302 results about "Large dynamic range" patented technology

The present disclosure relates to an active graded magnetic compensation system and method for an unshielded SERF magnetometer. The system comprises: a detection laser, a half-wave plate, a magnetic field compensation coil, a magnetic field modulation coil, a non-magnetic heating assembly, an alkali-metal atomic vapor cell, a polarizing beam splitter prism, a balanced photodetector, a graded feedback control module, a pump laser, a quarter-wave plate, a focusing lens and a photodetector. By means of the present disclosure, a graded compensation system is used to realize high-precision compensation for a magnetic field within a large dynamic range in a geomagnetic environment, thereby ensuring that an instrument carries out high-sensitivity magnetic field measurement under geomagnetic conditions.

An optical frequency domain reflectometer with environmental disturbance resistance and large strain measurement capability belongs to the field of distributed optical fiber sensing and comprises an opposite sweep frequency light frequency modulation continuous wave signal generation module, a light splitting device, a modulation device, a circulator, a polarization controller, an optical coupling device, a photoelectric conversion module and a data acquisition and processing module. An optical signal generated by an opposite sweep frequency light frequency modulation continuous wave signal generation module is divided into probe light and local oscillation light through a light splitting device, the probe light is modulated through a modulation device and sent to an optical fiber through a circulator, and a Rayleigh back scattering light signal generated by the optical fiber and the local oscillation light interfere in an optical coupling device to obtain interference light; the photoelectric conversion module mixes beat frequency signals of interference light, and the data acquisition and processing module analyzes and processes the beat frequency signals. According to the invention, the position information of the Rayleigh backscattering point is marked by using the modulated probe light, the Rayleigh scattering signal at the corresponding position is restored, crosstalk between channels is inhibited, and high-precision measurement in a large dynamic range and resistant to environmental disturbance is realized.

The invention provides a lighting device and a dark field detection system and method, and the method comprises the steps: carrying out the pre-detection of the distribution positions of bright defects and dark defects on the surface of a to-be-detected wafer based on a wide-view-field imaging device, and obtaining a defect distribution map of the to-be-detected wafer; classifying the brightness degree of each defect in the defect distribution map, and obtaining light source brightness level distribution corresponding to each position of the wafer to be detected; in the dark field detection device, a light source is provided for a to-be-detected area of a to-be-detected wafer based on linear illumination light, each to-be-detected area on the to-be-detected wafer is scanned, the intensity of a detection light signal is regulated and controlled according to the brightness level of the corresponding light source, and the adjusted detection light signal is collected so as to realize dark field detection. During dark field detection, the detection sensitivity consistency of different pixel positions is good, the light source intensity utilization rate is high, and the image acquisition dynamic range is large.

The invention provides a correlated double-sampling program-controlled gain amplifier for a high-energy particle detection pixel sensor and an implementation method, and solves the technical problem that a large dynamic range and high readout precision cannot be considered at the same time during existing high-energy particle detection. The circuit comprises a correlated double-sampling circuit, a signal polarity conversion circuit, an amplification feedback circuit and a configuration automatic judgment circuit. The correlated double sampling circuit is used for performing double sampling on the output voltage of the pixel signal to obtain twice sampling voltage; the configuration automatic judgment circuit is used for selecting configurations for switching according to the voltage difference between the two sampling voltages to obtain an output signal; and the amplification feedback circuit is used for performing fixed gain voltage amplification on the output signal to obtain an amplified voltage signal. The circuit can be widely applied to the technical field of integrated circuits.

The invention discloses a semi-aviation transient electromagnetic signal adaptive gain method and system, and relates to the technical field of geophysical exploration, and the method comprises the steps: obtaining a differential signal of a receiving coil, and carrying out the chopping self-stabilization zero amplification processing of the differential signal; the method comprises the following steps: dividing a total time window of a differential signal into a plurality of time channels under a set time reference, adjusting the length of each time channel according to a signal attenuation characteristic, calculating the time length and data point number of each time channel according to a sampling rate and the total time window, and calculating the time length and data point number of each time channel; the data points are distributed to an early time channel, a middle time channel and a late time channel, so that different gain multiples are switched, and adaptive gain amplification is carried out; and the differential signal subjected to adaptive gain amplification is transmitted to a receiver after being collected by an ADC (Analog to Digital Converter). By dynamically adjusting the gain coefficient in different time channels, the technical problems of large dynamic range of transient electromagnetic signals and low signal-to-noise ratio of weak signals are solved, and high-fidelity acquisition of full-time-domain signals is realized.

The invention relates to optical fiber channel security detection, in particular to an optical transport network equipment channel security detection system and method based on quantum measurement and an optical time domain quantum detection device, which are used for carrying out signal detection with high spatial resolution and large dynamic range based on quantum measurement and realizing high-precision sensing of multi-dimensional parameters of an optical fiber channel. The main control software is applied to realize equipment control, data processing and analysis based on an artificial intelligence algorithm and application layer communication; the optical transport network equipment performs information interaction with the application master control software through the management and control system and executes a corresponding security policy; the wave combination control module is used for carrying out beam combination on the optical signal output by the optical time domain quantum detection device and a service signal output by the optical transport network equipment, entering an optical fiber channel and controlling to switch a detection line; according to the technical scheme, the defects that high-spatial-resolution and large-dynamic-range signal detection is difficult to carry out, and accurate event type judgment and high-precision spatial discrimination cannot be carried out on tiny loss events can be overcome.

The invention discloses an image sonar gain adaptive control method based on an FPGA. The method comprises the following steps: an upper computer sends a control message carrying a manual gain parameter to a sonar signal processing board based on an Ethernet UDP protocol so as to execute manual gain control; a codeword gain and voltage gain cooperative control architecture is provided; pID closed-loop feedback control is carried out based on beam pattern characteristics, and when a manual gain value changing message issued by the Ethernet is received, the adaptive gain compensation value and the PID historical state are cleared, and the manual gain code is switched to an instruction specified value. According to the invention, conflict-free switching between a self-adaptive mode and a manual mode can be realized, and in addition, the quality of sonar images and the stability of gain regulation and control are improved while large dynamic range and high-precision adjustment of time-varying gain are realized.

The present application discloses a low-cost and high-performance radio-frequency amplifier, comprising an input stage circuit, a common-gate stage circuit, and an output load circuit. The input stage circuit implements conversion from a single-ended signal to a differential signal, implements input impedance matching, and converts an inputted radio-frequency voltage signal into a radio-frequency current signal. The input stage circuit comprises a first three-coil transformer, consisting of a primary coil, a secondary coil, and a third coil. The common-gate stage circuit transmits the radio-frequency current signal outputted by the input stage circuit to the output load circuit, increases the withstand voltage and equivalent output impedance of the circuit, and implements gain control in at least two modes. The output load circuit converts the radio-frequency current signal from the common-gate stage circuit into a radio-frequency voltage signal, implements conversion from a differential signal to a single-ended signal, and outputs an amplified radio-frequency voltage signal. The present application provides a radio-frequency amplifier having a small size, broadband matching, high linearity, a large dynamic range, and low design complexity.

An SIP module integrated direct wave amplifier comprises a power supply control module, an X-band down-conversion module and an L-band down-conversion module, the power supply control module provides attenuation control signals and a low-ripple power supply for the X-band down-conversion module and the L-band down-conversion module, the X-band down-conversion module performs primary frequency conversion on externally received radio frequency signals, and the L-band down-conversion module performs secondary frequency conversion on the externally received radio frequency signals. The L-band down-conversion module performs secondary frequency conversion on the radio frequency signal subjected to primary frequency conversion by the X-band down-conversion module, the two down-conversion modules are arranged to realize structure modularization and standardization by adopting a SiP modularization mode, and each module is independent in function, so that the structure is simple, the cost is low, and the cost is low. Meanwhile, the serial-parallel conversion chip control circuit is adopted to control the numerical control attenuator to meet the requirements for high gain and large dynamic range of the direct wave amplifier, the architecture and the number of control circuits are simplified, and the circuit is easy to build, easy to use, convenient to integrate and high in selection flexibility.

The invention relates to the technical field of wafer detection, in particular to a wafer surface pollution defect detection method and device, and the method comprises the steps: carrying out the dark field shooting of a target wafer, obtaining a surface dark field scattering image of the wafer, traversing each pixel in the dark field image, forming an SNR estimation graph through the neighborhood setting and SNR estimation calculation, and carrying out the detection of the surface pollution defect of the wafer. Global threshold segmentation is carried out on the SNR estimation image through a double-threshold principle to obtain a low-threshold binary image and a high-threshold binary image, a connected region in the low-threshold binary image is traversed, if at least one pixel in the connected region is marked as a defect in the high-threshold binary image, all pixels in the connected region are marked as real defects, and if at least one pixel in the connected region is marked as a defect in the high-threshold binary image, all pixels in the connected region are marked as real defects. Otherwise, marking the defect as a pseudo defect. According to the invention, under the conditions of large dynamic range of background noise, small number of defect pixels, weak defect signals and the like, defects and defect contours can still be detected stably.

The invention relates to the field of spaceflight measurement and control, and discloses a large-scale constellation multiple access measurement and control spread spectrum signal de-spreading bit width quantization method. Signal samples are counted, a noise deterioration factor and a bit width quantification model are respectively established, the de-spreading bit width is accurately expanded, and the optimal balance of resources and performance is realized. The method solves the problem that the detection range of strong and weak signals is limited when a single receiver detects multi-satellite same-frequency signals at the same time, remarkably improves the system capacity, and has the characteristics of quantizability, large dynamic range and multi-constellation adaptation.

The present invention relates to a simple VHF frequency band channel transceiver, belonging to the technical field of very high frequency transceivers. It is composed of a device box and a circuit board. The device box is composed of a shell, a cover plate and a shielding cavity. The receiving / transmitting channel module installed on the circuit board contains a receiving circuit, a transmitting circuit and a power supply circuit; the receiving circuit is composed of a low-noise amplifier frequency selection, mixing, intermediate frequency amplification, intermediate frequency crystal filtering, automatic gain control, receiving demodulation and receiving frequency synthesis circuit; the transmitting circuit is composed of a transmitting frequency synthesis, a transmitting pre-stage drive amplifier, a transmitting post-stage drive amplifier and a power detection circuit; a plurality of shielding cavities are milled in the shell and the cover plate, and the shielding cavities are respectively equipped with individual module circuits of the receiving circuit and the transmitting circuit, and the shell and the cover plate are sealed and shielded for the circuit board. The integrated design of the transceiver channel machine and the radio frequency carrier 4FSK digital signal modulation are realized. The receiving intermediate frequency, image frequency, intermodulation and spurious response indicators are excellent, the multi-channel operation has no crosstalk, the analog sensitivity is high, the volume is small, the noise is small, the harmonic spurious suppression is high, and the receiving dynamic range is large.

The invention discloses a large dynamic range Hartmann sensor out-of-focus measurement method and device, and belongs to the technical field of wavefront detection, and the method calculates the out-of-focus amount by measuring the change of the distance from a sub-light spot to the center of a light spot array, thereby achieving the out-of-focus measurement of an ultra-large dynamic range. According to the method, under the condition that the defocusing amount is too large and the sub-light spots cross the sub-apertures, the defocusing amount is estimated by measuring the distance variation of the sub-light spots to the center of the light spot array. According to the method, the defocusing amount is calculated by analyzing the position change of the sub light spots and calculating the distance difference between the sub light spots and the center of the target surface, so that the limitation of the traditional Hartmann measurement method on the dynamic range is overcome. According to the method, the light spot distance is used as a measurement basis, and the out-of-focus range capable of being detected by the Hartmann sensor is remarkably expanded. The estimation mode based on the light spot distance is suitable for the situation that sub-light spots cross sub-apertures, and an efficient and reliable defocus measurement scheme is provided for a large optical system.

The invention relates to a low-power-consumption clock delay method and system in the technical field of integrated circuits, and the method comprises the following steps: carrying out the phase alignment of a counting clock signal and a to-be-delayed clock signal based on the counting clock signal, and generating a first phase clock alignment signal and a second phase clock alignment signal; extracting rising edge information and falling edge information of the first phase clock alignment signal to obtain a pulse signal; splitting the clock rising edge information and the clock falling edge information to obtain a first pulse filtering signal and a second pulse filtering signal; performing coarse delay on the first pulse filtering signal and the second pulse filtering signal in sequence, and performing signal synthesis processing after coarse delay to obtain a coarse delay clock signal; and performing fine delay on the coarse delay clock signal based on the digital time converter to obtain a fine delay clock signal, thereby solving the problem that the existing delay technology cannot simultaneously realize high delay precision and large dynamic range under the condition of low power consumption.

The invention provides an echo wall mode microcavity time-varying signal sensing method and system. The echo wall mode microcavity time-varying signal sensing method comprises the steps of S1, building an echo wall mode microcavity time-varying signal sensing experiment platform based on a double-optical-comb spectrum technology; s2, starting a dual-light frequency comb; s3, sensing a time-varying signal through coupling of a coupling device and the echo wall mode microcavity; s4, performing Fourier transform on the output of the reference path and the signal path within one sampling time, and extracting a time-varying signal by using a plurality of modes of the microcavity; and S5, repeatedly executing the step S4 until the measurement is finished. Time-varying parameter sensing is achieved through multiple modes of the microcavity, high sensitivity is achieved, meanwhile, high precision and a large dynamic range are achieved, and application of microcavity sensing is further expanded.

The invention belongs to the field of acceleration measurement, and particularly discloses a multi-acceleration-sensor data fusion method and system, and the method comprises the steps: obtaining acceleration signals measured by each accelerometer when a preset acceleration signal is inputted into calibration equipment when an accelerometer assembly composed of N accelerometers is disposed on the calibration equipment, the measuring ranges of the N accelerometers are complementary to the noise level range; considering the inclination angle error of the rotary table, the installation angle error of each accelerometer and the non-orthogonal error of each accelerometer, the coordinate system of each accelerometer is converted to the same geographic coordinate system, and each accelerometer is calibrated by combining the acceleration signal measured by each accelerometer and the input preset acceleration signal. Obtaining calibration parameters of each accelerometer; the calibration parameters are used for compensating acceleration signals measured by the accelerometers. According to the invention, large-dynamic-range acceleration measurement is realized.

Multiple images that include a first image, a second image, and a third image are received. The multiple images are such that the second image is temporally between the first image and the third image. The first image, the second image, and the third image are combined to obtain a long-exposure image. High dynamic range processing is applied to the second image and the long-exposure image to obtain an output image with a larger dynamic range than a dynamic range of the second image. The high dynamic range processing uses the second image as a short-exposure image. An image based on the output image is transmitted, stored, or displayed.

This invention discloses a sub-aperture stitching interferometric measurement device and method for optical freeform surfaces. The device includes a laser interferometer, a variable phase compensator, and a multi-axis motion stage for motion control of the mirror under test. The variable phase compensator consists of two freeform surface mirrors and two wedges, used to achieve phase compensation with a large dynamic range for each sub-aperture. The system automatically adjusts the compensation phase of the sub-apertures using a weighted stochastic gradient descent algorithm and performs in-situ measurement of the compensation phase using a micro-translation misalignment measurement method. The system can realize three measurement modes: full aperture coverage stitching measurement, sub-aperture coverage stitching measurement, and comprehensive measurement. This invention enables high-precision measurement of flexible, complex optical freeform surfaces (such as gull-wing surfaces).

This invention discloses an on-board calibration device, relating to the field of on-board calibration technology, comprising: a calibration source and a calibration lens; the calibration source includes a blackbody radiating surface, a temperature measuring unit, a support structure, conductive components, and a housing; wherein, the blackbody radiating surface is fabricated using MEMS technology and includes a metal heating layer and a specific coating for generating infrared radiation; the conductive components are used to power the blackbody radiating surface; the support structure is used to fix and support the blackbody radiating surface; the temperature measuring unit is used to monitor the temperature of the blackbody radiating surface; the housing is used to encapsulate the calibration source; the calibration lens is disposed in the light output path of the calibration source and is used to collect and compress the infrared radiation light emitted by the calibration source before introducing it into the lens of a remote sensing camera. This invention uses MEMS technology to fabricate the calibration source, which has excellent performance characteristics such as high emissivity, fast response, large dynamic range, and high temperature measurement accuracy, and is small in size and light in weight.

The utility model provides an auxiliary device for an L wave band test. According to the auxiliary device for the L wave band test, an installation shell is installed at the position, close to one side, of the top of a test board, an input head is installed on one side of the installation shell through an input line, a driving amplifier is installed at the other end of the input line, and the output end of the driving amplifier is connected with the input end of a final amplifier; and the output end of the final-stage amplifier is connected with the input end of the directional coupler. According to the auxiliary device for the L wave band test, better linearity and larger dynamic range are achieved through the design method, better harmonic wave, clutter suppression, gain flatness and intermodulation indexes can be obtained, the L wave band test frequency source generates two paths of signal output, the two paths of signals can be controlled through the upper computer, and the test accuracy is improved. The frequency consistency and the power consistency are good, good out-of-band rejection is achieved, and the accuracy of L-band test data is improved.

This disclosure relates to a large dynamic range radiation detector and method that simultaneously achieves particle counting and energy integration. The radiation detector includes one or more detection channels, each channel comprising: a sensor, an analog front-end circuit, an analog-to-digital converter, a digital counting module, and a charge integration module. The sensor converts incident radiation into a current signal, the radiation including rays or particles. The analog front-end circuit amplifies the current signal and converts it into a voltage signal. The analog-to-digital converter converts the voltage signal into a digital waveform, the digital waveform including discretized voltage sample values. The digital counting module determines the pulse count information of the radiation based on the digital waveform. The charge integration module determines the charge integration information of the radiation based on the digital waveform. Therefore, both particle counting and energy integration detection methods can be implemented in the digital domain, effectively improving the performance of the radiation detector in terms of noise, energy resolution, and dynamic range.

The application provides an IsCMOS camera dynamic range calibration system, which comprises an LED calibration light source system, a driving circuit, a notched structure, an enhanced mirror reflection film and an optical fiber; the LED calibration light source system is arranged at an outlet position below a HERD energy meter system; the LED calibration light source system comprises a plurality of groups of LED calibration light sources; the LED calibration light source system comprises a structural panel, the notched structure is arranged on the structural panel, the enhanced mirror reflection film is laid in the notched structure, the optical fiber passes through the notched structure from the enhanced mirror reflection film, a PCB plate assembled with the plurality of groups of LED calibration light sources is covered on the notched structure, each notched structure is configured with an independent group of LED calibration light sources, and the driving circuit matched with the plurality of groups of LED calibration light sources is arranged on the PCB plate. The application solves the problem of HERD energy meter IsCMOS camera large dynamic range calibration.

The present invention discloses a large dynamic range resonant fiber optic gyroscope, belonging to the technical field of optical sensing. It solves the problem that current optical gyroscopes have a small dynamic range and are non-adjustable, making it difficult to meet the needs of places with a large range of rotational speed variations, and that the direction of rotational speed can only be determined by phase modulation of light. The invention comprises first and second voltage signal sources, a laser, a polarization controller, a fiber coupler, a fiber ring, a piezoelectric ceramic tube, a detector, and a signal processing and control system. The invention utilizes the piezoelectric ceramic tube to control the cavity length of the fiber resonant cavity, thereby achieving a large dynamic range. At the same time, a narrow linewidth laser is utilized to output continuous, constant-intensity, frequency-tunable narrow linewidth laser light to obtain the transmission spectrum of the fiber resonant cavity. By accurately locating the resonant frequency, the magnitude and direction of the rotational speed can be simultaneously determined. The invention has the advantages of a large dynamic range, a large rotation rate measurement range, and the ability to determine the direction of rotational speed without phase modulation of light.

The present invention discloses a negative temperature drift bandgap reference circuit suitable for a large dynamic range logarithmic amplifier. The circuit relates to the field of integrated circuit technology and includes a startup circuit for providing a startup current; and a reference core circuit comprising a plurality of transistors and a plurality of resistors, the transistors being electrically connected to the resistors. The reference core circuit is configured to provide a reference voltage with a negative temperature coefficient, biasing a rectifier, thereby ensuring an extremely low DC bias current temperature coefficient of the rectifier at temperatures between -55°C and 125°C. Compared to conventional zero temperature coefficient bandgap reference circuits, the present invention is more suitable for large dynamic range logarithmic amplifiers, enabling them to exhibit excellent temperature characteristics, including slope and logarithmic consistency error.

The invention discloses a remote sensing load ultra-large dynamic range radiometric calibration device and method, and relates to the field of radiometric calibration, and the device comprises a driving module, and a light source, a diffuse reflection plate structure, a two-dimensional scanning mirror, an aperture diaphragm, a shutter and a detector which are sequentially arranged according to a light path transmission direction; the two-dimensional scanning mirror, the aperture diaphragm, the shutter and the detector are all connected with the driving module; light emitted by the light source passes through the diffuse reflection plate structure and the two-dimensional scanning mirror and then is subjected to first-time radiation quantity value attenuation, and passes through the aperture diaphragm and then is subjected to second-time radiation quantity value attenuation; the driving module is used for driving the two-dimensional scanning mirror, the aperture diaphragm, the shutter and the detector; the shutter is arranged at the front end of the photosensitive area of the detector; the shutter and the detector are used for detecting the light radiation quantity after two times of radiation quantity value attenuation. According to the invention, the remote sensing load can be subjected to radiometric calibration by using an intense radiometric calibration source such as the sun to obtain the same radiation reference as other in-orbit remote sensing loads, so that the reference unification of remote sensing data is ensured.

The invention relates to the field of wave absorbing devices, and particularly discloses a dual-polarization electromagnetic wave reflectivity large dynamic range real-time adjustable material plate, which comprises a plurality of structural units which are periodically and repeatedly arranged, and each structural unit comprises a regulation and control layer, a first isolation layer, a wave absorbing layer, a second isolation layer and a metal substrate layer which are sequentially stacked from top to bottom, impedance matching is regulated and controlled through the regulation and control layer, and electromagnetic waves in respective corresponding polarization directions are absorbed through the metal patch patterns on the front side and the back side of the wave absorbing layer. An electronic signal regulation and control mode is adopted, the real-time reversible regulation and control function of the material plate on the electromagnetic wave reflectivity is achieved, the characteristic of large regulation and control range is achieved, and the electromagnetic wave reflection characteristic can be remarkably regulated; the material plate is light in weight, good cost economy and cost-effectiveness ratio can be achieved through simple circuit board design and component resistance value control, and an ideal material structure style is provided for equipment radar characteristic regulation and control.

The invention provides a novel large dynamic range signal acquisition circuit, which is used for solving the technical problem of high signal acquisition cost caused by the fact that more channels are needed to carry out measuring range lap joint if an existing large dynamic range acquisition circuit needs to finely acquire signals in a larger range. The large dynamic range signal acquisition circuit provided by the invention comprises a power divider, M comparators, an attenuation link, an ADC conversion module, a splicing circuit and an FPGA, large dynamic range signal acquisition can be realized by adopting a single signal channel through a design method of signal equal division, feature extraction and attenuation control, the range coverage range is from a millivolt level to a kilovolt level, and the measurement range is wide. The signal acquisition range is widened, the number of channels is reduced, the economic use efficiency of the channels is improved, the test cost is saved, and the analog-to-digital conversion method has important significance on analog-to-digital conversion of uncertain amplitude signals in a specific environment.

The invention relates to the technical field of differential absorption spectrum inversion, and discloses an ozone precursor monitoring method and system based on a two-channel differential absorption spectrum and nonlinear inversion, a terminal and a storage medium, the method comprises the following steps: synchronously obtaining a target spectrum and a reference spectrum of a target area to calculate a multiband atmospheric differential optical thickness; building a combination model based on the difference optical thickness of each wave band, dividing a fitting window, and obtaining the difference inclined column concentration through multi-angle fitting; and inverting a vertical concentration distribution profile of the ozone precursor by using different sensitivities in combination with a radiation transmission model and a logarithmic space iterative inversion algorithm. According to the invention, through a high-performance dual-channel spectrometer observation system and a high-precision nonlinear inversion algorithm, high-spectral-resolution measurement of ultraviolet-visible light full wavebands is realized, logarithmic space processing is introduced in inversion, the inherent problems of strong nonlinearity and large dynamic range of a vertical profile of aerosol and trace gas are effectively solved, and the measurement accuracy is improved. And the measurement precision and stability are improved.

The invention discloses a low-power-consumption capacitance digital converter based on SAR (Synthetic Aperture Radar) logic and a coarse-fine binary counter, and relates to a low-power-consumption capacitance digital converter. The invention aims to solve the problem that a micro capacitance measuring circuit cannot meet the requirements of large dynamic range, low noise and good spurious resistance. The system comprises an ultra-low power consumption relaxation oscillator, an asynchronous tracking algorithm circuit, a coarse-fine binary counter, a bootstrap switch circuit and a fully differential SAR logic capacitance digital-to-analog converter. The ultra-low power consumption relaxation oscillator is used for generating a clock signal Scan, and the clock signal Scan is an input signal of the asynchronous tracking algorithm circuit, the coarse and fine binary counter and the bootstrap switch circuit; the asynchronous tracking algorithm circuit is used for generating a clock signal Valid, and the clock signal Valid is a clock signal of the coarse and fine binary counter; and the coarse and fine binary counter is used for generating a control signal of the fully differential SAR logic capacitance digital-to-analog converter and controlling a switch time sequence. The invention belongs to the technical field of analog-to-digital conversion and capacitive sensor interface circuits.

This application provides an early warning method for the supply of power materials in temporary construction warehouses, comprising: establishing a three-dimensional electromagnetic field distribution model based on the relative positional relationship between temporary construction warehouses and high-voltage transmission lines on highways, and obtaining the theoretical distribution of the electromagnetic environment of each warehouse; within the temporary warehouses, deploying electromagnetic sensors for materials whose electronic components are highly sensitive to electromagnetic interference, and deploying large dynamic range electromagnetic sensors for materials whose metallic materials are susceptible to strong electromagnetic fields; transmitting the monitoring data collected by various electromagnetic sensors in the warehouses back to the power grid dispatch center in real time through a low-power wide-area Internet of Things, and correlating it with the structural parameters of the warehouse materials to construct a database; mining historical data on power grid load and electromagnetic environment, extracting the correlation between electromagnetic interference characteristics and the operating conditions of transmission lines, and establishing a collaborative prediction model of the electromagnetic safety status of multiple warehouses.