16 results about "Pulse-density modulation" patented technology

The application provides a pulse density modulation interface implementation method and device of an analog-to-digital converter, electronic equipment and a storage medium. The method comprises the following steps: designing a circuit architecture of an analog-to-digital converter, and setting working variable parameters for components in the circuit architecture; determining a transfer function of an output signal and a transfer function of noise based on the working variable parameters; in the case that an oversampling rate (OSR) is a first set value, a filter order is a second set value, and a quantization bit number is a third set value, calculating an optimal solution of the transfer function of the noise; determining a value corresponding to the working variable parameters of the components according to the optimal solution; and selecting corresponding components for the circuit architecture based on the value, and generating a pulse density modulation interface of an analog-to-digital converter. The application can accurately design a PDM interface, and improves the signal processing performance of the interface.

A driving device includes a pulse intensity modulation module, a pulse width modulation module, a pulse density modulation module, and a driving module. The pulse intensity modulation module receives an image processing signal related to a pixel and generates a pulse intensity according to the image processing signal. The pulse width modulation module receives the image processing signal and generates a pulse width according to the image processing signal. The pulse density modulation module receives the image processing signal and generates a pulse density according to the image processing signal. The driving module receives the pulse intensity, the pulse width, and the pulse density and generates a driving signal to the pixel according to the pulse intensity, the pulse width, and the pulse density.

The invention provides a frequency jittering clock signal generation method and device, and relates to the technical field of electronics. The method comprises the following steps: acquiring target jitter frequency parameters including a jitter frequency center frequency, a jitter frequency mode and a jitter frequency width; a modulation signal and a source clock signal are determined according to the target jitter frequency parameter, the amplitude of the modulation signal changes along with time, and the amplitude change range of the modulation signal is configured to enable the first-order sigma-delta modulator to work in an unsaturated linear response area; inputting the modulation signal to a first-order sigma-delta modulator, and under the driving of the source clock signal, performing pulse density modulation on the modulation signal by the first-order sigma-delta modulator and outputting a unit pulse density modulation code stream; and carrying out edge detection on the unit pulse density modulation code stream to generate a jittering frequency clock signal. According to the technical scheme, a complex phase-locked loop circuit is replaced by a scheme which is extremely simple in structure and is completely realized by digital logic, and the problem of balancing the integration level, the cost and the signal purity is synchronously solved.

This invention belongs to the field of acoustic detection technology for partial discharge in power equipment, and relates to an array-type acoustic imaging partial discharge detection method and system. The method includes: establishing the correspondence between channel identifier sequences and array geometric parameters; dividing the array into subgroups according to a fixed subgrid and generating a synchronous sampling time sequence to acquire multi-channel pulse density modulation signals; demodulating and extracting the signals, bandpass filtering and pulse framing; constructing a forward-backward spatial smoothing covariance matrix and using minimum variance distortionless response beamforming to calculate the spatial spectrum to generate an acoustic image; and registering and superimposing the acoustic image with a visible light image to output the positioning result. The technical solution of this application achieves high-contrast imaging and stable positioning output through temporal and geometric consistency constraints, which can improve the consistency of on-site interpretation and meet the requirement of repeatable positioning under weak partial discharge ultrasonic conditions.

Disclosed is a sensor-processing system including, in some embodiments, a sensor, one or more sample pre-processing modules, one or more sample-processing modules, one or more neuromorphic integrated circuits (“ICs”), and a microcontroller. The one or more sample pre-processing modules are configured to process raw sensor data for use in the sensor-processing system. The one or more sample-processing modules are configured to process pre-processed sensor data including extracting features from the pre-processed sensor data. Each of the neuromorphic ICs includes at least one neural network configured to arrive at actionable decisions of the neural network from the features extracted from the pre-processed sensor data. The microcontroller includes a CPU along with memory including instructions for operating the sensor-processing system. In some embodiments, the sensor is a pulse-density modulation (“PDM”) microphone, and the sensor-processing system is configured for keyword spotting. Also disclosed are methods of such a keyword spotting sensor-processing system.

Various examples disclosed herein relate to digital signal processing, and more particularly, to identifying metrics of audio samples to dynamically adjust the gain of audio data. In an example embodiment, a pulse density modulation system is provided that includes sample generation circuitry and gain control circuitry coupled to the sample generation circuitry. The sample generation circuitry is configured to sample audio data to produce samples of the audio data and output the samples to a processor and to the gain control circuitry. The gain control circuitry is configured to determine one or more metrics based on the samples of the audio data and output the one or more metrics to the processor.

The present invention provides, a device for a controlling a quantum computer is provided. The device comprises a Quantum Computer Control System, QCCS, channel. The QCCS channel comprises a transceiver configured generate a 1-bit pulse stream and modulate the 1-bit pulse stream by pulse density modulation to generate a modulated signal, a low pass filter configured to filter the modulated signal and output a corresponding qubit control signal for a quantum computer. The invention further comprises a corresponding system, method and a use of a transceiver for controlling a qubit of a quantum computer.

This invention discloses a pulse density modulation full-bridge converter capable of eliminating inter-frequency harmonics, belonging to the field of power electronic control technology. The pulse density modulator provided by this invention includes an adder for adding a pulse density command signal and a feedback signal to obtain a signal to be quantized, x. A quantizer quantizes the signal to be quantized, x, to obtain a pulse signal, a. A register delays pulse signal a by half a switching cycle to generate a pulse signal, b. Pulse signals a and b are input into an XOR gate and then subtracted from the signal to be quantized, x, to obtain a quantization error, e. The quantization error, e, is then filtered by a digital filter to obtain a feedback signal. Pulse signals a and b control the switching state of the full-bridge converter. This invention can be applied to various resonant converters, controlling the converter's output voltage or power through pulse density modulation; it can eliminate inter-frequency harmonics based on the resonant network, avoiding oscillation and ensuring stable converter operation.

The application discloses a soft-start control method and system of an LLC resonant converter, and realizes soft-start of the LLC resonant converter. The method comprises the following steps: when a start command is received, a driving signal for controlling the LLC resonant converter is generated by using a pulse density modulation mode in an output quantity closed-loop control system of the LLC resonant converter; when the pulse density of the driving signal reaches a set value, the driving signal is generated by switching to using a pulse width plus frequency modulation mode, and until the closed-loop control system reaches a steady state, the soft-start of the LLC resonant converter is completed; wherein the pulse width plus frequency modulation mode refers to a modulation mode in which a pulse width modulation mode and a pulse frequency modulation mode act simultaneously.

This invention discloses a phase-shifted Delta-Sigma pulse density modulator and its operating method for multilevel converters, belonging to the field of power electronic control technology. In the modulator provided by this invention, the pulse density command signal is input to a first multiplexer to obtain multiple signals to be quantized. These multiple signals are then input to a quantizer to obtain a first set of pulse signals. After a delay, the first set of pulse signals is used to obtain a second set of pulse signals. For a multilevel converter using full-bridge submodules, the first set of pulse signals is used to generate the switching signals for the leading arms of each submodule, and the second set of pulse signals is used to generate the switching signals for the lagging arms of each submodule. This invention uses pulse density modulation, making it suitable for resonant circuits and achieving wide-range soft switching under a fixed switching frequency. It provides different pulse density modulation waves for each submodule of the multilevel converter, reducing the harmonic content between converters.

The invention discloses a pulse width modulation excitation and pulse density modulation acquisition method, and relates to the technical field of electronic testing and measuring instruments, and the method comprises the steps: S1, employing a pulse width modulation (PWM) peripheral of a microcontroller MCU, and cooperating with an external low-pass filter to generate an AC excitation voltage; wherein one path of AC excitation voltage is applied to a known reference resistor to generate a reference current, and the other path of adjustable balanced voltage is applied to a to-be-tested device to generate a to-be-tested current. According to the pulse width modulation excitation and pulse density modulation acquisition method provided by the invention, traditional high-cost ADC and DAC components are abandoned, high-precision alternating current excitation is generated by utilizing a built-in PWM peripheral and an external low-pass filter of a microcontroller, and meanwhile, an error signal is converted into a PDM digital signal flow through an analog comparator; according to the invention, digitalization and simplification of signal acquisition are realized, the system cost and the complexity of circuit design are greatly reduced, the expandability of the system is obviously enhanced, and multichannel parallel measurement can be realized.

A measurement is made of jitter present in a jittery clock signal. A digital sinusoid generator circuit clocked by the jittery clock signal generates a pulse density modulation (PDM) signal corresponding to a sinusoid waveform. The PDM signal is converted by a sigma-delta modulator circuit to an oscillating frequency signal with an output of digital values digital values indicative of oscillating frequency signal phase. Responsive to the jittery clock signal, the digital values indicative of oscillating frequency signal phase are sampled. A digital differentiator circuit determines a digital difference between consecutive samples of the digital values indicative of oscillating frequency signal phase. The digital difference is processed by a digital signal processing circuit to generate a frequency spectrum and determine from signal-to-noise ratio a measurement of jitter in the jittery clock signal.

An analog-to-digital conversion circuit includes: a variable gain amplifier; a delta-sigma modulator that modulates an output of the variable gain amplifier to a pulse density modulation (PDM) signal; and a decimation filter that downsamples the PDM signal to output a first digital signal that is converted into a multi-bit digital signal. The decimation filter includes: a weight change unit that converts the PDM signal into a second digital signal that is weighted by multiplying a weight of the PDM signal by a reciprocal of an amplification factor of the variable gain amplifier; and a first digital filter that receives the second digital signal as an input, and outputs the first digital signal.

The invention discloses a pulse width modulation control method and system for a three-phase inverter, and the method comprises the steps: obtaining a change trend curve of an inductive current ripple output by the three-phase inverter in a power frequency period, so as to obtain a reference characteristic curve; on the basis of the reference characteristic curve, the carrier frequency in a power frequency period is determined, and the carrier frequency is dynamically changed; generating discontinuous pulse width modulation waves; and generating a pulse width modulation signal for controlling a switching tube in the three-phase inverter according to the discontinuous pulse width modulation wave and the carrier frequency in one power frequency period. According to the pulse width modulation control method for the three-phase inverter, pulse density modulation is introduced into a modulation link of the inverter, dynamic change of carrier frequency is achieved by adjusting pulse density in different intervals in the modulation process, switching loss is remarkably reduced by directly reducing the switching frequency in a power frequency period, and the switching efficiency is improved. And the modulation wave is easy to generate and high in controllability.

The invention discloses a remote audio monitoring method and system based on electromagnetic leakage, and belongs to the technical field of electronic information engineering and safety. An electromagnetic leakage signal of the digital microphone is received through the radio frequency antenna; pre-amplifying the received signal, and performing targeted filtering by using a first band-pass filter which sets a passband according to the PDM clock frequency to extract a characteristic spectrum component; inputting the filtered signal into a low-noise amplifier for gain boosting; carrying out secondary noise suppression through a second band-pass filter; and then analog-to-digital conversion is carried out, and a special PDM demodulation algorithm is adopted to demodulate the digital signal so as to restore the audio. Therefore, the technical problems that in the prior art, the monitoring effect on electromagnetic leakage generated by pulse density modulation signals of a digital microphone is poor, the signal-to-noise ratio of reduced audio is low, and the effective action distance is short are solved, effective capture and clear reduction of weak digital modulation leakage signals are achieved, and the monitoring distance, the audio quality and the anti-interference capacity are improved.