Integral conversion circuit based on atmospheric component detection

Abstract

The utility model relates to an electric energy conversion device, in particular to an integral conversion circuit based on atmospheric composition detection, which comprises a capacitor circuit, a high-precision voltage reference source and a high-precision analog-to-digital converter. In the capacitor circuit, an integrator receives a current signal of the high-voltage electrode, carries out integration processing and stores charges, and two ends of a capacitor are connected with the high-voltage electrode and a feedback path of the amplifier; the high-precision voltage reference source provides a reference voltage, the amplifier increases the voltage of an input signal and generates an output voltage, the voltage reference compares the reference voltage with the output voltage, and the feedback network adjusts the output voltage according to a comparison result; the high-precision analog-to-digital converter converts voltage signals at the two ends of the integrating capacitor into digital signals and outputs the digital signals. The integration precision and stability of weak current are improved, and the sensor can detect the concentration of volatile organic compounds more accurately and reliably.

Description

Technical Field

[0001] The utility model relates to the technical field of integrated circuits, in particular to an integral conversion circuit based on atmospheric component detection. Background Art

[0002] Air pollution monitoring refers to the process of observing the main pollutants in a region's atmosphere and evaluating the quality of the atmospheric environment. Air quality monitoring typically involves regularly monitoring a specified area using a few or a dozen representative sampling points, based on factors such as the region's size, the distribution of air pollution sources, meteorological conditions, and topography.

[0003] An integrator circuit makes its output signal proportional to the time-integrated value of its input signal. It is primarily used in waveform transformation, eliminating offset voltage in amplifier circuits, and performing integral compensation in feedback control. The integrator circuit is a widely used analog signal processing circuit. It is the basic unit of analog computers, used to simulate differential equations. It is also a crucial element commonly used in control and measurement systems, leveraging its charge and discharge processes to achieve time delay, timing, and various waveform generation. The integrator circuit outputs the integral of the input signal over a frequency range based on the circuit's time constant and the amplifier's bandwidth. An input signal is applied to the inverting input to invert the output relative to the input signal's extremes.

[0004] The DDC112 is a current-input A / D converter chip manufactured by Texas Instruments. It features a wide input range, high resolution (up to 20 bits), and a fast sampling speed (1.5 kHz), meeting the requirements of near-infrared spectroscopy data acquisition. The DDC112 primarily relies on capacitor integration to acquire the input current signal. When the DDC112 is operating, the integrating capacitor first charges VREF. As the DDC112 and the capacitor continue to integrate, the input current signal releases the capacitor's charge, causing the output voltage of the operational amplifier to decrease. When integration is complete, the input signal switches to the other terminal, where the internal voltage-input ADC measures the held value of VREF. This process repeats continuously and efficiently, continuously integrating the input signal and completing the A / D conversion of the current signal.

[0005] For example, the Chinese invention patent with announcement number CN114189246A discloses a current-voltage conversion circuit and method, an integrator, and an analog-to-digital converter. A current scaling control unit is configured between the input circuit unit and the output circuit unit of the current-voltage conversion circuit. The current scaling control unit can adaptively scale the input current according to the set current gear to obtain an intermediate current that meets the set current range. The output circuit unit converts the intermediate current into an output voltage signal. The current scaling control unit includes a preamplifier and a multi-stage current mirror branch. The multi-stage current mirror branch is configured with outputs of multiple current gears and can select a set current gear from the multiple current gears as needed. Thus, the input current is adaptively scaled by setting the number and width of the multi-stage current mirror branches. For a large current range from small current to large current, it is possible to obtain a reasonable output voltage while ensuring the high bandwidth performance of the current-voltage conversion circuit.

[0006] Conventional integration circuits currently suffer from low detection accuracy and poor stability for extremely small currents. To address these issues, this utility model proposes an integration and conversion circuit based on atmospheric composition detection. The circuit receives a weak current signal from a high-voltage electrode, integrates it through a capacitor, and then calibrates and stabilizes the integrated voltage signal using a high-precision voltage reference source. The signal is then converted to digital using a high-precision ADC, ultimately outputting a digitized current value. Utility Model Content

[0007] The purpose of the utility model is to overcome the problems of low detection accuracy and poor stability of extremely small current in the prior art, and to provide an integral conversion circuit based on atmospheric component detection.

[0008] In a first aspect, the utility model provides an integral conversion circuit based on atmospheric component detection, comprising a capacitor circuit, a high-precision voltage reference source, and a high-precision analog-to-digital converter;

[0009] In the capacitor circuit, the integrator receives the weak current signal of the high-voltage electrode, performs integration processing and stores charge, and the two ends of the capacitor are connected to the high-voltage electrode and the feedback path of the amplifier;

[0010] The high-precision voltage reference source provides a reference voltage, the amplifier increases the voltage of the input signal to generate an output voltage, the voltage reference compares the reference voltage with the output voltage, and the feedback network adjusts the output voltage based on the comparison result;

[0011] The high-precision analog-to-digital converter converts the voltage signal across the integrating capacitor into a digital signal, which is then output to the MCU for digital signal processing and analysis, and outputs a digitized current.

[0012] By using a high-precision voltage reference source and a high-precision analog-to-digital converter, and optimizing the design of the integration circuit, high-precision integration processing of weak currents is achieved, improving the accuracy and stability of detection. The technical effect is mainly reflected in the improvement of the integration accuracy and stability of weak currents, making the sensor more accurate and reliable in detecting volatile organic compound concentrations.

[0013] A high-precision voltage reference is a circuit or device that provides a stable, accurate, and reliable reference voltage. In electronic systems, reference voltages play a crucial role, serving as a reference voltage for a variety of applications, including comparison, calibration, and measurement. By utilizing high-quality components and sophisticated design, high-precision voltage references maintain output voltage stability under varying operating conditions, preventing output voltage deviations caused by factors such as temperature changes and supply voltage fluctuations.

[0014] Preferably, the circuit of the high-precision analog-to-digital converter (U4) includes IN1 (1), AGND (2), CAP1B (3), CAP1B (4), CAP1A (5), CAP1A (6), AVDD (7), DVDD (14), DGND (15), AGND (21), VREF (22), CAP2A (23), CAP2A (24), CAP2B (25), CAP2B (26), AGND (27), IN2 (28) and resistor R1;

[0015] The AGND (2), AGND (21), AGND (27) and DGND (15) are grounded;

[0016] The DVDD (14) is connected to a 5V power supply;

[0017] One end of the R1 is connected to the IN1 (1), and the other end is connected to the voltage signal.

[0018] The high-precision analog-to-digital converter (U4) adopts the DDC112U chip.

[0019] A high-precision voltage reference source provides a stable, accurate, and reliable reference voltage. It uses high-quality components and sophisticated design to achieve a high-precision output voltage, with high stability, low noise, and low drift.

[0020] Preferably, the integrator of the capacitor circuit includes a capacitor C20, a capacitor C21, a capacitor C22 and a capacitor C23;

[0021] One end of C20 is connected to CAP2B (25), and the other end is connected to CAP2B (26);

[0022] One end of C21 is connected to CAP1B (3), and the other end is connected to CAP1B (4);

[0023] One end of C22 is connected to CAP1A (5), and the other end is connected to CAP1A (6);

[0024] One end of C23 is connected to CAP2A (23), and the other end is connected to CAP2A (24).

[0025] The capacitor C20, the capacitor C21, the capacitor C22 and the capacitor C23 are all GRM1555C1H271FA01D.

[0026] An integrator is an analog circuit that integrates an input signal. That is, the output signal is the time integral of the input signal. In continuous-time systems, an integrator typically consists of an operational amplifier and a capacitor.

[0027] In a second aspect, the utility model provides a circuit of a high-precision voltage reference source including a voltage reference (U3), an amplifier (U2), a capacitor C11, a capacitor C12, a capacitor C13, a capacitor C14, and a capacitor C15;

[0028] The voltage reference (U3) includes IN (1), OUT (2), and GND (3);

[0029] The amplifier (U2) includes a V-terminal, a V+terminal, a non-inverting input terminal, a reverse input terminal and an OUT terminal;

[0030] One end of C11 is connected to 5V voltage and IN (1), and the other end is grounded;

[0031] C12 and C13 are connected in parallel, one end of C12 is connected to OUT (2), and the other end is connected to GND (3) and grounded; one end of C13 is connected to the in-phase input terminal, and the other end is grounded;

[0032] The reverse input terminal is connected to the OUT terminal, one end of C15 is connected to the reference voltage, and the other end is grounded;

[0033] One end of C14 is connected to the OUT terminal, and the other end is grounded.

[0034] Preferably, the voltage reference (U3) adopts a REF3040AIDBZT chip, and the amplifier (U2) adopts an RS821XF chip.

[0035] In summary, the high-precision voltage reference source circuit achieves high-precision and high-stability output of the voltage reference signal through carefully designed filtering, decoupling and negative feedback mechanisms.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The utility model provides an integration conversion circuit based on atmospheric composition detection. By adopting a high-precision voltage reference source and a high-precision ADC, it can achieve high-precision integration processing of weak currents, thereby improving the accuracy and stability of detection. This is mainly manifested in improving the integration accuracy and stability of weak currents, making the sensor's detection of volatile organic compound concentrations more accurate and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a structural block diagram of Example 1 of the present utility model;

[0039] Figure 2 The integral conversion circuit diagram of Example 1;

[0040] Figure 3 This is a circuit diagram of a capacitor in Example 1;

[0041] Figure 4 This is the reference voltage source diagram of Example 1;

[0042] Figure 5 This is a diagram of a high-precision analog-to-digital converter according to Example 1;

[0043] Figure 6 This is a circuit diagram of the simulation part of Example 1;

[0044] Figure 7 This is the circuit diagram of the digital part of Example 1;

[0045] Figure 8 This is a circuit diagram of the power supply portion of Example 1;

[0046] Figure 9 This is a practical application diagram of Example 1. DETAILED DESCRIPTION

[0047] The present invention is further described in detail below with reference to test examples and specific implementation methods. However, this should not be construed as limiting the scope of the present invention to the following embodiments. All technologies implemented based on the present invention fall within the scope of the present invention.

[0048] In addition, the expressions "first", "second", "third", etc. that appear in the terms are merely descriptions used to distinguish the same or similar components and should not be understood as emphasizing or implying the relative importance of specific components.

[0049] In addition, in the description of the embodiments of the present invention, "several", "a plurality", and "a number" represent at least 2. It can be any number such as 2, 3, 4, 5, 6, 7, 8, 9, and even more than 9.

[0050] Furthermore, in the description of the technical solutions of this utility model, unless otherwise expressly specified / defined / restricted, the terms "disposed," "installed," "connected," "connected," "provided with," "laid," and "arranged" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections. They may be welding, riveting, bolting, threading, or other commonly used connection methods in the art. Such connections may be mechanical, electrical, or communication connections; they may be direct connections, indirect connections through an intermediate medium, or internal connections between two components.

[0051] Example 1

[0052] like Figure 1 As shown, an integral conversion circuit based on atmospheric component detection includes a capacitor circuit and a high-precision analog-to-digital converter;

[0053] In the capacitor circuit, the integrator receives the weak current signal of the high-voltage electrode, performs integration processing and stores charge, and the two ends of the capacitor are connected to the high-voltage electrode and the feedback path of the amplifier;

[0054] The high-precision analog-to-digital converter converts the voltage signal across the integrating capacitor into a digital signal, which is then output to the MCU for digital signal processing and analysis, and outputs a digitized current.

[0055] like Figure 3 As shown, the working principle of the capacitor circuit is:

[0056] 1. The sampling switch is closed, the output enable is disconnected (to prevent the back-end sampling from absorbing charge and affecting the accuracy), and the charge flows into the integration capacitor through the path.

[0057] 2. After the charge is injected into the capacitor, the voltage value on the integrating capacitor will change.

[0058] 3. After the voltage on the capacitor changes, due to the "virtual short" effect of the op amp, in order to maintain the voltage at the negative input and positive input of the op amp the same (here is 0V), the output of the op amp will output a voltage value, which is equal to the voltage value on the capacitor and has opposite polarity.

[0059] 4. Current is continuously injected during the sampling period (integration time). The integrating capacitor is continuously injected during the sampling period (integration time). Given the integration time and the capacitance of the capacitor, the current can be calculated by calculating the amount of charge injected per unit time. After the sampling period ends, the sampling enable is disconnected, the clock input enable is enabled, and the voltage on the capacitor begins to be collected.

[0060] 5. At the end of a sampling cycle, the sampling enable switch is turned off and the integration reset switch is closed to release the charge in the capacitor and prepare for the next integration.

[0061] 6. Disconnect the reset switch, close the sampling enable switch, and continue charging for the next cycle.

[0062] like Figure 5 As shown, the circuit of the high-precision analog-to-digital converter (U4) includes IN1 (1), AGND (2), CAP1B (3), CAP1B (4), CAP1A (5), CAP1A (6), AVDD (7), DVDD (14), DGND (15), AGND (21), VREF (22), CAP2A (23), CAP2A (24), CAP2B (25), CAP2B (26), AGND (27), IN2 (28) and resistor R1;

[0063] The AGND (2), AGND (21), AGND (27) and DGND (15) are grounded;

[0064] The DVDD (14) is connected to a 5V power supply;

[0065] One end of the R1 is connected to the IN1 (1), and the other end is connected to the voltage signal.

[0066] like Figure 2 As shown, the integrator of the capacitor circuit includes capacitor C20, capacitor C21, capacitor C22 and capacitor C23;

[0067] One end of C20 is connected to CAP2B (25), and the other end is connected to CAP2B (26);

[0068] One end of C21 is connected to CAP1B (3), and the other end is connected to CAP1B (4);

[0069] One end of C22 is connected to CAP1A (5), and the other end is connected to CAP1A (6);

[0070] One end of C23 is connected to CAP2A (23), and the other end is connected to CAP2A (24).

[0071] The high-precision analog-to-digital converter (U4) adopts the DDC112U chip, and the capacitors C20, C21, C22 and C23 all adopt the GRM1555C1H271FA01D.

[0072] like Figure 4As shown, the high-precision voltage reference source provides a reference voltage, the amplifier increases the voltage of the input signal to generate an output voltage, the voltage reference compares the reference voltage with the output voltage, and the feedback network adjusts the output voltage according to the comparison result.

[0073] The circuit of the high-precision voltage reference source includes a voltage reference (U3), an amplifier (U2), a capacitor C11, a capacitor C12, a capacitor C13, a capacitor C14 and a capacitor C15;

[0074] The voltage reference (U3) includes IN (1), OUT (2), and GND (3);

[0075] The amplifier (U2) includes a V-terminal, a V+terminal, a non-inverting input terminal, a reverse input terminal and an OUT terminal;

[0076] One end of C11 is connected to 5V voltage and IN (1), and the other end is grounded;

[0077] C12 and C13 are connected in parallel, one end of C12 is connected to OUT (2), and the other end is connected to GND (3) and grounded; one end of C13 is connected to the in-phase input terminal, and the other end is grounded;

[0078] The reverse input terminal is connected to the OUT terminal, one end of C15 is connected to the reference voltage, and the other end is grounded;

[0079] One end of C14 is connected to the OUT terminal, and the other end is grounded.

[0080] The voltage reference (U3) adopts the REF3040AIDBZT chip, and the amplifier (U2) adopts the RS821XF chip.

[0081] Voltage Reference (U3) Stability: The voltage reference (U3) is the heart of the circuit, providing a stable reference voltage (typically with an extremely low temperature coefficient and high accuracy). IN (1) is the input, OUT (2) is the output, and GND (3) is the ground. Through complex internal circuit design and precise calibration, U3 is able to output an extremely stable voltage value that serves as the reference for the entire circuit.

[0082] Filtering and decoupling: Capacitor C11 is connected between the 5V voltage source and the IN (1) terminal of the voltage reference, acting as a filter, reducing the impact of high-frequency noise from the power supply on the voltage reference and improving the purity of the input signal. C12 and C13 are connected in parallel between the OUT (2) terminal of the voltage reference and ground, and the other end of C13 is connected to the non-inverting input terminal of the amplifier, providing decoupling for the output of the voltage reference, reducing the impact of power supply fluctuations on the output voltage, and also enhancing the filtering effect through the parallel capacitor, further improving the voltage stability. The amplifier (U2) adopts a negative feedback configuration (the inverting input terminal is connected to the OUT terminal), which greatly improves the stability and linearity of the amplifier. Negative feedback causes the output voltage of the amplifier to tend to a stable value, that is, the voltage received by its non-inverting input terminal (coupled through C13 and the voltage reference OUT (2)). In this way, even if there are slight fluctuations in the input signal or power supply, the amplifier can quickly adjust its output to maintain the stability and accuracy of the output voltage. C14 is connected between the OUT terminal of the amplifier and the ground, which further filters out the high-frequency noise at the output of the amplifier and ensures the high accuracy and stability of the final output voltage.

[0083] like Figure 6 As shown, other circuits in the analog section include a voltage regulator (U1), a converter (U5), and a converter (U6);

[0084] The voltage regulator (U1) uses a KF50BD-TR chip, and the converter (U5) and the converter (U6) use a TXS0108EPWR chip;

[0085] The circuit of the voltage regulator (U1) includes VIN (8), VOUT (1), GND (2), GND (3), capacitor C1, capacitor C3, capacitor C4, capacitor C6, capacitor C7, capacitor C10 and inductor L1;

[0086] One end of C1 is connected to VIN, C1, C2, C3, and C4 are connected in parallel to ground, and C6 is connected to VIN (8);

[0087] C7 and C10 are connected in parallel, one end of C7 is connected to VOUT (1) and 5V analog voltage, and the other end is connected to GND (2) and GND (3) for grounding;

[0088] The KF50BD-TR chip serves as the core of the voltage regulator U1. Its main function is to convert the unstable input voltage (VIN) into a stable output voltage (VOUT) with low ripple. This achieves effective conversion of the input voltage and stable, low-noise output voltage, providing high-quality power supply guarantee for subsequent circuits.

[0089] The TXS0108EPWR is an 8-bit non-inverting translator with two independent, configurable power rails. The A port is designed to track VCCA, which accepts a 1.2 to 3.6V supply voltage; the B port is designed to track VCCB, which accepts a 1.65 to 5.5V supply voltage. This allows low-voltage bidirectional translation between any 1.2, 1.5, 1.8, 2.5, 3.3, and 5V voltage nodes. When the output enable (OE) input is LOW, all outputs are placed in a high-impedance state. To ensure the high-impedance state during power-up or power-down, OE should be connected to GND through a pull-down resistor. The minimum resistor value is determined by the current-sourcing capability of the driver.

[0090] like Figure 7 As shown, other digital circuits include MCU (U8), digital temperature and humidity sensor (U7), memory (U9) and digital-to-analog converter (U11);

[0091] The MCU (U8) uses stm32f411ceu6, the digital temperature and humidity sensor (U7) uses the SHT20 chip, the memory (U9) uses the W25Q128JVSIQ chip, and the digital-to-analog converter (U11) uses the MCP4725A0T-E / CH chip;

[0092] The MCU (U8) includes PH0-OSC_IN (5), PH0-OSC_OUT (6), VDDA / VREF+ (9), VSSA / VREF- (8), VCAP1 (22), BOOT0 (44), VSS (23), VSS (35), VSS (47), PAD (0);

[0093] A crystal oscillator circuit is connected between PH0-OSC_IN (5) and PH0-OSC_OUT (6), and the crystal oscillator circuit includes capacitors C9, C28, C29, and crystal oscillator Y1. Y1 is connected to both ends of PH0-OSC_IN (5) and PH0-OSC_OUT (6). Capacitors C9 and C28 are connected to both ends of the crystal oscillator, respectively, and C28 is grounded.

[0094] The VDDA / VREF+ (9) is connected to VDD;

[0095] The VCAP1 (22) is connected to C29, and the other end of C29 is grounded;

[0096] The BOOT0 (44) is connected to R3, and the other end of R3 is grounded;

[0097] The VSSA / VREF-(8), VSS(23), VSS(35), VSS(47) and PAD(0) are grounded;

[0098] The circuit of the digital temperature and humidity sensor (U7) includes VDD (5) and a capacitor C5, one end of C5 is connected to VDD (5) and VDD, and the other end is grounded;

[0099] The memory (U9) includes WP (3), VCC (8), HOLDorRESET (7);

[0100] The WP (3) is connected to VCC;

[0101] The VCC and HOLDorRESET (7) are connected to VDD, one end of the capacitor is connected to VCC, and the other end is grounded;

[0102] The circuit of the digital-to-analog converter (U11) includes A0 (6), SCL (5), SDA (4), VDD (3), VSS (2), VOUT (1), resistor R4, resistor R5, resistor R6 and capacitor C39;

[0103] A0 (6) and VSS (2) are grounded;

[0104] One end of C39 is connected to VDD (3) and analog power supply 5V, and the other end is grounded;

[0105] One end of R4 is connected to VOUT (1), and the other end outputs the digital-to-analog conversion result;

[0106] One end of R6 is connected to VDD and the other end is connected to SCL (5); one end of R5 is connected to VDD and the other end is connected to SDA (4);

[0107] like Figure 8 As shown, the power supply circuit includes a voltage regulator (U10), the voltage regulator (U10) includes a VIN terminal, a GND terminal, an EN terminal, a VOUT terminal and an NC terminal, and the circuit of the voltage regulator (U10) includes a capacitor C30, a capacitor C31, a capacitor C32, a capacitor C33 and a capacitor C34, and an inductor L5;

[0108] One end of the inductor L5 is connected to the 5V power supply, and the other end is connected to the VIN terminal;

[0109] One end of C30 and C31 is connected in series with L5, the other end is grounded, and the EN end is connected to the VIN end;

[0110] The C32, C33 and C34 are connected in parallel and connected to the VDD terminal, and the other end is grounded.

[0111] The voltage regulator (U10) adopts LP5907MFX-3.3 / NOPB chip.

[0112] like Figure 9As shown, the charge / current conversion formula is:

[0113] 1. According to capacitor voltage = charge / capacitance, where the voltage is measured through the circuit and the capacitance is known, the charge can be calculated.

[0114] 2. Current = charge / charging time.

[0115] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An integral conversion circuit based on atmospheric component detection, characterized in that: Including capacitor circuit, high-precision voltage reference source, high-precision analog-to-digital converter; In the capacitor circuit, the integrator receives the current signal of the high-voltage electrode, performs integration processing and stores charge, and the two ends of the capacitor are connected to the high-voltage electrode and the feedback path of the amplifier; The high-precision voltage reference source provides a reference voltage, the amplifier increases the voltage of the input signal to generate an output voltage, the voltage reference compares the reference voltage with the output voltage, and the feedback network adjusts the output voltage based on the comparison result; The high-precision analog-to-digital converter converts the voltage signal across the integration capacitor into a digital signal for output.

2. The integral conversion circuit based on atmospheric component detection according to claim 1, characterized in that: The high-precision analog-to-digital converter (U4) adopts the DDC112U chip.

3. The integral conversion circuit based on atmospheric component detection according to claim 1, characterized in that: The circuit of the high-precision analog-to-digital converter (U4) includes a resistor R1, AGND (2), AGND (21), AGND (27), DGND (15), DVDD (14) and IN1 (1); AGND (2), AGND (21), AGND (27) and DGND (15) are grounded; DVDD (14) is connected to 5V power supply; One end of R1 is connected to IN1 (1), and the other end is connected to the voltage signal.

4. The integral conversion circuit based on atmospheric component detection according to claim 3, characterized in that: The integrator of the capacitor circuit includes a capacitor C20, a capacitor C21, a capacitor C22 and a capacitor C23; One end of C20 is connected to CAP2B (25), and the other end is connected to CAP2B (26); One end of C21 is connected to CAP1B (3), and the other end is connected to CAP1B (4); One end of C22 is connected to CAP1A (5), and the other end is connected to CAP1A (6); One end of C23 is connected to CAP2A (23), and the other end is connected to CAP2A (24).

5. The integral conversion circuit based on atmospheric component detection according to claim 4, characterized in that: The capacitor C20, the capacitor C21, the capacitor C22 and the capacitor C23 are all GRM1555C1H271FA01D.

6. The integral conversion circuit based on atmospheric component detection according to claim 1, characterized in that: The circuit of the high-precision voltage reference source includes a voltage reference (U3), an amplifier (U2), a capacitor C11, a capacitor C12, a capacitor C13, a capacitor C14 and a capacitor C15; The voltage reference (U3) includes IN (1), OUT (2), and GND (3); The amplifier (U2) includes a V-terminal, a V+terminal, a non-inverting input terminal, a reverse input terminal and an OUT terminal; One end of C11 is connected to 5V voltage and IN (1), and the other end is grounded; C12 and C13 are connected in parallel, one end of C12 is connected to OUT (2), and the other end is connected to GND (3) and grounded; one end of C13 is connected to the in-phase input terminal, and the other end is grounded; The reverse input terminal is connected to the OUT terminal, one end of C15 is connected to the reference voltage, and the other end is grounded; One end of C14 is connected to the OUT terminal, and the other end is grounded.

7. The integral conversion circuit based on atmospheric component detection according to claim 1, characterized in that: The voltage reference (U3) adopts the REF3040AIDBZT chip, and the amplifier (U2) adopts the RS821XF chip.

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