A multi-step integration circuit for infrared detection

Abstract

This invention proposes an infrared detection multi-step integration circuit, comprising an integrator and a multi-step integration control module. The integrator is an analog circuit, while the multi-step integration control module is a digital circuit. The integrator and the multi-step integration control module are connected via four signal paths, used for logic control, timing control, pre-integration voltage transmission, and sensor signal integration voltage transmission, respectively. This invention enables dynamic adjustment of the signal acquisition capability of the infrared detector in high-dynamic scenarios, thereby improving the quality of infrared thermal images.

Description

Technical Field

[0001] This invention relates to the field of infrared detection, and more specifically to an infrared detection multi-step integration circuit for infrared thermal imaging signal readout circuits. Background Technology

[0002] Infrared thermal imaging is a passive photoelectric imaging technology that utilizes the differences in thermal radiation from different parts of a target to obtain image details, converting infrared radiation signals into visual thermal images. An infrared thermal imager consists of an uncooled optical system, photosensitive elements, and optical windows. The optical system transfers the received infrared heat to photodiodes in the electronic circuitry, converting it into current and generating voltage pulses. After signal conditioning, these pulses enter an integrating circuit, ultimately transforming into an electrical signal corresponding to temperature. The parameters of the integrating circuit determine the quality of the infrared thermal imaging. In high-dynamic scenes, the integration time is severely limited. Therefore, using a fixed integrating capacitor will result in insufficient or excessive capture of radiation signals in high-dynamic scenes, causing distortion of the thermal image.

[0003] Currently, there are two main control methods for integrators in infrared signal readout circuits: integration time control and integration capacitor control. Although the former is widely used, it is not suitable for high dynamic scenarios, while the latter has disadvantages such as time consumption, high cost, and difficulty in adjustment, which means that infrared detection still has performance bottlenecks in high dynamic scenarios. Summary of the Invention

[0004] The purpose of this invention is to propose an infrared detection multi-step integration circuit to solve the problem of insufficient or excessive ability to capture radiation signals in high dynamic scenes.

[0005] The technical solution to achieve the purpose of this invention is as follows: an infrared detection multi-step integration circuit, comprising an integrator and a multi-step integration control module. The integrator is composed of an analog circuit, and the multi-step integration control module is composed of a digital circuit. The integrator and the multi-step integration control module are connected through four signal paths, which are respectively used for logic control, timing control, and pre-integration voltage V. int and the sensor signal integrated voltage V out The transmission;

[0006] Driven by the timing control signal output from the multi-step integration control module, the integrator pre-integrates the input sensor current signal to obtain the pre-integrated voltage V. int Synchronously transmitted to the multi-step integral control module; the multi-step integral control module, based on the pre-integrated voltage V... int A logic control signal is generated to control the analog switch inside the integrator, thereby achieving adaptive adjustment of the integrating capacitor. After the integrating capacitor is configured, the integrator performs formal integration of the sensor current signal and outputs the obtained integrated voltage V.out The signal is converted into a digital signal by the sample-and-hold circuit and the ADC module and stored in the output register.

[0007] Furthermore, the integrator consists of operational amplifier A1, integrating capacitor C1, integrating capacitor C2, and pre-integrating capacitor C. int It consists of analog switches S0 to S5, all of which are implemented using MOSFETs, and a pre-integration capacitor C. int The analog switch S5 is connected in series with the output and inverting input of operational amplifier A1. The analog switch S5 is a single-pole double-throw switch, with contacts 1 and 2 connected to the inverting input and output of operational amplifier A1, respectively. The pre-integration capacitor C... int Connect the inverting input terminal of operational amplifier A1 and the remote contact side of analog switch S5 respectively; the integrating capacitor C1, analog switch S2, and integrating capacitor C2 are connected in series and then connected across the output terminal and the inverting input terminal of operational amplifier A1. Analog switch S2 is a double-pole double-throw switch, with contact 1 connected to V. com Contact 3 is connected to analog switch S3. Integrating capacitor C1 is connected to the inverting input terminal of operational amplifier A1 and the second pole of analog switch S2, respectively. Integrating capacitor C2 is connected to the output terminal of operational amplifier A1 and contact 2 of analog switch S2, respectively. S0 is a single-pole single-throw switch, with its two ends connected to the output terminal and the inverting input terminal of operational amplifier A1, respectively. Analog switch S1 is a single-pole single-throw switch, with its two ends connected to the inverting input terminal of operational amplifier A1 and the first pole of analog switch S2, respectively. Analog switch S3 is a single-pole single-throw switch, with its two ends connected to contact 3 of analog switch S2 and the output terminal of operational amplifier A1, respectively. Analog switch S4 is a single-pole single-throw switch, connected in series between the contact of analog switch S3 and contact 2 of analog switch S5.

[0008] The integrator's input signals include: logic control signals, timing control signals, and sensor current signals; its output signal includes: pre-integrated voltage V. int and integral voltage V out The principle of the integrator is as follows: a multi-stage adjustable integrating capacitor composed of integrating capacitors C1 and C2 is connected across the output terminal and the inverting input terminal of the operational amplifier to form an integrating circuit. An analog switch is used to control the adjustment of the integrating capacitor value, the clearing of the integrating capacitor, and the execution of the circuit timing control signal.

[0009] Furthermore, the multi-step integration control module comprises seven parts: a comparator, an encoder, a combinational logic circuit, a sample-and-hold circuit, an ADC, a register, and a multi-step integration timing controller. The multi-step integration timing controller is connected to the combinational logic circuit, the encoder, the comparator, and the sample-and-hold circuit via output signal lines; the sample-and-hold circuit is connected to the ADC via output signal lines; the ADC is connected to the register via output signal lines; the comparator is connected to the encoder via output signal lines; and the encoder is connected to the combinational logic circuit via output signal lines.

[0010] The input signals of the multi-step integral control module include: pre-integral voltage V int and integral voltage V out The output signals include: logic control signals and timing control signals. The principle of the multi-step integral control module is as follows: under the drive and control of the multi-step integral timing controller, the comparator will convert the pre-integrated voltage V... int The signal is compared with the set threshold voltage and the result is temporarily stored. Then, the pre-integrated voltage V is... int After the hierarchical comparison is completed, the comparison result is encoded into a control word by an encoder. The obtained control word is input into a combinational logic circuit, mapped to obtain a logic control signal, and then output. Under the action of the logic control signal and the timing control signal, the integrator completes the adaptive adjustment of the integrating capacitor, and then performs formal integration on the sensor current signal. After a fixed integration time is reached, the sample-and-hold circuit adjusts the integrated voltage V. out During sampling and holding, the ADC converts the integrated voltage locked in the sample-and-hold circuit into a digital signal and stores it in a register.

[0011] Furthermore, in the pre-integration stage, the pre-integration capacitor C... int Connect across operational amplifier A1, disconnect integrating capacitors C1 and C2, and keep the voltage across C1 and C2 zero. The sensor current signal is then connected across the pre-integration capacitor C. int The integrated voltage V on out The comparator, which receives the input in real time, is used to convert the integral voltage V during the pre-integration process. outThe voltage is compared three times with a threshold voltage. Each time, the comparator outputs one binary bit. A value less than the threshold voltage is represented by 0. Therefore, the voltage comparison results are: "000", "001", "011", and "111". This result is mapped to a control word by an encoder. The control word uses two binary bits to represent the four output results, respectively represented as "00", "01", "10", and "11". The combinational logic circuit maps the control word to a logic control signal, which then controls the analog switch to dynamically combine the integrating capacitors C1 and C2. The specific process of adjusting the integrating capacitors using the control word is as follows: When the control word is "00", the combinational logic circuit controls integrating capacitors C1 and C2 to be connected in series; when the control word is "01", the combinational logic circuit controls only integrating capacitor C1 to be connected; when the control word is "10", the combinational logic circuit controls only integrating capacitor C2 to be connected; when the control word is "11", the combinational logic circuit controls integrating capacitors C1 and C2 to be connected in parallel.

[0012] The pre-integration phase ends here. Disconnect and clear the pre-integration capacitor C. int The sensor current signal is integrated by a dynamic combination of integrating capacitors C1 and C2. The high-quality infrared image voltage signal obtained by the integrator is converted into a digital signal by a sample-and-hold circuit and an ADC, and stored in a register for output.

[0013] Furthermore, assuming the integrating capacitors C1 and C2 are 0.1µF and 0.2µF respectively, four different integrating capacitor values ​​are obtained: C1 and C2 in series, C1 only, C2 only, and C1 and C2 in parallel. The pre-integrating capacitor C... int It lies between the two smaller integrating capacitor values, i.e., 0.067uf < C. int <0.1uf.

[0014] A control method for an integrator of an infrared signal readout circuit is provided, which is implemented based on the aforementioned infrared detection multi-step integration circuit.

[0015] Compared with the prior art, the significant advantage of this invention is that it can dynamically adjust the signal capturing capability of the infrared detector in high dynamic scenes, thereby improving the quality of infrared thermal images. Attached Figure Description

[0016] Figure 1 This is a structural diagram of the infrared detection multi-step integration circuit of the present invention.

[0017] Figure 2 This is a schematic diagram of the combinational logic circuit decoding control word of the present invention.

[0018] Figure 3 This is a timing diagram of the infrared detection multi-step integration circuit of the present invention.

[0019] Figure 4 This is a schematic diagram illustrating the working principle of the infrared detection multi-step integration circuit of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0021] The structure of the infrared detection multi-step integration circuit of the present invention is as follows: Figure 1 As shown, it includes two parts: an integrator and a multi-step integration control module. The integrator and the multi-step integration module are connected by four signal paths, which are used for logic control, timing control, and pre-integration voltage V, respectively. int and the sensor signal integrated voltage V out The infrared detection multi-step integration circuit transmits signals, with the input being a compensated sensor current signal and the output being a digital signal characterizing the infrared thermal image voltage. The specific process of input-output mapping is as follows: First, driven by the timing control signal output by the multi-step integration control module, the integrator pre-integrates the input sensor current signal to obtain the pre-integrated voltage V. int The data is synchronously transmitted to the multi-step integral control module, which then processes it according to the pre-integrated voltage V. int A logic control signal is generated, which controls the analog switch inside the integrator to achieve adaptive adjustment of the integrating capacitor. Finally, after the integrating capacitor of the integrator is configured, the integrator performs formal integration of the sensor current signal and obtains the integrated voltage V. out The signal is converted into a digital signal in a register by a sample-and-hold circuit and an ADC module.

[0022] The integrator consists of operational amplifier A1, integrating capacitors C1 and C2, and pre-integrating capacitor C. int It consists of analog switches S0 to S5 (implemented through MOSFETs), and its specific circuit structure is as follows: Figure 1 As shown in Figure C. int After being connected in series with S5, it is connected across the output terminal and the inverting input terminal (C) of A1. intConnect A1's inverting input and S5's remote contact side respectively; C1, S2, and C2 are connected in series and then bridging A1's output and inverting input (C1 is connected to A1's inverting input and S2's second pole respectively, and C2 is connected to A1's output and S2's contact 2 respectively); S0 is a single-pole single-throw switch, with its two ends connected to A1's output and inverting input respectively; S1 is a single-pole single-throw switch, with its two ends connected to A1's inverting input and S2's first pole respectively; S2 is a double-pole double-throw switch (open: first pole contact 1, second pole contact 2; closed: first pole contact 2, second pole contact 3), its contact 1 is connected to V com Contact 3 is connected to S3; S3 is a single-pole single-throw switch, with its two ends connected to contact 3 of S2 and the output terminal of A1 respectively; S4 is a single-pole single-throw switch, connected in series between the contacts of S3 and S5; S5 is a single-pole double-throw switch (contact 1 when open, contact 2 when closed), with its contacts 1 and 2 connected to the inverting input terminal and output terminal of A1 respectively.

[0023] The analog switch is in the following state: Figure 1 The state shown is defined as "off state", that is, the switch signal is logic low, where S0 is determined by Φ. rst (Controlled by the timing control signal for clearing the integrating capacitor) S2 is controlled by (Series-parallel switching logic control signal s) w Non-integral zeroing timing control signal Control, S4 and S5 are respectively controlled by and Φ int (Pre-integration enable timing control signal) control; S1 and S3 are directly controlled by their corresponding logic control signals. Pre-integration capacitor C int After being connected in series with analog switch S5, it is connected across the inverting input and output terminals of operational amplifier A1. When S5 is open, C int When short-circuited (cleared), C is closed when S5 is closed. int The signal is pre-integrated. When S2 is open, the integrating capacitors C1 and C2 are connected in series with switch S4, and then the whole circuit is connected across the inverting input and output of operational amplifier A1. At this time, switches S1 and S3 are ineffective, and their actual state does not affect the overall circuit function. When S2 is closed, the integrating capacitors C1 and C2 are connected in series with switches S3 and S1 respectively, and then connected in series with switch S4. The whole circuit is connected across the inverting input and output of operational amplifier A1. At this time, the opening or closing of switches S1 and S3 controls the corresponding capacitors to be opened or closed. The combination structure of switch S0 and capacitors C1 and C2 is connected in parallel and in series with switch S4. When S0 is closed, capacitors C1 and C2 are cleared to zero.

[0024] The integrator's input signals include: logic control signals, timing control signals, and sensor current signals; its output signal includes: pre-integrated voltage V. intand integral voltage V out The principle of the integrator is as follows: (The integrator is defined by C...) int A pre-integration circuit is formed by bridging the inverting input and output terminals to predict the sensor current signal; an adjustable integrating capacitor structure composed of C1 and C2 is connected across the inverting input and output terminals of operational amplifier A1 to form an integrating circuit to integrate the sensor current signal; the integrator performs pre-integration, integration, capacitor clearing, and integrating capacitor value adjustment under the control of the logic control signal and timing control signal output by the multi-step integration control module.

[0025] The multi-step integration control module comprises seven parts: a comparator, an encoder, combinational logic circuits, a sample-and-hold circuit, an ADC, a register, and a multi-step integration timing controller. Its specific circuit structure is as follows: Figure 1 As shown, multiple integral timing controllers are connected to combinational logic circuits, encoders, comparators, and sample-and-hold circuits via output signal lines; the sample-and-hold circuits are connected to the ADC via output signal lines; the ADC is connected to the register via output signal lines; the comparators are connected to the encoder via output signal lines; and the encoder is connected to the combinational logic circuits via output signal lines.

[0026] The function of the comparator is to convert the pre-integrated voltage V int With threshold V TH Comparison, when V int Greater than V TH Output 1 otherwise output 0 (V) TH (Can be set to 90% of the maximum integrating voltage); the encoder's function is to map "000", "001", "011", and "111" to control words "00", "01", "10", and "11" respectively; the combinational logic circuit's function is to map the control words to logic control signals (S1, S3, S...). w The control word decoding is illustrated as follows: Figure 2 As shown, Figure 2 C in H C L These represent the high and low bits of the control word, respectively. The combinational logic circuit maps the control word to a logic control signal, and then controls the analog switch through the logic control signal to achieve the dynamic combination of integrating capacitors C1 and C2. The specific process of adjusting the integrating capacitor through the control word is as follows: when the control word is "00", the combinational logic circuit outputs the control signal S. w =0, S1=0, S3=0, at this time the integrating capacitors C1 and C2 are combination 1: C1 and C2 are connected in series (the combined capacitance value is the smallest); when the control word is "01", the combinational logic circuit outputs the control signal S w=1, S1=0, S3=1. At this time, the integrating capacitors C1 and C2 are in combination 2: only C1 is connected (the combined capacitance value is small); when the control word is "10", the combinational logic circuit outputs the control signal S w =1, S1=1, S3=0, at this time the integrating capacitors C1 and C2 are combination 3: only C2 is connected (the combined capacitance value is large); when the control word is "11", the combinational logic circuit outputs the control signal S w =1, S1=1, S3=1, at this time the integrating capacitors C1 and C2 are combination 4: C1 and C2 in parallel (the combined capacitance value is the largest).

[0027] The function of the sample-and-hold circuit is to integrate the voltage V. out The sampling and holding circuit performs sampling and holding for use by the ADC; the ADC performs analog-to-digital conversion on the voltage value locked by the sample-and-hold circuit; the register latches the digital-to-analog conversion result for output; the multi-step integration timing controller provides timing control signals to the infrared detection multi-step integration circuit, including Φ rst Φ int and Φ smp (Sampling / Comparison Timing Control Signal) and CLK (Clock Signal), the timing signals generated by the multi-step integration timing controller, i.e., the timing of the infrared detection multi-step integration circuit, are as follows: Figure 3 As shown.

[0028] The input signals of the multi-step integral control module include: pre-integral voltage V int and integral voltage V out The output signals include logic control signals and timing control signals. The principle of the multi-step integral control module is as follows: under the drive and control of the multi-step integral timing controller, the comparator will input the pre-integrated voltage V... int With threshold voltage V TH The comparison is performed and the result is temporarily stored, based on the pre-integrated voltage V. int After the hierarchical comparison is completed, the comparison result is encoded into a control word by an encoder. The obtained control word is input into a combinational logic circuit, which maps to obtain the output logic control signal. Under the action of the logic control signal and the timing control signal, the integrator completes the adaptive adjustment of the integrating capacitor, and then performs formal integration on the sensor current signal. After a fixed integration time is reached, the sample-and-hold circuit sets the integrated voltage V. out During sampling and holding, the ADC converts the integrated voltage locked in the sample-and-hold circuit into a digital signal and stores it in a register.

[0029] The principle of the infrared detection multi-step integration circuit is as follows: Figure 4 As shown, Figure 4 a to Figure 4d illustrates four different integration capacitor adjustment schemes for multi-step integration. Therefore, the function of the infrared detection multi-step integration circuit of this invention can be summarized as follows: to achieve adaptive adjustment of the integration capacitor based on the pre-integration result of the sensor current signal, so as to enhance the infrared detector's capture quality of infrared thermal radiation signals in high dynamic scenarios (i.e., under conditions where integration time is limited).

[0030] Assuming the integrating capacitors C1 and C2 in this embodiment are 0.1µF and 0.2µF respectively, four different integrating capacitor values ​​can be obtained: C1 and C2 in series (0.067µF), C1 only (0.1µF), C2 only (0.2µF), and C1 and C2 in parallel (0.3µF). The pre-integrating capacitor C... int The value is generally between the two smaller integrating capacitor values, i.e., 0.067uf < C. int <0.1uf. For example... Figure 3 As shown, Φ int When the rising edge arrives, the pre-integration phase begins, at which point only capacitor C... int It is connected across operational amplifier A1 and pre-integrated on the sensor current signal whenever Φ smp When the rising edge arrives, the comparator produces a one-bit result, and the pre-integration process will produce a three-bit comparison result (the comparison result is left-shifted and expanded), at Φ int When the falling edge arrives, the pre-integration ends, and capacitor C is disconnected and cleared to zero. int The combination of capacitors C1 and C2 is connected, in Figure 3 During the analog switch delay process, the encoder encodes the voltage comparison result into a control word, the logic circuit maps the control word into a logic control signal, and the integrator adjusts the value of the integrating capacitor according to the logic control signal. rst When the falling edge arrives, the integrating circuit consisting of the combination of capacitors C1 and C2 and operational amplifier A1 begins to integrate the sensor current signal. smp When the falling edge arrives, the sample-and-hold circuit adjusts the integral voltage V. out The sample-and-hold function performs analog-to-digital conversion on the voltage and sends it to a register. When Φ rst When the rising edge arrives, capacitors C1 and C2 are cleared to zero, thus completing the capture of an infrared thermal radiation signal based on the infrared detection multi-step integration circuit of this invention.

[0031] It should be understood that, in order to more clearly illustrate the implementation method of the present invention, the dynamic combination of sampling integration capacitors C1 and C2 in this embodiment is used as the integration capacitor of the integrator. In practical applications, the integration capacitor can be increased as needed to provide a wider range of adjustable capacitance values. Under these circumstances, the present invention can still achieve dynamic adjustment of the signal capturing capability of the infrared detector in high dynamic scenarios, thereby improving the quality of infrared thermal images.

[0032] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0033] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. An infrared detection multi-step integration circuit, characterized in that, The system comprises two parts: an integrator and a multi-step integration control module. The integrator is an analog circuit, while the multi-step integration control module is a digital circuit. The integrator and the multi-step integration control module are connected via four signal paths, which are used for logic control, timing control, and pre-integration voltage V, respectively. int and the sensor signal integrated voltage V out The transmission; Driven by the timing control signal output from the multi-step integration control module, the integrator pre-integrates the input sensor current signal to obtain the pre-integrated voltage V. int Synchronously transmitted to the multi-step integral control module; the multi-step integral control module, based on the pre-integrated voltage V... int A logic control signal is generated to control the analog switch inside the integrator, thereby achieving adaptive adjustment of the integrating capacitor. After the integrating capacitor is configured, the integrator performs formal integration of the sensor current signal and outputs the obtained integrated voltage V. out The signal is converted into a digital signal by the sample-and-hold circuit and the ADC module and stored in the output register.

2. The infrared detection multi-step integration circuit according to claim 1, characterized in that, The integrator consists of operational amplifier A1, integrating capacitor C1, integrating capacitor C2, and pre-integrating capacitor C. int It consists of analog switches S0 to S5, all of which are implemented using MOSFETs, and a pre-integration capacitor C. int The analog switch S5 is connected in series with the output and inverting input of operational amplifier A1. The analog switch S5 is a single-pole double-throw switch, with contacts 1 and 2 connected to the inverting input and output of operational amplifier A1, respectively. The pre-integration capacitor C... int Connect the inverting input terminal of operational amplifier A1 and the remote contact side of analog switch S5 respectively; the integrating capacitor C1, analog switch S2, and integrating capacitor C2 are connected in series and then connected across the output terminal and the inverting input terminal of operational amplifier A1. Analog switch S2 is a double-pole double-throw switch, with contact 1 connected to V. com Contact 3 is connected to analog switch S3. Integrating capacitor C1 is connected to the inverting input terminal of operational amplifier A1 and the second pole of analog switch S2, respectively. Integrating capacitor C2 is connected to the output terminal of operational amplifier A1 and contact 2 of analog switch S2, respectively. S0 is a single-pole single-throw switch, with its two ends connected to the output terminal and the inverting input terminal of operational amplifier A1, respectively. Analog switch S1 is a single-pole single-throw switch, with its two ends connected to the inverting input terminal of operational amplifier A1 and the first pole of analog switch S2, respectively. Analog switch S3 is a single-pole single-throw switch, with its two ends connected to contact 3 of analog switch S2 and the output terminal of operational amplifier A1, respectively. Analog switch S4 is a single-pole single-throw switch, connected in series between the contact of analog switch S3 and contact 2 of analog switch S5. The integrator's input signals include: logic control signals, timing control signals, and sensor current signals; its output signal includes: pre-integrated voltage V. int and integral voltage V out The principle of the integrator is as follows: a multi-stage adjustable integrating capacitor composed of integrating capacitors C1 and C2 is connected across the output terminal and the inverting input terminal of the operational amplifier to form an integrating circuit. An analog switch is used to control the adjustment of the integrating capacitor value, the clearing of the integrating capacitor, and the execution of the circuit timing control signal.

3. The infrared detection multi-step integration circuit according to claim 1, characterized in that, The multi-step integration control module comprises seven parts: a comparator, an encoder, a combinational logic circuit, a sample-and-hold circuit, an ADC, a register, and a multi-step integration timing controller. The multi-step integration timing controller is connected to the combinational logic circuit, the encoder, the comparator, and the sample-and-hold circuit via output signal lines. The sample-and-hold circuit is connected to the ADC via an output signal line. The ADC is connected to the register via an output signal line. The comparator is connected to the encoder via an output signal line. The encoder is connected to the combinational logic circuit via an output signal line. The input signals of the multi-step integral control module include: pre-integral voltage V int and integral voltage V out The output signals include: logic control signals and timing control signals. The principle of the multi-step integral control module is as follows: under the drive and control of the multi-step integral timing controller, the comparator will convert the pre-integrated voltage V... int The signal is compared with the set threshold voltage and the result is temporarily stored. Then, the pre-integrated voltage V is... int After the hierarchical comparison is completed, the comparison result is encoded into a control word by an encoder. The obtained control word is input into a combinational logic circuit, mapped to obtain a logic control signal, and then output. Under the action of the logic control signal and the timing control signal, the integrator completes the adaptive adjustment of the integrating capacitor, and then performs formal integration on the sensor current signal. After a fixed integration time is reached, the sample-and-hold circuit adjusts the integrated voltage V. out During sampling and holding, the ADC converts the integrated voltage locked in the sample-and-hold circuit into a digital signal and stores it in a register.

4. The infrared detection multi-step integration circuit according to claim 1, characterized in that, During the pre-integration phase, the pre-integration capacitor C int Connect across operational amplifier A1, disconnect integrating capacitors C1 and C2, and keep the voltage across C1 and C2 zero. The sensor current signal is then connected across the pre-integration capacitor C. int The integrated voltage V on out The comparator, which receives the input in real time, is used to convert the integral voltage V during the pre-integration process. out The voltage is compared three times with a threshold voltage. Each time, the comparator outputs one binary bit. A value less than the threshold voltage is represented by 0. Therefore, the voltage comparison results are: "000", "001", "011", and "111". This result is mapped to a control word by an encoder. The control word uses two binary bits to represent the four output results, respectively represented as "00", "01", "10", and "11". The combinational logic circuit maps the control word to a logic control signal, which in turn controls the analog switch to dynamically combine the integrating capacitors C1 and C2. The specific process of adjusting the integrating capacitors through the control word is as follows: when the control word is "00", the combinational logic circuit controls the integrating capacitors C1 and C2 to be connected in series; when the control word is "01", the combinational logic circuit controls only the integrating capacitor C1 to be connected; when the control word is "10", the combinational logic circuit controls only the integrating capacitor C2 to be connected; when the control word is "11", the combinational logic circuit controls the integrating capacitors C1 and C2 to be connected in parallel. The pre-integration phase ends here. Disconnect and clear the pre-integration capacitor C. int The sensor current signal is integrated by a dynamic combination of integrating capacitors C1 and C2. The high-quality infrared image voltage signal obtained by the integrator is converted into a digital signal by a sample-and-hold circuit and an ADC, and stored in a register for output.

5. The infrared detection multi-step integration circuit according to claim 1, characterized in that, ... With integrating capacitors C1 and C2 being 0.1µF and 0.2µF respectively, four different integrating capacitor values ​​are obtained: C1 and C2 in series, C1 only, C2 only, and C1 and C2 in parallel. The pre-integrating capacitor C... int It lies between the two smaller integrating capacitance values, i.e., 0.067uf < C. int <0.1uf.

6. A control method for an integrator of an infrared signal readout circuit, characterized in that, It is implemented based on the infrared detection multi-step integration circuit according to any one of claims 1-5.

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