Driving circuit of second-class superlattice refrigeration type double-color infrared detector
Patent Information
- Application Number
- CN202510320372.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-18
- Publication Date
- 2025-07-11
Smart Images
Figure CN120295181A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of infrared detectors, and in particular to a driving circuit for a two - color infrared detector of a second - class superlattice refrigeration type. Background Art
[0002] Due to its significant advantages in aspects such as band coverage range, quantum efficiency, structure design, and potential for performance improvement, the second - class superlattice refrigeration type infrared detector has become a key research direction for promoting the development of infrared detection technology. There are many redundant designs in the existing infrared detector driving circuits, with low system integration and poor synchronization of output image data. Therefore, the existing technology is difficult to meet the performance requirements of the second - class superlattice refrigeration type two - color infrared detector, and further improvement and optimization are urgently needed. Summary of the Invention
[0003] The present invention provides a driving circuit for a two - color infrared detector of a second - class superlattice refrigeration type, aiming to solve the defects of many redundant designs, low system integration, and poor synchronization of output image data in the existing infrared detector driving circuits. The circuit of the present invention has high integration and strong synchronization of image data.
[0004] The present invention provides a driving circuit for a two - color infrared detector of a second - class superlattice refrigeration type, including a temperature acquisition module, a central control module, and a driving function module; the driving function module includes a power supply driving module, a timing driving module, a variable reference source module, a state configuration module, an analog operation modulation module, an analog - to - digital conversion module, and an image transmission expansion module; the temperature acquisition module is used to acquire the temperature of the two - color infrared detector of the second - class superlattice refrigeration type; the central control module is used to control the start of the driving function module when the temperature of the two - color infrared detector reaches the working temperature; and to control the shutdown of the driving function module when the operation of the two - color infrared detector ends; the power supply driving module is used to supply power to the two - color infrared detector; the timing driving module is used to provide a timing driving signal to the two - color infrared detector; the variable reference source module is used to provide a reference source signal to the two - color infrared detector and the analog operation modulation module; the state configuration module is used to configure the working state of the two - color infrared detector; the analog operation modulation module is used to perform operations and modulations on the analog image signal output by the two - color infrared detector based on the reference source signal; the analog - to - digital conversion module is used to convert the output signal of the analog operation modulation module from analog to digital image signal; and the image transmission expansion module is used to determine and transmit a two - color infrared image according to the digital image signal.
[0005] A driving circuit for a two-color infrared detector of a type-II superlattice refrigeration type according to the present invention, wherein the temperature acquisition module includes an ambient temperature acquisition circuit and a detector temperature acquisition circuit; the ambient temperature acquisition circuit is used to acquire the ambient temperature, and the detector temperature acquisition circuit is used to acquire the temperature of the two-color infrared detector.
[0006] A driving circuit for a two-color infrared detector of a type-II superlattice refrigeration type according to the present invention, wherein the power supply driving module includes a power supply control and management chip and a functional power supply; the functional power supply includes a digital core power supply, a digital logic power supply, an analog basic power supply, and an analog IO power supply; the power supply control and management chip is used to control the power-on and power-off sequence of the functional power supply based on the power-on and power-off enable signal sent by the central control module; the digital core power supply is used to supply power to the core circuit of the two-color infrared detector, the digital logic power supply is used to supply power to the digital logic interface of the two-color infrared detector, the analog basic power supply is used to supply power to the analog integrated circuit of the two-color infrared detector, and the analog IO power supply is used to supply power to the analog input / output interface of the two-color infrared detector.
[0007] A driving circuit for a two-color infrared detector of a type-II superlattice refrigeration type according to the present invention, wherein the timing driving module includes a first FPGA and a level conversion chip; the first FPGA is used to generate a basic timing signal based on the reference clock signal sent by the central control module, and the level conversion chip is used to perform level conversion on the basic timing signal to obtain the timing driving signal; the timing driving signal includes a clock driving signal, a detector reset signal, a frame synchronization signal, an integration time control signal, and a data synchronization and interaction signal.
[0008] A driving circuit for a two-color infrared detector of a type-II superlattice refrigeration type according to the present invention, wherein the variable reference source module includes a digital-to-analog converter and an operational amplifier; the digital-to-analog converter is used to generate a reference level based on the digital voltage value signal sent by the central control module, and the operational amplifier is used to generate the reference source signal based on the reference level.
[0009] A driving circuit for a two-color infrared detector of a type-II superlattice refrigeration type according to the present invention, wherein the state configuration module includes a second FPGA and an EPROM chip; the EPROM chip is used to store the working state parameters of the two-color infrared detector, and the second FPGA is used to read the working state parameters from the EPROM chip based on the read / write flag signal sent by the central control module to configure the working state of the two-color infrared detector.
[0010] A driving circuit for a two - class superlattice refrigeration type dual - color infrared detector provided by the present invention, wherein the analog operation modulation module includes a single - ended amplifier circuit, a reference source operation circuit, and a differential modulation circuit; the single - ended amplifier circuit is used for single - ended amplifying the analog image signal output by the dual - color infrared detector, the reference source operation circuit is used for generating a modulation reference voltage based on the reference source signal, and the differential modulation circuit is used for differentially modulating the single - ended amplified analog image signal according to the modulation reference voltage to obtain the output signal of the analog operation modulation module.
[0011] A driving circuit for a two - class superlattice refrigeration type dual - color infrared detector provided by the present invention, wherein the central control module is further used for encoding and image pre - processing the digital image signal, and sending the processed dual - color digital image to the image transmission and expansion module.
[0012] A driving circuit for a two - class superlattice refrigeration type dual - color infrared detector provided by the present invention, wherein the image transmission and expansion module is specifically used for, based on the dual - color digital image, shaking hands with the host computer / monitor and confirming the transmission protocol, and then transmitting the dual - color infrared image corresponding to the protocol.
[0013] The present invention also provides an infrared detection system, including a two - class superlattice refrigeration type dual - color infrared detector, and further including the driving circuit of the two - class superlattice refrigeration type dual - color infrared detector as described above.
[0014] A driving circuit for a two - class superlattice refrigeration type dual - color infrared detector provided by the present invention, wherein the temperature acquisition module acquires the temperature of the dual - color infrared detector; the central control module controls the driving function module to start when the temperature of the detector reaches the working temperature, and controls the driving function module to close when the detector ends its operation; the power supply driving module supplies power to the detector; the timing driving module provides a timing driving signal to the detector; the variable reference source module provides a reference source signal to the detector and the analog operation modulation module; the state configuration module configures the working state of the detector; the analog operation modulation module performs operation and modulation on the analog image signal output by the detector based on the reference source signal; the analog - to - digital conversion module converts the output signal of the analog operation modulation module into a digital image signal through analog - to - digital conversion; the image transmission and expansion module determines and transmits the dual - color infrared image according to the digital image signal, with high circuit integration degree and strong image data synchronization. Brief Description of the Drawings
[0015] To more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0016] Figure 1 It is a schematic diagram of the principle of a driving circuit for a two-color infrared detector of a type-II superlattice refrigeration type provided by the present invention.
[0017] Figure 2 It is a schematic diagram of the principle of the temperature acquisition module provided by the present invention.
[0018] Figure 3 It is a schematic diagram of the principle of the power supply driving module provided by the present invention.
[0019] Figure 4 It is a schematic diagram of the principle of the timing driving module provided by the present invention.
[0020] Figure 5 It is a schematic diagram of the principle of the variable reference source module provided by the present invention.
[0021] Figure 6 It is a schematic diagram of the principle of the status configuration module provided by the present invention.
[0022] Figure 7 It is a schematic diagram of the principle of the analog operation modulation module provided by the present invention.
[0023] Figure 8 It is a schematic diagram of the principle of the analog-to-digital conversion module provided by the present invention.
[0024] Figure 9 It is a schematic diagram of the principle of the central control module provided by the present invention.
[0025] Figure 10 It is a schematic diagram of the principle of the image transmission expansion module provided by the present invention. Detailed implementation manners
[0026] To make the objectives, technical solutions and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions in the present invention in conjunction with the drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments in the present invention fall within the scope of protection of the present invention.
[0027] Considering that the existing detector drive circuits cannot meet the functional requirements of the type-II superlattice cooled dual-color infrared detector during normal imaging. The present invention provides a drive circuit for a type-II superlattice cooled dual-color infrared detector, which includes a temperature acquisition module 1, a central control module 2, and a drive function module; the drive function module includes a power supply drive module 3, a timing drive module 4, a variable reference source module 6, a status configuration module 5, an analog operation and modulation module 7, an analog-to-digital conversion module 8, and an image transmission and expansion module 9; the temperature acquisition module 1 is used to acquire the temperature of the type-II superlattice cooled dual-color infrared detector; the central control module 2 is used to control the start of the drive function module when the temperature of the dual-color infrared detector reaches the operating temperature; and to control the shutdown of the drive function module when the operation of the dual-color infrared detector ends; the power supply drive module 3 is used to supply power to the dual-color infrared detector; the timing drive module 4 is used to provide a timing drive signal to the dual-color infrared detector; the variable reference source module 6 is used to provide a reference source signal to the dual-color infrared detector and the analog operation and modulation module 7; the status configuration module 5 is used to configure the operating status of the dual-color infrared detector; the analog operation and modulation module 7 is used to perform operations and modulations on the analog image signal output by the dual-color infrared detector based on the reference source signal; the analog-to-digital conversion module 8 is used to convert the output signal of the analog operation and modulation module 7 from analog to digital to obtain a digital image signal; and the image transmission and expansion module 9 is used to determine and transmit a dual-color infrared image based on the digital image signal.
[0028] Please refer to Figure 1 , Figure 1 which is a schematic diagram of the principle of a drive circuit for a type-II superlattice cooled dual-color infrared detector provided by the present invention.
[0029] The present invention aims to fill the technical gap in the field of detector drive circuits and provides a drive circuit for a type-II superlattice cooled dual-color infrared detector. The circuit consists of a temperature acquisition module 1, a central control module 2, a power supply drive module 3, a timing drive module 4, a variable reference source module 6, a status configuration module 5, an analog operation and modulation module 7, an analog-to-digital conversion module 8, and an image transmission and expansion module 9.
[0030] Before power-on, it is necessary to check whether the connections between the circuit modules are good and whether the connectors are loose.
[0031] Connect the power supply drive module 3, set the power supply voltage in the range of 9 - 18V, and set the maximum current to 1A.
[0032] The circuit is powered on and starts, and each module begins to initialize. The temperature acquisition module 1 starts to work, continuously sending the temperature of the type-II superlattice cooled dual-color infrared detector and the ambient temperature to the central control module 2 to support the stability and reliability of the system.
[0033] After waiting for the dual-color infrared detector to reach the operating temperature, the central control module 2 provides a power-on enable signal to the power supply drive module 3, and the power supply drive module 3 generates the power supply required for the dual-color infrared detector.
[0034] After the power supply of the dual-color infrared detector is stable, the timing drive module 4 generates the basic digital logic signals required for the dual-color infrared detector based on the reference clock signal provided by the central control module 2, including the clock drive signal and the reset signal.
[0035] The central control module 2 sends a start command to the variable reference source module 6 through the SDIO bus, and the variable reference source module 6 sends a reference source signal to the dual-color infrared detector and the analog operation modulation module 7.
[0036] After waiting for 5 ms to ensure the stability of the power supply and digital logic signals, the central control module 2 starts the status configuration module 5 to configure the working status of the dual-color infrared detector according to the application scenario.
[0037] After the status configuration, the dual-color infrared detector enters the normal working state and sends a data synchronization interaction signal to the timing drive module 4.
[0038] After receiving the data synchronization interaction signal, the timing drive module 4 sends a frame synchronization signal, an integration time control signal, and a data synchronization interaction signal to the dual-color infrared detector to control parameters such as the frame rate and integration time of the dual-color infrared detector.
[0039] After the dual-color infrared detector integrates, the short-wave and long-wave images (analog image signals) are read out through 16 analog channels, and the analog operation modulation module 7 modulates the signals of the short-wave analog channel and the long-wave analog channel according to the reference source respectively.
[0040] The modulated short-wave and long-wave analog signals are encoded into 16 LVDS18 differential digital signals (digital image signals) through the analog-to-digital conversion circuit and can be transmitted to the central control module 2 through the inter-board connector.
[0041] After the central control module 2 and the image transmission expansion module 9 handshake with the upper computer / monitor and confirm the transmission protocol, a frame of short-wave and long-wave dual-color infrared image corresponding to the protocol is transmitted.
[0042] The above steps can be repeated during normal operation.
[0043] After the work is completed, the central control module 2 pulls down the power-on and power-off enable signals to power down the dual-color infrared detector sequentially.
[0044] The circuit of the present invention can provide the power supply, reference source and precise timing drive signal required for the normal operation of the detector, and support flexible adjustment of the detector parameters in the short-wave and long-wave working bands according to user needs. At the same time, it can achieve efficient acquisition, precise processing and multi-protocol stable output of the dual-color image signal, thereby greatly improving the comprehensive performance of the detection system and meeting its requirements in practical applications.
[0045] It should be noted that: The short-wave infrared (SWIR, Short-Wave Infrared) has a wavelength range in the electromagnetic spectrum band from 1000 nanometers (1 µm) to 2500 nanometers (2.5 µm). The infrared light in this range cannot be directly seen by the human eye, but can be captured by specific sensors and detectors. SWIR light has unique characteristics, making it widely used in scientific research, industrial inspection and the defense field.
[0046] The long-wave infrared (LWIR, Long-Wave Infrared) has a wavelength range in the electromagnetic spectrum band from 8 µm (8000 nanometers) to 14 µm (14000 nanometers). The infrared light in this range mainly exists in the form of thermal radiation, and the thermal energy of an object is particularly significant in this wavelength band, usually closely related to temperature measurement and thermal imaging.
[0047] Please refer to Figure 2 , Figure 2 which is the schematic diagram of the principle of the temperature acquisition module provided by the present invention.
[0048] As a preferred embodiment, the temperature acquisition module 1 includes an ambient temperature acquisition circuit and a detector temperature acquisition circuit; the ambient temperature acquisition circuit is used to acquire the ambient temperature, and the detector temperature acquisition circuit is used to acquire the temperature of the dual-color infrared detector.
[0049] In this embodiment, the temperature acquisition module 1 includes an ambient temperature acquisition circuit and a detector temperature acquisition circuit. The detector temperature acquisition circuit uses a voltage comparator and its peripheral circuits to continuously acquire the temperature of the dual-color infrared detector. The detector will output differential level signals internally, and the voltage comparator converts these differential signals into digital values, representing the temperature inside the detector. The ambient temperature acquisition circuit uses a temperature sensor to continuously detect the external ambient temperature and converts it into a digital value for further processing and monitoring. The ambient temperature and the detector temperature are transmitted back to the central control module 2 through the IIC protocol respectively.
[0050] The model of the voltage comparator selected in the present invention is CS1237, and the model of the temperature sensor selected is AD7414.
[0051] Please refer to Figure 3 , Figure 3Schematic diagram of the principle of the power drive module provided by the present invention.
[0052] As a preferred embodiment, the power drive module 3 includes a power control and management chip and a functional power supply; the functional power supply includes a digital core power supply, a digital logic power supply, an analog basic power supply, and an analog IO power supply; the power control and management chip is used to control the power-on and power-off sequence of the functional power supply based on the power-on and power-off enable signals sent by the central control module 2; the digital core power supply is used to supply power to the core circuit of the dual-color infrared detector, the digital logic power supply is used to supply power to the digital logic interface of the dual-color infrared detector, the analog basic power supply is used to supply power to the analog integrated circuit of the dual-color infrared detector, and the analog IO power supply is used to supply power to the analog input / output interface of the dual-color infrared detector.
[0053] In this embodiment, the power drive module 3 provides the ultra-low noise and high-current digital power supply and analog power supply required by the dual-color infrared detector, which are used to drive the ROIC (Readout Integrated Circuit) integrated on the dual-color infrared detector chip. The driving ability of this module is greater than the maximum power consumption required by the detector, which is 310 mW, ensuring the stable operation of the detector.
[0054] Specifically, the power drive module 3 includes a power control and management chip, a digital core power supply, a digital logic power supply, an analog basic power supply, and an analog IO power supply. The power drive module 3 can implement multiple power rails required by the dual-color infrared detector, including digital power rails and analog power rails. The power drive module 3 receives the power-on enable signal sent by the central control module 2, starts the power control and management chip, and supplies power to the detector strictly in the power-on sequence. The power-on sequence follows the requirement of "digital first and then analog", and supplies power to the digital core power supply (VDD_AUX), digital logic power supply (VDD33), analog basic power supply (AVDD38), and analog IO power supply (AVDD_IO) in sequence. The power-off sequence follows the principle of "analog first and then digital" to ensure the safe shutdown of the detector. The power-on interval is adjusted by replacing the configuration resistor to ensure the stable operation of the dual-color infrared detector.
[0055] The model of the power control and management chip selected in the present invention is TPS7H3014-SP. This chip is used to control the power-on and power-off sequence of the power supply to ensure the stable operation of the dual-color infrared detector. The low-dropout voltage regulator chips corresponding to each power supply are selected as follows: LT1763 or ET63118 for VDD_AUX; LT1762 or ME6212 series for VDD33; TPS76138 for AVDD38; and LT3074 for AVDD_IO.
[0056] Please refer to Figure 4 , Figure 4 Schematic diagram of the principle of the timing drive module provided by the present invention.
[0057] As a preferred embodiment, the timing drive module 4 includes a first FPGA and a level conversion chip; the first FPGA is used to generate a basic timing signal based on the reference clock signal sent by the central control module 2, and the level conversion chip is used to perform level conversion on the basic timing signal to obtain a timing drive signal; the timing drive signal includes a clock drive signal, a detector reset signal, a frame synchronization signal, an integration time control signal, and a data synchronization interaction signal.
[0058] In this embodiment, the timing drive module 4 provides a timing drive signal to the dual-color infrared detector, including a clock drive signal (CLK), a detector reset signal (RST), a frame synchronization signal (FVAL), a data synchronization interaction signal (DIO), and (INT).
[0059] Specifically, the timing drive module 4 includes a first FPGA, a level conversion chip, and its peripheral circuits. The reference clock signal is provided by the central control module 2. The first FPGA generates a basic timing signal and performs level conversion processing through the level conversion chip, which can improve the signal quality and enhance the driving ability of the digital timing signal to obtain a timing drive signal. The selected model of the level conversion chip is SN74LVC4245A.
[0060] The timing drive module 4 supports flexible timing adjustment, including: the adjustable range of the operating clock is 1~20 MHz; the adjustable range of the frame rates of the short-wave and long-wave output images is 1~120 frames; the independent adjustable range of the integration times of the short-wave and long-wave is 190 μs~900 ms.
[0061] It should be noted that: FPGA (Field-Programmable Gate Array) is an integrated circuit based on programmable logic devices, allowing users to define hardware logic functions through programming. Different from the application-specific integrated circuit (ASIC) with fixed functions, the logic function of the FPGA can be reprogrammed multiple times after leaving the factory, which gives it high flexibility and wide adaptability.
[0062] Please refer to Figure 5 , Figure 5 which is the schematic diagram of the principle of the variable reference source module provided by the present invention.
[0063] As a preferred embodiment, the variable reference source module 6 includes a digital-to-analog converter and an operational amplifier; the digital-to-analog converter is used to generate a reference level based on the digital voltage value signal sent by the central control module 2, and the operational amplifier is used to generate a reference source signal based on the reference level.
[0064] In this embodiment, the variable reference source module 6 provides a reference source signal with high precision, large range, and low noise to the detector according to the digital voltage value signal of the central control module 2. The reference source signal can adjust the range and average value of the analog output signal of the detector, and provide the required level reference for the analog operation modulation module 7.
[0065] Specifically, the variable reference source module 6 includes a digital-to-analog converter, an operational amplifier, and their peripheral circuits. The digital-to-analog converter (DAC, Digital-to-Analog Converter) receives the input of the digital voltage value signal from the central control module 2 and converts it into an adjustable reference level through the SDIO interface. The operational amplifier generates a short-long wave reference source voltage with high driving ability and low noise based on the reference level and provides it for use by the dual-color detector. The variable reference source module 6 supports independent adjustment of the short-wave bias reference voltage, long-wave bias reference voltage, short-wave reset reference voltage, long-wave reset reference voltage, short-wave upper limit reference voltage, and long-wave upper limit reference voltage. The variable reference source module 6 supports providing a level reference for the analog operation modulation module 7.
[0066] The selected DAC model of the present invention is DAC80516 or DAC80508, and the selected operational amplifier model is ADA4806 or LTC6252. With the selected devices, each voltage is independently adjustable, the adjustment accuracy is 1 mV, and the adjustment range is 0 to 4.0 V.
[0067] It should be noted that: GPOL (Gate Polarization Voltage) refers to the bias voltage of the photodiode in the detector, which is used to adjust the gate voltage of the MOSFET or similar structure in the detector to make it work under optimal conditions. By adjusting the GPOL voltage, the reverse bias can be controlled, thereby affecting its response characteristics and noise level. In an infrared detector, the GPOL voltage is usually used to adjust or control the potential of the gate, thereby optimizing the performance of the device, such as improving the signal-to-noise ratio or adjusting the sensitivity.
[0068] Please refer to Figure 6 , Figure 6 which is a schematic diagram of the principle of the state configuration module provided by the present invention.
[0069] As a preferred embodiment, the state configuration module 5 includes a second FPGA and an EPROM chip; the EPROM chip is used to store the working state parameters of the dual-color infrared detector, and the second FPGA is used to read the working state parameters from the EPROM chip based on the read-write flag signal sent by the central control module 2 to configure the working state of the dual-color infrared detector.
[0070] In this embodiment, when powered on or reset, the status configuration module 5 adjusts the basic working state parameters by configuring the on-chip registers of the dual-color infrared detector, including the number of output channels, the number of working bands, the gain magnitudes of different bands, the window size, the integration capacitance, etc., to meet various working requirements.
[0071] Specifically, the status configuration module 5 includes a second FPGA and an EPROM (Erasable Programmable Read-Only Memory) chip and its peripheral circuits. The EPROM chip stores various working state parameters of the dual-color infrared detector, which are stored at specific addresses in the EPROM. After the system is powered on, the second FPGA receives the read-write flag signal, and the second FPGA reads the corresponding working state parameter data from the EPROM chip according to the read-write flag signal. The data is sequentially written into the on-chip registers of the detector through the configuration signal (REG0) to complete the configuration writing of the basic working state of the detector. After the second FPGA confirms the configuration writing through the register read signal (REG1), the status configuration module 5 enters the sleep state. The EPROM chip can adopt DS2505+. The status configuration module 5 realizes the fast loading and configuration of the working state of the detector, and has high flexibility and automation.
[0072] Please refer to Figure 7 , Figure 7 which is the schematic diagram of the principle of the analog operation modulation module provided by the present invention.
[0073] As a preferred embodiment, the analog operation modulation module 7 includes a single-ended amplifier circuit, a reference source operation circuit, and a differential modulation circuit; the single-ended amplifier circuit is used to perform single-ended amplification on the analog image signal output by the dual-color infrared detector, the reference source operation circuit is used to generate a modulation reference voltage based on the reference source signal, and the differential modulation circuit is used to perform differential modulation on the single-ended amplified analog image signal according to the modulation reference voltage to obtain the output signal of the analog operation modulation module 7.
[0074] In this embodiment, the analog operation modulation module 7 performs operations and modulations on the 16-channel analog image signal output by the dual-color infrared detector to enhance the signal's load-carrying capacity. At the same time, the dynamic range is optimized by adjusting the upper and lower limit ranges of the signal.
[0075] Specifically, the analog operation modulation module 7 includes a single-ended amplification circuit (a short-wave 8-channel signal single-ended amplification circuit and a long-wave 8-channel signal single-ended amplification circuit), a reference source operation circuit (a short-wave reference source operation circuit and a long-wave reference source operation circuit), and a differential modulation circuit (a short-wave 8-channel signal differential modulation circuit and a long-wave 8-channel differential modulation circuit). The single-ended amplification circuit processes 16-channel analog image signals, with 8 channels of short-wave and 8 channels of long-wave image signals each. The analog image signals 1. First, enhance the driving ability through the single-ended amplification circuit, and the waveform of the amplified signal remains unchanged. The reference source operation circuit generates modulation reference voltages for short-wave and long-wave based on the reference source signal. Taking the short-wave as an example, the short-wave modulation reference voltage can be expressed as: , where is the short-wave upper limit reference voltage, is the short-wave reset reference voltage.
[0076] The voltage value of the modulated short-wave first-channel differential signal and the voltage value of the original short-wave first-channel signal The relationship can be expressed as: , where is the feedback resistor, is the input resistor.
[0077] The single-ended amplified analog image signals are respectively DC-coupled with the corresponding modulation reference voltages through the short-wave and long-wave differential modulation circuits according to the band; after modulation, the single-ended signals are converted into differential signals, and the signal range is adjusted to adapt to the input requirements of the analog-to-digital conversion module 8.
[0078] The model number of the operational amplifier used in the single-ended amplification circuit selected in the present invention is AD8065, and the model number of the operational amplifier used in the differential modulation circuit selected is ADA4945.
[0079] Please refer to Figure 8 , Figure 8 which is the schematic diagram of the principle of the analog-to-digital conversion module provided by the present invention.
[0080] The analog-to-digital conversion module 8 processes the modulated 16-channel analog image signals through a high-speed ADC, and cross-codes them into 16-channel LVDS18 differential signals according to the clock cycle, providing an efficient digital output (digital image signals).
[0081] Specifically, the analog-to-digital conversion module 8 includes an LVDS clock source, an SPI configuration chip, a 16-channel analog-to-digital conversion chip, and its peripheral circuits. The 16-channel image signals of the analog operation modulation module 7 are input into the analog-to-digital conversion chip for conversion from analog signals to digital signals. After analog-to-digital conversion, the image signals are encoded in two's complement format. The converted 16-channel digital signals generate 16-channel LVDS18 differential image signals, which are suitable for subsequent processing and transmission.
[0082] Optional models of the analog-to-digital conversion chip of the present invention include AD9249BBCZ, AD9257-40, AD9253-80, or LTC2171-14. The selected chip model of the LVDS clock source chip is SIT9121AI-2B1-33E65.000000E, and the selected SPI (Serial Peripheral Interface) configuration chip model is W25Q64JVZPIQ.
[0083] It should be noted that: An ADC (Analog-to-Digital Converter) is an electronic chip whose function is to convert continuous analog signals (such as voltage or current) into discrete digital signals. This conversion process is the key interface between analog signal processing and digital signal processing in modern electronic systems.
[0084] LVDS18 (Low-Voltage Differential Signal 1.8V) is a differential signal transmission technology with a low voltage swing, having advantages such as low power consumption, low noise, low crosstalk, and high transmission rate.
[0085] Please refer to Figure 9 , Figure 9 which is the schematic diagram of the principle of the central control module provided by the present invention.
[0086] As a preferred embodiment, the central control module 2 is also used to encode and preprocess the digital image signals, and send the processed two-color digital images to the image transmission expansion module 9.
[0087] In this embodiment, the central control module 2 takes the FPGA as the core and is the control center of the entire system. Its main functions include controlling and coordinating the normal operation of each functional module, decoding LVDS18 differential signals, and preprocessing two-color image data to provide high-quality short-wave and long-wave two-color infrared image data output.
[0088] Specifically, the central control module 2 includes an FPGA, a DDR3, a FLASH, and peripheral circuits and connectors. The central control module 2 coordinates all modules through the FPGA, executes complex image processing tasks, and effectively manages the image data stream. The FPGA has the advantages of parallel processing, flexibility, generality, high efficiency, and low power consumption. In addition to the GPIO in the FPGA being used to control and coordinate other modules, the on-chip logic resources such as LUT, REG, and DSP48 can simultaneously decode short-long dual-color images, read algorithm parameters from the FLASH, perform non-uniform correction on the short-long dual-color images, execute the inter-frame image preprocessing algorithm. During the processing, the DDR3 chip serves as an off-chip image cache, and the short-long wave dual-color image after image preprocessing is connected to the image expansion output module through parallel image pins.
[0089] The selected FPGA model for this invention is XC7A50T, the selected FLASH chip is W25Q128JVSIQ, the selected DDR3 chip is MT41K256M16TW-107, the selected differential signal connector is DF36-40P-0.4SD, the selected module interaction connector is AFC24-S50FIC-00, and the selected parallel image connector is DF40C-60DP-0.4V(51).
[0090] It should be noted that: DDR3 (Double Data Rate 3 Synchronous Dynamic Random-Access Memory, the third-generation double data rate synchronous dynamic random access memory) is a computer memory technology and belongs to the third-generation standard of SDRAM (synchronous dynamic random access memory). The data transfer rate range of DDR3 is usually 800MT / s to 2133MT / s (million transfers per second), corresponding to frequencies of 400MHz to 1066MHz, and can be applied to desktop computers, laptops, servers, and embedded systems.
[0091] ROIC (Readout Integrated Circuit) is responsible for converting the signals captured by sensors (such as infrared focal plane arrays) into processable electrical signals.
[0092] NOR Flash (NOR-type Flash Memory) is a type of non-volatile memory and belongs to a category of Flash Memory. Its name comes from the connection method of its internal storage units, which is similar to the "NOR gate" structure in digital logic circuits. The main feature of NOR Flash is that it supports random access, allowing direct reading of data from storage units, similar to the addressing method of traditional memories.
[0093] Please refer to Figure 10 , Figure 10 which is a schematic diagram of the principle of the image transmission expansion module provided by the present invention.
[0094] As a preferred embodiment, the image transmission expansion module 9 is specifically configured to transmit a dual-color infrared image corresponding to a protocol after shaking hands with and confirming the transmission protocol with a host computer / monitor based on a dual-color digital image.
[0095] In this embodiment, the image transmission expansion module 9 is interconnected with the central control module 2 through an inter-board connector. By configuring general-purpose parallel differential pins and controlling a high-speed signal gating circuit, the function of transmitting dual-color infrared image signals with different protocols is realized. Through software and hardware cooperation, the image transmission expansion module 9 can flexibly switch between multiple communication protocols without replacing hardware, adapting to diverse application scenarios.
[0096] Specifically, the image transmission expansion module 9 includes a high-speed signal gating chip, an MIPI (Mobile Industry Processor Interface) level bridging chip, a TDMS protocol conversion chip, a PAL encoding chip, a CML parallel-serial conversion chip, and its peripheral circuits. The image transmission expansion module 9 has the function of supporting multiple image transmission protocols. Through the coordinated work of software programs and hardware circuits, differential GPIO multiplexing is achieved, and a limited number of differential GPIOs are transmitted to the corresponding video chips through a high-speed signal gater; the control signals of different communication protocols are connected to a single-selected GPIO through the gater to achieve two-way communication, such as the CEC function of HDMI; it can encode short-wave and long-wave dual-color images into any one of the supported transmission protocols according to the type of the host computer (or monitor). The supported transmission protocols include Camera Serial Interface (MIPI CSI-2), Display Serial Interface (MIPI DSI), High Definition Multimedia Interface (HDMI), DisplayPort (DP), Phase Alteration Line (PAL), and Current Mode Logic (CML), a total of six video formats. In addition, the image transmission expansion module 9 supports independent encoding and hybrid encoding of short-wave and long-wave images, improving the compatibility of the usage scenarios of the present invention. It can be connected to the host computer through common acquisition devices and also meet the functional requirements such as simultaneous display, separate display, and CEC control of dual-color images using a monitor.
[0097] The selected MIPI level bridging chip model of the present invention is LT8918, the selected TDMS protocol conversion chip is IT6251FN, the selected CML chip model is TLK1501, and the selected PAL encoding chip is ADV7392.
[0098] The beneficial effects of the present invention are as follows: The present invention can drive a type-II superlattice cooled short-wave and long-wave dual-color infrared detector, meeting its strict requirements for power supply, reference source, and timing signals.
[0099] The present invention can modulate and efficiently acquire the dual-color 16-channel analog signals output by the detector, ensuring signal integrity.
[0100] The present invention can achieve precise processing and stable output of dual-color infrared image data, meeting the requirements of high-quality imaging.
[0101] The present invention adopts a highly modular system architecture. By replacing some modules, it can easily adapt to different models of type-II superlattice cooled dual-color detectors. This flexibility enables this circuit solution to be applicable not only to the current detector models but also to have certain reference value and scalability for the design of other type-II superlattice cooled dual-color detection imaging circuits in the future.
[0102] The circuit architecture of the present invention supports multiple output formats through software configuration, including electrical interfaces and data protocols such as MIPI CSI-2, MIPI DSI, HDMI, DP, CML, and PAL. This design provides wide interface compatibility for subsequent advanced image processing tasks and can meet the requirements of various application scenarios.
[0103] The circuit solution provided by the present invention can not only effectively exert the overall performance of the dual-color infrared detector but also provide a highly integrated and scalable solution idea for the design of the driving and signal processing circuits of similar detectors. Its flexibility and versatility make it have important application prospects and play a role in promoting technology in the future infrared detection technology field.
[0104] The infrared detection system provided by the present invention will be described below. The infrared detection system described below can be correspondingly referred to the driving circuit of the type-II superlattice cooled dual-color infrared detector described above.
[0105] The present invention also provides an infrared detection system, which includes a type-II superlattice cooled dual-color infrared detector and also includes the driving circuit of the above-mentioned type-II superlattice cooled dual-color infrared detector.
[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.
Claims
1. A driving circuit for a two-color infrared detector of a type-II superlattice refrigeration type, characterized in that, It includes a temperature acquisition module, a central control module, and a drive function module; the drive function module includes a power supply drive module, a timing drive module, a variable reference source module, a status configuration module, an analog operation modulation module, an analog-to-digital conversion module, and an image transmission expansion module; The temperature acquisition module is used to acquire the temperature of a two-color infrared detector of a type-II superlattice refrigeration type; The central control module is used to control the start of the drive function module when the temperature of the two-color infrared detector reaches the operating temperature; and to control the shutdown of the drive function module when the operation of the two-color infrared detector ends; The power supply drive module is used to supply power to the two-color infrared detector; The timing drive module is used to provide a timing drive signal to the two-color infrared detector; The variable reference source module is used to provide a reference source signal to the two-color infrared detector and the analog operation modulation module; The status configuration module is used to configure the operating status of the two-color infrared detector; The analog operation modulation module is used to perform operations and modulation on the analog image signal output by the two-color infrared detector based on the reference source signal; The analog-to-digital conversion module is used to convert the output signal of the analog operation modulation module from analog to digital to obtain a digital image signal; The image transmission expansion module is used to determine and transmit a two-color infrared image based on the digital image signal.
2. The driving circuit of the two-color infrared detector of the second-class superlattice refrigeration type according to claim 1, wherein, The temperature acquisition module includes an ambient temperature acquisition circuit and a detector temperature acquisition circuit; the ambient temperature acquisition circuit is used to acquire the ambient temperature, and the detector temperature acquisition circuit is used to acquire the temperature of the two-color infrared detector.
3. The driving circuit of the two-color infrared detector of the second-class superlattice refrigeration type according to claim 1, characterized in that, The power supply drive module includes a power supply control management chip and a functional power supply; the functional power supply includes a digital core power supply, a digital logic power supply, an analog basic power supply, and an analog IO power supply; the power supply control management chip is used to control the power-on and power-off sequence of the functional power supply based on the power-on and power-off enable signal sent by the central control module; the digital core power supply is used to supply power to the core circuit of the two-color infrared detector, the digital logic power supply is used to supply power to the digital logic interface of the two-color infrared detector, the analog basic power supply is used to supply power to the analog integrated circuit of the two-color infrared detector, and the analog IO power supply is used to supply power to the analog input / output interface of the two-color infrared detector.
4. The drive circuit of the two-color infrared detector of the second-class superlattice refrigeration type according to claim 1, characterized in that, The timing drive module includes a first FPGA and a level conversion chip; the first FPGA is used to generate a basic timing signal based on the reference clock signal sent by the central control module, and the level conversion chip is used to perform level conversion on the basic timing signal to obtain the timing drive signal; The timing drive signal includes a clock drive signal, a detector reset signal, a frame synchronization signal, an integration time control signal, and a data synchronization and interaction signal.
5. The driving circuit of the two-color infrared detector of the second-class superlattice refrigeration type according to claim 1, characterized in that, The variable reference source module includes a digital-to-analog converter and an operational amplifier; the digital-to-analog converter is used to generate a reference level based on the digital voltage value signal sent by the central control module, and the operational amplifier is used to generate the reference source signal based on the reference level.
6. The drive circuit of the two-color infrared detector of the second-class superlattice refrigeration type according to claim 1, characterized in that, The state configuration module includes a second FPGA and an EPROM chip; the EPROM chip is used to store the operating state parameters of the dual-color infrared detector, and the second FPGA is used to read the operating state parameters from the EPROM chip based on the read-write flag signal sent by the central control module to configure the operating state of the dual-color infrared detector.
7. The driving circuit of the two-color infrared detector of the second-class superlattice refrigeration type according to claim 1, characterized in that, The analog operation modulation module includes a single-ended amplifier circuit, a reference source operation circuit, and a differential modulation circuit; the single-ended amplifier circuit is used to perform single-ended amplification on the analog image signal output by the dual-color infrared detector, the reference source operation circuit is used to generate a modulation reference voltage based on the reference source signal, and the differential modulation circuit is used to perform differential modulation on the single-ended amplified analog image signal according to the modulation reference voltage to obtain the output signal of the analog operation modulation module.
8. The driving circuit of the two-color infrared detector of the second-class superlattice refrigeration type according to any one of claims 1 to 7, characterized in that, The central control module is further used to encode and preprocess the digital image signal and send the processed dual-color digital image to the image transmission expansion module.
9. The driving circuit of the two-color infrared detector of the second-class superlattice refrigeration type according to claim 8, characterized in that, The image transmission expansion module is specifically used to transmit the dual-color infrared image corresponding to the protocol after shaking hands with the host computer / monitor and confirming the transmission protocol based on the dual-color digital image.
10. An infrared detection system, characterized in that, It includes a dual-color infrared detector of type-II superlattice refrigeration type, and also includes the drive circuit of the dual-color infrared detector of type-II superlattice refrigeration type according to any one of claims 1 to 9.