149 results about "Common mode noise" patented technology

The invention discloses an active pen and touch screen interaction system resistant to common-mode interference and a signal demodulation method. The system comprises a signal receiving terminal and a signal transmitting terminal. The signal transmitting terminal modulates data to be transmitted by adopting a differential binary phase shift keying modulation method, and transmits a generated modulation signal to the signal receiving terminal; the analog front-end receiving module is coupled with the signal transmitting terminal, receives the modulation signal and outputs a digital square wave signal after fidelity extraction processing; and the digital demodulation processing module performs differential coherent digital demodulation on the digital square wave signal based on the prior characteristics of the modulation signal, inhibits residual noise and recovers data to be sent. The analog front end focuses strong common-mode noise suppression and analog filtering, the digital demodulation algorithm performs secondary digital purification by using signal time sequence characteristics, and the two constructs an efficient anti-interference pipeline. Meanwhile, the regular square wave signals can be directly processed through differential coherent demodulation, and the requirements for performance and power consumption of a rear-end processor are lowered.

An active compensation device including a first element group including an integrated sensing / compensation unit configured to generate a sensing signal corresponding to at least one of common-mode noise and differential-mode noise on at least two high-current paths, and a second element group including a compensation control unit including a negative impedance converter and configured to generate a compensation signal corresponding to the sensing signal and provide the compensation signal to the integrated sensing / compensation unit. The compensation control unit further including a stabilization unit configured to prevent oscillation caused by the sensed noise. The first element group and the second element group are mounted on a single substrate.

The invention provides an anti-interference pressure sensor signal conditioning circuit based on a differential amplification structure, and the circuit comprises a differential input module which is used for receiving a differential signal outputted by a pressure sensor, and carrying out the amplification and filtering of the outputted differential signal, and obtaining a first differential signal; the common-mode suppression module is electrically connected with the differential input module and is used for suppressing a common-mode signal in the first differential signal to obtain a second differential signal; the programmable gain amplification module is electrically connected with the common-mode suppression module and is used for performing programmable gain amplification on the second differential signal to obtain a third differential signal; the low-pass filtering module is electrically connected with the programmable gain amplification module and is used for filtering high-frequency noise in the third differential signal to obtain a fourth differential signal; and the output buffer module is electrically connected with the low-pass filtering module and is used for converting the fourth differential signal into a single-ended signal and outputting the single-ended signal. According to the invention, external electromagnetic interference and common-mode noise can be effectively suppressed, and the stability and accuracy of signal transmission are improved.

The invention provides a vehicle-gauge-level dynamic equalization SerDes system and a working method, and belongs to the technical field of high-speed serial communication, and the method is characterized in that the system comprises an environment feedback module which collects temperature, cable impedance and common-mode noise data in real time; the dynamic equalizer is used for adjusting parameters of the pre-emphasis, the continuous time linear equalizer and the decision feedback equalizer based on the data acquired by the environment feedback module; the link health monitoring unit is used for counting the bit error rate through a hardware counter and triggering a self-repairing process; and the repair controller is used for executing a self-repair process which comprises redundant channel switching, transmission rate degradation and link retraining operation. According to the invention, the hardware-level environment adaptive equalization and millisecond-level self-healing capability of the SerDes link can be realized, and meanwhile, the redundancy design cost is reduced.

A resonant converter is provided. The resonant converter includes a primary circuit, an integrated transformer, a secondary circuit, a local ground, a first Y capacitor and a second Y capacitor. The primary circuit has a first positive line and a first negative line. The integrated transformer is electrically connected to the primary circuit. The secondary circuit is electrically connected to the integrated transformer and has a second positive line and a second negative line. The first Y capacitor is coupled between the local ground and the first positive line or the first negative line of the primary circuit. The second Y capacitor is coupled between the local ground and the second positive line or the second negative line of the secondary circuit. The first Y capacitor, the second Y capacitor and the local ground are configured to circulate common mode noise currents between the primary circuit and the secondary circuit.

Disclosed in the present invention is a filter circuit. A first PCB layer consists of a power line, a power interface, a second filter capacitor, and a first filter capacitor; the power line comprises a power supply network and a GND network; the second PCB layer is provided with a conductor plane; the power interface is connected to the GND network and is further connected to the conductor plane; the GND network, the second filter capacitor, and the conductor plane are sequentially connected; the power supply network, the first filter capacitor, and the conductor plane are sequentially connected. The circuit design of the circuit structure and the overall layout design idea in the present invention have a good suppression effect on common-mode noise, differential mode noise, radiation noise and conduction noise.

The invention provides a photoacoustic gas measurement method and a photoacoustic gas measurement system based on a series sensibilization technology, and relates to the technical field of optical gas sensing. The first-stage light absorption enhancement structure is used for carrying out maximum photoacoustic conversion on target gas to generate an initial photoacoustic pressure signal, the second-stage acoustic resonance structure is introduced to carry out resonance amplification on sound waves with specific frequency, a tandem cascade sensibilization framework of light absorption enhancement and acoustic resonance amplification is constructed, and through mutual verification analysis, the sensitivity of the target gas is improved. Calculating coherence outside preset noise analysis frequency band data, identifying and inhibiting common-mode noise interference caused by environment vibration and the like, generating feedback control parameters while calculating final gas concentration, adaptively adjusting intensity modulation frequency and wavelength modulation depth, and realizing high-precision and high-precision measurement. The measurement reliability, the dynamic range and the adaptive capacity of the system under complex working conditions are improved, and multiplier-level breakthrough of the sensitivity of the system and collaborative optimization of the performance are achieved.

This invention provides a planar transformer and a power conversion circuit, comprising a first composite winding layer, a second composite winding layer, a third composite winding layer, a fourth composite winding layer, and a primary winding, arranged sequentially from top to bottom. The first composite winding layer includes a first winding and a second winding; the second composite winding layer includes a third winding; the third composite winding layer includes a fourth winding; and the fourth composite winding layer includes a fifth winding and a sixth winding. The advantages of this invention are: it provides a planar transformer with a reasonable structure that can effectively suppress common-mode noise. This planar transformer does not have a shielding winding between the primary and secondary windings; by adjusting the structure of the secondary winding, it achieves the purpose of reducing common-mode noise, reducing the number of PCB layers, lowering production costs, and reducing debugging time, thus possessing good practical and application value.

The invention belongs to the technical field of EMI (Electro-Magnetic Interference) suppression, and relates to an EMI filtering method based on dual-frequency spread spectrum and dual-frequency recombination common-mode noise cancellation waveform, which comprises the following steps of: selecting a frequency as a composition frequency; enabling the EUT to work normally by taking a selected frequency as a switching PWM frequency, and obtaining common-mode noise amplitude data of multiple times of the frequency; acquiring a common-mode voltage amplitude, and calculating an amplitude transformation ratio and an amplitude of an injected offset waveform; acquiring a common-mode voltage amplitude, and calculating the phase of the injected offset waveform; injection offset waveform data is obtained through calculation, and the common-mode voltage is offset; according to the invention, common-mode noise is taken as a main scene, and common-mode suppression can be realized while the size is reduced.

This utility model discloses a frequency converter controller, including a control unit, a first filtering topology, and a second filtering topology. The first filtering topology includes a differential-mode inductor unit, and the second filtering topology includes a common-mode inductor unit. The first filtering topology is connected to the live wire, neutral wire, and protective ground wire, and receives the input signal from the power input terminal, suppresses the differential-mode noise and common-mode noise of the input signal from the power input terminal, and generates a first electrical signal. The second filtering topology receives the first electrical signal, suppresses the differential-mode noise and common-mode noise of the first electrical signal, and generates a second electrical signal. The control unit receives the second electrical signal. Because a differential-mode inductor unit is added to the first filtering topology, the number of magnetic rings can be reduced, the number of installation steps can be reduced, and costs can be optimized.

The invention relates to the technical field of aviation electric connectors, and discloses an isolation coupler, which adopts tin soldering to fix a shell and a shell cover so as to ensure the sealing performance and the stability of the shell and prevent the influence of external interference on signal transmission. And meanwhile, the shielding layers of the signal input lead and the signal output lead are welded with the shell, so that the anti-interference capability of signal transmission can be further improved. The circuit board assembly adopts the epoxy glass cloth board with the characteristic impedance of 77 ohms, so that the stability and the consistency of signal transmission can be ensured. Moreover, a leakage protection function is realized by adopting a single-point grounding structure of the first coupling transformer, a discharge path is provided for common-mode noise, the safety and reliability of the isolation coupler can be improved, and meanwhile, a ground loop can be cut off and power frequency interference can be eliminated by adopting a single-point grounding structure of the second coupling transformer, so that the accuracy of signal transmission is improved.

The present application relates to a communication device. A communication device having a common mode noise filter and improved heat resistance is provided. A communication device that performs data transmission based on a differential transmission method includes a first common mode noise filter including a first coil, a second coil, and a third coil; a communication control circuit that transmits and receives a signal through a first line connected to the first coil and a second line connected to the second coil; and at least one resistor disposed outside the first common mode noise filter, a first end of the resistor being connected to the third coil, and a second end of the resistor being grounded.

To provide a technique capable of suppressing differential mode noise in addition to common mode noise in a noise filter connected to a pair of power lines.SOLUTION: A noise filter disclosed in the present specification is a noise filter connected to a pair of power lines, and includes a first bypass capacitor connected between one of the pair of power lines and a ground, a second bypass capacitor connected between the other of the pair of power lines and the ground, a first resistive element connected in series with the first bypass capacitor, and a second resistive element connected in series with the second bypass capacitor.SELECTED DRAWING: Figure 2

An object is to provide a noise filter that can achieve high reliability. A noise filter includes: a noise detection unit which detects a common mode noise flowing through an electric path; an amplification unit which, on the basis of the common mode noise detected by the noise detection unit, generates a cancellation signal for canceling out the common mode noise; an injection unit which injects the cancellation signal into the electric path; an abnormality detection unit which detects abnormality of the noise filter on the basis of output voltage or output current of the cancellation signal, and outputs an abnormality detection signal; and a protection circuit which inhibits an abnormal cancellation signal from being injected into the electric path, on the basis of the abnormality detection signal.

The application provides a metal film thickness measurement method and device for tungsten gate chemical mechanical polishing, comprising a sensor probe, a power module, a signal excitation module, a differential amplification module, a synchronous demodulation module, a data acquisition and processing module; the sensor probe comprises coaxially arranged excitation coils, detection coils and balance coils; the signal excitation module drives the three-coil resonance module to induce eddy current effect at the metal film to be measured; the differential amplification module converts the equivalent impedance change caused by the eddy current effect in the coils into a differential signal, and simultaneously improves the dynamic range through low-noise amplification; subsequently, the synchronous demodulation module multiplies the differential signal with a reference signal, and extracts a direct current component proportional to the signal amplitude through a low-pass filter; the obtained voltage amplitude signal is input into the data acquisition and processing module; the application can significantly amplify the weak signal related to the film thickness, effectively suppress common-mode noise, obtain nanometer-level thickness resolution, and has a high signal-to-noise ratio.

The application discloses a low-delay level shift circuit with high CMTI, comprising a V / C conversion circuit, wherein the V / C conversion circuit is connected with a C / V conversion circuit and a short-time pulse generation circuit respectively, the C / V conversion circuit is connected with a clamping circuit, a CLK generation circuit and a register circuit respectively, the short-time pulse generation circuit is connected with a high-frequency transient voltage zero elimination circuit, the high-frequency transient voltage zero elimination circuit is connected with the CLK generation circuit and the register circuit, and the CLK generation circuit is connected with the register circuit. The low-delay level shift circuit with high CMTI combines high-speed level shift technology with anti-common-mode noise technology; wherein, the high-speed level shift adopts a pre-storage technology, and the next output state is loaded in advance, so that the signal transmission delay of the level shift circuit is effectively reduced; on this basis, the circuit increases a common-mode noise compensation technology, and high-frequency transient common-mode noise can be collected to compensate the adverse effects of the common-mode noise on the level shift output signal.

The application provides a chip testing system, comprising: an automatic testing machine, which generates at least a set of testing signals and a set of adjusting signals, wherein the testing signals comprise positive testing signals and negative testing signals, and the adjusting signals comprise positive adjusting signals and negative adjusting signals; and an adjusting circuit, which comprises a positive adjusting module and a negative adjusting module, the positive adjusting module receives the positive testing signals and the positive adjusting signals, and the negative adjusting module receives the negative testing signals and the negative adjusting signals, so as to continuously adjust the voltage amplitude of the testing signals and / or add common-mode noise to the testing signals based on the adjusting signals. Through the chip testing system provided by the application, the problem that the differential signals of the ATE cannot be continuously changed in voltage amplitude and cannot directly add common-mode noise in the prior testing system using the ATE is solved.

An RF differential system comprises an RF differential circuit and a winding connected to the RF differential circuit. The winding has a center tap. A bias terminal is provided to receive a bias signal. A suppression network is connected between the center tap and the bias terminal.

The application belongs to the technical field of electronic measurement, and discloses a semiconductor device capacitance voltage test system and method. The power supply circuit based on the combination of high-frequency PWM voltage increase and symmetrical topology voltage multiplier chain is used to solve the bottleneck problem that the existing portable device is difficult to efficiently generate a wide range of symmetrical bipolar high-voltage bias in a compact volume. The differential pulse width modulation measurement circuit based on AC / DC isolation is used to inject measurement pulses with opposite phases and perform differential sampling, so as to solve the problem that the existing single-ended measurement method is extremely sensitive to common-mode noise and ground line interference, resulting in low reliability in the field environment, and improve the measurement accuracy and stability. The software timing control method based on dynamic output baseline correction is proposed, and the intelligent sequence of stabilization-evaluation output baseline-measurement-compensation is used at each bias point to solve the slow response phenomenon existing in the existing method.

According to the laser detection system for detecting the health condition of the underground comprehensive pipe gallery provided by the invention, the narrow-linewidth high-stable-frequency laser is combined with a balance detection technology, so that the capability of detecting weak ultrasonic signals of a pipe wall is remarkably improved, and environmental common-mode noise is effectively inhibited; the attenuation problem of laser in long-distance transmission is overcome by using an erbium-doped optical fiber amplifier light amplification technology, and continuous health monitoring of a several-kilometer-level pipe gallery is realized; through cooperative work of the 180-degree mixer and the signal acquisition system, high-precision analysis of phase change of reflected light is realized, and the position of a damage or disturbance source can be accurately positioned without contact with a pipe wall; furthermore, through feature analysis of the ultrasonic frequency spectrum, the system can sensitively capture early hidden defects such as internal cracks and corrosion of the pipe gallery structure and threats such as external construction excavation, and reliable data support is provided for health assessment and risk early warning of the pipe gallery structure.

The application discloses a kind of arc detection device, method and photovoltaic power generation system, it is related to electric power technical field, including: at least one current detection component, it is set on the at least one pair of direct current cable of generating reverse magnetic field, for detecting the differential mode signal of the at least one pair of direct current cable, the at least one pair of direct current cable includes first cable and second cable;Wherein, the first cable and the second cable are connected on different photovoltaic group string respectively, and pass through the current detection component along the same direction.It simplifies wiring structure, reduces installation difficulty and human error, while making two cables generate reverse magnetic field in current detection component, let the magnetic flux variation generated by common mode noise current flowing therein offset each other, significantly improve the signal-to-noise ratio and detection accuracy of arc signal.

The invention provides a multi-channel synchronous sampling system for weak current detection and a control method thereof. According to the method, a low-noise trans-impedance amplifier array is used for converting multiple paths of weak current signals into multiple paths of analog voltage signals; at least one reference channel for outputting reference noise data; the synchronous analog-to-digital conversion array is used for synchronously sampling the multi-path analog voltage signals and the reference noise data after receiving the global conversion starting signal sent by the field programmable gate array, and converting the multi-path analog voltage signals and the reference noise data into multi-path synchronous first digital data to be output; the field programmable gate array is used for receiving the first digital data and carrying out delay compensation and amplitude correction on the first digital data to obtain multiple paths of time-aligned and amplitude-normalized second digital data; and a filter for referencing the first digital data converted from the reference noise data and eliminating the common-mode noise component in the second digital data to output purified third digital data.

The invention relates to a debugging circuit, method and device of a transformer, an application circuit of the transformer, equipment, a storage medium and a program product. The debugging circuit comprises the components of a transformer which comprises a primary coil and a secondary coil; the signal generator is connected with the two ends of the primary coil and used for providing input voltage for the primary coil; one end of the current adjusting assembly is connected with the negative electrode end of the primary coil, and the other end is connected with the positive electrode end of the secondary coil; and the oscilloscope is connected with the current adjusting assembly and is used for outputting the voltage change after the current is adjusted by the current adjusting assembly so as to determine the compensation capacitance of the transformer and adjust the coil winding of the transformer based on the voltage change. The common-mode noise of the transformer is effectively suppressed through the debugging circuit, and the electromagnetic anti-interference capability of the transformer in the use process is improved.

This invention proposes a design method for a full-band compact hybrid EMI filter circuit based on current feedback. The method includes: constructing an electromagnetic interference test circuit to obtain the common-mode EMI spectrum required for attenuation by the PWM converter, and establishing a high-frequency equivalent circuit for the PWM converter; obtaining the optimal hybrid EMI filter topology based on the high-frequency equivalent models of active and passive EMI filter circuits and the noise attenuation characteristics of the hybrid EMI filter circuit topology; designing the active EMI filter topology and its high-frequency equivalent model based on the noise cancellation principle of the active EMI filter and the common-mode EMI spectrum; designing the active EMI filter topology based on the noise cancellation principle of the active EMI filter and the common-mode EMI spectrum; designing the passive EMI filter structure based on the common-mode EMI noise spectrum after adding the active EMI filter; and designing the hybrid EMI filter circuit based on the hybrid EMI filter topology, the active EMI filter topology, the passive EMI filter structure, and the high-frequency equivalent models of the active and passive EMI filter circuits.

The utility model relates to power supply technical field, concretely relates to a take three -wire common mode inductance DC -DC vehicle -mounted step -down power supply, including input interface, output interface, ground connection, three -wire common mode inductance, synchronous rectification module, BUCK control module and MUC control module, three -wire common mode inductance includes first winding, second winding and third winding, one end between first winding and second winding is equipped with capacitor C94, the other end between first winding and second winding is equipped with capacitor C51, one end between third winding and second winding is equipped with capacitor C91, the other end between third winding and second winding is equipped with capacitor C62, the utility model discloses the combination of setting three -wire common mode inductance and pi type filter assembly, effectively reduces common mode noise, helps equipment to satisfy electromagnetic interference standard, can effectively suppress high -frequency noise and low -frequency ripple simultaneously.

The invention discloses a fingerprint identification device and a display device, and a sensing module comprises a plurality of sensing pixels, and each sensing pixel is configured to generate an ultrasonic signal transmitted to the side where a to-be-identified object is located according to an excitation signal, and receive a reflected sound wave signal reflected by the to-be-identified object to generate a to-be-detected signal. Each noise reduction unit in the noise reduction module is electrically connected with at least two sensing pixels, and each noise reduction unit is configured to perform differential amplification processing on a corresponding to-be-detected signal to obtain a corresponding feature amplification signal. And an identification control module electrically connected to the sensing module and the noise reduction module is configured to generate an excitation signal and obtain an identification result of the to-be-identified object according to the plurality of feature amplification signals. By arranging the noise reduction module, common-mode noise between the to-be-detected signals is reduced, the difference between the to-be-detected signals is amplified, and the recognition precision of the to-be-recognized object is improved.

The application discloses a kind of active chip in dual-to-single circuit P wave band signal transmission method, comprising: obtaining P wave band signal transmission state data;Bias voltage data is obtained, combined with P wave band signal transmission common-mode noise, even harmonic, electrostatic leakage data, generates different bias voltage measurement, the bias influence optimization result of dividing resistance value;P wave band signal unit time signal loss value is obtained, combined with P wave band signal transmission common-mode noise, even harmonic, electrostatic leakage data, power voltage, the bias influence optimization of dividing resistance value is carried out to different P wave band signal unit time signal loss calculation model, generates different P wave band signal unit time signal loss calculation model power voltage, the bias influence optimization of dividing resistance value, combined with different P wave band signal unit time signal loss calculation model power voltage, the bias influence optimization of dividing resistance value is carried out circuit adjustment control, solves the technical problem of low transmission efficiency of P wave band signal.

A communication device performs data transmission according to a differential transmission method. The communication device includes a first common mode noise filter including a first coil, a second coil, and a third coil, a communication control circuit that transmits and receives a signal through a first line connected to the first coil and a second line connected to the second coil, and at least one resistor that has a first end connected to the third coil and a second end connected to GND, and that is disposed outside the first common mode noise filter.

The application relates to the field of semiconductor technology and discloses a microwave reflection photoconductance measurement system for wafer film carrier lifetime, which comprises a reconfigurable differential metasurface probe, which interacts with a wafer film to be measured in a near-field coupling mode; an optical excitation module, which performs pulsed light irradiation on the wafer film below a measurement area to generate non-equilibrium carriers; a dual-channel microwave transceiving module, which feeds microwave signals to the measurement area and a reference area; a closed-loop feedback control module, which receives the differential signal as input before the optical excitation module works; and a data acquisition and processing module, which collects transient changes of the differential signal after the optical excitation module works. The closed-loop feedback control module actively adjusts the microwave response of the reconfigurable probe reference area, the differential signal baseline is locked to zero before measurement, common-mode noise is suppressed, and the signal-to-noise ratio of the transient decay curve and the measurement accuracy are improved.

The application discloses a wideband active EMI filter circuit and a control method thereof, which comprises a high-frequency common-mode inductance module, an amplification filter module and a differential-mode filter module, the high-frequency common-mode inductance module further comprises two sampling signal output ports, and the sampling common-mode noise is connected to two input ports of the amplification filter module respectively after sampling; the output port of the amplification filter module is connected to the differential-mode filter module, and the differential-mode noise is filtered in the differential-mode filter module after the loop noise current is eliminated. Through the wideband active EMI filter circuit and the control method thereof, the compensation current signal is obtained through a novel sampling mode, the novel sampling mode is adopted, the purpose of wideband filtering is achieved, the stability of the filter is improved, meanwhile, the filter is small in size, wide in frequency band, high in stability, applicable to various space-limited scenes such as aerospace and industrial application, and the hardware design can make the matched product meet the electromagnetic compatibility requirement.