55results about "Limiting amplitude" patented technology

The invention discloses a final-stage voltage tracking anti-clipping circuit for an audio power amplifier, and relates to the technical field of power amplifiers, and the circuit comprises a voltage division circuit which is used for receiving final-stage voltage from target power amplifier equipment and generating a combined voltage signal; the audio attenuation module is used for receiving an audio input signal and a final-stage voltage, and judging whether amplitude limiting modulation is carried out on the audio input signal or not to complete power amplifier output by judging whether a starting signal is received or not; and the starting judgment module is used for receiving the combined voltage signal and the first output signal, and comparing the combined voltage signal with the first output signal to generate a starting signal. According to the invention, the collected final-stage voltage of the target power amplifier is set as the dynamic amplitude limiting threshold, so that an over-high signal can be effectively suppressed to a safe range quickly when the power supply drops instantaneously, and the effects of avoiding hearing deterioration caused by power amplifier signal waveform truncation and avoiding potential safety hazards caused by amplitude limiting and topping to the loudspeaker are achieved.

The invention belongs to the technical field of integrated circuit signal processing, and discloses a temperature compensation circuit for a logarithmic detector and the logarithmic detector thereof, and the temperature compensation circuit for the logarithmic detector comprises a first temperature compensation module, a second temperature compensation module and a third temperature compensation module. The first temperature compensation module is used for performing temperature compensation on the current summation module, the second temperature compensation module is used for performing temperature compensation on bias voltage and current of the limiting amplifier module, and the third temperature compensation module is used for performing temperature compensation on bias voltage and current of the rectifier module. The logarithmic detector temperature compensation circuit is suitable for performing temperature compensation on the current summation module, the limiting amplifier module and the rectifier module of the logarithmic detector, and the output precision and consistency of the logarithmic detector are improved.

The signal amplitude limiting circuit comprises a first voltage division circuit, a signal amplification circuit and a second voltage division circuit, the second voltage division circuit comprises a first resistor R1 and a third triode PQ3, the base electrode of the third triode PQ3 is electrically connected with the output end of the signal amplification circuit, the emitter electrode of the third triode PQ3 is grounded, and the first resistor R1 is electrically connected with the output end of the signal amplification circuit. The collector electrode of the third triode PQ3 is electrically connected with the second end of the first resistor R1, and the first end of the first resistor R1 is electrically connected with the signal output end. By arranging a first voltage division circuit, a signal amplification circuit and a second voltage division circuit, when an input signal exceeds a normal range, the input signal can drive a third triode PQ3 of the second voltage division circuit to enter an amplification state after passing through the first voltage division circuit and being amplified, and at the moment, an output signal is influenced by voltage division of a first resistor R1 and the third triode PQ3; and the output signal is not increased along with the increase of the input signal, so that distortion or overhigh power is avoided.

The invention discloses a P-band high-power filtering and amplitude limiting assembly, which belongs to the technical field of microwaves and comprises a filter, an amplitude limiter, a polarizer, a coupler and a metal cavity. The amplitude limiter is installed on the bottom layer of the metal cavity, the filter and the polarizer are installed on the top layer of the metal cavity, the coupler is installed on the side wall of the metal cavity, the filter, the low-pass filter and the polarizer are connected in a wall-penetrating welding mode through a 50-ohm metal connecting rod, and the polarizer is fixed to the metal cavity through a medium supporting column. The whole assembly belongs to an upper-lower layer structure. According to the assembly, the transmission path between devices is shortened, the emission loss of the assembly is reduced, the size of the filtering and amplitude limiting assembly is greatly reduced under the condition that composite multiple functions are met, and the purposes of high power and high integration are achieved.

A data slicer may include an input transistor configured to generate an internal output voltage based on an input voltage at an input node. An output node may be configured to output an output voltage based on the internal output voltage, and a feedback transistor may be configured to adjust the internal output voltage based on a correction voltage corresponding to output of the output node in a previous cycle.

A clipping detector circuit (12) is configured to detect clipping of a pulse-width modulated signal (PWMout ) and comprises a timer circuit (120) configured to monitor edges of the pulse-width modulated signal (PWMout ) and to monitor a time period elapsing since a last occurrence of an edge in the pulse-width modulated signal (PWMout ), assert a first signal (ClipDet) when said time period elapses, and de-assert the first signal (ClipDet) and reset said time period as a result of an edge occurring in the pulse-width modulated signal (PWMout ); and a counter circuit (122) configured to monitor the pulse-width modulated signal (PWMout ) and the first signal (ClipDet), determine the number of pulses in said pulse-width modulated signal (PWMout ) since the last de-assertion of the first signal (ClipDet), and assert a second signal (ClipOut) when the number of pulses in said pulse-width modulated signal (PWMout ) since the last de-assertion of the first signal (ClipDet) reaches a certain number m of pulses. The clipping detector circuit (12) is configured (124) for generating at output a clipping detection signal ( ClipDet' ) indicative of whether the pulse-width modulated signal ( PWMout ) is clipped or not as a function of the first signal ( ClipDet ) and the second signal ( ClipOut ).

The invention provides a special amplitude limiting circuit for a PLC (Programmable Logic Controller), relates to the technical field of power line carrier communication, and aims to solve the technical problems that an AGC (Automatic Gain Control) circuit in an existing PLC communication system is limited in adjusting range, signal identification fails and the circuit burning risk is high. The system comprises a micro-control unit MCU, a current-limiting resistor, an optocoupler, a PLC signal coupling circuit and a PLC chip, and compared with a conventional PLC communication PLC chip signal path and process, a PLC amplitude limiting circuit is additionally arranged in front of the receiving ends RX + and RX-of the PLC chip; through the function that receiving ends RX + and RX-of a PLC chip identify the signal to noise ratio, the PLC chip communicates with a micro-control unit MCU through serial ports TX and RX, and through two modes of controlling and accessing different resistance values of series resistors to limit current and controlling and accessing different resistance values of divider resistors, the amplitude of a PLC signal is limited, so that the size of the PLC signal is changed, and the signal to noise ratio of the PLC signal is adjusted.

The utility model provides an absorption type amplitude limiter, which relates to the technical field of absorption type amplitude limiters and comprises a mounting mechanism, an amplitude limiter main body is mounted at the top end of the mounting mechanism, the mounting mechanism comprises a base, a bottom plate is arranged at the top end of the base, an insertion groove is formed in the front surface of the base, an insertion rod is slidably connected in the insertion groove, and the insertion rod is fixedly connected with the base. The top end of the inserting rod is fixed to the front face of the bottom plate, built-in grooves are formed in the positions, close to the front face and the right side, of the interior of the base, fixing assemblies are installed in the built-in grooves, a rotary knob is rotated to be disengaged from a sliding rod, the sliding rod is pushed out of a circular groove through a spring, and fixing of the inserting rod is relieved; and finally, the amplitude limiter main body is pushed forwards, and the amplitude limiter main body, the bottom plate and the insertion rod are taken out together for maintenance, so that compared with a traditional fixing mode, the operation convenience is greatly improved, and the maintenance efficiency is effectively improved.

The invention relates to the technical field of anti-interference receiving, and discloses a tunable high-temperature superconducting amplitude limiter based on voltage regulation. Comprising a radio-frequency signal input end P1, a first impedance conversion node assembly, a superconducting amplitude limiting node L4, a direct-current bias regulation and control circuit for introducing bias current to the superconducting amplitude limiting node L4, a second impedance conversion node assembly and a radio-frequency signal output end P2 which are electrically connected in sequence, the first impedance conversion node assembly and the second impedance conversion node assembly are the same in structure, and each of the first impedance conversion node assembly and the second impedance conversion node assembly comprises a superconducting microstrip transmission line, a blocking capacitor and an impedance conversion node, on the premise that geometric structure parameters of the high-temperature superconducting amplitude limiting section are not changed, the working current density of the high-temperature superconducting amplitude limiting section can be changed within the range close to or away from the critical current density of the superconducting material by adjusting the magnitude of the bias current, and therefore tuning of the amplitude limiting threshold value and the power bearing capacity of the amplitude limiter is achieved.

The present invention provides a digital audio processing device that can generate harmonic signals ideal for improving sound quality, even when the digital audio signal contains waveforms with multiple consecutive samples of the same value as a maximum or minimum sample. [Solution] The maximum / minimum sample detection unit 11 detects the maximum and minimum samples in a series of samples that constitute a digital audio signal. The maximum / minimum sample correction unit 12, when there are consecutive samples with the same value as the maximum or minimum sample, assigns a maximum sample tag or a minimum sample tag to samples that are different from the maximum or minimum sample among the consecutive samples. If no consecutive samples exist, the maximum / minimum sample correction unit 12 assigns a maximum sample tag to the maximum sample and a minimum sample tag to the minimum sample.

This application relates to methods and apparatus for clipping prevention. A driver apparatus for driving a load with an output signal has a switching driver with a switch network and a modulator configured to control the switch network to switch output nodes between different switching voltages with a controlled duty-cycle. A quantizer controller receives a quantizer input signal based on an input signal and a feedback signal and controls the duty-cycle of the switch network. A clipping prevention controller is configured to control a gain applied to the input signal so as to provide limiting of the input signal to avoid clipping, wherein the clipping prevention controller is configured to dynamically control at least one limiting threshold used to determine when to apply limiting of the input signal based on an indication of said quantizer input signal.

The invention discloses a broadband amplitude limiting module with low reflection after overvoltage. The broadband amplitude limiting module comprises an impedance matching circuit, a high-input impedance amplifying circuit and a low-frequency gain control circuit, wherein the impedance matching circuit is used for performing 50 omega termination matching between an input signal and the high input impedance amplification circuit, and in the high input impedance amplification circuit, a low and medium frequency signal fed back by the low frequency gain control circuit and a high frequency signal coupled by the high frequency coupling capacitor are synthesized and then input to the differential operation amplification circuit; therefore, the problem of reflection caused by overvoltage in the circuit is solved, and the waveform quality of a signal path is ensured.

Novel tools and techniques are provided for implementing a novel integrated programmable gain amplifier "PGA" and protection circuit. In various embodiments, a circuit is provided that includes a PGA, an analog-to-digital converter "ADC", and a protection circuit, all disposed on the same semiconductor chip. The PGA is configured to receive a wireless signal received from an antenna as input, and to output an amplified wireless signal at its output based on amplifying the wireless signal by a programmable gain amount. The protection circuit is configured to, in response to detecting a spike in gain at the output of the PGA that exceeds a threshold magnitude, control a reduction in the programmable gain amount to bring the resulting signal at the output of the PGA below the threshold magnitude. A normally open switch can also be added at the differential output of the PGA to further clamp the PGA output.

The present invention provides a power adaptive link allocation front-end receiving component, which mainly includes a front-end radio frequency circuit module, a detection signal operation circuit module, a radio frequency signal amplification circuit module, and an output power adjustment circuit module. A large-dynamic detector is used to detect the signal of the radio frequency receiving front-end to obtain a power-related level signal, and then the level signal is amplified by an operational amplifier. Then, according to the reference level set for radio frequency signals with different powers, the control level of the single-pole triple-throw switch in the subsequent circuit is automatically converted, and then different back-end signal processing links are selected to complete the signal processing function of the front-end receiving component, and finally the adaptive allocation feature of the receiving front-end is realized. The present invention can realize adaptive link allocation according to the magnitude of the radio frequency input power, and has the advantages of adaptive implementation, large dynamic range, high detection sensitivity, etc.

A coaxial speaker protection method, a coaxial speaker protection system, a coaxial speaker protection device, and a coaxial speaker protector are provided. The coaxial speaker protection method includes modeling a temperature of a tweeter to obtain a tweeter voltage-temperature transfer function, modeling a temperature and an amplitude of a woofer to obtain a woofer voltage-amplitude-temperature transfer function, modeling a coaxial device having the tweeter and the woofer to obtain a thermal conduction function of the coaxial device, predicting a temperature at a next moment of the tweeter according to temperature information fed back by a current at a previous moment of the tweeter, etc. The tweeter and the woofer are protected through a feedforward manner, so that sound quality of a coaxial speaker is improved.

A driver apparatus 100a for driving a transducer (Fig.1, 102) has a switching driver 101 configured to switch at least one output node (Fig.1, 103a, 103b) between different switching voltages with a c

An audio system includes an amplifier, regulating circuitry, and a filter. The regulating circuitry generates an audio voltage threshold signal based on an estimated value of the supply voltage source of the system, the estimated ESR between the system voltage supply and amplifier voltage supply pin, and the measured output resistance of the system. From these measurements / estimates, an anti-clipping voltage limit signal is generated. Power-budget-based and current-budget-based voltage limit signals are also determined based on first and second functions of the estimated value of the voltage source, respectively. The minimum of these three voltage limit signals is selected as the audio voltage threshold signal. The measurements, estimates and calculations are performed on a periodic basis to continually update the audio voltage threshold signal and thus adaptively regulate the audio system. A de-emphasis filter in the audio signal path compensates for capacitive ripple of the voltage at the amplifier's voltage supply pin.

The invention relates to a broadband logarithmic detector. The amplitude limiting amplifier comprises an amplitude limiting amplifier link used for carrying out amplitude limiting amplification on a signal to be detected, amplitude limiting amplification gains comprise a first amplitude limiting amplification gain or a second amplitude limiting amplification gain, and the numerical value of the first amplitude limiting amplification gain is larger than that of the second amplitude limiting amplification gain, when the amplitude limiting amplification gain of the amplitude limiting amplifier link is the first amplitude limiting amplification gain, the amplitude limiting amplifiers of the first stage are connected, and each amplitude limiting amplifier provides a single-stage first amplification gain; when the amplitude-limiting amplification gain of the amplitude-limiting amplifier link is a second amplitude-limiting amplification gain, accessing a second-stage amplitude-limiting amplifier, and providing a single-stage second amplification gain by each amplitude-limiting amplifier; the first stage number is smaller than the second stage number, and the single-stage first amplification gain is larger than the single-stage second amplification gain. According to the method, translation of the RSSI output characteristic curve of the logarithmic detector can be effectively stabilized, and the output characteristic and the process robustness of the logarithmic detector are improved.

The application discloses an output limiting device applied to a switching power supply, comprising an error amplifier, an output resistor, an amplifier and a current biasing module; the input end of the error amplifier is connected with the switching power supply, a reference voltage and the current biasing module, and the reference voltage is used for limiting the output voltage of the switching power supply within a preset range; the output end of the error amplifier is connected with the first end of the output resistor; the input end of the amplifier is connected with the reference voltage and the current biasing module; the output end of the amplifier is connected with the second end of the output resistor and the input end of the amplifier; and the current biasing module is connected with the reference voltage. The output limiting voltage of the application is related to the reference voltage and the output resistor. Since the resistors have good matching on the same chip and the accuracy of the reference voltage is high, the limiting voltage is less affected by process fluctuation, more accurate limiting control can be realized, and the influence of the size deviation of the traditional MOS tube on the limiting voltage is avoided.

The present invention discloses a 22KHz signal anti-interference tuning and amplifying circuit for a high-frequency head, which includes a tuning and amplifying circuit, a peak detection circuit and a data limiter circuit; the peak detection circuit is connected to the tuning and amplifying circuit, and the peak detection circuit is connected to the data limiter circuit; the signal is input from the tuning and amplifying circuit and output from the data limiter circuit; the tuning and amplifying circuit is used for tuning and amplifying analog signals; the peak detection circuit extracts and holds the peak value of the tuned and amplified signal; the data limiter circuit is used for converting the amplitude-modulated wave envelope signal extracted by the peak detection circuit into a digital signal; this anti-interference tuning and amplifying circuit has the characteristics of using fewer components, improving the anti-noise ability and reducing the error rate in signal conversion.

A maximum / minimum sample detection unit (11) detects a maximum sample and a minimum sample in a series of samples constituting a digital audio signal. When there are consecutive samples in which samples having the same value as the maximum sample or the minimum sample are consecutive, a maximum / minimum sample correction unit (12) assigns a maximum sample tag or a minimum sample tag to samples differing from the maximum sample or the minimum sample rather than to the consecutive samples. If there are no consecutive samples, the maximum / minimum sample correction unit (12) assigns a maximum sample tag to the maximum sample and assigns a minimum sample tag to the minimum sample.

The utility model relates to the technical field of microwave frequency, in particular to an X-waveband amplitude-limiting low-noise amplifier device. Comprising a high-frequency input port, an amplitude limiter, a first switch and a second switch which are connected in sequence, and the first switch is used for dividing signals into a first path and a second path; the first path comprises a step attenuator and an amplifier I which are connected in sequence; the second path comprises an amplifier II; and the switch II is used for selecting an output signal of the first path or the second path and transmitting the output signal to the output port through the filter, the final amplifier and the power divider. The problems of high isolation, low noise coefficient and low cost compatibility in the single-channel topology are solved.

To provide an amplitude limiting circuit and an operational amplifier capable of limiting the amplitude of a signal output from a fully differential output circuit.SOLUTION: An amplitude limiting circuit includes a first NMOS transistor connected to a positive output terminal of an output circuit, a second NMOS transistor connected to a negative output terminal of the output circuit, a first current source connected in common between the first NMOS transistor and the second NMOS transistor and ground, and a voltage generating unit that generates a voltage to be applied to the gates of the first NMOS transistor and the second NMOS transistor.SELECTED DRAWING: Figure 1

The present application relates to a kind of wideband log detector.It includes the limiting amplifier link for the limiting amplification of signal to be detected, the limiting amplification gain includes first limiting amplification gain or second limiting amplification gain, the value of first limiting amplification gain is greater than the value of second limiting amplification gain, wherein, when the limiting amplification gain of limiting amplifier link is first limiting amplification gain, access the limiting amplifier of first stage number, and each limiting amplifier provides single-stage first amplification gain;When the limiting amplification gain of limiting amplifier link is second limiting amplification gain, access the limiting amplifier of second stage number, and each limiting amplifier provides single-stage second amplification gain;First stage number is less than second stage number, and single-stage first amplification gain is greater than single-stage second amplification gain.The present application can effectively stabilize the translation of the RSSI output characteristic curve of log detector, improve the output characteristic and process robustness of log detector.

This application relates to methods and apparatus for clipping prevention. A driver apparatus for driving a transducer has a switching driver configured to switch at least one output node between different switching voltages with a controlled duty-cycle to drive an output signal across the transducer. A clipping prevention controller is configured to control a gain applied to the input signal so as to provide limiting of the input signal to avoid clipping of the output signal. The clipping prevention controller is configured to dynamically control at least one limiting threshold used to determine when to apply limiting of the input signal based on an indication of load resistance of the transducer and the input voltage to the switching driver.

A method for performing loudness normalization, the method being performed by an audio signal processing device, includes the steps of receiving an audio signal; receiving information about an integrated loudness of the audio signal; receiving information about a target loudness of the audio signal; correcting the integrated loudness based on one or more processing steps to obtain a corrected integrated loudness; and normalizing the audio signal based on the corrected integrated loudness and the target loudness to obtain a normalized audio signal.

A controller regulates the voltage delivered to the load and current drawn from the battery in an audio system depending on ripple in the battery voltage which is input to the controller to allocate power for audio playback. Regulation maximizes available headroom while avoiding audio clipping. The effect of internal battery and external parasitic resistance (ESR) on ripple is compensated by an iterative process. ESR is rapidly increased whenever the minimum of the battery voltage input to the controller falls below a clipping threshold and slowly decreased whenever such voltage exceeds such threshold and the audio is under compression. A limiter allocates power to utilize more of the available audio headroom. A de-emphasis filter in each audio signal path compensates for capacitive ripple in the battery voltage input to the controller. As the frequency of the audio input changes, the filter(s) allow frequency-dependent power / current regulation to fill the full audio range without distortion.