Pulse laser ranging echo signal precision conditioning circuit

Abstract

The utility model discloses a pulse laser ranging echo signal precision conditioning circuit. The circuit comprises a filter circuit unit, a multiple switching unit and an operational amplifier circuit unit. The filtering power supply unit is connected with the operational amplifier single-path unit, the operational amplifier single-path unit is connected with the operational amplifier circuit unit, the operational amplifier unit adopts a precision amplifier to realize IV conversion of an avalanche photodiode (APD) circuit, and an extremely high dynamic input range is ensured through two-gear selectable transimpedance gain. Various modulation-demodulation transimpedance amplification applications are flexibly adapted, and a digital circuit is used for switching resistors to realize the amplification factor of an operational amplifier; in order to solve the problem that signals are prone to fixed-frequency interference, two-stage filters are used after two-stage amplification, and interference removal is achieved. Signals are received, a high-pass filter is adopted in the first stage, signals with the signal frequency larger than 0.05 HZ can pass through the first stage, a low-pass filter is adopted in the second stage, signals with the signal frequency lower than 100 HZ can pass through the second stage, various fixed-frequency interferences are effectively restrained, and effective signals are limited in a certain interval range.

Description

TECHNICAL FIELD

[0001] The utility model relates to laser ranging technical field, concretely relates to a pulse laser ranging echo signal precision conditioning circuit. BACKGROUND

[0002] The principle of pulse laser ranging method is simply that the time difference of laser from departure to return to the same position is detected to calculate the distance. The specific implementation process is that the laser transmitter projects a laser beam forward, and the timer starts at the same time, when the emitted laser encounters the object to be measured, the laser returns to the laser receiver, and the timer stops timing at this time. The time is multiplied by the speed of light under the current condition, and the distance between the laser emission position and the target object can be obtained. For the circuit, the echo signal is particularly important, the better the signal, the more obvious the distance that can be collected. The echo signal is also susceptible to interference, how to generate a stable echo signal is an important technical index in the laser ranging industry. SUMMARY

[0003] The main purpose of the utility model is to provide a pulse laser ranging echo signal precision conditioning circuit in order to solve the above technical problems, the utility model provides a pulse laser ranging echo signal precision conditioning circuit, which comprises: a filter circuit unit, a multiple switching unit, an operational amplifier circuit unit;

[0004] The filter power supply unit is connected with the operational amplifier single circuit unit, and the operational amplifier single circuit unit is connected with the operational amplifier circuit unit.

[0005] The multiple switching unit comprises a first switch unit and a second switch unit.

[0006] The first switch circuit unit comprises capacitors C4 and C5, high-speed digital switch chips U1A and U3A.

[0007] The high-speed digital switch chip U1A comprises a port X, a port Y, a power supply end and a CNTL signal end, wherein the port X is used as an S0 port of the multiple switching unit, the port Y is used as an S2 port of the multiple switching unit, and the power supply end is connected with a voltage source VCC3_02 and a power supply end of the high-speed digital switch chip U3A.

[0008] The high-speed digital switch chip U3A comprises a port X, a port Y, a power supply end and a CNTL signal end, wherein the port X is used as an S1 port of the multiple switching unit, and the port Y is used as an S2 port of the multiple switching unit.

[0009] The capacitors C4 and C5 are connected with the power supply end of the high-speed digital switch chip U1A, and the other ends of the capacitors C4 and C5 are grounded.

[0010] The second switch circuit unit comprises capacitors C8 and C9, high-speed digital switch chips U4A and U5A;

[0011] The high-speed digital switch chip U4A comprises a port X, a port Y, a power supply end, and a CNTL signal end, wherein the port X is used as an S3 port of the multiple switching unit, the port Y is used as an S5 port of the multiple switching unit, and the power supply end is connected with a voltage source VCC3_02 and a power supply end of the high-speed digital switch chip U3A;

[0012] The high-speed digital switch chip U5A comprises a port X, a port Y, a power supply end, and a CNTL signal end, wherein the port X is used as an S4 port of the multiple switching unit, and the port Y is used as an S5 port of the multiple switching unit.

[0013] The capacitors C8 and C9 are both connected with the power supply end of the high-speed digital switch chip U1A, and the other ends of the capacitors C8 and C9 are both grounded.

[0014] Further, the filter circuit unit comprises capacitors C1, C2, C3, C6 and C7, resistors R4, R5, R6 and R7, and operational amplifiers U2A and U2B.

[0015] The reverse input end of the operational amplifier U2A is connected with the output end, and the forward input end is simultaneously connected with the capacitor C3 and the resistor R7, and the other end of the resistor R7 is grounded; the capacitor C3 is simultaneously connected with the capacitor C2 and the resistor R4, the other end of the capacitor C3 is used as an input end Sig_receive0_02, the other end of the resistor R4 is connected with the output end of the operational amplifier U2A; the output end of the operational amplifier U2A is connected with the resistor R6; the resistor R6 is simultaneously connected with the resistor R5 and the capacitor C1, the other end of the capacitor C1 is connected with the output end of the operational amplifier U2B, the other end of the resistor R5 is connected with the capacitor C7 and the forward input end of the operational amplifier U2B; the other end of the capacitor C7 is grounded; the reverse input end of the operational amplifier U2A is connected with the output end, wherein the output end of the operational amplifier U2A is used as an output end Sig_receive_02 of the filter circuit unit.

[0016] Further, the operational amplifier circuit unit comprises a transimpedance amplification unit and a two-stage amplification unit, and the output end of the transimpedance amplification unit is connected with the input end of the two-stage amplification unit.

[0017] The transimpedance amplification unit comprises a transistor Q3, a transistor Q4, capacitors C37, C38, C39 and C40, resistors R25, R26, R28, R29 and R30, and an avalanche photodiode U6.

[0018] The negative electrode of the avalanche photodiode U6 is connected with the resistor R29 and the capacitor C39, the other end of the capacitor C39 is grounded, the other end of the resistor R29 is connected with the resistor R30 and the capacitor C40, the other end of the capacitor C40 is grounded, and the other end of the resistor R30 is connected with the power supply VCC_H_02;

[0019] The positive electrode of the avalanche photodiode U6 is connected with the resistor R25 and the base of the triode Q3, the emitter of the triode Q3 is connected with the resistor R31 and the base of the triode Q4, the other end of the resistor R31 is grounded, the collector of the triode Q3 is connected with the resistor R26, the emitter of the triode Q4 is grounded, the collector of the triode Q4 is connected with the resistor R28 and the resistor R25, the resistor R28 is connected with the collector of the triode Q3, and the resistor R25 is used as a signal output end of a transimpedance amplification unit; the capacitor C37 and the capacitor C38 are connected between the resistor R28 and the resistor R26, and the other ends of the capacitor C37 and the capacitor C38 are grounded.

[0020] Further, the two-stage amplification unit comprises: an operational amplifier U7A, an operational amplifier U7B, capacitors C47, C45, C42, C41, C43, C44, C48, resistors R40, R42, R1, R33, R38, R34, R37, R35, R2, R36, R43, R41.

[0021] The output end of the transimpedance amplification unit is connected with the reverse input end of the operational amplifier U7A, the forward input end of the operational amplifier U7A is connected with the resistor R42, the resistor R40 and the capacitor C47, the other ends of the resistor R42 and the capacitor C47 are grounded, and the other end of the resistor R40 is connected with the power supply VCC3_02; the power supply negative input end of the operational amplifier U7A is grounded; the power supply positive input end of the operational amplifier U7A is connected with the capacitor C42, the capacitor C45 and the resistor R38, wherein the capacitor C42 and the capacitor C45 are grounded, the resistor R38 is connected with the power supply VCC3_02, the reverse input end connected with the operational amplifier U7A is connected with the capacitor C41, the resistor R1 and the resistor R33, the other end of the resistor R1 is connected with the S0 port of the multiple switching unit, the other end of the resistor R33 is connected with the S1 port of the multiple switching unit, and the other end of the capacitor C41 is connected with the S2 port of the multiple switching unit and the output end connected with the operational amplifier U7A; the output end of the operational amplifier U7A is connected with the capacitor C46, and the other end of the capacitor C46 is connected with the forward input end of the operational amplifier U7B.

[0022] The reverse input end of the operational amplifier U7B is connected with the resistor R43, the resistor R2, the resistor R36 and the capacitor C44, wherein the other end of the resistor R43 is connected with the capacitor C48, the other end of the capacitor C48 is grounded; the other end of the resistor R2 is connected with the S3 port of the multiple switching unit; the other end of the resistor R36 is connected with the S4 port of the multiple switching unit; and the other end of the capacitor C44 is connected with the S5 port of the multiple switching unit and the output end of the operational amplifier U7B.

[0023] The output end of the operational amplifier U7B is connected with the resistor R41, and the other end of the resistor R41 is connected with the input end Sig_receive0_02 of the filter unit.

[0024] The resistor R35 is connected with the capacitor C46 at one end, and is connected with the resistor R34, the resistor R37 and the capacitor C43 at the other end, wherein the other end of the resistor R43 is connected with the power supply VCC3_02, the other end of the resistor R37 is grounded, and the other end of the capacitor C43 is grounded.

[0025] The beneficial effects of the utility model are shown in:

[0026] 1. The transimpedance amplification unit of the utility model guarantees extremely high dynamic input range through two selectable transimpedance gains, flexibly adapts to various modulation demodulation transimpedance amplification application, uses digital circuit to switch resistance to realize the amplification multiple of the operational amplifier, so that the amplification multiple is small at the near distance signal end, and the blind area is realized.

[0027] 2. The utility model realizes long distance transmission through the two-stage amplification unit long distance signal amplification, and eliminates the change of the threshold voltage of the switching transistor with the input signal through configuration, so that the on resistance is kept low in the whole working signal range. BRIEF DESCRIPTION OF DRAWINGS

[0028] The drawings accompanying the specification provide further understanding of the utility model, and the schematic embodiment of the utility model and the description thereof are used to explain the utility model, and do not constitute improper limitation on the utility model. In the drawings:

[0029] Figure 1 It is the filter circuit principle diagram of the utility model;

[0030] Figure 2 It is the multiple switching unit circuit principle diagram of the utility model;

[0031] Figure 3 It is the transimpedance amplification unit circuit principle diagram of the utility model;

[0032] Figure 4 It is the two-stage amplification unit circuit principle diagram of the utility model. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. In the case of no conflict, the embodiments in the application and the features in the embodiments can be combined with each other. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without creative labor are within the protection scope of the utility model.

[0034] The utility model provides a kind of pulse laser ranging echo signal precision conditioning circuit, comprising: filter circuit unit, multiple switching unit, operational amplifier circuit unit;Filter power unit is connected with operational amplifier single circuit unit, and operational amplifier single circuit unit is connected with operational amplifier circuit unit.

[0035] As Figure 1 As shown in the drawing, filter circuit unit includes: capacitor C1, C2, C3, C6, C7, resistance R4, R5, R6, R7, operational amplifier U2A, U2B;

[0036] The operational amplifier U2A reverse input end is connected with output end, and forward input end is simultaneously connected capacitor C3, resistance R7, and the other end of resistance R7 is grounded;Capacitor C3 is simultaneously connected capacitor C2 and resistance R4, and the other end of capacitor C3 is as input end Sig_receive0_02, and the other end of resistance R4 is connected the output end of operational amplifier U2A;The output end of operational amplifier area U2A is connected resistance R6;Resistance R6 is simultaneously connected resistance R5 and capacitor C1, and the other end of capacitor C1 is connected the output end of operational amplifier U2B, and the other end of resistance R5 is connected capacitor C7 and the forward input end of operational amplifier U2B;The other end of capacitor C7 is grounded;The operational amplifier U2A reverse input end is connected with output end, and the output end of operational amplifier U2A is as the output end Sig_receive_02 of filter electric element.

[0037] Operational amplifier U2A is 0.05HZ high-pass filter, and operational amplifier U2B is 100HZ low-pass filter, so as to ensure the stability of signal and remove burr interference.

[0038] As Figure 2 As shown in the drawing, multiple switching unit includes: first switch circuit unit and second switch electric unit;

[0039] First switch circuit unit includes: capacitor C4, C5, high-speed digital switch chip U1A, U3A;

[0040] The high-speed digital switch chip U1A includes port X, port Y, power supply terminal, and CNTL signal terminal. Port X serves as the SO port of the multiple switching unit, port Y serves as the S2 port of the multiple switching unit, and the power supply terminal is connected to the voltage source VCC3_02 and the power supply terminal of the high-speed digital switch chip U3A.

[0041] The high-speed digital switch chip U3A includes port X, port Y, power supply terminal, and CNTL signal terminal, wherein port X serves as the S1 port of the multiple switching unit, and port Y serves as the S2 port of the multiple switching unit.

[0042] Capacitors C4 and C5 are both connected to the power supply terminal of the high-speed digital switching chip U1A, and the other end of capacitors C4 and C5 is grounded.

[0043] The second switching circuit unit includes: capacitors C8 and C9, and high-speed digital switching chips U4A and U5A;

[0044] The high-speed digital switch chip U4A includes port X, port Y, power supply terminal, and CNTL signal terminal. Port X serves as the S3 port of the multiple switching unit, port Y serves as the S5 port of the multiple switching unit, and the power supply terminal is connected to the voltage source VCC3_02 and the power supply terminal of the high-speed digital switch chip U3A.

[0045] The high-speed digital switch chip U5A includes port X, port Y, power supply terminal, and CNTL signal terminal, wherein port X serves as the S4 port of the multiple switching unit, and port Y serves as the S5 port of the multiple switching unit.

[0046] Capacitors C8 and C9 are both connected to the power supply terminal of the high-speed digital switching chip U1A, and the other end of capacitors C8 and C9 is grounded.

[0047] CN0, CN1, CN2, and CN3 are the selector lines of the digital switch, which control the conduction of pins 1 and 2 (S0,S2), (S1,S2), (S3,S5), and (S4,S5).

[0048] like Figure 3 , 4 As shown, the operational amplifier circuit unit includes: a transimpedance amplifier unit and a two-stage amplifier unit, with the output terminal of the transimpedance amplifier unit connected to the input terminal of the two-stage amplifier unit;

[0049] The transimpedance amplification unit includes: transistors Q3 and Q4, capacitors C37, C38, C39, and C40, resistors R25, R26, R28, R29, and R30, and an avalanche photodiode U6.

[0050] The negative electrode of the avalanche photodiode U6 is connected with the resistor R29 and the capacitor C39, the other end of the capacitor C39 is connected with the ground, the other end of the resistor R29 is connected with the resistor R30 and the capacitor C40, the other end of the capacitor C40 is connected with the ground, and the other end of the resistor R30 is connected with the power supply VCC_H_02 (bias voltage) ;

[0051] The positive electrode of the avalanche photodiode U6 is connected with the resistor R25 and the base of the transistor Q3, the emitter of the transistor Q3 is connected with the resistor R31 and the base of the transistor Q4, the other end of the resistor R31 is connected with the ground, the collector of the transistor Q3 is connected with the resistor R26, the emitter of the transistor Q4 is connected with the ground, the collector of the transistor Q4 is connected with the resistor R28 and the resistor R25, and the resistor R28 is connected with the collector of the transistor Q3, the capacitor C37 and the capacitor C38 are connected between the resistor R28 and the resistor R26, and the other ends of the capacitor C37 and the capacitor C38 are connected with the ground.

[0052] In the trans-impedance amplifier unit, the resistor R30 and the capacitor C40, the resistor R29 and the capacitor C39 form a two-stage RC filter, and the resistor R25 adjusts the amplification factor of the transistor to form an IV conversion.

[0053] The IV conversion of the APD circuit is realized by using a precision amplifier, the trans-impedance amplifier has wide band, high speed overload recovery time, fast setting time, adjustable trans-impedance gain, and ultra-low noise, and can monitor various high-performance photoelectric systems.

[0054] The two-stage amplification unit includes the operational amplifier U7A, the operational amplifier U7B, the capacitor C47, the capacitor C45, the capacitor C42, the capacitor C41, the capacitor C43, the capacitor C44, the capacitor C48, the resistor R40, the resistor R42, the resistor R1, the resistor R33, the resistor R38, the resistor R34, the resistor R37, the resistor R35, the resistor R2, the resistor R36, the resistor R43, and the resistor R41.

[0055] The output end of the transimpedance amplification unit is connected to the reverse input end of the operational amplifier U7A, the forward input end of the operational amplifier U7A is connected to the resistor R42, the resistor R40 and the capacitor C47, the other end of the resistor R42 and the capacitor C47 is grounded, the other end of the resistor R40 is connected to the power supply VCC3_02; the power supply negative input end of the operational amplifier U7A is grounded; the power supply positive input end of the operational amplifier U7A is connected to the capacitor C42, the capacitor C45 and the resistor R38, wherein the capacitor C42 and the capacitor C45 are grounded, the resistor R38 is connected to the power supply VCC3_02, the reverse input end connected to the operational amplifier U7A is connected to the capacitor C41, the resistor R1 and the resistor R33, the other end of the resistor R1 is connected to the S0 port of the multiple switching unit, the other end of the resistor R33 is connected to the S1 port of the multiple switching unit, the other end of the capacitor C41 is connected to the S2 port of the multiple switching unit and the output end connected to the operational amplifier U7A at the same time; the output end of the operational amplifier U7A is connected to the capacitor C46, and the other end of the capacitor C46 is connected to the forward input end of the operational amplifier U7B.

[0056] The reverse input end of the operational amplifier U7B is connected to the resistor R43, the resistor R2, the resistor R36 and the capacitor C44, wherein the other end of the resistor R43 is connected to the capacitor C48, the other end of the capacitor C48 is grounded; the other end of the resistor R2 is connected to the S3 port of the multiple switching unit; the other end of the resistor R36 is connected to the S4 port of the multiple switching unit; the other end of the capacitor C44 is connected to the S5 port of the multiple switching unit and the output end of the operational amplifier U7B at the same time.

[0057] The output end of the operational amplifier U7B is connected to the resistor R41, and the other end of the resistor R41 is connected to the input end Sig_receive0_02 of the filtering unit.

[0058] One end of the resistor R35 is connected to the capacitor C46, and the other end of the resistor R35 is connected to the resistor R34, the resistor R37 and the capacitor C43 at the same time, wherein the other end of the resistor R43 is connected to the power supply VCC3_02, the other end of the resistor R37 is grounded, and the other end of the capacitor C43 is grounded.

[0059] In the two-stage amplification unit, the operational amplifier U7A is a negative amplification of a first-stage operational amplifier, the resistor R1 and the resistor R33 are used to adjust the amplification multiple, and the resistor R40 and the resistor R42 at the forward input end of the operational amplifier are bias voltage resistors; the operational amplifier U7B is a negative amplification of a second-stage operational amplifier, the resistor R12 and the resistor R36 are used to adjust the amplification multiple, and the resistor R34 and the resistor R37 at the forward input end of the operational amplifier U7B are bias voltage resistors; the two-stage operational amplifiers are coupled through the capacitor C46.

[0060] This invention's transimpedance amplifier unit ensures an extremely high dynamic input range through two selectable transimpedance gain levels, flexibly adapting to various modulation and demodulation transimpedance amplification applications. It uses digital circuitry to switch resistors to achieve the operational amplifier's amplification factor, resulting in a small amplification factor at close range signals and a small dead zone. This invention's two-stage amplification unit amplifies signals over long distances, enabling long-distance transmission. This configuration eliminates the variation in the switching transistor's threshold voltage with the input signal, thus maintaining a low on-resistance throughout the entire operating signal range. Advantages over a single-channel switch include a peak input signal voltage swing equal to the full supply voltage and a more constant on-state impedance across the input signal range.

[0061] To address the issue of signal susceptibility to fixed-frequency interference, a two-stage amplification process is employed, followed by a two-stage filter to remove interference. The receiving signal uses a high-pass filter in the first stage, allowing signals with frequencies greater than 0.05 Hz to pass through. The second stage uses a low-pass filter, allowing signals with frequencies below 100 Hz to pass through, effectively suppressing various fixed-frequency interferences and limiting the effective signal to a specific range.

[0062] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

[0063] Furthermore, it should be noted that if any directional indication (such as up, down, left, right, front, back, etc.) is involved in the embodiments of this utility model, the directional indication is only used to explain the relative positional relationship and movement of each component in a specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0064] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, in the embodiments of this utility model, "multiple" refers to two or more. Moreover, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

Claims

1. A precision conditioning circuit for pulsed laser ranging echo signals, characterized in that, include: Filter circuit unit, multiplier switching unit, operational amplifier circuit unit; Among them, the filter power supply unit is connected to the single-channel operational amplifier unit, and the single-channel operational amplifier unit is connected to the operational amplifier circuit unit; The multiple switching unit includes: a first-channel switching unit and a second-channel switching element; The first switching circuit unit includes: capacitors C4 and C5, high-speed digital switching chip U1A, and high-speed digital switching chip U3A; The high-speed digital switch chip U1A includes port X, port Y, power supply terminal, and CNTL signal terminal. Port X serves as the SO port of the multiple switching unit, port Y serves as the S2 port of the multiple switching unit, and the power supply terminal is connected to the voltage source VCC3_02 and the power supply terminal of the high-speed digital switch chip U3A. The high-speed digital switch chip U3A includes port X, port Y, power supply terminal, and CNTL signal terminal, wherein port X serves as the S1 port of the multiple switching unit, and port Y serves as the S2 port of the multiple switching unit. Capacitors C4 and C5 are both connected to the power supply terminal of the high-speed digital switching chip U1A, and the other end of capacitors C4 and C5 is grounded. The second switching circuit unit includes: capacitors C8 and C9, high-speed digital switching chip U4A and high-speed digital switching chip U5A; The high-speed digital switch chip U4A includes port X, port Y, power supply terminal, and CNTL signal terminal. Port X serves as the S3 port of the multiple switching unit, port Y serves as the S5 port of the multiple switching unit, and the power supply terminal is connected to the voltage source VCC3_02 and the power supply terminal of the high-speed digital switch chip U3A. The high-speed digital switch chip U5A includes port X, port Y, power supply terminal, and CNTL signal terminal, wherein port X serves as the S4 port of the multiple switching unit, and port Y serves as the S5 port of the multiple switching unit. Capacitors C8 and C9 are both connected to the power supply terminal of the high-speed digital switching chip U1A, and the other end of capacitors C8 and C9 is grounded.

2. The precision conditioning circuit for pulsed laser ranging echo signal as described in claim 1, characterized in that, The filter circuit unit includes: operational amplifier U2A and operational amplifier U2B; The operational amplifier U2A has its inverting input and output connected, and its non-inverting input connected to capacitor C3 and resistor R7, with the other end of resistor R7 grounded. Capacitor C3 is also connected to capacitor C2 and resistor R4, with the other end of capacitor C3 serving as the input terminal Sig_receive0_02, and the other end of resistor R4 connected to the output terminal of operational amplifier U2A. The output terminal of operational amplifier U2A is connected to resistor R6. Resistor R6 is also connected to resistor R5 and capacitor C1, with the other end of capacitor C1 connected to the output terminal of operational amplifier U2B, and the other end of resistor R5 connected to capacitor C7 and the non-inverting input terminal of operational amplifier U2B. The other end of capacitor C7 is grounded. The operational amplifier U2A has its inverting input and output connected, with the output terminal of operational amplifier U2A serving as the output terminal Sig_receive_02 of the filter element.

3. The precision conditioning circuit for pulsed laser ranging echo signal as described in claim 1, characterized in that, The operational amplifier circuit unit includes a transimpedance amplifier unit and a two-stage amplifier unit. The output terminal of the transimpedance amplifier unit is connected to the input terminal of the two-stage amplifier unit. The transimpedance amplifier unit includes: transistors Q3 and Q4, and avalanche diode U6; The negative terminal of the avalanche diode U6 is connected to both resistor R29 and capacitor C39. The other end of capacitor C39 is grounded. The other end of resistor R29 is connected to both resistor R30 and capacitor C40. The other end of capacitor C40 is grounded. The other end of resistor R30 is connected to power supply VCC_H_02. The avalanche diode U6's positive terminal is connected to both resistor R25 and the base of transistor Q3. The emitter of transistor Q3 is connected to both resistor R31 and the base of transistor Q4. The other end of resistor R31 is grounded. The collector of transistor Q3 is connected to resistor R26. The emitter of transistor Q4 is grounded. The collector of transistor Q4 is connected to both resistor R28 and resistor R25, serving as the signal output terminal of the transimpedance amplifier unit. The other end of resistor R28 is connected to the collector of transistor Q3. Capacitors C37 and C38 are connected between resistors R28 and R26. The other ends of capacitors C37 and C38 are grounded.

4. The precision conditioning circuit for pulsed laser ranging echo signal as described in claim 3, characterized in that, The two-stage amplification unit includes: operational amplifier U7A and operational amplifier U7B; The output of the transimpedance amplifier unit is connected to the inverting input of operational amplifier U7A. The non-inverting input of operational amplifier U7A is connected to resistors R42 and R40 and capacitor C47. The other ends of resistors R42 and C47 are grounded, and the other end of resistor R40 is connected to power supply VCC3_02. The negative input of the power supply of operational amplifier U7A is grounded. The positive input of the power supply of operational amplifier U7A is connected to capacitors C42 and C45 and resistor R38, where capacitors C42 and C45 are grounded, and resistor R38... Connect power supply VCC3_02. Connect capacitor C41, resistor R1, and resistor R33 to the inverting input terminal of operational amplifier U7A. Connect the other end of resistor R1 to port S0 of the multiplier switching unit, and the other end of resistor R33 to port S1 of the multiplier switching unit. Connect the other end of capacitor C41 to both port S2 of the multiplier switching unit and the output terminal of operational amplifier U7A. Connect capacitor C46 to the output terminal of operational amplifier U7A, and connect the other end of capacitor C46 to the non-inverting input terminal of operational amplifier U7B. The inverting input of operational amplifier U7B is connected to resistors R43, R2, R36, and capacitor C44. The other end of resistor R43 is connected to capacitor C48, and the other end of capacitor C48 is grounded. The other end of resistor R2 is connected to port S3 of the multiplier switching unit. The other end of resistor R36 is connected to port S4 of the multiplier switching unit. The other end of capacitor C44 is connected to both port S5 of the multiplier switching unit and the output of operational amplifier U7B. The output terminal of operational amplifier U7B is connected to resistor R41, and the other end of resistor R41 is connected to the input terminal Sig_receive0_02 of the filter unit. One end of resistor R35 is connected to capacitor C46, ​​and the other end is connected to resistor R34, resistor R37 and capacitor C43. The other end of resistor R43 is connected to power supply VCC3_02, the other end of resistor R37 is grounded, and the other end of capacitor C43 is grounded.

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