156results about How to "High Common Mode Rejection Ratio" patented technology

A pressure distribution detection device is characterized in that a flexible array sensor unit (2) is sequentially connected with a signal conditioning and data acquisition unit (3) and a data display and analysis unit (4); the flexible array sensor unit (2) consists of a sensor array (1) and a Wheatstone bridge circuit; the sensor array (1) consists of sensor nodes; each sensor node is a strain disc (6); the strain discs (6) are arranged to form the sensor array (1) in a line and row manner; and each strain disc (6) constitutes the Wheatstone bridge circuit with three precision resistors with known resistance values. When ambient pressure is applied on the strain discs (6), the resistors change, and the variation information of the resistance value of the flexible array sensor unit (2) is collected through the signal conditioning and data acquisition unit (3) and is transmitted to the data display and analysis unit (4) after analog-digital conversion to be displayed and analyzed. The invention is applicable to such fields as biomechanical engineering, medical rehabilitation and rehabilitation assistant property detection.

The invention discloses a high-performance direct current amplification device for acquiring biological electric signals, which comprises an input protection / filter circuit, an input buffer circuit, an instrument amplifying circuit, an RC low-pass filter circuit, an analog-digital conversion and peripheral circuit and a CPU connected in sequence, wherein the input protection / filter circuit acquires the biological electric signals and inputs the biological electric signals into the input buffer circuit, and then the biological electric signals pass through the instrument amplifying circuit, the RC low-pass filter circuit and the analog-digital conversion and peripheral circuit in turn; and the CPU controls the analog-digital conversion and peripheral circuit to work. The high-performance direct current amplification device performs impedance conversion on the biological electric signals first, then amplifies the signals, inhibits common-mode signals, and filters high-frequency noise, and a single-end transfer differential amplifier performs secondary amplification on the biological electric signals, so the indexes such as the noise, the common-mode rejection ratio and the like of the signals after analog-digital conversion reach a very high level; besides, a base line is very stable, the signal input dynamic range is large and is difficult to saturate, and simultaneously required devices are fewer, and the reliability of the high-performance direct current amplification device is improved.

This invention relates to a fully differential non-inverting parallel amplifier for detecting biology electrical signal, including input buffer circuits, differential filter circuits, data selector, non-inverting parallel amplifying circuits and analog-digital circuits. The biology electrical signal, first impeded and converted by the input buffer circuits, and then low-pass filtered by the differential filter circuits, shall be amplified with its common mode signal rejected by passing through the data selector and non-inverting parallel amplifier circuits. At last, the amplified biology electrical signal is output by analog to digital conversion in the analog-digital circuits after its noises beyond signal high frequency band are filtered by anti-aliasing filter net. This invention, with low noise and high common mode rejection ratio, stable baseline, large signal input dynamic range, is reliable and not easy to be saturated. Furthermore, it can support mature PACE Detecting with a low cost. It is notable in social and economical benefits for its simple electrical circuits and easy use in any biology electrical testing equipments and controlling system.

The invention discloses a circuit and a method for weak current detection and belongs to the current detection field. Geminate field effect transistors are employed by an input end to form a difference amplifier, and I-V conversion of a weak current is carried out; a voltage signal after conversion is sent to two sets of proportion operation circuits having symmetric in-phase input modes for proportion operation amplification; difference operation amplification of the voltage signal after proportion operation amplification is carried out, and a difference operation amplification voltage magnitude is measured. According to the method and the device, the junction type geminate field effect transistors are employed to form the difference amplifier as an input level, so input impedance is improved, and the relatively high common-mode inhibition ratio is acquired; the precise proportion operation circuit structures in the symmetric in-phase input modes are employed as the middle level, input impedance is further improved, and measurement precision is improved; the multiple operation amplifier difference amplification detection technology is employed, conflicts of useful-signal weakness and relatively high common-mode interference can be effectively solved, and high gain, high input resistance and the high common-mode inhibition ratio of the detection circuit are realized.

The invention belongs to the field of geophysical exploration and provides a method. Real-time acquisition of multiview stereo images can be realized by using fewer cameras. The invention provides a nanosecond acquisition board which can effectively suppress interference and has high integration level. The invention provides a multichannel seismic signal acquisition device with high synchronization accuracy. The device comprises a preamplifier and an analog-digital converter, wherein the signal detected by each sensor is transmitted to a channel of each analog-digital conversion chip after passing through the preamplifier, a multicircuit switch, a gain control circuit and a signal conditioning circuit respectively; and the data output by the analog-digital conversion chips are transmittedto a data receiving and retransmitting device by a data preprocessor. The device also comprises a gain control module, a self-check control module, a command decoder, a synchronous clock receiver andthe data receiving and retransmitting device. The device is mainly applied to geophysical exploration.

The invention provides a multichannel large-dynamic range data acquisition system, which is realized on the basis of FPGA. The data acquisition system comprises multiple paths of parallel data acquisition channels used for conditioning and amplifying to-be-detected analog signals and converting the analog signals after conditioning and amplifying into digital signals, an acquisition control module used for controlling and managing each data acquisition channel, that is, starting or stopping command of each channel, issuing of gain parameters, arrangement and extraction of data of each data acquisition channel and packing of upload data, a bus control module used for controlling the multichannel large-dynamic range data acquisition system to access and communicate with an external bus according to a CPCI bus protocol and self defining DSP and MCU interface, and a clock management module used for providing clock for the analog-to-digital converter of each data acquisition channel, the acquisition control module and the bus control module.

The invention relates to a biphase digital phase-locking amplifier (as shown in chart 1) and a digital domain synchronous phase-locking algorithm of the biphase digital phase-locking amplifier. The biphase digital phase-locking amplifier can be used for detecting weak current signals, and realize the functions of automatic filtering tracking and synchronous phase-locking. The biphase digital phase-locking amplifier can solve the problems that the volume of the existing phase-locking amplifier is large, the temperature excursion exists, and the speed is slow when the existing phase-locking amplifier is connected with a computer to carry out automatic measurement and control. The biphase digital phase-locking amplifier has the technical characteristics that the weak current signals pass through a 9-step RLC (radio link control) mixed type high-pass filter by a precise I / V conversion circuit, and is then connected with two low-noise instrument amplifiers, the connecting modes of which are different; the rear ends of the instrument amplifiers are respectively connected with an 8-step RLC mixed type high-pass filter, and a differential signal is formed by signals output by two low-pass filters. Meanwhile, reference signals pass through a 90-degree phase shifter of a phase-locking loop to output two TTL square waves, the phase difference of two phases of which is 90 degrees. Signals of three paths are collected by a data acquisition card, and are then transmitted to a PC (personal computer) machine. The biphase digital domain synchronous phase-locking algorithm (as shown in chart 2) provided by the invention is applied on the PC machine to carry out signal processing and filtering.

The invention discloses a programmable analog unit for processing a sensor signal, which comprises a first programmable switched capacitor group, a second programmable switched capacitor group, a programmable main fully differential operation amplifier, a first programmable auxiliary fully differential operation amplifier, a second programmable auxiliary fully differential operation amplifier, an output multiway selector and an output control module, wherein the first programmable switched capacitor group is used for receiving an external sensor differential signal; the second programmable switched capacitor group is used for receiving an external sensor differential signal; the programmable main fully differential operation amplifier is used for generating and outputting a main fully differential signal after signal processing; the first programmable auxiliary fully differential operation amplifier is used for generating and outputting an auxiliary fully differential signal; the second programmable auxiliary fully differential operation amplifier is used for generating and outputting an auxiliary fully differential signal; the output multiway selector is used for selecting and outputting one way of differential output signal; and the output control module is used for generating and outputting a positive-negative reverse-phase or modulated differential output signal. The programmable analog unit for processing the sensor signal can read out small capacitance and small voltage sensing signals and process analog signals, is applied to sensor signal detection of physical quantities such as an angular velocity, an accelerated velocity and the like, and is suitable for circuits of an FPAA (field programmable analog array), a FPMA (fixed preassigned multiple access) and a PSOC (programmable system on chip).

The invention provides a battery module multichannel synchronous detection device, which comprises a main controller, a signal detection module, an external communication interface module and a clock control system, wherein the main controller is connected with the battery module and the clock control system via the signal detection module and the external communication interface module respectively; and under effects of the clock control system, the main controller controls the signal detection module to synchronously detect parameters of each battery in the battery module. The detection device provided by the invention has a strong anti-interference ability; synchronous detection of multiple battery module parameters and synchronous and real-time detection of multiple parameters for each battery in the battery module can be realized; the channel number of the detection device is improved; and the device can be used by a user in a large-scaled synchronous detection situation.

The invention relates to a constant-transconductance rail-to-rail operational amplifier. The constant-transconductance rail-to-rail operational amplifier comprises a rail-to-rail input stage, a gain stage and an output stage in sequential connection. The rail-to-rail input stage a PMOS (p-channel metal oxide semiconductor) differential pair, an NMOS (n-channel metal oxide semiconductor) differential pair, PMOS differential pair and NMOS differential pair tail current sources and an NMOS differential pair load circuit, and the PMOS differential pair and the NMOS differential pair are complementary. The gain stage comprises a self-bias cascade current mirror, and source electrodes of NMOS tubes and PMOS tubes of the PMOS differential pair and the NMOS differential pair are connected with the self-bias cascade current mirror. The output stage comprises a first PMOS tube, a first NMOS tube and a Miller compensator, the first PMOS tube and the first NMOS tube are in common-source connection, grid electrodes of the first PMOS tube and the first NMOS tube are connected with the self-bias cascade current mirror, and the Miller compensator is formed by series connection of a Miller compensation capacitor and a compensation resistor. The constant-transconductance rail-to-rail operational amplifier has advantages that input stage constant transconductance in a full voltage operating range can be guaranteed effectively, the whole circuit structure is high in stability, the operating voltage range of the operational amplifier is expanded, low-voltage application is realized, and the common-mode rejection ratio of the operational amplifier is increased.

A method and apparatus for providing high common-mode rejection ratio (CMRR) in a single-ended CMOS operational transconductance amplifier is disclosed. A common-mode feedback boosts the OTA CMRR, while allowing integration of conventional OTA improvements.

The invention relates to a detection method and an in-situ detection device based on fluorescence intensity ratio of two detectors. The detection method comprises the following steps that: a light-exciting unit emits parallel light beams with certain wavelengths, and two photoelectric detectors positioned in the direction vertical to the parallel light beams and having an interval of d are used for detecting fluorescence signals; and based on the Lambert-Beer law, a proportional relation model between strength ratio of the two paths of fluorescence signals and the chlorophyll concentration in the water body is established. The detection device further comprises a signal processing unit, a window cleaning unit, a waterproof airtight cavity, an environmental protection cover unit and the like. With the adoption of the detection method and device, the influences caused by fluctuation of incident light, temperature variation, light scattering, pollution of a detection window and the like can be reduced, and the linear range of detection is expanded.

The invention discloses a weak current detecting circuit of a nitrogen-oxygen sensor, which comprises a current-voltage conversion circuit, a differential low-pass filter and an instrument operationalamplifier, which are connected in sequence. The current-voltage conversion circuit is formed by connecting a sampling resistor to a signal loop; the current-voltage conversion circuit is used for converting a current signal collected by a nitrogen-oxygen sensor into a voltage signal of N times; after high-frequency interference is filtered by the differential low-pass filter, the voltage signal is output after being accurately and effectively amplified by an instrument operational amplifier, wherein the value of N is equal to the value of resistance of the sampling resistor. The weak currentdetecting circuit of a nitrogen-oxygen sensor in the invention can accurately amplify the weak voltage signal. Such an instrument amplification circuit has the characteristics of low offset, low output error, high signal-to-noise ratio, high common-mode rejection ratio, high gain and the like.

The invention discloses a difference slit MIMO (Multiple Input Multiple Output) antenna with a high common mode rejection ratio. The antenna comprises a medium substrate and multiple antenna units. Each antenna unit comprises a floor and a micro-strip feed line, wherein the floor is arranged on the top floor of the medium substrate and is etched with a T-shaped slit, and the micro-strip feed line is arranged on the bottom floor of the medium substrate and divides the T-shaped slit into an open-circuit slit and a short-circuit slit. The floors of the multiple antenna units are connected and cover the top floor of the medium substrate. According to the antenna provided by the invention, the specific difference feed structure and the slit combination are adopted to achieve a high common mode rejection effect. The antenna is advantaged by miniaturization, simple structure, high common mode rejection ratio, dual band, high isolation and the like, can meet requirements for miniaturization, low cost, easy processing, and easy integration of a difference circuit, and can be widely applied to a WLAN (Wireless Local Area Network) system.

The invention discloses a wearable electro-cardio signal collection device based on a fabric electrode. The device can carry out complete collection of electro-cardio signals of a human body aiming at the fabric electrode which is a novel flexible electrode. The device is characterized in that input impedance conversion of the fabric electrode could be achieved by an impedance conversion circuit, so the problem about high input impedance of the fabric electrode could be solved; common mode rejection and differential amplification are completed by a low-pass filtering circuit and a differential circuit; and finally, AD sampling and data set package transmission could be achieved. In comparison with a traditional electro-cardio collection circuit, the device disclosed by the invention is characterized in that the impedance conversion circuit is added at the fabric electrode part; power is supplied by a single power source; and an operational amplifier with a high signal to noise ratio and high input impedance is selected. In this way, the puzzle that signals are incomplete when the traditional electro-cardio collection circuits are used to extract the electro-cardio signals of the human body with application of the fabric electrode could be solved. The device is characterized by good performance, the small size and low power consumption. The device can be widely applied to wearable electro-cardio signal collection based on the fabric electrode; and comfort and convenience of use are enhanced.

The invention discloses a programmable gain amplifier which comprises three levels of amplifying circuits. The same-phase input end and the opposite-phase input end of the first-level amplifying circuit serve as the same-phase input end and the opposite-phase input end of the programmable gain amplifier respectively and form a pair of differential input ends of the programmable gain amplifier; the same-phase input end of the second-level amplifying circuit is connected with the opposite-phase output end of the first-level amplifying circuit, and the opposite-phase input end of the second-level amplifying circuit is connected with the same-phase output end of the first-level amplifying circuit; the same-phase input end of the third-level amplifying circuit is connected with the opposite-phase output end of the second-level amplifying circuit, and the opposite-phase input end of the third-level amplifying circuit is connected with the same-phase output end of the second-level amplifying circuit; the same-phase output end and the opposite-phase output end of the third-level amplifying circuit form a pair of differential output ends. The programmable gain amplifier can be used for amplifying micro physiological signals in the field of medical electronics so that high-precision gain can be achieved; meanwhile, adjustment can be achieved within a certain gain dynamic range, and the requirement for different amplitudes of input signals is met.

A communication transformer includes a magnetic core 1, a plurality of transfer-purpose windings 2 and 3 wound on the magnetic core 1, and an additional winding 4 which is wound on the magnetic core 1 in such a manner that the additional winding 4 is positioned between the plurality transfer-purpose windings 2 and 3, and which does not contribute in signal transfer operations. The communication transformer is arranged by that a half way portion of the additional winding 4 along a length direction thereof is electrically connected to a constant potential.

The invention provides a multi-channel SERF atomic magnetometer device for brain magnetic measurement and an application method. The multi-channel atomic magnetometer is designed by utilizing latticebeam splitting characteristics of a diffractive optical element, so that imaging and acquisition of a magnetoencephalogram are realized. Compared with a traditional SQUID magnetoencephalogram instrument, the multi-channel SERF atomic magnetometer device has higher sensitivity, higher signal-to-noise ratio and higher spatial resolution. Compared with an existing multi-channel SERF atomic magnetometer, the multi-channel SERF atomic magnetometer device is easier to integrate and miniaturize, and is not limited to array type photoelectric detectors and lower inter-channel signal crosstalk. The multi-channel SERF atomic magnetometer device is mainly applied to the field of magnetoencephalogram research, and has potential application prospects in the fields of material chemical component and structure analysis, mineral deposit detection, geomagnetic navigation, earthquake prediction and the like. Meanwhile, the multi-channel design of the multi-channel SERF atomic magnetometer device can further be used in other optical pump atomic magnetometers, and universality and innovativeness are achieved.

The invention provides a gas leakage detection apparatus which comprises a factory compressed gas input port, an air pressure adjusting unit, a gas on-off control unit, a measuring range enlargement selection unit, a gas flow sensor and conditioning circuit, and a clamp unit. The factory compressed gas input port receives compressed gas used for detection, transmits the gas to the air pressure adjusting unit, and after obtaining flowing gas of suitable air pressure, transmits the gas to the gas on-off control unit. The gas on-off control unit is turned on, stable gas is transmitted to the measuring range enlargement selection unit, and the flowing gas is outputted to the clamp unit through the gas flow sensor and conditioning circuit. According to the invention, the measuring range enlargement selection unit is added, through a gas flow measurement apparatus, outputted gas reaches the clamp unit equipped with a device to be measured, a disadvantage that in previous airtight measurement an object to be detected should has certain internal volume is overcome.

The invention discloses an LTCC balanced band-pass filter based on multi-frequency coupling, comprising two half-wavelength resonators and two groups of feeders. The two half-wavelength resonators are each composed of micro-strip lines in three different conductor layers, and the micro-strip lines in different conductor layers are connected by metal through holes. First coupling regions (211) of the two half-wavelength resonators are coupled to each other in the form of parallel coupling. The two groups of feeders (501, 502, 503) are disposed in the same conductor layer, and feed second coupling regions (411) of the two half-wavelength resonators under the feeders in the form of vertical coupling. The size of the filter is reduced effectively. The filter has high common-mode rejection ratio. Source-load coupling is introduced between the feeders, three transmission zeros are produced, and the selectivity of pass band is improved.

The invention provides a portable collection device for a high precision myoelectric signal. The device comprises a power supply as well as a myoelectric signal collection module, a DSP and a Bluetooth connected in sequence. The myoelectric signal collection module comprises a surface electrode, a difference amplifier, a band-pass filter, a main amplifier, an electrical level lifting circuit, a high precision A / D and a buffer circuit. The DSP achieves digital processing as band-pass filtering for the signal, improved self-adaptive FIR notch filter for power-line interference, wavelet threshold denoising and the like as well as control for the whole device using a digital processing method. The Bluetooth sends the signal to a terminal using a digital processing method. The power supply supplies electricity for the whole device. The device combines an analog circuit and the digital processing technology, which enables very high input impedance and common mode rejection ratio, can effectively restrain noise, enables very high precision of the collected signal, has the advantages of low power consumption, is convenient to carry, and can be well applied to the fields of scientific research, wearable device, and the like.

The invention discloses a pre-amplification circuit with a high common mode rejection ratio for a biological myoelectricity data acquisition system. The input end of the pre-amplification circuit is connected with a first electrode and a second electrode. The pre-amplification circuit comprises first to fourteenth resistors, first to fourth capacitors and first to sixth amplifiers which construct the following four circuits: a high pass network, a parallel dual operational amplification amplifier, a high pass differential amplifier with an integral feedback circuit, and a common-mode signal sampling driving circuit. Dual-electrode input is adopted, and the high pass network is arranged at the front ends of the amplifiers without being grounded. If a common mode voltage is input, no current flows through the high pass network, and the potential at each point in the high pass network is equal, so that a common mode signal is not changed into a differential mode signal, and the high common mode rejection ratio can be realized. Moreover, the amplification factor of the pre-amplification circuit is set on a preamplifier, namely, the parallel dual operational amplification amplifier, so that an extremely-high common mode rejection ratio can be provided without intentional matching under the condition of restraining direct-current interference.

Disclosed is an electrocardiogram (ECG) signal conditioning circuit. The ECG signal conditioning circuit comprises a primary amplification circuit, a zeroing circuit, a 50Hz wave-limiting circuit, a bandpass filtering circuit and a secondary amplification circuit. The primary amplification circuit performs linear amplification on ECG signals extracted from a human body surface; after zero drifts are inhibited through the zeroing circuit, the signals are transmitted to the wave-limiting circuit and the bandpass filtering circuit, and clutter interference signals are eliminated; and then the signals are sent to an A / D conversion portion for signal sampling through the secondary amplification circuit. The conditioning circuit has the advantages of stable output waveforms, small noise and high common-mode inhibition ratio and improves the acquisition precision of the ECG signals.

The invention discloses a distributed sample hold circuit for the rail-to-rail input range, which comprises a rail-to-rail difference-differential preamplifier array, a resistance averaging network, a simple sample hold array and a capacitance averaging network. The rail-to-rail difference-differential preamplifier array comprises 2NT+1 identical rail-to-rail difference-differential preamplifiers, difference input signals vun+ and vin- are respectively inputted into a non-inverting input end of the rail-to-rail difference-differential preamplifier array, equally-spaced difference reference voltage +NTVR, -NTVR,..., +KVR, -KVR,..., 0, 0,..., -KVR, +KVR,..., -NTVR, +NTVR are respectively inputted to an inverting input end of the rail-to-rail difference-differential preamplifier array, and output of the rail-to-rail difference-differential preamplifier array and directly-connected nodes of resistance of the resistance averaging network are connected together to be inputted to a simple TH array. The distributed sample hold circuit for the rail-to-rail input range is high in speed and precision and good in common-mode rejection performance.

The invention discloses a building structure strain wireless monitoring system based on the Internet of Things. The system comprises a front-end acquisition module, a wireless transmission module anda background management server; the front-end acquisition module comprises a stress sampling signal amplification circuit, a composite stabilizing circuit, a noise reduction filter circuit, an A / D converter and a microprocessor; the stress sampling signal amplification circuit adopts a measurement amplifier to amplify a detection signal of a stress sensor; zero drift interference precision is avoided; system errors are effectively reduced; the composite stabilizing circuit performs amplitude stabilization and ripple elimination on an output signal of the stress sampling signal amplification circuit, and the resolution of the system is improved; the noise reduction filter circuit can well eliminate external electromagnetic interference by utilizing the principle of a low-pass filter, so that the processing precision of a stress detection signal is improved; the system provided by the invention is high in monitoring precision and strong in anti-interference capability, achieves high-precision acquisition and wireless transmission of strain signals of a building structure, and achieves a better monitoring effect.

The invention discloses a bio-robot system. The bio-robot system comprises an implantable nerve stimulation circuit system and a bio-robot electroencephalogram signal collecting system, wherein the implantable nerve stimulation circuit system comprises a backpack, the backpack is fixed to the back of a rat, and after the rat restores calm, a C8051F330 chip generates microcurrent for stimulating the nuclei of the brain, so that the motion direction of the rat is controlled; during the collecting process, filtering processing is carried out on signals; AD620 is adopted as the pre-amplifier, a band-pass filter composed of the pre-amplifier and an operational amplifier LM324 is placed on a mainboard, a measuring electrode is implanted to an M1 area, a shielded flexible wire is connected with the measuring electrode, the electroencephalogram signals can pass through a 50Hz wave trap before being emitted by QN8027, and the MCU C8051F330 on the mainboard collects the electroencephalogram signals and emits the electroencephalogram signals to a mobile part through QN8027 and a power amplifier circuit. The bio-robot system has the beneficial effects the microcurrent stimulation is adopted for realizing steering, and the system has the independent stimulating or electroencephalogram signal recording function.

The invention discloses a low power broadband transconductance error amplifier. A differential amplifier with a common mode feedback loop is designed at a first stage, so a common mode rejection ratioof a circuit is improved, and an output common mode level is stabilized. According to the design, gain and swing of the first stage can be further improved. Moreover, a common source level and classAB output level amplifier is employed at a second stage, the transconductance and circuit drive capability of the transconductance error amplifier are improved, and further a unit gain bandwidth of the circuit is improved. The design of a common mode negative feedback circuit is simplified, moreover, the power consumption is reduced, the stability of the circuit is improved, and the technical problem that the power consumption of the amplifier is increased to a certain degree due to the fact that the design of the traditional common mode negative feedback circuit is relatively complex is solved.

The invention discloses a portable physiological signal multi-mode collecting device. The device comprises an eight-passage electroencephalogram collecting electrode, a one-passage electrocatdiogram collecting electrode, a one-passage breath collecting electrode, a high-precision collecting conversion module, a low-power-consumption ARM processor, a data transmission module, a data memory module and real-time data displaying analyzing software; the eight-passage electroencephalogram collecting electrode, the one-passage electrocatdiogram collecting electrode and the one-passage breath collecting electrode are separately connected with the high-precision collecting conversion module, the high-precision collecting conversion module is connected with the low-power-consumption ARM processor, the low-power-consumption ARM processor is separately connected with the data transmission module and the data memory module, and the data transmission module is connected with the real-time data displaying analyzing software. The electroencephalogram collecting device can obtain the high common-mode rejection ratio and extremely low input noise and have ultralow power consumption, the overall power consumption is 40 ma, the integral performance is reliable, the structure is simple, the size is very small, and the device is light and can be conveniently worn on the body of a user.