879results about "Analogue conversion" patented technology

A method of operating a microelectromechanical system (MEMS) includes, in a first operational mode, converting an analog output of the MEMS into a first internal data stream and a first external data stream having a first sampling rate; transitioning from the first operational mode to a second operation mode without restarting the MEMS; and in the second operational mode, converting the analog output of the MEMS into a second internal data stream having a second sampling rate different from the first sampling rate, and performing a sampling rate conversion of the second internal data stream to generate a second external data stream.

A linear voltage regulator includes a converter circuit that provides a serial bitstream having a pulse density that is indicative of a difference between a regulated voltage of the linear voltage regulator and a reference voltage. The linear voltage regulator also includes a digital to analog converter circuit that includes an input to receive the serial bitstream. The digital to analog converter circuit includes an averager circuit that produces an output signal to control a voltage of a control terminal of a power transistor of the linear voltage regulator for regulating the regulated voltage based on the pulse density of the serial bitstream.

The noise-shaping successive-approximation-register analog-to-digital converter includes a capacitive digital-to-analog-converter, a loop filter including a plurality of integration capacitors, and a multi-input comparator. During an integration phase, the capacitive digital-to-analog converter couples to the plurality of integration capacitors to develop an integration voltage. The integration capacitors are then arranged to passively apply a first gain to the integration voltage. The multi-input comparator also provides a second gain to the integration voltage.

The invention relates to an integrator circuit for eliminating thermal noise and a Delta-sigma modulator, and belongs to the technical field of electronic signal processing, the modulator comprises at least two stages of integrators, a quantizer, a feedback DAC and an adder; the integrator comprises an integrator circuit, and the integrator circuit comprises a sampling module for sampling an input signal source; the double-path multi-phase clock control pre-amplification auxiliary storage circuit module alternately samples and stores thermal noise voltage and offset voltage; the integral amplifier is used for amplifying a signal output by the double-path multi-phase clock control pre-amplification auxiliary storage circuit module; and the integrating capacitor is connected between the integrating amplifier and the two-way multi-phase clock control pre-amplification auxiliary storage circuit module, and feeds back the signal after integration processing to the two-way multi-phase clock control pre-amplification auxiliary storage circuit module to realize signal modulation and noise shaping. The thermal noise introduced in the sampling process is effectively reduced, and the area of the whole chip is reduced while the signal-to-noise ratio is improved.

A voltage meter includes a sampler, a gain circuit, an accumulator and a feedback circuit. The sampler samples an input signal to generate a series of first signals and a series of second signals. The gain circuit, coupled to the sampler, modifies at least one of the series of first signals and the series of second signals, to generate a series of modified first signals and a series of modified second signals. The accumulator, coupled to the gain circuit, accumulates an operational result of the series of modified first signals and the series of modified second signals, to generate an accumulation result. The feedback circuit, coupled between the accumulator and the sampler, sends a feedback signal back to the sampler according to the accumulation result.

The invention provides a continuous time Sigma-Delta modulator with constant transconductance bias and negative resistance compensation. The continuous time Sigma-Delta modulator comprises a loop filter, a quantizer and a digital-to-analog converter, the loop filter is used for amplifying a signal in an effective signal bandwidth and attenuating an out-of-band signal at the same time, and the loop filter comprises a first-stage negative resistance compensation integrator and a second-stage negative resistance compensation integrator which are connected in sequence, the first-stage negative resistance compensation integrator comprises a first negative resistance unit containing a negative resistance of a constant transconductance bias circuit and a first integrator unit containing an operational amplifier, and a single operational amplifier resonator structure is formed to generate a second-order response; the integrator of the second-stage negative resistance compensation comprises a second negative resistance unit and a second integrator unit comprising an operational amplifier; and the quantizer is connected with the loop filter, adopts a successive approximation analog-to-digital converter, and is used for converting the analog voltage signal into a digital signal and outputting the digital signal. And the digital-to-analog converter is used for converting the digital signal into an analog signal and feeding back the analog signal to the loop filter.

A digital microphone includes at least one integrator; a state detection and parameter control component directly coupled to an output of the integrator; and a signal processing component coupled to an output of the state detection and parameter control component, wherein a parameter of the signal processing component includes a first value in a first operational mode and a second value in a second operational mode different from the first operational mode.

Aspects of the disclosure provide an integrated circuit. The integrated circuit includes an ADC with a continuous time integrator. The continuous time integrator includes an amplifier having an amplifier input and an amplifier output, a capacitor coupled between the amplifier input and the amplifier output, and a resistor. The resistor provides a first current for an integration in response to an analog input. The ADC also includes a DAC configured to generate a second current at an DAC output based on a digital output of the ADC and includes a switch circuit with a first switch circuit terminal coupled with the DAC output and a second switch circuit terminal coupled with the amplifier input. The switch circuit is configured to couple the DAC output with the amplifier input for a summation of the second current with the first current for the integration based on an integration control signal.

A photoelectric conversion apparatus includes a pixel which includes a photoelectric conversion element; a signal line connected with the pixel; a voltage-current conversion unit configured to convert a voltage signal of the signal line into current; and a conversion unit that includes an oversampling type analog-to-digital conversion circuit that converts the current outputted from the voltage-current conversion unit into digital signals. The voltage-current conversion unit converts the voltage signal of the signal line into the current without sampling and holding and outputs the converted current to the conversion unit.

Methods, controllers and electric machine systems are described that facilitate pulsed control of electric machines (e.g., electric motors and generators) to improve the machine's energy conversion efficiency. Under selected operating conditions, the electric machine is intermittently driven (pulsed). The pulsed operation causes the output of the electric machine to alternate between a first output level and an off state. The output levels are selected such that the electric machine has a higher energy conversion efficiency during the pulsed operation than the electric machine would have when operated at a third output level that would be required to drive the electric machine in a continuous manner to deliver the desired output. In some embodiments, the power converter it turned off during at least portions of the time that the electric machine is pulsed off.

The invention discloses a low-noise and high-precision analog front-end circuit for biological signal acquisition. The low-noise and high-precision analog front-end circuit comprises a chopping capacitance coupling type instrument amplifier circuit, a switched capacitor type programmable gain amplifier circuit and a Sigma-Delta analog-to-digital converter modulator circuit. T-type capacitance feedback, chopping modulation and programmable technologies are introduced on the basis of an existing amplifier, and the low-noise and programmable gain functions of the pre-amplifier are achieved. Through the three-order one-bit quantized feed-forward chopping type Sigma-Delta modulator, the signal to noise ratio and the effective bit number of the signal are improved. Compared with the prior art, the analog front-end circuit not only has the capability of changing the gain multiple according to the bio-electricity signal, but also has the low-noise and high-precision signal processing effect, and the problems that a traditional analog front-end circuit is large in noise and low in signal processing precision are solved. In addition, the biological signal acquisition-oriented circuit provided by the invention can also be used in other analog front ends, such as an audio processor and the like, and is wide in application range.

An apparatus for calibrating a digital filter to replicate a transfer function of a signal processing device comprising a detector with a first input to receive a first signal; a second input to receive a response signal of the signal processing device to the first signal; a signal modification block; a comparison block and a decimation block; wherein the comparison-block compares a phase and amplitude of the first signal after a correction has been applied by the signal modification block and decimation has been applied by the decimation block; and a feedback loop; wherein detector is configured to determine at least a feedback control signal at a first frequency and a second frequency, different to the first frequency and determine calibration information for programming of the transfer function of said digital filter.

The present application discloses an analog-to-digital conversion circuit, a chip, and a recording device. The analog-to-digital conversion circuit comprises a main path module, a dynamic range enhancement module, and a dynamic digital-to-analog conversion module. The main path module is used for converting an analog signal and an analog feedback signal into a digital signal to be processed for outputting to the dynamic range enhancement module, and obtaining a digital signal on the basis of the digital signal to be processed and a digital gain signal and outputting the digital signal. The dynamic range enhancement module is used for performing dynamic quantization processing on the digital signal to be processed to obtain a control signal, and generating the digital gain signal. The dynamic digital-to-analog conversion module is used for, on the basis of the control signal, dynamically controlling the activation and deactivation of each DAC element in a digital-to-analog conversion array, and generating an analog feedback signal. According to the analog-to-digital conversion circuit of the present application, the need for a front-end fixed-gain OPA is eliminated, reducing power consumption and reducing costs; moreover, dynamically controlling the activation and deactivation of each DAC element in the digital-to-analog conversion array further reduces the power consumption.

A nested Δ-Σ analog-to-digital conversion system and method, compromising: an analog filter, an analog comparator, a first feedback digital-to-analog converter (DAC), a second feedback DAC placed in front of the first feedback DAC, and a digital filter and an MSB quantizer placed at the output of the analog comparator; wherein the input of the first feedback DAC is connected to the output of the analog comparator; the analog filter, the analog comparator, and the first feedback DAC form an internal analog Δ-Σ loop; the input of the second feedback DAC is connected to the output of the MSB quantizer; the output of the second feedback DAC is connected to the output of the first feedback DAC and to the input of the analog filter; and the second feedback DAC, the internal analog Δ-Σ loop, the digital filter, and the MSB quantizer form an external hybrid Δ-Σ loop.

A calibration circuit for correcting timing errors introduced by a DAC in a signal path of an ADC, the calibration circuit comprising: an input subtraction module configured to subtract an estimated error from an output of the ADC and provide a corrected output; a filter module configured to approximate an error transfer function corresponding to the DAC timing errors; a correlation module configured to correlate the corrected output with an output from the filter module to extract an error term; an integrator module configured to integrate the error term to provide an updated error coefficient; and a correction module configured to correlate the updated error coefficient with the output from the filter module to provide the estimated error to the input subtraction module.

The invention relates to the technical field of industrial automation field data acquisition, in particular to an ultrahigh-precision load data implementation method and circuit and a measurement and control instrument. The method comprises the steps that an excitation signal is provided for the load sensor through the precise low-drift direct-current power supply, and the excitation signal is applied to the power input end of the sensor after high-frequency noise is eliminated through the pi-type filter network. According to the method, a temperature-load coupled multi-broken-line nonlinear regression curve cluster is constructed, and a temperature variable is introduced into dynamic interpolation calculation of segmented endpoints, so that an error nonlinear cumulative effect caused by endpoint drift under a wide-temperature working condition is effectively inhibited. In the hardware level, the background noise of a sensor signal is suppressed to a microvolt level through the collaborative design of a precise low-drift power supply and multi-stage anti-aliasing filtering, and original data with a high signal-to-noise ratio is provided for a software compensation algorithm.

A digital to analog converter (DAC) maps a digital word to an analog output. The DAC bits may have amplitude and timing errors. These errors (or sometimes referred herein as "non-idealities") result in distortion and degradation of the dynamic range in DACs. To reduce these negative effects, delta-sigma patterns can be provided to two bit cells, a reference bit cell and a bit cell under calibration, to perform, e.g., amplitude calibration and timing skew calibration. Delta-sigma patterns are particularly advantageous over square wave signals, which cannot be scaled to perform amplitude calibration between bit cells having different bit weights and are limited in frequency to integer fractions of the sampling clock.

The invention relates to the technical field of amplifiers, and discloses an analog-to-digital converter combination instrument amplifier which comprises a first-stage amplifier, the first-stage amplifier is in signal connection with a second-stage amplifier, the second-stage amplifier is in signal connection with a front-end low-pass filter (LPF), the front-end low-pass filter (LPF) is in signal connection with an analog-to-digital converter (ADC), and the analog-to-digital converter (ADC) is in signal connection with the analog-to-digital converter. And an unbalanced input-to-balanced differential circuit output module is arranged between the second-stage amplifier signal and a front-end low-pass filter (LPF). From the perspective of signal processing and conversion, a precise signal transition bridge is constructed by adding an unbalanced input-to-balanced differential circuit output module, unbalanced signals output by a second-stage amplifier are converted into double-end balanced differential signals, common-mode noise interference is effectively resisted through a differential transmission mode, the signal purity is guaranteed, and the signal quality is improved. The front-end low-pass filter and the analog-to-digital converter are adaptive to differential signals, so that the signal transmission is stable and anti-interference, and the analog-to-digital conversion is more accurate.

The utility model relates to the technical field of digital-to-analog conversion, and discloses a Delta-Sigma ADC data reading device, which comprises a power supply circuit, a photoelectric conversion circuit and a minimum system unit, one end of the power supply circuit is connected with an external direct-current power supply, and the other end of the power supply circuit is connected with the power supply end of the photoelectric conversion circuit and the power supply end of the minimum system unit; one end of the photoelectric conversion circuit is connected with an optical signal input end, and the other end of the photoelectric conversion circuit is connected with a signal end of the minimum system unit. According to the utility model, the minimum system unit with the built-in digital filter is adopted to replace a bit stream data conversion chip in the traditional scheme, so that the cost is reduced, and the area of a printed circuit board is saved; and the data interaction process between the active filter chip and the MCU is omitted, and the information transmission efficiency is improved.

The invention discloses a fractional frequency division frequency synthesizer with output signal phase synchronization and frequency modulation continuous wave functions, and the basic structure is a charge pump phase-locked loop. Comprising a phase frequency detector, a first charge pump, a second charge pump, a low-pass filter, a voltage-controlled oscillator, a first buffer, a second buffer, a two-frequency divider chain, an IQ undersampling circuit, a local oscillator generator, a programmable multimode frequency divider, a Delta-Sigma modulator (DSM), a first selector, a second selector, a third selector, a tracking phase accumulator, a numerical control oscillator, an accumulation phase difference register and an atan2 logic circuit. The device comprises a main phase control circuit, a phase adjusting circuit, an enabling control circuit, a waveform generator and a serial peripheral interface. The decimal frequency-division frequency synthesizer can be applied to a general-inductance integrated system, ensures that output signals provided by a plurality of decimal frequency-division frequency synthesizers are consistent in phase in a multi-channel radio frequency transceiving system adopting a multi-chip splicing mode, and can also be applied to the general-inductance integrated system as a sensing signal source; and the speed and the distance of an object can be quickly sensed by the high linearity and the quick chirp capability of an output signal. The decimal frequency division frequency synthesizer is applied to a linear frequency modulation continuous wave radar system, initial phase synchronization can be carried out firstly, then frequency continuous modulation is carried out, and measurement errors can be eliminated. In view of functional similarity of partial modules of the synchronous loop and the FMCW loop, such as a phase frequency detector, a charge pump, a voltage-controlled oscillator and the like, the modules can be shared, so that the power consumption and area cost of the system are remarkably reduced.

A fully differential switched capacitor amplifier receives a differential analog signal from a differential input terminal, amplifies the differential analog signal, and outputs an amplified signal from a differential output terminal. The fully differential switched capacitor amplifier includes: a sampling capacitor that respectively samples the differential analog signal input from the differential input terminal; a differential input switch connected to a path for inputting the differential analog signal between the differential input terminal and the sampling capacitor; a fully differential amplifier that amplifies the differential analog signal input to the sampling capacitor; and a differential input resistor connected between the differential input switch and the sampling capacitor.

The present invention relates to a circuit arrangement, in particular for a radar sensor (6, 9a-9d), for measuring a sensor value, comprising at least one sensor which generates a direct voltage as a sensor signal which is proportional to the respective sensor value to be measured, at least one A / D converter (5) via which the direct voltage is determined, and at least one polarity switch (11, 12, 13) which is connected downstream of the sensor and via which the polarity of the direct voltage can be determined, wherein the polarity of the direct voltage is switched from a first measurement M1 to a second measurement M2 via the polarity switch (11, 12, 13), and the sensor value is determined on the basis of the first measurement M1 and the second measurement M2, preferably by subtracting the measurement result of the second measurement M2 from the measurement result of the first measurement M1 and halving the resulting difference.

Certain aspects of the present disclosure provide techniques and apparatus for digital-to-analog conversion. An example apparatus generally includes a digital-to-analog converter (DAC), an incremental analog-to-digital converter (IADC) having a first input coupled to a first output of the DAC, and a controller coupled to the DAC and the IADC. The controller is configured to determine a direct current (DC) offset associated with the DAC using the IADC and control a mission-mode digital input signal of the DAC based on the DC offset.

A fractional-N PLL includes a reference oscillator, a multi-modulus divider-based phase-error-to-digital converter driven by the reference oscillator, a digital loop filter, and a digitally controlled oscillator. Digital-to-time to converter mismatch noise cancellation digital logic is between the phase-error-to-digital converter and the digital loop filter. Error from digital-to-time converter component mismatches is partially cancelled by the digital logic.

The invention discloses a capacitor mismatch error shaping circuit and method suitable for a multi-bit quantization Sigma-Delta ADC, and belongs to the technical field of integrated circuits, and the capacitor mismatch error shaping circuit comprises a data weight averaging module which is used for adopting a data weight averaging technology for high-bit quantization code words, and correcting the high-bit quantization code words according to the data weight averaging technology; averaging the mismatch error of the capacitor corresponding to the high-order quantization code word to obtain an averaged high-order capacitor; and the mismatch error shaping module is used for taking the averaged high-order capacitance as a reference, adopting a mismatch error shaping technology, keeping low-order feedback of the current low-order quantization code word of the lower polar plate of the capacitive digital-to-analog converter during Sigma-Delta ADC sampling, and realizing subtraction operation between two adjacent low-order quantization code words. According to the invention, the error caused by the mismatch of the CDAC capacitor fed back by the multi-bit quantization Sigma-Delta ADC can be effectively suppressed, the linearity of the system is improved, and the circuit overhead is remarkably reduced.

A digital microphone includes a logarithmic amplifier; an analog-to-digital converter (ADC) coupled to the logarithmic amplifier; a digital decompression component coupled to the ADC; and a digital filter coupled to the digital decompression component, wherein the digital filter includes a controlled upsampling component coupled to an input of the digital filter and a controlled downsampling component coupled to an output of the digital filter.

The invention discloses an attenuation compensation method and system for a signal transmission function in an analog-to-digital converter, and relates to the technical field of analog-to-digital converter circuit design and signal processing, and the method comprises the steps: setting the attenuation gain of an integrator, and carrying out the pre-attenuation processing of an analog signal in an analog domain of the integrator; performing analog-to-digital conversion on the pre-attenuated signal through a quantizer, and outputting a digital code stream; and performing gain compensation on the digital code stream in the digital domain, and constructing a digital domain recovery path corresponding to the analog domain attenuation parameter. Through the analog front end of the sigma-delta analog-to-digital converter, overload distortion, modulator instability or modulation out-of-control caused by the fact that a signal peak value exceeds a dynamic range of a quantizer is avoided, the system stability is improved, high-precision analog-to-digital conversion of a controlled amplitude signal is realized, a corresponding gain compensation factor is set according to an analog domain attenuation parameter, and the gain compensation precision is improved. Linear recovery processing of a low-amplitude digital signal is realized, and attenuation introduced by an analog domain is compensated.

This application relates to sensing of signals with a common-mode variation. Embodiments describe a switching driver circuit with a modulator configured to control modulation of an output node between different switching voltages and a current sensor configured to sense a voltage drop across a sense resistor connected in series with the output node. The current sensor performs sensing during a first time window that occurs at regular intervals and the modulator avoids any transition in switching voltage at the first output node during the first time window. Embodiments also describe a sensing circuit for sensing a differential voltage with a common-mode variation which has a first sensing portion implemented to provide a floating voltage domain and a second sensing portion implemented to provide a static voltage domain. At least one switched capacitor provides a boundary between the voltage domains and is switched to transfer charge between the voltage domains.

In one example, a system comprises a vector-by-matrix multiplication array comprising an array of non-volatile memory cells arranged in rows and columns; and a sigma-delta analog-to-digital converter to receive a current from a column of the vector-by-matrix multiplication array and to generate a digital output in response to the current.