational amplifier UA through the magnetic bead R0, and the voltage signal provided to the first operational amplifier UA is stabilized by the magnetic bead R0 to prevent signal mutation. In addition, the power input positive pin 8 of the operational amplifier UA is grounded through the third capacitor C3, and the third capacitor C3 is used for filtering to ensure the stability of the signal and improve the circuit reliability. The first conversion module 20 also includes a first voltage regulator tube D1, one end of the first voltage regulator tube D1 is connected to the gate of the first MOS tube Q1, and the other end is grounded. The signal transmitted to the first MOS tube Q1 is stabilized by the first voltage regulator tube D1 to improve the circuit reliability.

[0065] Optionally, Figure 6 FIG. 1 is another structural diagram of the current output adjustable circuit 100 provided in the embodiment of the present application. Please refer to FIG. Figure 6 The second conversion module 30 includes a second operational amplifier UB, a second channel positive input pin 5 of the second operational amplifier UB is connected to the third node N3, a second channel negative input pin 6 of the second operational amplifier UB is connected to the fourth node N4, and a second channel output pin 7 of the second operational amplifier UB is connected to the fifth node N5. For details, please refer to Figure 6 , the second conversion module 30 includes a second operational amplifier UB, the second channel positive input pin 5 of the second operational amplifier UB is connected to the third node N3, the second channel negative input pin 6 is connected to the fourth node N4, the second channel positive input pin 5 and the second channel negative input pin 6 are virtually shorted, therefore, the voltage of the third node N3 and the fourth node N4 are equal, so that the current of the third resistor R3 is Achieve 0mA / 4mA-20mA current output.

[0066] Optionally, Figure 7 FIG. 4 is a schematic diagram of a structure of a protection module 40 provided in an embodiment of the present application. Figure 7, the protection module 40 includes a second MOS tube Q2, a second current limiting resistor R12, and a fourth capacitor C4; one end of the second current limiting resistor R12 is connected to the second channel output pin 7 of the second operational amplifier UB, and the other end of the second current limiting resistor R12 is connected to the gate of the second MOS tube Q2; the drain of the second MOS tube Q2 is connected to the fourth node N4, and the source of the second MOS tube Q2 is grounded through the fourth capacitor C4. Preferably, please continue to refer to Figure 7 The protection module 40 includes a second voltage regulator tube D2 and a third voltage regulator tube D3, one end of the second voltage regulator tube D2 is connected to the gate of the second MOS tube Q2, and the other end of the second voltage regulator tube D2 is grounded; one end of the third voltage regulator tube D3 is connected to the gate of the second MOS tube Q2, and the other end of the second voltage regulator tube D2 is connected to the third signal input terminal V3.

[0067] Specifically, please refer to Figure 7 The protection module 40 includes a second MOS tube Q2 and a second current limiting resistor R12. The voltage signal output by the second operational amplifier UB is transmitted to the gate of the second MOS tube Q2 through the second current limiting resistor R12 to control the on and off of the second MOS tube Q2. When the second MOS tube Q2 is turned on, the current flowing through the third resistor R3 is transmitted to the output module 50 through the protection module 40 to achieve the output of the current signal. A fourth capacitor C4 is also provided in the protection module 40. The source of the second MOS tube Q2 is grounded through the fourth capacitor C4. The fourth capacitor C4 is used to stabilize and filter the output current to improve the stability of the output current. In addition, the protection module 40 also includes a second voltage regulator tube D2 and a third voltage regulator tube D3. One end of the second voltage regulator tube D2 is connected to the gate of the second MOS tube Q2, and the other end of the second voltage regulator tube D2 is grounded; one end of the third voltage regulator tube D3 is connected to the gate of the second MOS tube Q2, and the other end of the second voltage regulator tube D2 is connected to the third signal input terminal V3. By providing the voltage regulator tube, the second MOS tube Q2 can be protected to prevent the voltage signal from suddenly changing and damaging the second MOS tube Q2, thereby ensuring the normal operation of the circuit.

[0068] In the protection module 40, except Figure 7 In addition to the embodiment shown in the figure, other embodiments may also be used. Figure 8 FIG. 4 is another schematic diagram of the structure of the protection module 40 provided in the embodiment of the present application. Figure 8 The protection module 40 also includes a fifth resistor R5, a sixth resistor R6 and a transistor Q3; one end of the sixth resistor R6 is connected to the fourth node N4, and the other end of the sixth resistor R6 is connected to the drain of the second MOS transistor Q2; the emitter of the transistor Q3 is connected to the drain of the second MOS transistor Q2, the base of the transistor Q3 is connected to the fourth node N4, and the collector of the transistor Q3 is grounded through the fifth resistor R5.

[0069] Specifically, please refer to Figure 8In this embodiment, the protection module 40 further includes a fifth resistor R5, a sixth resistor R6 and a transistor Q3, wherein the two ends of the sixth resistor R6 are respectively connected to the fourth node N4 and the drain of the second MOS transistor Q2, and impedance matching is performed through the sixth resistor R6, thereby further improving the circuit stability. The emitter of the transistor Q3 is connected to the drain of the second MOS transistor Q2, the base is connected to the fourth node N4, and the collector is grounded through the fifth resistor R5. In this way, when the positive and negative poles are reversed, the transistor Q3 is turned on, and the current will be discharged to the ground through the fifth resistor R5, and the second MOS transistor Q2 is disconnected, thereby avoiding the problem of reverse connection of the device and damaging the load, which is conducive to improving the circuit stability and reducing the cost.

[0070] It can be seen from the above embodiments that the present application has the following beneficial effects:

[0071] The current output circuit 100 provided in the present application performs signal conversion after filtering the input signal through the filtering module, which can reduce interference in the input signal and improve signal stability; the first conversion module and the second conversion module are used to achieve 0mA / 4mA-20mA current output, and the output current is transmitted to the output module after passing through the protection module, so as to protect the current output adjustable circuit 100 and avoid the problem of high-voltage crosstalk, thereby avoiding the problem of circuit burning and ensuring reliable current output.

[0072] The above description shows and describes several preferred embodiments of the present application, but as mentioned above, it should be understood that the present application is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the invention concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not depart from the spirit and scope of the present application, and should be within the scope of protection of the claims attached to the present application.

Claims

1. A high-precision current output adjustable circuit, characterized in that: include: A first signal input terminal, a second signal input terminal and a current signal output terminal; A filtering module, wherein a first end of the filtering module is connected to the first signal input end, and a second end of the filtering module is connected to a first node; a first conversion module, wherein a first end of the first conversion module is connected to the first node, a second end of the first conversion module is connected to the second node, and a third end of the first conversion module is connected to a third node; a first resistor, one end of the first resistor being connected to the second node, and the other end of the first resistor being grounded; a second resistor, one end of the second resistor being connected to the third node, and the other end of the second resistor being connected to the second signal input end; a third resistor, one end of the third resistor being connected to the second signal input end, and the other end of the third resistor being connected to a fourth node; a second conversion module, wherein a first end of the second conversion module is connected to the third node, a second end of the second conversion module is connected to the fourth node, and a third end of the second conversion module is connected to the fifth node; a protection module, wherein a first end of the protection module is connected to the fifth node, and a second end of the protection module is connected to the fourth node; An output module, the output module comprising a transient suppression diode and a fuse; One end of the transient suppression diode and one end of the fuse are connected to the protection module, the other end of the transient suppression diode is grounded, and the other end of the fuse is connected to the current signal output end; The second conversion module includes a second operational amplifier, a second channel positive input pin of the second operational amplifier is connected to the third node, a second channel negative input pin of the second operational amplifier is connected to the fourth node, and a second channel output pin of the second operational amplifier is connected to the fifth node; The protection module includes a second voltage regulator tube and a third voltage regulator tube, one end of the second voltage regulator tube is connected to the gate of the second MOS tube, and the other end of the second voltage regulator tube is grounded; one end of the third voltage regulator tube is connected to the gate of the second MOS tube, and the other end of the second voltage regulator tube is connected to the third signal input terminal; The protection module also includes a fifth resistor, a sixth resistor and a transistor; one end of the sixth resistor is connected to the fourth node, and the other end of the sixth resistor is connected to the drain of the second MOS tube; the emitter of the transistor is connected to the drain of the second MOS tube, the base of the transistor is connected to the fourth node, and the collector of the transistor is grounded through the fifth resistor.

2. The current output adjustable circuit according to claim 1, characterized in that: The filtering module includes a fourth resistor and a first capacitor; One end of the fourth resistor is connected to the first signal input end, and the other end of the fourth resistor is connected to the first node; One end of the first capacitor is connected to the first node, and the other end of the first capacitor is grounded.

3. The current output adjustable circuit according to claim 2, characterized in that: It also includes a third signal input terminal; the first conversion module includes a first operational amplifier, a second capacitor, a first current limiting resistor and a first MOS tube; The first channel positive input pin of the first operational amplifier is connected to the first node, the first channel negative input pin of the first operational amplifier is connected to the second node, the power input positive pin of the first operational amplifier is connected to the third signal input terminal, and the power input negative pin of the first operational amplifier is grounded; the first channel output pin of the first operational amplifier is connected to the gate of the first MOS tube through the first current limiting resistor, the source of the first MOS tube is connected to the second node, and the drain of the first MOS tube is connected to the third node; one end of the second capacitor is connected to the second node, and the other end of the second capacitor is connected to the first channel output pin of the first operational amplifier UA.

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