Analog optical transmission equipment high sensitivity receiving module

Abstract

The utility model relates to optical receiver technical field, concretely relates to a kind of high sensitivity receiving module of analog optical transmission equipment, including optical receiver, circuit board is fixed in optical receiver, and the top surface of circuit board is provided with photoelectric detector, preamplifier, signal processor and controller, photoelectric detector, preamplifier and signal processor are electrically connected in turn, preamplifier uses three-stage common-source amplification circuit, and the amplification multiple of preamplifier is controlled based on signal processor output signal controller.The utility model in, controller passes through difference proportional operation, low-pass filter and automatic gain control circuit, dynamic detection signal processor output signal intensity, the amplification multiple of preamplifier is adjusted in real time, avoid weak signal amplification deficiency and strong signal saturation distortion, guarantee the stable output of different intensity optical signal.

Description

Technical Field

[0001] This utility model relates to the field of optical receiver technology, and more specifically, to a high-sensitivity receiving module for an analog optical transmission device. Background Technology

[0002] In the field of optical transmission technology, the receiver module is a core component of optical communication systems, and its performance directly determines the reception quality and transmission distance of optical signals. As optical transmission develops towards long distance, low power consumption, and high bandwidth, the sensitivity requirements for the receiver module are increasing. The receiver module needs to accurately capture weak optical signals and convert them into stable electrical signals, while avoiding saturation distortion of strong signals.

[0003] The utility model patent with publication number CN208723906U discloses a high-frequency analog signal photoelectric conversion device, including an optical transmitter and an optical receiver connected to the optical transmitter; the optical transmitter is used to process the input pulse signal to generate an optical signal; the optical receiver is used to process the transmitted optical signal to output a pulse signal.

[0004] Although this utility model effectively realizes an optical transmission device capable of transmitting EMP pulse signals with bandwidths from 0.1KHz to 125MHz by placing specific optical transmitters and receivers in a shielded enclosure, and has a perfect enclosure shielding structure, the signal amplification factor in its optical receiver is a fixed value. When faced with input optical signals of different intensities, it is prone to problems such as insufficient amplification of weak signals and saturation distortion of strong signals, resulting in poor signal adaptability. Utility Model Content

[0005] The purpose of this invention is to provide a high-sensitivity receiving module for an analog optical transmission device to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: A high-sensitivity receiving module for an analog optical transmission device includes an optical receiver with a circuit board fixed inside. A photodetector, a preamplifier, a signal processor, and a controller are disposed on the top surface of the circuit board. The photodetector, preamplifier, and signal processor are electrically connected in sequence. The preamplifier employs a three-stage common-source amplifier circuit. The signal processor is used to further amplify the signal. The controller controls the amplification factor of the preamplifier based on the output signal of the signal processor. The controller includes a differential proportional operational circuit, a low-pass filter circuit, and an automatic gain control circuit electrically connected in sequence. The automatic gain control circuit outputs a control voltage V6 to control the transimpedance of the control transistor and feedback resistor in the preamplifier.

[0007] Preferably, the preamplifier includes a power supply VDD, resistors R1, R2, and R3, MOSFETs M1, M2, and M3, capacitor C1, resistor R4, and MOSFET M4. MOSFETs M1, M2, M3, and M4 are all NMOS transistors. Resistor R4 is a feedback resistor, and MOSFET M4 is a control transistor. The first terminals of resistors R1, R2, and R3 are all connected to the power supply VDD. The second terminal of resistor R1 is connected to the drain of MOSFET M1, the source of MOSFET M1 is grounded, and the gate of MOSFET M1 is connected to the output terminal of the photodetector. The second terminal of resistor R2 is connected to the drain of MOSFET M2, the source of MOSFET M2 is grounded, and the gate of MOSFET M2 is connected to the second terminal of resistor R1. The second terminal of resistor R3 is connected to the drain of MOSFET M3, the source of MOSFET M3 is grounded, and the gate of MOSFET M3 is connected to the second terminal of resistor R2. The first terminal of resistor R4 is connected to the gate of MOSFET M1, and the second terminal of resistor R4 is connected to the drain of MOSFET M3. The first terminal of capacitor C1 is connected to the first terminal of resistor R4, and the second terminal of capacitor C1 is connected to the second terminal of resistor R4. The drain of MOSFET M4 is connected to the first terminal of resistor R4, and the source of MOSFET M4 is connected to the second terminal of resistor R4. The drain of MOSFET M3 serves as the output terminal of the preamplifier. This setting enables efficient initial amplification through the cross-group amplifier of the preamplifier, significantly enhancing the recognizability of weak signals.

[0008] Preferably, the signal processor includes a single-ended to differential circuit, a first-stage differential circuit, and a second-stage differential circuit that are electrically connected in sequence, wherein the input terminal of the single-ended to differential circuit is electrically connected to the output terminal of the preamplifier; In this setup, the single-ended to differential circuit can convert the single-ended electrical signal output by the preamplifier into a differential signal, greatly reducing the probability of external interference during signal transmission; the two-stage amplification structure composed of the first-stage differential circuit and the second-stage differential circuit can not only further improve the signal amplitude, but also effectively suppress common-mode noise and ensure the purity of the signal.

[0009] Preferably, the differential proportional operational circuit includes resistors R5, R6, R7, and R8, and operational amplifier U1; The first terminals of resistors R5 and R6 are respectively connected to the two output terminals of the two-stage differential circuit. The second terminal of resistor R5 is connected to the inverting input terminal of operational amplifier U1, the second terminal of resistor R6 is connected to the non-inverting input terminal of operational amplifier U1, the first terminal of resistor R7 is connected to the non-inverting input terminal of operational amplifier U1, the second terminal of resistor R7 is grounded, and the first terminal of resistor R8 is connected to the inverting input terminal of operational amplifier U1, and the second terminal of resistor R8 is connected to the output terminal of operational amplifier U1. Preferably, the low-pass filter circuit includes a resistor R9 and a capacitor C2; The first terminal of resistor R9 is connected to the output terminal of operational amplifier U1, the first terminal of capacitor C2 is connected to the first terminal of resistor R9, and the second terminal of capacitor C2 is grounded.

[0010] Preferably, the automatic gain control circuit includes MOSFETs M5, M6, PM1, PM2, and M7, resistors R10, R11, and R12, and MOSFET M8. MOSFETs M5, M6, M7, and M8 are all NMOS transistors, and MOSFETs PM1 and PM2 are both PMOS transistors. The gates of MOSFETs M5 and M6 are both connected to the second terminal of resistor R9. The sources of MOSFETs PM1 and PM2 are both connected to power supply VDD. The gate of MOSFET PM1 is connected to the gate of MOSFET PM2. The drain of MOSFET PM1 is connected to the gate of MOSFET PM1. The drain of MOSFET M5 is connected to the drain of MOSFET PM1. The source of MOSFET M5 is grounded. The drain of MOSFET PM2 is connected to the first terminal of resistor R10. The second terminal of resistor R10 is connected to the first terminal of resistor R11. The second terminal of resistor R11 is connected to the first terminal of resistor R12. The second terminal of resistor R12 is connected to the drain of MOSFET M6. The source of MOSFET M6 is grounded. The gate of MOSFET M7 is connected to the first terminal of resistor R10. The drain of MOSFET M7 is connected to the first terminal of resistor R11. The source of MOSFET M7 is connected to the second terminal of resistor R11. The gate of MOSFET M8 is connected to the second terminal of resistor R11. The drain of MOSFET M8 is connected to the first terminal of resistor R10. The source of MOSFET M8 is grounded. The first terminal of resistor R10 is connected to the gate of MOSFET M4 as the output terminal. In these three settings, the differential proportional operation circuit accurately converts the differential signal output by the signal processor into a single-ended signal, the low-pass filter circuit filters out high-frequency interference noise in the converted signal, and the automatic gain control circuit generates a stable control voltage V6. By adjusting the transimpedance of the control transistor and the feedback resistor in the preamplifier in real time, the dynamic adaptation of the preamplifier's amplification factor is achieved. This not only solves the problems of insufficient amplification of weak signals and saturation distortion of strong signals in traditional fixed amplification factor modules, but also ensures that optical signals of different intensities can be stably output after processing, significantly improving the signal adaptation capability and output stability of the receiving module.

[0011] Preferably, the photodetector receives optical signals via an optical fiber, and the signal processor transmits analog signals via a data line; This setup reduces the attenuation and distortion of the optical signal during transmission to the photodetector via optical fiber, ensuring the integrity of the initial optical signal; and enables efficient and stable transmission of analog signals via data cable.

[0012] Preferably, the optical receiver has several heat dissipation holes regularly opened on the left and right side walls, and a fan is installed on the left inner wall of the optical receiver; This setup creates an efficient heat dissipation circulation system that can quickly dissipate the heat generated by the electronic components on the circuit board during operation, preventing the components from degrading or being damaged due to prolonged high temperatures.

[0013] Compared with the prior art, the beneficial effects of this utility model are: 1. In this utility model, the preamplifier adopts a three-stage common-source amplifier circuit, which, together with the single-ended to differential and two-stage differential amplifier structure of the signal processor, realizes dual amplification of the signal, greatly improves the detection capability of weak light signals, and can adapt to the signal reception requirements in low-light power scenarios.

[0014] 2. In this utility model, the controller dynamically detects the output signal strength of the signal processor through differential proportional operation, low-pass filtering and automatic gain control circuit, and adjusts the amplification factor of the preamplifier in real time to avoid insufficient amplification of weak signals and saturation distortion of strong signals, thus ensuring stable output of optical signals of different intensities. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram showing the connection of the photodetector, preamplifier, signal processor and controller in this utility model; Figure 3 This is the circuit schematic diagram of the preamplifier in this utility model; Figure 4 This is a schematic diagram showing the connection of the preamplifier, the two-stage differential circuit, and the controller in this utility model; Figure 5 This is the circuit schematic diagram of the controller in this utility model; In the picture: 100. Optical receiver; 101. Heat dissipation vent; 200. Circuit board; 300. Fiber optic cable; 400. Photodetector; 500. Preamplifier; 600. Signal processor; 601. Single-ended to differential circuit; 602. First-stage differential circuit; 603. Second-stage differential circuit; 700, data cable; 800, Fan; 900. Controller; 901. Differential proportional operation circuit; 902. Low-pass filter circuit; 903. Automatic gain control circuit. Detailed Implementation

[0016] The technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0017] Please see Figures 1-5 The present invention provides the following technical solution: A high-sensitivity receiving module for an analog optical transmission device includes an optical receiver 100, with a circuit board 200 fixed inside the receiver 100. A photodetector 400, a preamplifier 500, a signal processor 600, and a controller 900 are disposed on the top surface of the circuit board 200. The photodetector 400, preamplifier 500, and signal processor 600 are electrically connected in sequence. The preamplifier 500 employs a three-stage common-source amplifier circuit. The signal processor 600 is used to further amplify the signal. The controller 900 controls the amplification factor of the preamplifier 500 based on the output signal of the signal processor 600. The controller 900 includes a differential proportional operational circuit 901, a low-pass filter circuit 902, and an automatic gain control circuit 903, all electrically connected in sequence. The automatic gain control circuit 903 outputs a control voltage V6 to control the transimpedance of the control transistor and feedback resistor in the preamplifier 500. Through a multi-stage amplification structure and closed-loop control design, adaptive processing of optical signals of different intensities is achieved, solving the problems of insufficient amplification of weak signals and saturation distortion of strong signals present in traditional fixed amplification factor modules.

[0018] In this embodiment, please refer to Figure 2 and Figure 3 The preamplifier 500 includes a power supply VDD, resistors R1, R2, and R3, MOSFETs M1, M2, and M3, capacitor C1, resistor R4, and MOSFET M4. MOSFETs M1, M2, M3, and M4 are all NMOS transistors. Resistor R4 is a feedback resistor, and MOSFET M4 is a control transistor. The three-stage common-source amplifier circuit achieves preliminary and efficient signal amplification, significantly improving the detection capability of weak light signals. Capacitor C1 is used to suppress signal jitter and ensure the stability of the amplified signal. NMOS transistor M4 responds to the control voltage V6 by changing its conduction state to adjust its transimpedance, thereby dynamically adjusting the amplification factor of the preamplifier 500 to adapt to input signals of different strengths. The first terminals of resistors R1, R2, and R3 are all connected to the power supply VDD. The second terminal of resistor R1 is connected to the drain of MOSFET M1, the source of MOSFET M1 is grounded, and the gate of MOSFET M1 is connected to the output terminal of photodetector 400. The second terminal of resistor R2 is connected to the drain of MOSFET M2, the source of MOSFET M2 is grounded, and the gate of MOSFET M2 is connected to the second terminal of resistor R1. The second terminal of resistor R3 is connected to the drain of MOSFET M3, the source of MOSFET M3 is grounded, and the gate of MOSFET M3 is connected to the second terminal of resistor R2. The first terminal of resistor R4 is connected to the gate of MOSFET M1, and the second terminal of resistor R4 is connected to the drain of MOSFET M3. The first terminal of capacitor C1 is connected to the first terminal of resistor R4, and the second terminal of capacitor C1 is connected to the second terminal of resistor R4. The drain of MOSFET M4 is connected to the first terminal of resistor R4, and the source of MOSFET M4 is connected to the second terminal of resistor R4. The drain of MOSFET M3 serves as the output terminal of preamplifier 500.

[0019] In this embodiment, please refer to 2. The signal processor 600 includes a single-ended to differential circuit 601, a first-stage differential circuit 602, and a second-stage differential circuit 603 connected in sequence. The input terminal of the single-ended to differential circuit 601 is electrically connected to the output terminal of the preamplifier 500. The single-ended to differential circuit 601 converts the single-ended signal into a differential signal, effectively improving the signal's anti-interference capability and reducing the impact of noise during transmission. The first-stage differential circuit 602 and the second-stage differential circuit 603 constitute a two-stage differential amplification structure, which further amplifies the signal strength while suppressing common-mode noise, ensuring the purity and amplitude of the signal, providing the controller 900 with accurate signal detection basis, and indirectly improving the sensitivity of the receiving module.

[0020] In this embodiment, please refer to 4 and Figure 5 The differential proportional operation circuit 901 includes resistors R5, R6, R7, and R8, and an operational amplifier U1. The differential proportional operation circuit 901 is used to convert differential signals into single-ended signals. The first terminals of resistors R5 and R6 are connected to the two output terminals of the two-stage differential circuit 603, respectively. The second terminal of resistor R5 is connected to the inverting input terminal of operational amplifier U1, and the second terminal of resistor R6 is connected to the non-inverting input terminal of operational amplifier U1. The first terminal of resistor R7 is connected to the non-inverting input terminal of operational amplifier U1, and the second terminal of resistor R7 is grounded. The first terminal of resistor R8 is connected to the inverting input terminal of operational amplifier U1, and the second terminal of resistor R8 is connected to the output terminal of operational amplifier U1.

[0021] Specifically, the low-pass filter circuit 902 includes a resistor R9 and a capacitor C2. The resistor R9 and the capacitor C2 constitute a low-pass filter, which filters high-frequency noise in the output signal of the operational amplifier U1 and retains the low-frequency effective components related to the signal strength. The first terminal of resistor R9 is connected to the output terminal of operational amplifier U1, the first terminal of capacitor C2 is connected to the first terminal of resistor R9, and the second terminal of capacitor C2 is grounded.

[0022] Furthermore, the automatic gain control circuit 903 includes MOSFETs M5, M6, PM1, PM2, and M7, resistors R10, R11, and R12, and MOSFET M8. MOSFETs M5, M6, M7, and M8 are all NMOS transistors, while MOSFETs PM1 and PM2 are both PMOS transistors. The gates of MOSFETs M5 and M6 are connected to a low-pass filtered signal, converting the voltage corresponding to the signal strength into drain current. MOSFETs PM1 and PM2 form a PMOS mirror current source, replicating the drain current of MOSFET M5 to the branch of MOSFET PM2. Through the series voltage division of resistors R10, R11, and R12, the current signal is converted into a gradient voltage, providing an adjustable reference for gain control. MOSFETs M7 and M8 form a feedback loop, with MOSFET M7 adjusting the voltage of the voltage divider node through its own conduction state to avoid sudden changes in control voltage. The gates of MOSFETs M5 and M6 are both connected to the second terminal of resistor R9. The sources of MOSFETs PM1 and PM2 are both connected to power supply VDD. The gate of MOSFET PM1 is connected to the gate of MOSFET PM2. The drain of MOSFET PM1 is connected to the gate of MOSFET PM1. The drain of MOSFET M5 is connected to the drain of MOSFET PM1. The source of MOSFET M5 is grounded. The drain of MOSFET PM2 is connected to the first terminal of resistor R10. The second terminal of resistor R10 is connected to the first terminal of resistor R11. The second terminal of resistor R11 is connected to the first terminal of resistor R12. The second terminal of resistor R12 is connected to the drain of MOSFET M6. The source of MOSFET M6 is grounded. The gate of MOSFET M7 is connected to the first terminal of resistor R10. The drain of MOSFET M7 is connected to the first terminal of resistor R11. The source of MOSFET M7 is connected to the second terminal of resistor R11. The gate of MOSFET M8 is connected to the second terminal of resistor R11. The drain of MOSFET M8 is connected to the first terminal of resistor R10. The source of MOSFET M8 is grounded. The first end of resistor R10 is connected to the gate of MOSFET M4 as the output terminal.

[0023] In this embodiment, please refer to Figure 1 The photodetector 400 receives optical signals through the optical fiber 300, and the signal processor 600 transmits analog signals through the data line 700. The optical fiber 300, as the optical signal transmission medium, has the characteristics of low loss and anti-interference, ensuring that the photodetector 400 receives optical signals efficiently and reducing attenuation and distortion during signal transmission. The data line 700 realizes the reliable output of analog signals, ensuring that the processed signals are accurately transmitted to external devices.

[0024] In this embodiment, please refer to Figure 1The optical receiver 100 also has several heat dissipation holes 101 regularly opened on the left and right side walls. A fan 800 is installed on the left inner wall of the optical receiver 100 to prevent the components from overheating and causing performance degradation or damage, to ensure that the receiving module works stably for a long time, to extend its service life, and to improve its reliability.

[0025] When the high-sensitivity receiving module of the analog optical transmission device of this utility model is in use, the optical signal is transmitted through the optical fiber 300 to the photodetector 400 in the optical receiver 100, and the photodetector 400 converts the optical signal into the initial electrical signal V1. The initial electrical signal V1 is transmitted to the preamplifier 500. The preamplifier 500 amplifies the electrical signal through its internal three-stage common-source amplifier circuit and outputs the amplified electrical signal V2. The electrical signal V2 is input to the signal processor 600, first converted into a differential signal by the single-ended to differential circuit 601, and then amplified and suppressed by the first-stage differential circuit 602 and the second-stage differential circuit 603 in sequence, finally outputting differential electrical signals V5+ and V5-.

[0026] The differential electrical signal is transmitted to the controller 900. In the first step, it is converted into a single-ended signal by the differential proportional operation circuit 901. In the second step, it is filtered by the low-pass filter circuit 902 to filter high-frequency noise and retain the effective signal. In the third step, the automatic gain control circuit 903 converts the processed signal into a control voltage V6, which is output to the MOS transistor M4 of the preamplifier 500. By adjusting the cross-resistance between the MOS transistor M4 and the resistor R4, the amplification factor of the preamplifier 500 is dynamically adjusted. After the electrical signal undergoes adaptive gain adjustment, it is processed by the signal processor 600 and then transmitted to an external device via the data line 700 to achieve stable output of the analog signal.

[0027] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A high-sensitivity receiving module for an analog optical transmission device, comprising an optical receiver (100), characterized in that: The optical receiver (100) has a circuit board (200) fixed inside. The top surface of the circuit board (200) is provided with a photodetector (400), a preamplifier (500), a signal processor (600), and a controller (900). The photodetector (400), the preamplifier (500), and the signal processor (600) are electrically connected in sequence. The preamplifier (500) adopts a three-stage common-source amplifier circuit. The signal processor (600) is used to amplify the signal again. The controller (900) controls the amplification factor of the preamplifier (500) based on the output signal of the signal processor (600). The controller (900) includes a differential proportional operation circuit (901), a low-pass filter circuit (902), and an automatic gain control circuit (903) that are electrically connected in sequence. The automatic gain control circuit (903) outputs a control voltage V6 to control the transresistance of the control tube and the feedback resistor in the preamplifier (500).

2. The high-sensitivity receiving module for analog optical transmission equipment according to claim 1, characterized in that: The preamplifier (500) includes a power supply VDD, resistors R1, R2, and R3, MOSFETs M1, M2, and M3, capacitor C1, resistor R4, and MOSFET M4. MOSFETs M1, M2, M3, and M4 are all NMOS transistors. Resistor R4 is a feedback resistor, and MOSFET M4 is a control transistor. The first terminals of resistors R1, R2, and R3 are all connected to the power supply VDD. The second terminal of resistor R1 is connected to the drain of MOSFET M1, the source of MOSFET M1 is grounded, and the gate of MOSFET M1 is connected to the output terminal of the photodetector (400). The second terminal of resistor R2 is connected to the drain of MOSFET M2, the source of MOSFET M2 is grounded, and the gate of MOSFET M2 is connected to the second terminal of resistor R1. The second terminal of resistor R3 is connected to the drain of MOSFET M3, the source of MOSFET M3 is grounded, and the gate of MOSFET M3 is connected to the second terminal of resistor R2. The first terminal of resistor R4 is connected to the gate of MOSFET M1, and the second terminal of resistor R4 is connected to the drain of MOSFET M3. The first terminal of capacitor C1 is connected to the first terminal of resistor R4, and the second terminal of capacitor C1 is connected to the second terminal of resistor R4. The drain of MOSFET M4 is connected to the first terminal of resistor R4, the source of MOSFET M4 is connected to the second terminal of resistor R4, and the drain of MOSFET M3 serves as the output terminal of the preamplifier (500).

3. The high-sensitivity receiving module for analog optical transmission equipment according to claim 2, characterized in that: The signal processor (600) includes a single-ended to differential circuit (601), a first-stage differential circuit (602), and a second-stage differential circuit (603) connected in sequence. The input terminal of the single-ended to differential circuit (601) is electrically connected to the output terminal of the preamplifier (500).

4. The high-sensitivity receiving module for analog optical transmission equipment according to claim 3, characterized in that: The differential proportional operational circuit (901) includes resistors R5, R6, R7, and R8, and operational amplifier U1; The first ends of resistors R5 and R6 are respectively connected to the two output ends of the two-stage differential circuit (603). The second end of resistor R5 is connected to the inverting input of operational amplifier U1, the second end of resistor R6 is connected to the non-inverting input of operational amplifier U1, the first end of resistor R7 is connected to the non-inverting input of operational amplifier U1, the second end of resistor R7 is grounded, the first end of resistor R8 is connected to the inverting input of operational amplifier U1, and the second end of resistor R8 is connected to the output end of operational amplifier U1.

5. The high-sensitivity receiving module for analog optical transmission equipment according to claim 4, characterized in that: The low-pass filter circuit (902) includes a resistor R9 and a capacitor C2; The first terminal of resistor R9 is connected to the output terminal of operational amplifier U1, the first terminal of capacitor C2 is connected to the first terminal of resistor R9, and the second terminal of capacitor C2 is grounded.

6. The high-sensitivity receiving module for analog optical transmission equipment according to claim 5, characterized in that: The automatic gain control circuit (903) includes MOSFETs M5, M6, PM1, PM2, and M7, resistors R10, R11, and R12, and MOSFET M8. MOSFETs M5, M6, M7, and M8 are all NMOS transistors, while MOSFETs PM1 and PM2 are both PMOS transistors. The gates of MOSFETs M5 and M6 are both connected to the second terminal of resistor R9. The sources of MOSFETs PM1 and PM2 are both connected to power supply VDD. The gate of MOSFET PM1 is connected to the gate of MOSFET PM2. The drain of MOSFET PM1 is connected to the gate of MOSFET PM1. The drain of MOSFET M5 is connected to the drain of MOSFET PM1. The source of MOSFET M5 is grounded. The drain of MOSFET PM2 is connected to the first terminal of resistor R10. The second terminal of resistor R10 is connected to the first terminal of resistor R11. The second terminal of resistor R11 is connected to the first terminal of resistor R12. The second terminal of resistor R12 is connected to the drain of MOSFET M6. The source of MOSFET M6 is grounded. The gate of MOSFET M7 is connected to the first terminal of resistor R10. The drain of MOSFET M7 is connected to the first terminal of resistor R11. The source of MOSFET M7 is connected to the second terminal of resistor R11. The gate of MOSFET M8 is connected to the second terminal of resistor R11. The drain of MOSFET M8 is connected to the first terminal of resistor R10. The source of MOSFET M8 is grounded. The first end of resistor R10 is connected to the gate of MOSFET M4 as the output terminal.

7. The high-sensitivity receiving module for analog optical transmission equipment according to claim 1, characterized in that: The photodetector (400) receives optical signals through an optical fiber (300), and the signal processor (600) transmits analog signals through a data line (700).

8. The high-sensitivity receiving module for analog optical transmission equipment according to claim 1, characterized in that: The optical receiver (100) also has several heat dissipation holes (101) regularly opened on the left and right side walls, and a fan (800) is installed on the left inner wall of the optical receiver (100).

Images