阅读说明：本技术 一种应用于激光测云雷达的信号采集电路 (Signal acquisition circuit applied to laser cloud detection radar ) 是由 蔡震 李琮 陈�峰 于 2020-12-01 设计创作，主要内容包括：本发明公开了一种应用于激光测云雷达的信号采集电路,属于信号采集电路技术领域,所述电源转换电路电性连接APD接收模块、跨阻放大电路和可变增益放大电路,所述APD接收模块电性连接温度监控电路,所述温度监控电路电性连接IIC总线接口,所述APD接收模块电性连接跨阻放大电路,所述跨阻放大电性连接可变增益放大电路,所述可变增益放大电路电性连接SPI总线接口和信号输出接口,将APD工作电压信息保存在数据存储器中,提高了模块之间的互换性,提高了工作状态的稳定性,同时多级可变增益功能的实现,保证了对不同信号幅度的适应性。(The invention discloses a signal acquisition circuit applied to a laser cloud detection radar, which belongs to the technical field of signal acquisition circuits, wherein a power supply conversion circuit is electrically connected with an APD (avalanche photo diode) receiving module, a transimpedance amplifier circuit and a variable gain amplifier circuit, the APD receiving module is electrically connected with a temperature monitoring circuit, the temperature monitoring circuit is electrically connected with an IIC (inter-integrated circuit) bus interface, the APD receiving module is electrically connected with the transimpedance amplifier circuit, the transimpedance amplifier circuit is electrically connected with the variable gain amplifier circuit, the variable gain amplifier circuit is electrically connected with an SPI (serial peripheral interface) bus interface and a signal output interface, APD working voltage information is stored in a data memory, interchangeability between modules is improved, stability of a working state is improved, and meanwhile, adaptability to different signal amplitudes is ensured due to the realization of a multi-stage variable gain function.)

1. The utility model provides a be applied to signal acquisition circuit of laser cloud radar which characterized in that: the system comprises a power supply conversion circuit, an APD receiving module, a temperature monitoring circuit, a trans-impedance amplifying circuit, a variable gain amplifying circuit, a signal output interface, a temperature monitoring circuit, an IIC bus interface and an SPI bus interface;

the power supply conversion circuit is used for carrying out voltage reduction conversion on external input voltage and supplying power to the APD receiving module, the trans-resistance amplifying circuit and the multistage variable gain amplifier circuit;

the APD receiving module is used for setting the APD working voltage and dynamically adjusting the APD amplification gain according to the external environment temperature;

the temperature monitoring circuit is used for transmitting the environmental temperature information to the external main control circuit through a data bus;

the transimpedance amplification circuit is used for converting a current signal received by the APD into a voltage signal;

the variable gain amplifying circuit is used for amplifying analog quantity data of photoelectric conversion, and ensuring that the amplitude of an output signal is always within a range allowed by a system;

the APD receiving module is electrically connected with the temperature monitoring circuit, the temperature monitoring circuit is electrically connected with the IIC bus interface, the APD receiving module is electrically connected with the transimpedance amplifier circuit, the transimpedance amplifier circuit is electrically connected with the variable gain amplifier circuit, and the variable gain amplifier circuit is electrically connected with the SPI bus interface and the signal output interface.

2. The signal acquisition circuit applied to the laser cloud radar according to claim 1, wherein: the power conversion circuit comprises a voltage stabilizer U7, the 3 terminal of the voltage stabilizer U7 is electrically connected with the anode of a pole capacitor CH1, the negative pole of the active capacitance CH1 is grounded, the 3 terminal of the voltage regulator U7 inputs +12VDC power, the 3 terminal of the voltage stabilizer U7 is also electrically connected with the cathode of a diode D23, the anode of the diode D23 is electrically connected with the cathode of a diode D22, the anode of the diode D22 is electrically connected to the 1 terminal of the regulator U7, the 2 terminal of the regulator U7 is electrically connected to one end of the resistor R216, the other end of the resistor R216 is electrically connected with the anode of a pole capacitor CT4, the cathode of the pole capacitor CT4 is grounded, the 1 terminal of the voltage stabilizer U7 is electrically connected with one end of the resistor R215, the other end of the resistor R215 is grounded, the other end of the resistor R216 is electrically connected with one end of the resistor R215, and the 2-terminal of the voltage stabilizer U7 outputs 5.1V power.

3. The signal acquisition circuit applied to the laser cloud radar according to claim 2, wherein: the temperature monitoring circuit comprises a digital temperature sensor U1 and a chip U13, the 4-terminal grounding of the digital temperature sensor U1, the 8-terminal electric connection one end of a capacitor C150 of the digital temperature sensor U1, the other end grounding of the capacitor C150, the 8-terminal electric connection power supply 3.3V of the digital temperature sensor U1, the 7, 6 and 5-terminal grounding of the digital temperature sensor U1, the 1-terminal of the chip U13 and the 8-terminal electric connection of the digital temperature sensor U1, the 2, 3 and 4-terminal grounding of the chip U13, the 8-terminal electric connection power supply 3.3V of the chip U13, the 8-terminal of the chip U13 is also electrically connected with one end of the capacitor C151, and the other end grounding of the capacitor C151.

4. The signal acquisition circuit applied to the laser cloud radar according to claim 3, wherein: the variable gain amplifying circuit comprises a linear amplifier U2, wherein the terminal 2 of the linear amplifier U2 is electrically connected with one end of a resistor R81, one end of a capacitor C73, the anode of a light-emitting diode D7 and one end of a resistor R221, the other end of the resistor R221 is grounded, the cathode of the light emitting diode D7 is electrically connected with one end of the resistor R80 and grounded, the other end of the resistor R80 is electrically connected with one end of the resistor R79, the other end of the resistor R79 is electrically connected with one end of the resistor R78, the other end of the resistor R221 is grounded, the 3 terminal of the linear amplifier U2 is grounded, the 4 terminal of the linear amplifier U2 is electrically connected with the 5 terminal of the linear amplifier U2, one end of the capacitor C137, the cathode of the polar capacitor CT1 and one end of the resistor R93, the other end of the resistor R93 is connected with a power supply, and the anode of the active capacitor CT1 is connected with the other end of the capacitor C137 and is grounded.

5. The signal acquisition circuit applied to the laser cloud radar according to claim 4, wherein: the terminals 8 and 7 of the linear amplifier U2 are electrically connected with one end of a capacitor C136, the anode of the polar capacitor CT2 and one end of a resistor R2, the terminal 6 of the linear amplifier U2 is electrically connected with one end of a capacitor C74, one end of a resistor R83, the terminal 5 of an operational amplifier U12B and the other end of a resistor R81, the other end of the resistor C73 is electrically connected with the other end of the resistor C74, the other end of the capacitor C136 is grounded with the cathode of the polar capacitor CT2, the other end of the resistor R2 is connected with a power supply, the other end of the resistor R83 is electrically connected with one end of a capacitor C75 and one end of a resistor R84, the other end of the capacitor C75 is grounded, the terminal 6 of the operational amplifier U12B is electrically connected with one end of a resistor R65, one end of a resistor R66 and the S pole of a field effect transistor Q5, the other end of the resistor R65 is electrically connected with one end of a resistor R64, one end of a resistor, resistance R62's other end electric connection field effect transistor Q4's G utmost point, field effect transistor Q4's G utmost point electric connection diode, field effect transistor Q4's D utmost point electric connection resistance R63's one end, field effect transistor Q5's D utmost point power, field effect transistor Q5's G utmost point electric connection operational amplifier U12B's 7 wiring end, operational amplifier U12B's 4 wiring end electric connection electric capacity C139's one end and power, electric capacity C139's other end ground connection, operational amplifier U12B's 8 wiring end electric connection power and electric capacity C138's one end, electric capacity C138's other end ground connection.

6. The signal acquisition circuit applied to the laser cloud radar according to claim 1, wherein: the other end of the resistor R63 is electrically connected with the terminal 3 of the operational amplifier U12A and one end of the capacitor C132, the other end of the capacitor C132 is grounded, the terminal 4 of the operational amplifier U12A is connected with a power supply, the terminal 8 of the operational amplifier U12A is connected with the power supply, the terminal 1 of the operational amplifier U12A and the terminal 2 of the operational amplifier U12A are both electrically connected with the terminal 4 of the voltage control type amplifier U8, the terminal 3 of the voltage control type amplifier U8 is electrically connected with the terminal 6 of the linear amplifier U2, the terminal 2 of the voltage control type amplifier U8 is electrically connected with one end of the resistor R91 and one end of the resistor R90, the other end of the resistor R91 is connected with the power supply, the other end of the resistor R90 is connected with one end of the capacitor C140 and the terminal 2 of the voltage control type amplifier U8 is electrically connected with the other end of the capacitor C140, the terminal 5 of the voltage control type amplifier U8 is electrically connected, the other end of the capacitor C158 is grounded, the 5 terminal of the voltage control type amplifier U8 is further electrically connected to one end of a resistor R222 and the D electrode of a fet Q1, the other end of the resistor R222 is electrically connected to one end of a resistor R59, one end of a resistor R60 and the 7 terminal of a voltage control type amplifier U8, the other end of the resistor R59 is electrically connected to the D electrode of a fet Q2, the G electrode of the fet Q2 is electrically connected to one end of a diode D4 and one end of a resistor R56, the S electrode of the fet Q2 is electrically connected to one end of a capacitor C77 and the 6 terminal of an operational amplifier U9B, and the other end of a resistor R56 is electrically connected to the 5 terminal of an operational amplifier U9B, the 2 terminal of an operational amplifier U11A and one end of a resistor R219.

7. The signal acquisition circuit applied to the laser cloud radar according to claim 6, wherein: the operational amplifier U9B has 6 electrically connected to one end of C77, the other end of the capacitor C77 is electrically connected to the 7 terminal of the operational amplifier U9B, the 8 terminal of the operational amplifier U9B is electrically connected to one end of the capacitor C142 and a power supply, the other end of the capacitor C142 is grounded, the 3 terminal of the operational amplifier U11A is electrically connected to the 18 terminal of the digital controlled variable gain amplifier U10, one end of the capacitor C154, the 8 terminal of the operational amplifier U11A is electrically connected to one end of the capacitor C144, the 1 terminal of the operational amplifier U11A is electrically connected to one end of a resistor R58, the other end of the resistor R58 is grounded, the 7 terminal of the operational amplifier U9B is electrically connected to the 3 terminal of the operational amplifier U9A, the 2 terminal of the operational amplifier U9A is electrically connected to one end of a resistor R5, the other end of the resistor R5 is electrically connected to one end of a resistor R95, the other end electrical connection resistance R57 ' S one end and the one end of electric capacity C71 of resistance R95, the other end of resistance R57 and the other end electrical connection resistance R219 ' S of electric capacity C71 the other end, the other end electrical connection operational amplifier U11B ' S7 terminal of resistance R95, the S utmost point of field effect transistor Q1 is connected to 2 terminal electrical connection of operational amplifier U9A, the G utmost point electrical connection R87 ' S one end of field effect transistor Q1, the 1 terminal of the other end electrical connection resistance R88 of resistance R87 and operational amplifier U9A, the D terminal electrical connection resistance R222 ' S one end of field effect transistor Q1.

8. The signal acquisition circuit applied to the laser cloud radar according to claim 7, wherein: the terminal 19 of the digital control type variable gain amplifier U10 is electrically connected with the other end of the resistor R60, the terminal 14 of the digital control type variable gain amplifier U10 is electrically connected with one end of the capacitor C155, the other end of the capacitor C155 is grounded, the terminal 5 of the digital control type variable gain amplifier U10 is electrically connected with one end of the resistor R72 and one end of the capacitor C156, the terminal 6 of the digital control type variable gain amplifier U10 is electrically connected with one end of the resistor R73, the terminal 10 of the digital control type variable gain amplifier U10 is electrically connected with the J2, the terminals 7, 8 and 9 of the digital control type variable gain amplifier U10 are electrically connected with one end of the capacitor C147, one end of the capacitor C149 and one end of the capacitor C148, the other end of the capacitor C147 is grounded, and the other end of the capacitor C149 is grounded.

Technical Field

The invention relates to a signal acquisition circuit, in particular to a signal acquisition circuit applied to a laser cloud finding radar, and belongs to the technical field of signal acquisition circuits.

Background

The basic principle of the laser cloud-measuring radar system is that a laser at a transmitting end in the cloud-measuring radar is controlled to transmit short pulse laser with a certain period, the laser can be reflected back to a receiving end of the cloud-measuring radar after reaching a cloud base, and information related to the height of the cloud base and a cloud layer is obtained by performing post-processing on a received signal at the receiving end.

The signal information that cloud radar can obtain mainly depends on that signal acquisition circuit can obtain analog signal, and the higher the signal to noise ratio, higher sensitivity, the more the cloud cover signal that can obtain after adopting specific algorithm in the main control panel can be, the more is favorable to the meteorological information of analysis cloud cover.

The signal acquisition circuit applied to the laser cloud-measuring radar in the prior art is narrow in working environment temperature range, incapable of dynamically adjusting gain and low in signal-to-noise ratio, so that the signal acquisition circuit applied to the laser cloud-measuring radar is designed to improve the problems.

Disclosure of Invention

The invention mainly aims to provide a signal acquisition circuit applied to a laser cloud-finding radar, which stores APD working voltage information in a data memory, improves interchangeability between modules and stability of a working state, and ensures adaptability to different signal amplitudes by realizing a multi-stage variable gain function.

The purpose of the invention can be achieved by adopting the following technical scheme:

a signal acquisition circuit applied to a laser cloud measuring radar comprises a power supply conversion circuit, an APD receiving module, a temperature monitoring circuit, a trans-impedance amplifying circuit, a variable gain amplifying circuit, a signal output interface, a temperature monitoring circuit, an IIC bus interface and an SPI bus interface;

the power supply conversion circuit is used for carrying out voltage reduction conversion on external input voltage and supplying power to the APD receiving module, the trans-resistance amplifying circuit and the multistage variable gain amplifier circuit;

the APD receiving module is used for setting the APD working voltage and dynamically adjusting the APD amplification gain according to the external environment temperature;

the temperature monitoring circuit is used for transmitting the environmental temperature information to the external main control circuit through a data bus;

the transimpedance amplification circuit is used for converting a current signal received by the APD into a voltage signal;

the variable gain amplifying circuit is used for amplifying analog quantity data of photoelectric conversion, and ensuring that the amplitude of an output signal is always within a range allowed by a system;

the APD receiving module is electrically connected with the temperature monitoring circuit, the temperature monitoring circuit is electrically connected with the IIC bus interface, the APD receiving module is electrically connected with the transimpedance amplifier circuit, the transimpedance amplifier circuit is electrically connected with the variable gain amplifier circuit, and the variable gain amplifier circuit is electrically connected with the SPI bus interface and the signal output interface.

Preferably, the power conversion circuit includes a voltage regulator U7, the 3 terminal of the voltage regulator U7 is electrically connected to the anode of a terminal capacitor CH1, the cathode of the terminal capacitor CH1 is grounded, the 3 terminal of the voltage regulator U7 inputs a +12VDC power, the 3 terminal of the voltage regulator U7 is also electrically connected to the cathode of a diode D23, the anode of the diode D23 is electrically connected to the cathode of a diode D22, the anode of a diode D22 is electrically connected to the 1 terminal of the voltage regulator U7, the 2 terminal of the voltage regulator U7 is electrically connected to one end of a resistor R216, the other end of the resistor R216 is electrically connected to the anode of a terminal capacitor CT4, the cathode of the terminal capacitor CT4 is grounded, the 1 terminal of the voltage regulator U7 is electrically connected to one end of a resistor R215, the other end of the resistor R215 is grounded, and the other end of the resistor R216 is electrically connected to one end of the resistor R215, the 2-terminal of the voltage regulator U7 outputs 5.1V power.

Preferably, the temperature monitoring circuit includes a digital temperature sensor U1 and a chip U13, the 4-terminal ground of the digital temperature sensor U1, the 8-terminal electrical connection of the digital temperature sensor U1 is connected to one end of a capacitor C150, the other end of the capacitor C150 is connected to ground, the 8-terminal electrical connection of the digital temperature sensor U1 is connected to 3.3V, the 7, 6 and 5-terminal ground of the digital temperature sensor U1, the 1-terminal of the chip U13 is connected to the 8-terminal electrical connection of the digital temperature sensor U1, the 2, 3 and 4-terminal ground of the chip U13, the 8-terminal electrical connection of the chip U13 is connected to 3.3V, the 8-terminal of the chip U13 is also connected to one end of a capacitor C151, and the other end of the capacitor C151 is connected to ground.

Preferably, the variable gain amplifying circuit comprises a linear amplifier U2, wherein the terminal 2 of the linear amplifier U2 is electrically connected with one end of a resistor R81, one end of a capacitor C73, the anode of a light emitting diode D7 and one end of a resistor R221, the other end of the resistor R221 is grounded, the cathode of the light emitting diode D7 is electrically connected with one end of the resistor R80 and grounded, the other end of the resistor R80 is electrically connected with one end of the resistor R79, the other end of the resistor R79 is electrically connected with one end of the resistor R78, the other end of the resistor R221 is grounded, the 3 terminal of the linear amplifier U2 is grounded, the 4 terminal of the linear amplifier U2 is electrically connected with the 5 terminal of the linear amplifier U2, one end of the capacitor C137, the cathode of the polar capacitor CT1 and one end of the resistor R93, the other end of the resistor R93 is connected with a power supply, and the anode of the active capacitor CT1 is connected with the other end of the capacitor C137 and is grounded.

Preferably, the terminals 8 and 7 of the linear amplifier U2 are electrically connected to one end of a capacitor C136, the anode of the polar capacitor CT2 and one end of a resistor R2, the terminal 6 of the linear amplifier U2 is electrically connected to one end of a capacitor C74, one end of a resistor R83, the terminal 5 of an operational amplifier U12B and the other end of a resistor R81, the other end of the resistor C73 is electrically connected to the other end of the resistor C74, the other end of the capacitor C136 and the cathode of the polar capacitor CT2 are grounded, the other end of the resistor R2 is connected to a power supply, the other end of the resistor R83 is electrically connected to one end of a capacitor C75 and one end of a resistor R84, the other end of the capacitor C75 is grounded, the terminal 6 of the operational amplifier U12B is electrically connected to one end of a resistor R65, one end of a resistor R66 and the S pole of a fet Q5, the other end of the resistor R65 is electrically connected to one end of a resistor R64, one end of a resistor R6353, resistance R62's other end electric connection field effect transistor Q4's G utmost point, field effect transistor Q4's G utmost point electric connection diode, field effect transistor Q4's D utmost point electric connection resistance R63's one end, field effect transistor Q5's D utmost point power, field effect transistor Q5's G utmost point electric connection operational amplifier U12B's 7 wiring end, operational amplifier U12B's 4 wiring end electric connection electric capacity C139's one end and power, electric capacity C139's other end ground connection, operational amplifier U12B's 8 wiring end electric connection power and electric capacity C138's one end, electric capacity C138's other end ground connection.

Preferably, the other end of the resistor R63 is electrically connected to the terminal 3 of the operational amplifier U12A and the one end of the capacitor C132, the other end of the capacitor C132 is grounded, the terminal 4 of the operational amplifier U12A is connected to a power supply, the terminal 8 of the operational amplifier U12A is connected to the power supply, the terminal 1 of the operational amplifier U12A and the terminal 2 of the operational amplifier U12A are both electrically connected to the terminal 4 of the voltage-controlled amplifier U8, the terminal 3 of the voltage-controlled amplifier U8 is electrically connected to the terminal 6 of the linear amplifier U2, the terminal 2 of the voltage-controlled amplifier U8 is electrically connected to the one end of the resistor R91 and the one end of the resistor R90, the other end of the resistor R91 is connected to the power supply, the other end of the resistor R90 is connected to the one end of the capacitor C140, and the terminal 2 of the voltage-controlled amplifier U8 is electrically connected to the, the 5 terminal of the voltage control type amplifier U8 is electrically connected with one end of a capacitor C158, the other end of the capacitor C158 is grounded, the 5 terminal of the voltage control type amplifier U8 is also electrically connected with one end of a resistor R222 and the D pole of a field effect transistor Q1, the other end of the resistor R222 is electrically connected with one end of a resistor R59, one end of a resistor R60 and the 7 terminal of a voltage control type amplifier U8, the other end of the resistor R59 is electrically connected with the D pole of a field effect transistor Q2, the G pole of the field effect transistor Q2 is electrically connected with one end of a diode D4 and a resistor R56, the S pole of the field effect transistor Q2 is electrically connected with one end of the capacitor C77 and the 6 terminal of an operational amplifier U9B, and the other end of the resistor R56 is electrically connected with the 5 terminal of the operational amplifier U9B, the 2 terminal of the operational amplifier U11A and.

Preferably, the operational amplifier U9B has a terminal 6 electrically connected to a terminal C77, the other terminal C77 electrically connected to a terminal 7 of the operational amplifier U9B, the terminal 8 of the operational amplifier U9B electrically connected to a terminal C142 and a power supply, the other terminal of the capacitor C142 grounded, the terminal 3 of the operational amplifier U11A electrically connected to a terminal 18 of the digitally controlled variable gain amplifier U10, the terminal C154 has a terminal 8 of the operational amplifier U11A electrically connected to a terminal C144, the terminal 1 of the operational amplifier U11A electrically connected to a terminal R58, the other terminal R58 grounded, the terminal 7 of the operational amplifier U9B electrically connected to a terminal 3 of the operational amplifier U9A, the terminal 2 of the operational amplifier U9A electrically connected to a terminal R5, the other terminal R5 electrically connected to a terminal R95, the other end electrical connection resistance R57 ' S one end and the one end of electric capacity C71 of resistance R95, the other end of resistance R57 and the other end electrical connection resistance R219 ' S of electric capacity C71 the other end, the other end electrical connection operational amplifier U11B ' S7 terminal of resistance R95, the S utmost point of field effect transistor Q1 is connected to 2 terminal electrical connection of operational amplifier U9A, the G utmost point electrical connection R87 ' S one end of field effect transistor Q1, the 1 terminal of the other end electrical connection resistance R88 of resistance R87 and operational amplifier U9A, the D terminal electrical connection resistance R222 ' S one end of field effect transistor Q1.

Preferably, the terminal 19 of the digitally controlled variable gain amplifier U10 is electrically connected to the other end of the resistor R60, the terminal 14 of the digitally controlled variable gain amplifier U10 is electrically connected to one end of a capacitor C155, the other end of the capacitor C155 is grounded, the terminal 5 of the digital control type variable gain amplifier U10 is electrically connected with one end of the resistor R72 and one end of the capacitor C156, the terminal 6 of the digital control type variable gain amplifier U10 is electrically connected with one end of a resistor R73, the terminal 10 of the digital control type variable gain amplifier U10 is electrically connected with J2, the terminals 7, 8 and 9 of the digital control type variable gain amplifier U10 are electrically connected with one end of a capacitor C147, one end of a capacitor C149 and one end of a capacitor C148, the other end of the capacitor C147 is grounded, and the other ends of the capacitor C149 and the capacitor C148 are grounded.

The invention has the beneficial technical effects that:

the signal acquisition circuit applied to the laser cloud finding radar stores the APD working voltage information in the data memory, improves interchangeability among modules, improves stability of working states, and ensures adaptability to different signal amplitudes by realizing the function of multi-stage variable gain.

Drawings

FIG. 1 is a system diagram of a preferred embodiment of a signal acquisition circuit for a lidar in accordance with the present invention;

FIG. 2 is a power conversion circuit diagram of a preferred embodiment of a signal acquisition circuit for a laser cloud radar according to the present invention;

FIG. 3 is a temperature monitoring circuit diagram of a preferred embodiment of a signal acquisition circuit for a lidar in accordance with the present invention;

FIG. 4 is a circuit diagram of a first portion of a TIA and constant gain amplification circuit of a preferred embodiment of a signal acquisition circuit for a laser cloud radar according to the present invention;

fig. 5 is a circuit diagram of a second part of the TIA and constant gain amplifier circuit according to a preferred embodiment of the signal acquisition circuit applied to the laser cloud radar.

Detailed Description

In order to make the technical solutions of the present invention more clear and definite for those skilled in the art, the present invention is further described in detail below with reference to the examples and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

As shown in fig. 1 to 5, the signal acquisition circuit applied to the laser cloud radar in this embodiment includes a power conversion circuit, an APD receiving module, a temperature monitoring circuit, a transimpedance amplifier circuit, a variable gain amplifier circuit, a signal output interface, a temperature monitoring circuit, an IIC bus interface, and an SPI bus interface;

the power supply conversion circuit is used for carrying out voltage reduction conversion on external input voltage and supplying power to the APD receiving module, the trans-resistance amplifying circuit and the multistage variable gain amplifier circuit;

the APD receiving module is used for setting the APD working voltage and dynamically adjusting the APD amplification gain according to the external environment temperature;

the temperature monitoring circuit is used for transmitting the environmental temperature information to the external main control circuit through a data bus;

the transimpedance amplification circuit is used for converting a current signal received by the APD into a voltage signal;

the variable gain amplifying circuit is used for amplifying analog quantity data of photoelectric conversion, and ensuring that the amplitude of an output signal is always within a range allowed by a system;

the APD receiving module is electrically connected with the temperature monitoring circuit, the temperature monitoring circuit is electrically connected with the IIC bus interface, the APD receiving module is electrically connected with the transimpedance amplifier circuit, the transimpedance amplifier circuit is electrically connected with the variable gain amplifier circuit, and the variable gain amplifier circuit is electrically connected with the SPI bus interface and the signal output interface.

The data in the data memory is read, and the working voltage of the APD module is set, so that the consistency of the amplification gain factor in the whole temperature range is ensured;

the trans-impedance amplifier circuit converts an output current signal of the APD module into a voltage signal;

the circuit system dynamically adjusts the parameters of the multistage variable gain amplifier circuit according to the amplitude of the converted voltage signal, and the correctness of the output voltage signal is ensured.

In this embodiment, the power conversion circuit includes a voltage regulator U7, the 3 terminal of the voltage regulator U7 is electrically connected to the anode of the electrode capacitor CH1, the cathode of the electrode capacitor CH1 is grounded, the 3 terminal of the voltage regulator U7 inputs +12VDC power, the 3 terminal of the voltage regulator U7 is also electrically connected to the cathode of the diode D23, the anode of the diode D23 is electrically connected to the cathode of the diode D22, the anode of the diode D22 is electrically connected to the 1 terminal of the voltage regulator U7, the 2 terminal of the voltage regulator U7 is electrically connected to one end of a resistor R216, the other end of the resistor R216 is electrically connected to the anode of the electrode capacitor CT4, the cathode of the electrode capacitor CT4 is grounded, the 1 terminal of the voltage regulator U7 is electrically connected to one end of a resistor R215, the other end of the resistor R215 is grounded, and the other end of the resistor R216 is electrically connected to one end of the resistor R215, the 2-terminal of the voltage regulator U7 outputs 5.1V power.

In this embodiment, the temperature monitoring circuit includes digital temperature sensor U1 and chip U13, digital temperature sensor U1's 4 terminals are grounded, digital temperature sensor U1's 8 terminals are electrically connected with one end of electric capacity C150, electric capacity C150's the other end is grounded, digital temperature sensor U1's 8 terminals are electrically connected with power 3.3V, digital temperature sensor U1's 7, 6 and 5 terminals are grounded, chip U13's 1 terminal with digital temperature sensor U1's 8 terminals are electrically connected, chip U13's 2, 3 and 4 terminals are grounded, chip U13's 8 terminals are electrically connected with power 3.3V, chip U13's 8 terminals are still electrically connected with one end of electric capacity C151, the other end of electric capacity C151 is grounded.

In this embodiment, the variable gain amplifier circuit includes a linear amplifier U2, the 2-terminal of the linear amplifier U2 is electrically connected to one end of a resistor R81, one end of a capacitor C73, the anode of a light emitting diode D7 and one end of a resistor R221, the other end of the resistor R221 is grounded, the cathode of the light emitting diode D7 is electrically connected with one end of the resistor R80 and grounded, the other end of the resistor R80 is electrically connected with one end of the resistor R79, the other end of the resistor R79 is electrically connected with one end of the resistor R78, the other end of the resistor R221 is grounded, the 3 terminal of the linear amplifier U2 is grounded, the 4 terminal of the linear amplifier U2 is electrically connected with the 5 terminal of the linear amplifier U2, one end of the capacitor C137, the cathode of the polar capacitor CT1 and one end of the resistor R93, the other end of the resistor R93 is connected with a power supply, and the anode of the active capacitor CT1 is connected with the other end of the capacitor C137 and is grounded.

In this embodiment, the terminals 8 and 7 of the linear amplifier U2 are electrically connected to one end of the capacitor C136, the anode of the polar capacitor CT2 and one end of the resistor R2, the terminal 6 of the linear amplifier U2 is electrically connected to one end of the capacitor C74, one end of the resistor R83, the terminal 5 of the operational amplifier U12B and the other end of the resistor R81, the other end of the resistor C73 is electrically connected to the other end of the resistor C74, the other end of the capacitor C136 is grounded to the cathode of the polar capacitor CT2, the other end of the resistor R2 is connected to the power supply, the other end of the resistor R83 is electrically connected to one end of the capacitor C75 and one end of the resistor R84, the other end of the capacitor C75 is grounded, the terminal 6 of the operational amplifier U12B is electrically connected to one end of the resistor R65, one end of the resistor R66 and the S pole of the fet Q5, and the other end of the resistor R65 is electrically connected, One end of resistor R62 and the S pole of field effect transistor Q4, the G pole of field effect transistor Q4 is connected to the other end electrical connection of resistor R62, the G pole electrical connection diode of field effect transistor Q4, the one end of D pole electrical connection resistance R63 of field effect transistor Q4, the D pole power connection of field effect transistor Q5, the 7 terminal of operational amplifier U12B is connected to the G pole electrical connection of field effect transistor Q5, the one end and the power of electric capacity C139 are connected to the 4 terminal electrical connection of operational amplifier U12B, the other end ground connection of electric capacity C139, the 8 terminal electrical connection power of operational amplifier U12B and the one end of electric capacity C138, the other end ground connection of electric capacity C138.

In this embodiment, the other end of the resistor R63 is electrically connected to the terminal 3 of the operational amplifier U12A and the one end of the capacitor C132, the other end of the capacitor C132 is grounded, the terminal 4 of the operational amplifier U12A is connected to a power supply, the terminal 8 of the operational amplifier U12A is connected to the power supply, the terminal 1 of the operational amplifier U12A and the terminal 2 of the operational amplifier U12A are both electrically connected to the terminal 4 of the voltage-controlled amplifier U8, the terminal 3 of the voltage-controlled amplifier U8 is electrically connected to the terminal 6 of the linear amplifier U2, the terminal 2 of the voltage-controlled amplifier U8 is electrically connected to the one end of the resistor R91 and the one end of the resistor R90, the other end of the resistor R91 is connected to the power supply, the other end of the resistor R90 is connected to the one end of the capacitor C140, and the terminal 2 of the voltage-controlled amplifier U8 is electrically connected to, the 5 terminal of the voltage control type amplifier U8 is electrically connected with one end of a capacitor C158, the other end of the capacitor C158 is grounded, the 5 terminal of the voltage control type amplifier U8 is also electrically connected with one end of a resistor R222 and the D pole of a field effect transistor Q1, the other end of the resistor R222 is electrically connected with one end of a resistor R59, one end of a resistor R60 and the 7 terminal of a voltage control type amplifier U8, the other end of the resistor R59 is electrically connected with the D pole of a field effect transistor Q2, the G pole of the field effect transistor Q2 is electrically connected with one end of a diode D4 and a resistor R56, the S pole of the field effect transistor Q2 is electrically connected with one end of the capacitor C77 and the 6 terminal of an operational amplifier U9B, and the other end of the resistor R56 is electrically connected with the 5 terminal of the operational amplifier U9B, the 2 terminal of the operational amplifier U11A and.

In this embodiment, the operational amplifier U9B has 6 electrically connected to one end of a capacitor C77, the other end of the capacitor C77 is electrically connected to the 7 terminal of the operational amplifier U9B, the 8 terminal of the operational amplifier U9B is electrically connected to one end of a capacitor C142 and a power supply, the other end of the capacitor C142 is grounded, the 3 terminal of an operational amplifier U11A is electrically connected to the 18 terminal of a digitally controlled variable gain amplifier U10, one end of the capacitor C154, the 8 terminal of the operational amplifier U11A is electrically connected to one end of a capacitor C144, the 1 terminal of the operational amplifier U11A is electrically connected to one end of a resistor R58, the other end of the resistor R58 is grounded, the 7 terminal of the operational amplifier U9B is electrically connected to the 3 terminal of an operational amplifier U9A, the 2 terminal of the operational amplifier U9A is electrically connected to one end of a resistor R5, and the other end of the resistor R5 is electrically connected to one end of a resistor, the other end electrical connection resistance R57 ' S one end and the one end of electric capacity C71 of resistance R95, the other end of resistance R57 and the other end electrical connection resistance R219 ' S of electric capacity C71 the other end, the other end electrical connection operational amplifier U11B ' S7 terminal of resistance R95, the S utmost point of field effect transistor Q1 is connected to 2 terminal electrical connection of operational amplifier U9A, the G utmost point electrical connection R87 ' S one end of field effect transistor Q1, the 1 terminal of the other end electrical connection resistance R88 of resistance R87 and operational amplifier U9A, the D terminal electrical connection resistance R222 ' S one end of field effect transistor Q1.

In this embodiment, the terminal 19 of the digitally controlled variable gain amplifier U10 is electrically connected to the other end of the resistor R60, the terminal 14 of the digitally controlled variable gain amplifier U10 is electrically connected to one end of a capacitor C155, the other end of the capacitor C155 is grounded, the terminal 5 of the digital control type variable gain amplifier U10 is electrically connected with one end of the resistor R72 and one end of the capacitor C156, the terminal 6 of the digital control type variable gain amplifier U10 is electrically connected with one end of a resistor R73, the terminal 10 of the digital control type variable gain amplifier U10 is electrically connected with J2, the terminals 7, 8 and 9 of the digital control type variable gain amplifier U10 are electrically connected with one end of a capacitor C147, one end of a capacitor C149 and one end of a capacitor C148, the other end of the capacitor C147 is grounded, and the other ends of the capacitor C149 and the capacitor C148 are grounded.

The above description is only for the purpose of illustrating the present invention and is not intended to limit the scope of the present invention, and any person skilled in the art can substitute or change the technical solution of the present invention and its conception within the scope of the present invention.