Signal transmission system and electronic equipment

Abstract

The utility model discloses a signal transmission system. The signal transmission system comprises an amplification branch, N current generation branches, an electro-optical conversion branch and a signal receiving branch. The first end of the amplification branch is connected with an input voltage, the second end of the amplification branch is connected with the N current generation branches, and the amplification branch is configured to amplify the input voltage and then input the amplified input voltage to the N current generation branches. And the N current generation branches are also connected with the electro-optical conversion branch, the N current generation branches are configured to be operated by any current generation branch in the N current generation branches and generate corresponding current, and the generated current flows through the electro-optical conversion branch. The electro-optical conversion branch is configured to output an optical signal based on the current flowing through the electro-optical conversion branch and transmit the optical signal through the analog optical fiber. The signal receiving branch is configured to receive an optical signal from the analog optical fiber and output a first voltage corresponding to the optical signal. In this way, the method can be suitable for transmission of different signals and is high in practicability.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of signal transmission, in particular to a signal transmission system and an electronic device. BACKGROUND

[0002] An optical fiber signal transmission system is usually composed of three parts. The three parts include a transmitter that converts an electrical signal into an optical signal, an analog optical fiber that connects the transmitter and a receiver to transmit the optical signal, and a receiver that converts the optical signal into an electrical signal. The advantage of using an analog optical fiber to transmit a signal is that it has strong anti-interference performance and can withstand very high voltage.

[0003] At present, the range of input voltage of the optical fiber signal transmission system also needs to remain unchanged on the premise that the range of output voltage of the optical fiber signal transmission system remains unchanged, that is, the optical fiber signal transmission system can only be used for transmission of a single signal (the voltage range corresponding to the signal is the range of input voltage of the optical fiber signal transmission system), and cannot be applied to transmission of different signals, and has poor practicability. CONTENT OF THE INVENTION

[0004] Embodiments of the present application provide a signal transmission system and an electronic device, which can be applied to transmission of different signals and have strong practicability.

[0005] In a first aspect, embodiments of the present application provide a signal transmission system, comprising:

[0006] The amplification branch, the N current generation branches, the electro-optical conversion branch, and the signal receiving branch, wherein N is an integer greater than or equal to 2;

[0007] A first end of the amplification branch is connected with an input voltage, a second end of the amplification branch is connected with the N current generation branches, and the amplification branch is configured to amplify the input voltage and input the amplified input voltage to the N current generation branches;

[0008] The N current generation branches are further connected with the electro-optical conversion branch, and the N current generation branches are configured to operate any current generation branch in the N current generation branches and generate a corresponding current, and the generated current flows through the electro-optical conversion branch;

[0009] The electro-optical conversion branch is configured to output an optical signal based on the current flowing through the electro-optical conversion branch, and transmit the optical signal through an analog optical fiber;

[0010] The signal receiving branch is configured to receive the optical signal from the analog optical fiber and output a first voltage corresponding to the optical signal.

[0011] In one or more embodiments, the signal transmission system further comprises a controller and a switch branch, the switch branch being connected between the third end of the amplification branch and the N current generation branches;

[0012] The controller is connected with the switch branch and the N current generation branches respectively, and the controller is configured to determine the current generation branch in operation state, and control the switch branch to establish the connection between the third end of the amplification branch and the current generation branch in operation state, and disconnect the connection between the third end of the amplification branch and the current generation branch not in operation state.

[0013] In one or more embodiments, the amplification branch comprises a first amplifier;

[0014] The non-inverting input end of the first amplifier is connected with the input voltage, the inverting input end of the first amplifier is connected with the switch branch, and the output end of the first amplifier is connected with the N current generation branches, wherein the non-inverting input end of the first amplifier is the first end of the amplification branch, the output end of the first amplifier is the second end of the amplification branch, and the inverting input end of the first amplifier is the third end of the amplification branch.

[0015] In one or more embodiments, the current generation branch comprises a switch tube, a first resistor, a second resistor and a negative voltage source;

[0016] The first end of the switch tube is connected with the second end of the amplification branch, the second end of the switch tube is connected with the first end of the first resistor, the second end of the first resistor is connected with the negative voltage source and the first end of the second resistor respectively, and the second end of the second resistor is connected with a positive voltage source.

[0017] In one or more embodiments, in the N current generation branches, the ratio of the negative voltage source to the first resistor in each current generation branch is configured to be the same.

[0018] In one or more embodiments, in the N current generation branches, the resistance of the first resistor in any two current generation branches is configured to be different.

[0019] In one or more embodiments, the electro-optical conversion branch comprises a laser diode;

[0020] The anode of the laser diode is connected with the positive voltage source, and the cathode of the laser diode is connected with the N current generation branches.

[0021] In one or more embodiments, the signal receiving branch comprises a photodiode and a second amplifier;

[0022] The cathode of the photodiode is connected with a positive voltage source, the cathode of the photodiode is connected with the output end of the second amplifier, and the output end of the second amplifier outputs the first voltage.

[0023] In one or more embodiments, the switch branch includes a single-pole multi-throw switch including a single input contact and N output contacts;

[0024] The input contact is connected with the third end of the amplification branch, each of the N output contacts is connected with one of the N current generation branches, and the single-pole multi-throw switch is connected with the controller.

[0025] In a second aspect, the embodiments of the present application provide an electronic device, which includes the signal transmission system as described above.

[0026] The signal transmission system provided by the embodiments of the present application includes an amplification branch, N current generation branches, an electro-optical conversion branch and a signal receiving branch, where N is an integer greater than or equal to 2. The first end of the amplification branch is connected with an input voltage, the second end of the amplification branch is connected with the N current generation branches, and the amplification branch is configured to amplify the input voltage and input the amplified input voltage to the N current generation branches. The N current generation branches are further connected with the electro-optical conversion branch, and the N current generation branches are configured to operate any of the N current generation branches and generate a corresponding current, and the generated current flows through the electro-optical conversion branch. The electro-optical conversion branch is configured to output an optical signal based on the current flowing through the electro-optical conversion branch and transmit the optical signal through an analog optical fiber. The signal receiving branch is configured to receive the optical signal from the analog optical fiber and output a first voltage corresponding to the optical signal. Thus, when different signals (different signals correspond to different ranges of input voltages) are input, only by selecting a corresponding current generation branch, the current flowing through the electro-optical conversion unit can be adjusted, and the gain of the system can be adjusted, so that the first voltage remains unchanged. It can be seen that the signal transmission system can be applied to the transmission of different signals and has strong practicability. BRIEF DESCRIPTION OF DRAWINGS

[0027] One or more embodiments are exemplarily illustrated by pictures in the drawings corresponding thereto, and the exemplarily illustrations do not configure limitations on the embodiments, and elements with the same reference numerals in the drawings represent similar elements.

[0028] Figure 1 is a schematic diagram of a constituent block diagram of the signal transmission system provided by the embodiments of the present application Figure 1 ;

[0029] Figure 2 is a schematic diagram of a constituent block diagram of the signal transmission system provided by the embodiments of the present application Figure 2 ;

[0030] Figure 3 is a circuit structure diagram corresponding to the composition block diagram shown in Figure 2

[0031] Figure 4 is a schematic diagram of the first voltage and the current flowing through the laser diode provided by the embodiment of the present application. DETAILED DESCRIPTION

[0032] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and in detail below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.

[0033] It should be noted that when one element is described as being “connected” to another element, it can be directly connected to the other element or one or more intermediate elements can be present therebetween.

[0034] In addition, the technical features involved in each of the embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0035] Please refer to Figure 1 , Figure 1 is a schematic diagram of a composition block diagram of a signal transmission system provided by the embodiment of the present application. As shown in Figure 1 , the signal transmission system 100 includes an amplification branch 10, an N-way current generation branch, an electro-optical conversion branch 20 and a signal receiving branch 30, wherein N is an integer greater than or equal to 2. The N-way current generation branch includes a first current generation branch A1, a second current generation branch A2, …, and an Nth current generation branch AN.

[0036] The first end of the amplification branch 10 is connected with an input voltage VIN. The second end of the amplification branch 10 is connected with the N-way current generation branch, and the N-way current generation branch is also connected with the electro-optical conversion branch 20. Specifically, the first end of the first current generation branch A1, the first end of the second current generation branch A2, …, and the first end of the Nth current generation branch AN are all connected with the second end of the amplification branch 10; the second end of the first current generation branch A1, the second end of the second current generation branch A2, …, and the second end of the Nth current generation branch AN are all connected with the electro-optical conversion branch 20.

[0037] ​Specifically, the amplification branch 10 is configured to amplify the input voltage VIN and input to the N current generation branches. The N current generation branches are configured to operate any one of the N current generation branches and generate a corresponding current, and the generated current flows through the electro-optical conversion branch 20. The electro-optical conversion branch 20 is configured to output an optical signal based on the current flowing through the electro-optical conversion branch 20 and transmit through the analog optical fiber 200. The signal receiving branch 30 is configured to receive the optical signal from the analog optical fiber 200 and output a first voltage V1 corresponding to the optical signal.

[0038] In the actual application, when different signals (the input voltages corresponding to different signals are different) are input, only by selecting the corresponding current generation branch, the current flowing through the electro-optical conversion unit 20 can be adjusted, and then the gain of the signal transmission system 100 can be adjusted, so that the first voltage V1 remains unchanged.

[0039] It can be understood that the input voltages corresponding to different signals are different, for example, in some embodiments, different signals include a signal (denoted as a first signal) with an input voltage range of [-1V, +1V] and a signal (denoted as a second signal) with an input voltage range of [-0.1V, +0.1V]. The gain of the signal transmission system 100 refers to the ratio of the output signal to the input signal, which is expressed as the ratio of the voltages (i.e. the ratio of the first voltage V1 to the input voltage VIN) in this embodiment, and the gain can be linear (proportional constant) or logarithmic (usually in decibels dB). For an input signal, one of the N current generation branches can be set to operate and generate a current (the other current generation branches do not operate and do not generate a current), for example, in some embodiments, only the first current generation branch A1 is set to operate and generate a current, and the second current generation branch A2, …, the Nth current generation branch AN are all stopped.

[0040] Then, when different signals are input, the gain of the signal transmission system 100 can be adjusted in the above manner, so that the output signal (i.e., the first voltage V1) can be kept unchanged. For example, in some embodiments, the first voltage V1 is kept in the range of [-1V, +1V], if the first signal is input, one of the N current generating branches is selected to operate, so that the gain of the signal transmission system 100 is adjusted to 1; if the second signal is input, another of the N current generating branches is selected to operate, so that the gain of the signal transmission system 100 is adjusted to 10. It can be seen that the signal transmission system 100 provided by the embodiments of the present application can be applied to the transmission of different signals, and has strong practicability.

[0041] In some embodiments, as shown in Figure 2 , the signal transmission system 100 further comprises a controller 40 and a switch branch 50. The switch branch 50 is connected between the third end of the amplification branch 10 and the N current generating branches, specifically, the first end of the switch branch 50 is connected with the third end of the amplification branch 10. The second end of the switch branch 50 is connected with the first current generating branch A1; the third end of the switch branch 50 is connected with the second current generating branch A2; …; the (N+1)th end of the switch branch 50 is connected with the Nth current generating branch AN. The controller 40 is connected with the switch branch 50 and the N current generating branches respectively.

[0042] Specifically, the controller 40 is configured to determine the current generating branch in the operating state, and control the switch branch 50 to establish the connection between the third end of the amplification branch 10 and the current generating branch in the operating state, and break the connection between the third end of the amplification branch 10 and the current generating branch not in the operating state. That is, the controller 40 can determine which of the N current generating branches is in the operating state in real time, and then control the switch branch 50 to connect the current generating branch in the operating state with the third end of the amplification branch 10, so that the current generating branch in the operating state can also output the voltage feedback to the third end of the amplification branch 10, thereby keeping the current generated by the current generating branch in the operating state stable, and keeping the current flowing through the electro-optical conversion branch 20 stable, so as to improve the stability and reliability of the operation of the electro-optical conversion branch 20; at the same time, the controller 40 also controls the switch branch 50 to break the connection between the current generating branch not in the operating state and the third end of the amplification branch 10.

[0043] Please refer to Figure 3 , Figure 3 for a circuit structure corresponding to the block diagram shown in Figure 2 . As shown in Figure 3 , the amplification branch 10 comprises a first amplifier U1.

[0044] The non-inverting input terminal of the first amplifier U1 is connected with the input voltage VIN, the inverting input terminal of the first amplifier U1 is connected with the switch branch 50, and the output terminal of the first amplifier U1 is connected with the N current generating branches, wherein the non-inverting input terminal of the first amplifier U1 is the first end of the amplification branch 10, the output terminal of the first amplifier U1 is the second end of the amplification branch 10, and the inverting input terminal of the first amplifier U1 is the third end of the amplification branch 10. The first amplifier U1 is used for amplifying and outputting the input voltage VIN.

[0045] In this embodiment, any current generating branch includes a switch tube, a first resistor, a second resistor and a negative voltage source. That is, the first current generating branch A1 includes a switch tube Q1_1, a first resistor R1_1, a second resistor R1_2 and a negative voltage source V1; the second current generating branch A2 includes a switch tube Q2_1, a first resistor R2_1, a second resistor R2_2 and a negative voltage source V2; and the Nth current generating branch AN includes a switch tube QN_1, a first resistor RN_1, a second resistor RN_2 and a negative voltage source VN.

[0046] Specifically, for any current generating branch, the first end of the switch tube is connected with the second end of the amplification branch, the second end of the switch tube is connected with the first end of the first resistor, the second end of the first resistor is respectively connected with the negative voltage source and the first end of the second resistor, and the second end of the second resistor is connected with the positive voltage source. Taking the first current generating branch A1 as an example, the first end of the switch tube Q1_1 is connected with the second end of the amplification branch 10, the second end of the switch tube Q1_1 is connected with the first end of the first resistor R1_1, the second end of the first resistor R1_1 is respectively connected with the negative voltage source V1 and the first end of the second resistor R2_1, and the second end of the second resistor R2_1 is connected with the positive voltage source V+.

[0047] Specifically, taking the first current generating branch A1 as an example, and the second current generating branch A2 to the Nth current generating branch AN are not running. At this time, the negative voltage source V1 is running, and the output terminal of the negative voltage source V1 (i.e. the end of the negative voltage source V1 connected with the first resistor R1_1) outputs a negative voltage. The first amplifier U1 amplifies the input voltage VIN and inputs it to the switch tube Q1_1, so that the switch tube Q1_1 is turned on and generates a current, and the current flows through the electro-optical conversion unit 20.

[0048] Meanwhile, the negative voltage sources V2 to VN stop running, the output terminals of the negative voltage sources V2 to VN present high resistance to the outside, and the second current generation branch A2 to the Nth current generation branch AN generate no current. Taking the second current generation branch A2 as an example, due to the pull-up action of the positive voltage source V+, the emitter voltage of the switch tube Q2_1 is pulled up by the positive voltage source V+. Since the base voltage of the switch tube Q2_1 is also the output voltage of the first amplifier U1, the voltage is necessarily smaller than the voltage of the positive voltage source V+ (because the positive voltage source V+ is taken as the first amplifier U1 in this embodiment), and thus the base voltage of the switch tube Q2_1 is smaller than the emitter voltage, the switch tube Q2_1 is turned off, and no current is generated, that is, the second current generation branch A2 does not generate current and does not run. In this embodiment, the second resistors in the current generation branches are pull-up resistors, which can completely turn off (that is, stop running) the unused current generation branches. It can be understood that the pull-up resistors have a relatively large resistance value, generally 1KΩ to 100KΩ, so as not to affect the voltage output of the negative voltage sources. At the same time, when the negative voltage sources stop running, the emitter voltage of the corresponding switch tube can be pulled up to the voltage of the positive voltage source V+.

[0049] In this embodiment, each switch tube (including the switch tube Q1_1 to the switch tube QN_1) is taken as an NPN triode as an example. The base of the NPN triode is the first end of each switch tube, the emitter of the NPN triode is the second end of each switch tube, and the collector of the NPN triode is the third end of each switch tube.

[0050] Each switch tube can be any controllable switch, such as an insulated gate bipolar transistor (IGBT) device, an integrated gate-commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a silicon controlled rectifier (SCR) device, a junction gate field-effect transistor (JFET) device, a MOS-controlled thyristor (MCT) device, etc.

[0051] In this embodiment, in the N-path current generating branches, the ratio of the negative voltage source to the first resistor in each current generating branch is configured to be the same. That is, V1 / R1_1=V2 / R2_1=…=VN / RN_1, where V1, V2, …, VN are all negative voltages. This also means that when different current generating branches are switched, the static working current of the electro-optical conversion unit 20 is constant, and the static working current is the current flowing through the electro-optical conversion unit 20 when the input voltage VIN is 0, where the static working current IS1 of the first current generating branch A1 is -V1 / R1_1; the static working current IS2 of the second current generating branch A2 is -V2 / R2_1; …; and the static working current ISN of the Nth current generating branch AN is -VN / RN_1. Thus, the static working current can be kept constant, which is beneficial to prevent the electro-optical conversion unit 20 from being damaged due to excessive current.

[0052] In this embodiment, in the N-path current generating branches, the resistance values of the first resistors in any two current generating branches are configured to be different. That is, R1_1≠R2_1≠…≠RN_1, so 1 / R1_1≠1 / R2_1≠…≠1 / RN_1. This also means that when different current generating branches are switched, the gain of the signal transmission system 100 can be changed accordingly. Wherein, when the first current generating branch A1 is running, the corresponding gain K1=1 / R1_1; when the second current generating branch A2 is running, the corresponding gain K2=1 / R2_1; …; and when the Nth current generating branch AN is running, the corresponding gain KN=1 / RN_1.

[0053] In this embodiment, the electro-optical conversion branch 20 includes a laser diode LD1.

[0054] Wherein, the anode of the laser diode LD1 is connected to the positive voltage source V+, and the cathode of the laser diode LD1 is connected to the N-path current generating branches, i.e. the cathode of the laser diode LD1 is connected to the collector of the switching tube Q1_1, the collector of the switching tube Q2_1, …, the collector of the switching tube QN_1.

[0055] Specifically, the laser diode LD1 is a kind of semiconductor laser, also known as LD (Laser Diode). It uses semiconductor materials to generate and amplify laser beams. The working principle of the laser diode LD1 is to inject current into the semiconductor material to produce stimulated radiation and amplify it into a laser (i.e. output optical signal).

[0056] In this embodiment, the signal receiving branch 30 includes a photodiode PD1 and a second amplifier U2.

[0057] The cathode of the photodiode PD1 is connected with a positive voltage source V+, and the cathode of the photodiode PD1 is connected with the output terminal of the second amplifier U2, and the output terminal of the second amplifier U2 outputs the first voltage V1.

[0058] Specifically, the photodiode PD1 receives an optical signal from the analog optical fiber 200 and converts the optical signal into a second voltage. The second voltage is amplified by the second amplifier U2 and becomes the first voltage V1.

[0059] In this embodiment, the switch branch 50 includes a single-pole multi-throw switch, which includes a single input contact S1 and N output contacts. The N output contacts include a first output contact S2_1, a second output contact S2_2,..., and an Nth output contact S2_N.

[0060] The input contact S1 is connected with the third terminal of the amplification branch 10 (i.e., the inverting input terminal of the first amplifier U1). Each of the N output contacts is connected with one of the N current generation branches, i.e., the first output contact S2_1 is connected with the first current generation branch A1; the second output contact S2_2 is connected with the second current generation branch A2;..., and the Nth output contact S2_N is connected with the Nth current generation branch AN. The single-pole multi-throw switch is connected with the controller 40.

[0061] Specifically, when any one of the current generation branches is running, a connection is established between the corresponding output contact and the input contact S1, for example, when the first current generation branch A1 is running, a connection is established between the first output contact S2_1 and the input contact S1, thereby realizing the voltage feedback function.

[0062] In the related art, the range of the input voltage of the optical fiber signal transmission system also needs to remain unchanged on the premise that the range of the output voltage of the optical fiber signal transmission system remains unchanged, i.e., the optical fiber signal transmission system can only be used for transmission of a single signal (the voltage range corresponding to the signal is the range of the input voltage of the optical fiber signal transmission system), and cannot be applied to transmission of different signals.

[0063] In the embodiments of the present application, as shown in FIG. 1, the switch branch 50 is connected with the amplification branch 10, and the switch branch 50 is connected with the N current generation branches A1, A2,..., and AN. Figure 3In the shown embodiment, based on the virtual short and virtual open characteristics of the first amplifier U1, the voltages at the two input terminals of the first amplifier U1 will eventually be equal. Taking the first current generation branch A1 as an example, the input voltage VIN is equal to the voltage at the first terminal of the first resistor R1_1, and the voltage at the second terminal of the first resistor R1_1 is the voltage provided by the negative voltage source V1. Then the current ILD1 flowing through the laser diode LD1 is (VIN-V1) / R1_1 (denoted as formula ①). According to formula ①, 1 / R1_1 is the gain of the combination of the amplification branch 10 and the first current generation branch A1 (denoted as voltage-to-current conversion gain). Since the current ILD1 has a linear relationship with the optical signal, and the optical signal has a linear relationship with the first voltage V1, the gain of the entire signal transmission system 100 can be adjusted by adjusting the voltage-to-current conversion gain. The voltage-to-current conversion gain corresponding to the first current generation branch A1 is 1 / R1_1; the voltage-to-current conversion gain corresponding to the second current generation branch A2 is 1 / R2_1; and the voltage-to-current conversion gain corresponding to the Nth current generation branch AN is 1 / RN_1.

[0064] As can be seen from the above, by selecting different current generation branches to operate, different first resistors can be configured to obtain different voltage-to-current conversion gains, that is, the purpose of adjusting the voltage-to-current conversion gain is achieved. Correspondingly, the gain of the entire signal transmission system 100 will also change, thereby achieving the purpose of adjusting the gain of the signal transmission system 100.

[0065] As can be seen from the above, when different signals are input (the ranges of input voltages corresponding to different signals are different), the gain of the signal transmission system 100 can be adjusted by selecting different current generation branches, so that the first voltage V1 remains unchanged. It can be seen that the signal transmission system 100 can be applied to the transmission of different signals, and has strong practicability.

[0066] Secondly, in the embodiments of the present application, the ratio of the negative voltage source to the first resistor in each current generation branch is configured to be the same, so as to keep the static operating current constant, which is beneficial to prevent the laser diode LD1 from being damaged due to excessive current.

[0067] Please refer to Figure 3 and Figure 4 , Figure 4 for example, a way of the current flowing through the laser diode LD1 and the first voltage is shown. As Figure 4As shown, the abscissa is the current ILD1 flowing through the laser diode LD1, and the ordinate is the first voltage V1. Still taking the operation of the first current generating branch A1 as an example, before the current ILD1 increases to equal the threshold current Ith, the laser diode LD1 does not output an optical signal, and in this case the first voltage V1 remains 0. After the current ILD1 increases to be greater than the threshold current Ith, the first voltage V1 also increases with the increase of the current ILD1. Moreover, the current ILD1 and the first voltage V1 are in a positive proportional relationship. For example, if the waveform of the current ILD1 is as shown by the curve L1, then the waveform of the first voltage V1 is as shown by the curve L2. It can be seen that the waveform of the current ILD1 and the waveform of the first voltage V1 are in a positive proportional relationship, and the ratio is the electro-optical conversion coefficient of the laser diode LD1.

[0068] Meanwhile, in this embodiment, when the input voltage VIN is 0, according to the formula ①, it can be obtained that the current ILD1 = -V1 / R1_1. The current ILD1 at this time is denoted as the static working current IS1 of the laser diode LD1. By setting the static working current IS1 for the laser diode LD1, when the input voltage VIN is input to the signal transmission system 100, the working current of the laser diode LD1 can be fluctuated up and down in a linear interval around the static working current IS1, so that the first voltage V1 also changes linearly. In this way, the first voltage V1 will not produce signal distortion.

[0069] By analogy, it can be obtained that the static working current IS1 of the first current generating branch A1 is -V1 / R1_1; the static working current IS2 of the second current generating branch A2 is -V2 / R2_1; …; and the static working current ISN of the Nth current generating branch AN is -VN / RN_1. Therefore, by setting the ratio of the negative voltage source and the first resistor in each current generating branch to be the same, the static working current can remain unchanged regardless of which current generating branch operates, which is conducive to preventing the laser diode LD1 from being damaged due to excessive current.

[0070] The above only describes the embodiments of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent flow transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

[0071] The above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; under the idea of the present application, the technical features in the above examples or different examples can also be combined, and the steps can be implemented in any order. Those skilled in the art should understand that the technical solutions recorded in the foregoing examples can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the examples of the present application.

Claims

1. A signal transmission system, characterized in that, include: The circuit consists of an amplification branch, N current generation branches, an electro-optic conversion branch, and a signal receiving branch, where N is an integer greater than or equal to 2. The first end of the amplification branch is connected to the input voltage, and the second end of the amplification branch is connected to the N-way current generation branch. The amplification branch is configured to amplify the input voltage and then input it to the N-way current generation branch. The N current generation branches are also connected to the electro-optic conversion branch. The N current generation branches are configured to operate as any one of the N current generation branches, and generate the corresponding current, and the generated current flows through the electro-optic conversion branch. The electro-optic conversion branch is configured to output an optical signal based on the current flowing through the electro-optic conversion branch and transmit it through an analog optical fiber; The signal receiving branch is configured to receive the optical signal from the analog optical fiber and output a first voltage corresponding to the optical signal.

2. The signal transmission system according to claim 1, characterized in that, The signal transmission system also includes a controller and a switching branch, wherein the switching branch is connected between the third terminal of the amplification branch and the N current generation branches; The controller is connected to the switching branch and the N current generation branches respectively. The controller is configured to determine the current generation branch that is in operation and control the switching branch to establish a connection between the third terminal of the amplification branch and the current generation branch that is in operation, and to disconnect the connection between the third terminal of the amplification branch and the current generation branch that is not in operation.

3. The signal transmission system according to claim 2, characterized in that, The amplification branch includes a first amplifier; The non-inverting input terminal of the first amplifier is connected to the input voltage, the inverting input terminal of the first amplifier is connected to the switching branch, and the output terminal of the first amplifier is connected to the N-channel current generation branch. The non-inverting input terminal of the first amplifier is the first terminal of the amplification branch, the output terminal of the first amplifier is the second terminal of the amplification branch, and the inverting input terminal of the first amplifier is the third terminal of the amplification branch.

4. The signal transmission system according to claim 1 or 2, characterized in that, The current generation branch includes a switching transistor, a first resistor, a second resistor, and a negative voltage source; The first end of the switching transistor is connected to the second end of the amplification branch, the second end of the switching transistor is connected to the first end of the first resistor, the second end of the first resistor is connected to the negative voltage source and the first end of the second resistor respectively, and the second end of the second resistor is connected to the positive voltage source.

5. The signal transmission system according to claim 4, characterized in that, In the N current generation branches, the ratio of the negative voltage source to the first resistor in each current generation branch is configured to be the same.

6. The signal transmission system according to claim 4, characterized in that, In the N current generation branches, the resistance values ​​of the first resistors in any two current generation branches are configured to be different.

7. The signal transmission system according to claim 1 or 2, characterized in that, The electro-optic conversion branch includes a laser diode; The anode of the laser diode is connected to a positive voltage source, and the cathode of the laser diode is connected to the N-channel current generation branch.

8. The signal transmission system according to claim 1 or 2, characterized in that, The signal receiving branch includes a photodiode and a second amplifier; The cathode of the photodiode is connected to a positive voltage source, and the cathode of the photodiode is connected to the output terminal of a second amplifier, which outputs the first voltage.

9. The signal transmission system according to claim 2, characterized in that, The switch branch includes a single-pole multi-throw switch, which includes a single input contact and N output contacts; The input contact is connected to the third end of the amplification branch, each of the N output contacts is connected to one of the N current generation branches, and the single-pole multi-throw switch is connected to the controller.

10. An electronic device, characterized in that, Includes the signal transmission system as described in any one of claims 1-9.

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