39 results about "Pulse-density modulation" patented technology

Disclosed in the present invention is a high-dynamic capacitive digital microphone system based on electrostatic force feedback. The system comprises an MEMS microphone and an interface circuit chip thereof, wherein the interface circuit chip comprises a charge pump, an analog front end, an analog-to-digital conversion circuit, an amplitude detection module, an amplitude adjustment control module and a pulse density modulation module. In the present invention, the characteristic of the sensitivity being able to be adjusted by means of changing a bias voltage by a capacitive sensor is used, and a charge pump with an adjustable output voltage is used to provide electrostatic force feedback, thereby further expanding the adjustable range of a front-end gain, and also reducing requirements for the noise performance of a readout circuit. Therefore, the system in the present application has the characteristics of high dynamic range and high-precision quantization.

A system comprising a current sensor for sensing an average output current and / or an average input current of a circuit is presented. There is a first switch, the first switch being arranged to selectively couple a sensing node of the circuit to a first voltage, wherein the current sensor comprises a pulse density modulator configured to generate a pulse density modulated signal. The pulse density modulated signal is dependent on an average current flowing through the first switch. The current sensor is configured to sense the average output current and / or the average input current of the circuit using the pulse density modulated signal.

The invention provides a pulse modulation LED dimming system and method based on an STM32 single-chip microcomputer. The system is mainly composed of an STM32F103C8T6-single-chip microcomputer module, an OLED display module, a signal acquisition module, a matrix key module, a Bluetooth module, an LED lamp module and the like. The system method comprises the following steps: step 1, optimizing a hybrid modulation strategy and carrier allocation, and establishing a dynamic carrier frequency allocation model through a multi-mode hybrid scheme fusing pulse width modulation and pulse density modulation; step 2, collecting an LED load current waveform in real time through a current sampling module, dynamically adjusting a gain coefficient based on a harmonic distortion rate, and counteracting a main harmonic component of a current signal in real time; and step 3, implementing nonlinear compensation of volt-ampere characteristics. The system supports 0%-100% stepless dimming, brightness adjustment is smooth and flicker-free, the system has four dimming modes of normally-on, single-point, circulating and sliding, matrix key local control and Bluetooth remote control are supported, and a flexible and stable LED dimming scheme is provided for a user.

The invention relates to the technical field of digital health monitoring, in particular to a multi-source health risk prediction method, which comprises the following steps of: synchronously acquiring inertia, vital signs, near-infrared and visual events, and sending the events into a photon pulse network to generate an event tensor after quaternary wavelet and pulse density modulation; a topology signature is obtained through persistent coherence and optimal transmission, Hamiltonian power students are embedded into the topology signature to form risk energy, and the risk energy is stored on a chain and fed back to the network. The risk, topology and timestamps are input into a regular strategy optimization network, touch pressure, stride frequency, respiration and illumination control quantity are output to drive an actuator to perform closed-loop intervention, an award drives a model and dissipation coefficient to perform adaptive updating, and end-side high-precision prediction and personalized real-time intervention are achieved.

A system with dimming control includes a luminance signal, a variable-frequency-clock signal generator responsive to the luminance signal operable to generate a variable-frequency clock signal, a pixel-control signal generator responsive to the variable-frequency clock signal operable to generate a pixel-control signal, and a pixel including a light emitter responsive to the pixel-control signal. The pixel-control signal can be a temporally modulated signal such as a pulse-width modulation signal or a pulse-density modulation signal. A display can comprise an array of pixels and a display controller. The pixel or the display controller can include the variable-frequency clock signal or the pixel-control signal generator, or both.

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.

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.

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.

An integrated circuit comprises a sigma-delta modulator (SDM) coupled to a receiving electrode that is selectively coupled to multiple unit cell sensors. A demodulator is directly coupled to the SDM, and the demodulator is designed to generate a digital multi-bit signal by demodulating a digital pulse-density modulated (PDM) signal received by the SDM. The demodulation may involve multiplying digitized cosine values ​​by the digital PDM signal. A cascaded integrator-differentiator (CIC) filter is coupled to the demodulator and comprises a first integrator and a second integrator cascaded together to accumulate a multitude of samples of the digital multi-bit signal at the second integrator.The CIC filter includes a single-comb circuit coupled to the second integrator, whereby the single-comb circuit is intended to generate a bitstream with measured amplitude from the accumulated sample values.

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.

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.

An integrated circuit includes a sigma-delta modulator (SDM) coupled to a receive electrode, which is selectively coupled to multiple unit cell sensors. A demodulator is coupled directly to the SDM, the demodulator to generate a multibit digital signal by demodulating a digital pulse density modulated (PDM) signal received from the SDM. The demodulating can include multiplying digitized cosine values with the digital PDM signal. A cascaded integrator-comb (CIC) filter is coupled to the demodulator and includes a first integrator and a second integrator cascaded together and to accumulate, at the second integrator, a plurality of samples of the multibit digital signal. The CIC filter includes a single comb circuit coupled to the second integrator, the single comb circuit to generate a measured amplitude bitstream from the accumulated samples.

A transmitter (19; 36) configured to drive the transmitter (19; 19 ') with an antenna signal (21) of a substantially sinusoidal current / voltage having a carrier frequency in the RFID frequency range of 100 kHz to 100 MHz; 36), the transmitter (19; 36) comprises: a power amplifier (22) configured to provide an amplified transmitter signal (23); an electromagnetic interference filter (33) configured to filter the amplified transmitter signal (23) and to provide a filtered transmitter signal (34); a matching circuit (35) connected to the electromagnetic interference filter (33) and the RFID antenna (20) and configured to match their impedance and to receive the filtered transmitter signal (34) and to provide the antenna signal (21) to the RFID antenna (20), in which the transmitter (19; 36) comprises a transmitter signal source (25; 37) connected to the power amplifier (22) and configured to provide the pulse density modulated signal as a transmitter signal (26) to the power amplifier (22).

An encoding technique for reducing the power of PDM microphones is disclosed. Digital MEMS microphones utilize a modulation technique called Pulse Density Modulation (PDM), where a single data line (PDMDAT) is used to convey the digital information from the microphone source to a receiver. A characteristic of PDM is that a low noise signal will produce the most transitions, a zero signal will produce an alternating bitstream of logic-1s and logic-0s, and low noise bitstreams will be rich in singleton and doubleton 1s / 0s. Typically, CMOS drivers transmit the PDM bitstream signal. CMOS drivers consume power primarily when they transition, so a bitstream rich in singletons and doubletons will increase power consumption. Differential encoding with an XNOR function is used as a singleton-suppression encoder, and a differential encoding with an XOR function is used as a doubleton-suppression encoder. In some embodiments, such as a dual PDM microphone configuration, the microphones alternate sending data on the rising (transition to logic-1) and falling (transition to logic-0) edges of PDMCLK. In other embodiments, a Voice Activity Detection (VAD) function may be added. In some other embodiments, a suppressed clock pulse duration modulator may be added.

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.

A voice wake-up method, an electronic device, and a computer-readable storage medium are provided. The voice wake-up method comprises collecting an original voice signal input by a user; generating pulse density modulation data according to the original voice signal; decoding the pulse density modulation data to generate decoded data; performing preprocessing and feature extraction processing on the decoded data to generate voice features; performing pattern matching on the voice features according to a hidden Markov model to generate a recognition result; and waking up an external processor of the electronic device according to the recognition result. In the voice wake-up method, a voice wake-up function of the electronic device is realized, which reduce the power consumption of the electronic devices while improving the accuracy of voice wake-up.

The application discloses a high dynamic capacitance type digital microphone system based on electrostatic force feedback, comprising a MEMS microphone and an interface circuit chip thereof, wherein the interface circuit chip comprises a charge pump, an analog front end, an analog-digital conversion circuit, an amplitude detection module, an amplitude adjustment control module and a pulse density modulation module. The application utilizes the characteristic that the capacitance type sensor can adjust sensitivity by changing a bias voltage, adopts an output voltage adjustable charge pump to provide electrostatic force feedback, further improves the adjustable range of the front end gain, and relaxes the requirement on the noise performance of a readout circuit. Therefore, the system has the characteristics of high dynamic range and high precision quantization.

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.

An apparatus includes a reference signal generator, a voltage droop detection circuit, a digital frequency locked loop (DFLL), and a DFLL control circuit. The reference signal generator receives a digital value and generates a pulse density modulated signal based on the digital value. The voltage droop detection circuit converts the pulse density modulated signal to an analog signal, compares the analog signal to a monitored supply voltage, and generates a voltage droop detection signal in response to detecting that the monitored supply voltage is lower than a specified value relative to the analog signal. The DFLL provides a clock signal for a circuit within a domain of the monitored supply voltage. The DFLL control circuit causes the DFLL to slow the clock signal in response to receiving the voltage droop detection signal.

The invention discloses a pulse density modulation sequence design method and device for wireless power transmission, and relates to the technical field of wireless power transmission, and the method comprises the steps: obtaining a modulation sequence period, determining a modulation step length based on the modulation sequence period, and setting an initial sequence for modulation density based on the modulation step length; extracting compensation topology, and calculating the minimum harmonic distortion rate of output current of the compensation topology when each modulation sequence is adopted under the same modulation density by taking the initial sequence as a starting point; and sorting the minimum harmonic distortion rates of all the output currents, and taking a sequence corresponding to a minimum value in the minimum harmonic distortion rates of the output currents as a modulation sequence under the modulation density.

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.

The invention discloses a plasma generation-oriented parameterized high-voltage modulation alternating-current power supply, and belongs to the technical field of electronic power supplies. The power supply is composed of a multi-stage conversion module. A DC boost part adopts a BOOST circuit to boost an input low-voltage DC power supply to a high-voltage DC power supply. The inversion part adopts a phase-shifted full-bridge inversion circuit and converts the boosted direct-current high voltage into a high-frequency alternating-current signal; the rear stage is connected to the high-voltage transformer to further boost and output the alternating current waveform; a pulse density modulation control mode is adopted, and effective voltage and modulation parameters are accurately controlled and output by adjusting pulse switch density, so that strict requirements on high-voltage pulse signal characteristics in a plasma excitation process are met; the high-voltage alternating-current pulse power supply is simple and compact in circuit structure, wide in parameter adjustable range, high in control precision and excellent in conversion efficiency, can provide a stable and flexible high-voltage alternating-current pulse power supply for various plasma generation or excitation systems, and improves the performance and reliability of a plasma device.

A pulse density modulator encodes an electrical parameter of an external element into a data stream signal. The electrical parameter has a property which causes a predetermined error in the data stream signal. The pulse density modulator includes a digital to analog converter having a sensor element connectable to the external element, and an adjuster circuit adapted to adjust an output of the digital to analog converter based on the data stream signal to correct the predetermined error in the data stream signal. A corresponding method of correcting a data stream signal of a pulse density modulator is also presented.

An integrated circuit includes a sigma-delta modulator (SDM) coupled to a receive electrode, which is selectively coupled to multiple unit cell sensors. A demodulator is coupled directly to the SDM, the demodulator to generate a multibit digital signal by demodulating a digital pulse density modulated (PDM) signal received from the SDM. The demodulating can include multiplying digitized cosine values with the digital PDM signal. A cascaded integrator-comb (CIC) filter is coupled to the demodulator and includes a first integrator and a second integrator cascaded together and to accumulate, at the second integrator, a plurality of samples of the multibit digital signal. The CIC filter includes a single comb circuit coupled to the second integrator, the single comb circuit to generate a measured amplitude bitstream from the accumulated samples.

The invention provides a multichannel ultrasonic signal parallel processing method and system, which can be applied to the technical field of high-frequency sound signal positioning detection. The method comprises the following steps: respectively carrying out signal modulation processing on ultrasonic signals of a plurality of channels to obtain a pulse density modulation signal of each channel; decoding the pulse density modulation signals of the plurality of channels to obtain pulse code modulation signals; adjusting the bit width of the pulse code modulation signal to obtain an ultrasonic output signal; and carrying out positioning processing on the ultrasonic output signal based on a beam forming positioning algorithm to obtain visual positioning information of the ultrasonic output signal.