42results about "Positive-feedback-circuit arrangements" patented technology

The invention discloses a high-stability common-mode feedback circuit which is used for accurately adjusting the common-mode level of a differential amplifier. The circuit comprises an amplifying circuit module, a common-mode detection module and a substrate adjusting module, by introducing a substrate adjusting technology, the size of an amplifying tube is reduced, and the stability and bandwidth of common-mode feedback are remarkably improved. Wherein the common-mode detection module adopts a source follower structure and detects common-mode voltage of differential output in real time; the substrate adjusting module can greatly reduce the size of the common-mode adjusting transistor in the common-mode feedback amplifier by adjusting the body port voltage of the common-mode adjusting transistor in the common-mode feedback module and reducing the threshold voltage of the transistor and utilizing the back gate characteristic of the transistor, the parasitic capacitance of the common-mode adjusting transistor is reduced, and the performance of the common-mode feedback amplifier is improved. And meanwhile, the common-mode level stability in a wide input range is realized, and the method is suitable for scenes such as high-speed analog-to-digital converters and low-noise amplifiers which have strict requirements on the common-mode stability.

A power amplifier using multi-path common-mode feedback loops for radio frequency linearization is disclosed. In one aspect, a complementary metal oxide semiconductor (CMOS) power amplifier containing cascoded n-type field effect transistors (NFETs) and cascoded p-type FETs (PFETs) may have a common-mode feedback network and provides bias voltages that are dynamically varying with the signal power to keep the output common-mode fixed around a half-supply level, while the small-signal and large-signal transconductances of the FET's are kept balanced. A further feedback network may be associated with the supply voltage to assist in providing a symmetrical supply signal. The symmetrical supply signal allows for supply variations without introducing distortion for the power amplifier stage.

The invention relates to the field of digital amplifiers, in particular to a system and method for improving feedback and stability in digital amplifiers. The system comprises a signal acquisition module, a feedback signal processing module, an adaptive adjustment module, a comparison and control module and a digital amplifier main body module, the signal acquisition module accurately acquires an output signal; the feedback signal processing module filters and amplifies output information and compensates delay, amplitude attenuation and environmental factors; the adaptive adjustment module adjusts equipment feedback parameters in real time through a fuzzy control algorithm and a neural network model; the comparison and control module adjusts the input signal according to the error signal, and the digital amplifier body outputs the amplified signal. The invention not only can greatly improve the precision of feedback signals and enhance the stability of the amplifier under various working conditions, but also can effectively improve the quality of transmission signals, reduce distortion and noise, improve the reliability of the system and prolong the service life of the system, and has a good application prospect.

The invention provides a pre-amplification module of a multi-mode vector hydrophone, which can be programmed through pins and has multiple working modes so as to adapt to three main types of vector hydrophones, namely an accelerometer co-oscillation type vector hydrophone, a speedometer co-oscillation type vector hydrophone and a differential pressure vector hydrophone. Therefore, the integration difficulty of the hybrid vector array equipment is effectively reduced, and the maintainability of the equipment is improved. The pre-amplification module of the multi-mode vector hydrophone comprises an amplification unit, a constant current source unit, a filtering unit and a programming configuration unit, wherein a plurality of different circuit units are configured in the programming configuration unit and are respectively used for adapting to different types of vector hydrophones; and the programming configuration unit adapts to signals output by the front-end vector hydrophone by switching internal circuit units participating in signal processing.

The application provides a signal amplifier circuit and a display device. In the signal amplifier circuit, the gate of the drive transistor of the first inverter is connected to the output end of the reset module. When the impedance of the optoelectronic device changes, the potential of the gate of the drive transistor of the first inverter changes, causing potential changes at all nodes of the first inverter to amplify the signal.At the same time, the first compensation transistor is connected between the second gate of the first drive transistor and the first output node, the potential of the first output node is precharged to the second gate of the first drive transistor to adjust the threshold voltage of the first drive transistor, improve the difference in threshold voltage between different transistors, and solve the technical problem of signal unevenness after amplification by the inverter.

The invention provides an analog amplifier circuit based on capacitance feedback, which relates to the technical field of signal processing, and comprises a positive voltage local voltage stabilization module, an amplifier module, a bias module and a negative voltage local voltage stabilization module, the positive voltage local voltage stabilization module, the bias module and the negative voltage local voltage stabilization module are all connected with the amplifier module; the positive voltage local voltage stabilization module is used for providing a first stable power supply for the amplifier module; the amplifier module is used for receiving a to-be-amplified signal input externally, performing signal amplification on the to-be-amplified signal to obtain an amplified signal, and outputting the amplified signal; the signal amplification is realized based on a transistor and a feedback capacitor in the amplifier module; the bias module is used for providing first bias voltage for the amplifier module; the negative voltage local voltage stabilization module is used for providing a second stable power supply for the amplifier module. The driving requirement and energy consumption of the amplifier are reduced by adopting capacitance feedback, the energy efficiency of the amplifier circuit is improved, signal amplification is realized through the transistor, and the amplifier circuit with a small area is realized.

The utility model discloses a resistance value measuring circuit for an electromagnetic oil nozzle. The resistance value measuring circuit for the electromagnetic oil nozzle comprises a control chip and an acquisition and measurement circuit, the control chip is provided with two or more PB pin ends and AD pin ends; the collecting and measuring circuit is provided with an electric connecting end, a plurality of oil nozzle connecting ends and an operational amplifier module U1. According to the utility model, the control chip and the acquisition and measurement circuit are arranged, and the acquisition and measurement circuit is provided with two or more PB pin ends and AD pin ends, so that the electromagnetic oil nozzle resistance value measurement circuit is used for carrying out resistance detection on a plurality of electromagnetic oil nozzles, and repeated plugging of the electromagnetic oil nozzles is not needed; the steps are simplified, the detection and measurement efficiency is improved, the connected electromagnetic oil nozzles are controlled to be detected one by one, the consistency is ensured, and the resistance detection precision is improved.

Bias circuitry 100a for a capacitive transducer 120, e.g. a MEMS transducer, includes a high impedance element 110 for coupling between a first terminal 112 of the capacitive transducer and a referenc

The utility model provides a kind of sensor reference power supply of automobile air conditioner, automobile air conditioner and car, and this sensor reference power supply includes: the positive input pin of operational amplifier is connected with the one end of first resistance, and the other end of first resistance is connected with 5V power supply, the one end of first filter capacitor respectively;The negative input pin of operational amplifier is connected with the one end of second resistance, and the other end of second resistance is connected with the cathode of diode;The positive side power supply pin of operational amplifier is connected with 12V power supply, the one end of second filter capacitor respectively;The output pin of operational amplifier is connected with the one end of third resistance, and the other end of third resistance is connected with the anode of diode, the cathode of diode is connected with the other end of second resistance, the one end of inductance, the other end of inductance is connected with the one end of third filter capacitor.The utility model's scheme can effectively reduce material cost under the premise of not reducing reference power supply precision and reliability, increase market competitiveness for enterprise.

An integrated circuit device (100) is provided. In some examples, the integrated circuit device (100) includes an amplifier stage (106) that receives an input signal (102 A) and a control signal (110) and provides an amplified signal (102B) in response. A main path (116, 120, 122) is coupled to the amplifier stage (106) that receives the amplified signal and provides a first feedback signal (124) corresponding to a signal strength of a data-bearing portion of the input signal (102A). A control path (126, 128, 134) also receives the amplified signal (102B) and provides a second feedback signal (136) corresponding to a signal strength of the data-bearing portion and an interference component. A gain control circuit (108) is coupled to the main path (116, 120, 122) and the control path (126, 128, 134) that receives the first and second feedback signals (124, 136) and provides the control signal (110) in response to the feedback signals. In some such examples, the control path (126, 128, 134) and main path (116, 120, 122) include separate mixer stages (116, 126) with different performance characteristics.

The application discloses a speed threshold device, wherein the speed threshold device comprises a speed acquisition module, a signal amplification module, a frequency-voltage conversion module and a threshold output module; the output end of the speed acquisition module is connected with the input end of the signal amplification module; the signal amplification module receives the output signal of the speed acquisition module and amplifies the output signal; the signal amplification module transmits the amplified signal to the frequency-voltage conversion module; the frequency-voltage conversion module is used for converting the frequency signal into a voltage signal; and the threshold output module is used for controlling the working state of the engine according to the voltage signal output by the frequency-voltage conversion module. The speed threshold device provided by the application adopts digital logic such as signal amplification and frequency-voltage conversion to process the speed threshold, finally realizes the control of the working state of the engine, and avoids the complicated authentication process of using programs to realize the speed threshold control.

The present application relates to the field of digital amplifier, specifically to a system and method for improving feedback and stability in digital amplifier. The system comprises a signal acquisition module, a feedback signal processing module, an adaptive adjustment module, a comparison and control module and a digital amplifier main module; the signal acquisition module accurately acquires output signals; the feedback signal processing module filters, amplifies and compensates for delay, amplitude attenuation and environmental factors on the output information; the adaptive adjustment module adjusts the feedback parameters of the device in real time through a fuzzy control algorithm and a neural network model; the comparison and control module adjusts the input signal according to the error signal, and the digital amplifier main module outputs the amplified signal. The present application not only greatly improves the accuracy of the feedback signal, enhances the stability of the amplifier under various working conditions, but also effectively improves the quality of the transmission signal, reduces distortion and noise, improves the reliability of the system and prolongs its service life, and has good application prospect.

A circuit includes an operational amplifier and a resistor network coupled to an output of the operational amplifier. The resistor network includes a first set of resistors coupled between the output of the operational amplifier and a first node of the resistor network, wherein the resistors of the first set are electrically connected in series with each other, a second set of resistors coupled between the first node and a second node of the resistor network, wherein the resistors of the second set are electrically connected in series with each other and include a first number of resistors, a third set of resistors coupled between the second node and a third node of the resistor network, wherein the third node is coupled to a first voltage, and wherein the resistors of the third set are electrically connected in parallel with each other and include a second number of resistors, and a resistor coupled between the first node and the second node and arranged in parallel with the second set of resistors.

This invention relates to a self-biased power amplifier circuit and a self-biased self-resonant power amplifier circuit, belonging to the field of radio frequency circuit technology. In this invention, the source of the power device is connected to a voltage divider module. The internal resistance of the power device and the voltage divider module divide the drain voltage. The voltage obtained across the voltage divider module serves as the source voltage. Since the gate of the power device is grounded, a negative voltage difference is formed between the gate and the source, providing voltage to the source of the power device and achieving self-biasing. Simultaneously, by designing a feedback resonant network composed of a fourth microstrip line, a coupling capacitor, a third microstrip line, an input capacitor, a first microstrip line, and a sixth microstrip line, the DC energy of the drain current is converted into a specific frequency radio frequency signal due to the feedback mechanism, even without an external periodic excitation signal. Part of this signal is coupled through the second and fourth microstrip lines and input to the feedback resonant network; the other part is output through the second microstrip line, the output capacitor, and the fifth microstrip line.

Disclosed in the present invention are a radio frequency power amplifier based on power detection feedback, a chip, and a communication terminal. The radio frequency power amplifier comprises multiple stages of amplifier circuits and at least one power detection feedback circuit; the input end of the power detection feedback circuit is connected to the output end of a current stage of amplifier circuit, and the output end of the power detection feedback circuit is connected to the input ends of the current stage of amplifier circuit and at least one stage of amplifier circuit located prior to the current stage of amplifier circuit. The power detection feedback circuit generates, according to the detected output power of the current stage of amplifier circuit, a control voltage varying inversely with the output power, so that the power detection feedback circuit outputs current varying positively with the control voltage. The quiescent operating current of the current stage of amplifier circuit and at least one stage of amplifier circuit located prior to the current stage of amplifier circuit is controlled by means of the current, so that the radio frequency power amplifier operates in a state in which the gain and the output power are stable.

Radio frequency transmitting and / or receiving integrated circuit comprising at least one radio frequency signal amplifier, said at least one amplifier being configured in operational mode to perform an amplification function of a radio frequency signal applied at the input, said amplifier being configured to perform an oscillator function in a self-test mode of the integrated circuit, to generate a radio frequency signal on at least one of the input or output of said amplifier, characterized in that the integrated circuit is configured to allow, in said self-test mode, the propagation of said radio frequency signal in at least one component of said radio frequency integrated circuit, distinct from said amplifier, and in that it also comprises a circuit for measuring a signal generated following propagation of said radio frequency signal in said component of said integrated circuit and representative of at least one characteristic of said component.Self-testing method for such an integrated circuit.

The invention is a multi-element resonator, and provides a resonant tank including a first capacitor formed on a semiconductor substrate, a first inductor formed on the semiconductor substrate, a second capacitor formed on the semiconductor substrate, and a second inductor formed on the semiconductor substrate. The first capacitor, the first inductor, the second capacitor and the second inductor are connected together in the form of a ring structure, each capacitor is connected between a pair of the inductors, and each inductor is connected between a pair of the capacitors. An amplifier circuit is coupled with the resonant tank and is configured to amplify a signal in the resonant tank.

The utility model relates to an in-phase and inverted-phase automatic switching circuit, in particular to an in-phase and inverted-phase automatic switching circuit applied to a flying capacitor three-level circuit, which is used for solving the problems that in the prior art, an analog switch is used for switching circuits, the internal resistance of the analog switch is relatively large, the stray capacitance effect is obvious, extra interference is possibly introduced, and the cost is low. And the accuracy and the stability of control are influenced. The in-phase and inverted-phase automatic switching circuit applied to the flying capacitor three-level circuit realizes automatic switching of in-phase and inverted-phase signals through two operational amplifiers and a series of feedback resistors and capacitors in combination with an input signal Dx and an inductive current signal IL and through control of an NMOS transistor N1, thereby realizing regulation and balance of voltage.

The utility model discloses an operational amplifier circuit with variable output response characteristics in the technical field of circuit design, which comprises an operational amplifier, and a direct current bias compensation circuit is arranged between the output end and the inverted input end of the operational amplifier. The compensation circuit comprises two capacitors and a resistor, one input end of an operational amplifier is connected with one end of a first capacitor and one end of a second capacitor, the other end of the first capacitor is connected with one end of a first resistor and the direct current bias circuit, and the other end of the second capacitor is connected with the other end of a second resistor. The other end of the first resistor and the other end of the second capacitor are connected with the output end of the operational amplifier. According to the utility model, the capacitor and the resistor are connected with the direct-current bias circuit, so that the gain of the operational amplifier circuit can be changed, and the response performance of circuit output is changed; moreover, the whole direct-current bias compensation circuit is simple in structure, few components are used, and the power consumption and the production difficulty of the whole circuit are reduced.

A transimpedance amplifier system (TIA) for stabilizing high gain and high frequency signals while minimizing parasitic capacitance effects on the transimpedance amplifier system. The TIA includes an operational amplifier having a first input terminal, a second input terminal, and an output terminal. The TIA also includes a signal generating device operatively connected with the first input terminal of the operational amplifier. The TIA also includes a T-network feedback architecture operatively connected with the operational amplifier at the first input terminal of the operational amplifier and the output terminal of the operational amplifier. The T-network feedback architecture has a first impedance network and a second impedance network. The T-network feedback architecture is configured to suppress parasitic capacitance from the transimpedance amplifier system.

The present application belongs to the technical field of analog circuit, and particularly relates to a programmable gain amplifier suitable for a high-precision ADC front end. The programmable gain amplifier of the present application adopts a whole differential structure, and comprises a whole differential amplifier. The amplifier completes the function of signal amplification, and has the characteristics of high gain and high linearity. The switches of the network of the switching feedback resistance and capacitance all adopt transmission gate switches, so as to reduce the channel charge injection effect of the switches and the nonlinearity of the on-resistance of the switches. The feedback network of the programmable gain amplifier changes the size of the feedback resistance and capacitance through the transmission gate and the resistance-capacitance combination, so as to realize the control of the gain. The input signal is amplified by the accurate amplification multiple, and meanwhile the size of the feedback resistance and capacitance is impedance-matched, so as to ensure that the-3dB bandwidth of the whole programmable gain amplifier remains basically unchanged, so that the working speed of the programmable gain amplifier under different gain conditions remains consistent, and the linearity is greatly improved.

The present invention provides a dual-feedforward path low-noise amplification circuit and an amplifier based on electromagnetic dual coupling, belonging to the technical field of integrated circuits, comprising: an input module, an output module, a transistor, a magnetic coupling feedforward path and an electrical coupling feedforward path; the input module is connected in series with the output module through a transistor, the magnetic coupling feedforward path is connected in parallel with the transistor, and the electrical coupling feedforward path is connected in parallel with the transistor; the magnetic coupling feedforward path is used to control the input matching and inter-stage matching between the input module and the transistor; the electrical coupling feedforward path is used to remove the coupling of the parasitic capacitance of the transistor; the input module is used to match the input signal to the transistor, the transistor is used to amplify the input signal, and the output module is used to match the amplified signal to the load, the equivalent transconductance is enhanced by the magnetic coupling feedforward path, the stability is guaranteed by the electrical coupling feedforward path, and the two feedforward paths guarantee a sufficiently high gain and a sufficiently low noise coefficient.

Systems and methods that integrate a directional coupling function with directivity that does not have output loss are disclosed. For example, a power amplifier circuit arrangement includes an input terminal to receive an input signal; amplifier circuitry including a first amplifier stage, a second amplifier stage, and a virtual ground node, where an input of the first amplifier stage is coupled to the input terminal, an output of the first amplifier stage is coupled to an input of the second amplifier stage via the virtual ground node, and an output of the second amplifier stage is coupled to the input of the first amplifier stage via feedback circuitry; an output terminal coupled to the output of the second amplifier stage, the output terminal to output an amplified signal; and a directional coupler terminal coupled to the virtual ground node.

A biasing circuit for a capacitive transducer comprises: a high impedance element (Rpd) for coupling between a terminal of the capacitive transducer and a reference voltage (Vref); and a unity gain circuit coupled in parallel with at least two back-to-back diodes, where when the bias circuit is used, the coupled unity gain circuit and one terminal of the at least two back-to-back diodes are coupled to the one terminal of the capacitive transducer.

The invention discloses a coal mine underground drilling hydrological advanced network monitoring device and method. The device comprises a signal receiving circuit, a receiving control circuit, a monitoring calculation circuit and a signal transmission circuit. The signal receiving circuit is used for receiving electric signals according to set parameters and transmitting the received electric signals to the receiving control circuit, and the receiving control circuit preliminarily processes the received signals, controls operation of the whole circuit, guarantees transmission of the signals and transmits the preliminarily processed signals to the monitoring calculation circuit. The monitoring calculation circuit further conditions the received signal and transmits the conditioned signal to the signal transmission circuit, and the signal transmission circuit modulates the signal and then transmits the signal in an electric field mode. According to the invention, the drilling hydrological parameter condition can be monitored in real time, the accuracy of monitoring data can be ensured, and the anti-interference capability and the sensitivity of the received signal are improved, so that the development and the application of an underground coal mine exploration technology are promoted.

Circuitry 200a for coupling to a capacitive transducer 230, e.g. a MEMS transducer, comprises unity gain circuitry, a set of back-to-back diodes 210, and a negative feedback loop. The unity gain circu

This article proposes reducing the sensitivity of an electromechanical sensor. The electromechanical sensor includes sensitivity to changes in the mechanical-electrical gain of a sensing element of the electromechanical sensor; and a voltage-to-voltage converter component that minimizes the sensitivity by coupling a positive feedback voltage to a sensing electrode of the sensing element via a defined feedback capacitor. The sensing element is electrically coupled to the input of the voltage-to-voltage converter component. In one example, the voltage-to-voltage converter component minimizes the sensitivity by maintaining a constant charge at the sensing electrode via a defined feedback capacitor. In another example, the electromechanical sensor includes a capacitive sensing element including a first node having a sensing electrode. In addition, a bias voltage component can apply a bias voltage to a second node of the electromechanical sensor. In yet another example, the electromechanical sensor includes a piezoelectric sensing element.

The invention provides a signal loss detection circuit and a control method. The circuit comprises a waveform generator, a reference peak detector, a data peak detector, a comparator, a signal loss indicator, a digital-to-analog converter and a clock source. The waveform generator is connected with the digital-to-analog converter through a vref pin, the waveform generator is connected with the clock source through a clk pin, the waveform generator is connected with the signal loss indicator through a hys pin, and the waveform generator is connected with the reference peak detector through a vop pin and a von pin; the reference peak detector is connected with a normal phase input end of the comparator, the data peak detector is connected with an inverted phase input end of the comparator, and an output end of the comparator is connected with the signal loss indicator. According to the invention, the waveform generator is adopted to generate the reference waveform with the same four-level pulse amplitude modulation code pattern as the input data waveform, so that the problem of mismatching of conversion efficiency in the prior art is solved, and high-precision signal loss detection is realized.

The application provides a fourth-order feedforward compensation operational amplifier and a design method thereof, and is based on a structural design of "mainly taking a fourth-order operational amplifier path, and sequentially feeding forward compensation from a higher first order to a lower first order in adjacent two-order operational amplifier paths", so that a gain and three zero points of a transfer function can be easily obtained, only a feedforward branch exists, no feedback branch exists, four poles can be obtained by node parameters, and a transfer function of the fourth-order feedforward compensation operational amplifier can be obtained according to the obtained direct current gain, the three zero points and the four poles, that is, the transfer function can be easily obtained based on the circuit structural design; based on the obtained transfer function and a gain requirement of a continuous-time band-pass sigma-delta modulator, a transconductance constraint relationship between each transconductance amplification unit can be deduced, each transconductance amplification unit is selected and designed according to the corresponding transconductance constraint relationship, and the formed fourth-order feedforward compensation operational amplifier can effectively meet the use requirement of the continuous-time band-pass sigma-delta modulator.