Xmems Labs, Inc.

Vichip Corp. Limited

Neoparadigm Labs, Inc.

Hsi-Sheng Chen

Jemm Yue Liang

Chieh-Yao Chang

Chiung C Lo

Wen-Chien Chen

Chun-I Chang

Jing-Meng Liu

Hao-Hsin Chang

Hung-Chi Huang

Tsu-Chang Lee

Wen-Lung Chen

Yusong Huang

Li-Herng Yao

Zhihao Lin

The sound producing device includes a shutter element configured to obscure an aperture positioned to receive an amplitude-modulated acoustic wave; a blind element, wherein the aperture is formed within the blind element; and an amplitude-modulation means, configured to generate an amplitude-modulated acoustic wave toward the aperture; wherein the amplitude-modulated acoustic wave is produced according to an input audio signal.

Sound producing device and method

The sound suppression apparatus comprises a sound sensing device, configured to sense a sound; and a sound producing device comprising an air-pulse generating device, configured to generate a plurality of air pulses at an ultrasonic pulse rate. The plurality of air pulses at the ultrasonic pulse rate forms an anti-sound. The anti-sound comprises a component which is configured to suppress the sound.

Sound suppression apparatus, sound suppression system and wearable sound device

A feedback control system configured to drive a load is disclosed. The feedback control system includes an up-sampling circuit, configured to perform an un-sampling operation on a source signal and produce an up-sampled signal with an up-sampling frequency according to the up-sampled signal and a feedback signal from the load; a delta circuit, coupled to the up-sampling circuit and configured to produce a delta signal; a sigma circuit, configured to produce a density modulation signal according to the delta signal; and a driving device, configured to drive the load according to the density modulation signal with the up-sampling frequency.

Feedback control system achieving high performance via density modulation

The present invention discloses a feedback control system. The feedback control system comprises a plant, configured to produce an output according to a control signal; a first summing block, configured to produce a first difference between an input signal and a measured output signal; a first controller, configured to generate the control signal, such that the first difference decreases to be less than a first threshold or is less than the first threshold; wherein the first controller comprises a memory configured to store a table, and the table contains information of a plurality of transfer functions corresponding to a plurality of operating conditions; wherein the first controller determines an operating condition under which the plant operates, and chooses to utilize a transfer function corresponding to the operating condition to generate the control signal according to the transfer function and the first difference.

Two-tier feedback control system and related method

A method, which is applied in a driving circuit including an analog-to-digital convertor (ADC) and a switching circuit including an inductor and coupled to a load, includes steps of: performing an analog-to-digital conversion on a load voltage of the load at a first rate; and producing at least a current pulse flowing through the inductor at a second rate. Wherein, each current pulse among the at least a current pulse is accomplished within a second cycle corresponding to the second rate, all of the at least a current pulse are accomplished within a first cycle corresponding to the first rate, and a first length of the first cycle is longer than twice of a second length of the second cycle.

Method of reducing conduction loss and switching loss applied in driving circuit and driving circuit using the same

A method is applied in a pulse width modulation (PWM) controller within a driving circuit including a bidirectional circuit coupled to a load. The method includes steps of: obtaining a pulse width control code (PWCC) from a table stored in a memory within the PWM controller according to a difference between a first feedback signal from the load and an input signal, wherein the PWCC is corresponding to an intended voltage difference, and the first feedback signal is corresponding to a first cycle; generating a plurality of PWM signals according to the PWCC, wherein during a second cycle the bidirectional circuit performs a charging or discharging operation on the load according to the PWM signals; receiving a second feedback signal from the load corresponding to the second cycle; and updating the PWCC according to the first and second feedback signals, and saving the updated PWCC back to the table.

Method applied in driving circuit and driving circuit using the same

A successive approximation register (SAR) analog-to-digital converter (ADC) includes a comparator, a threshold generator and a controller. The comparator receives an analog signal and the SAR ADC outputs an output codeword. The comparator performs a plurality of first comparisons and a plurality of second comparisons. The controller determines a plurality of most significant bits of the output codeword according to a plurality of first comparison results corresponding to the first comparisons. The first comparisons are performed by comparing the analog signal with a plurality of first thresholds. The controller determines a plurality of least significant bits of the output codeword according to a plurality of second comparison results corresponding to the second comparisons. The second comparisons are performed by comparing the analog signal with a second threshold. The controller controls the threshold generator to produce the plurality of first thresholds and the second threshold according to the first comparison results.

SAR ADC and related method

A filter is disclosed. The filter includes at least one first multiplication approximation unit, for approximating at least one first multiplication operation corresponding to at least one first coefficient with at least one first bit-wise shift operation; and at least one second multiplication approximation unit, for approximating at least one second multiplication operation corresponding to at least one second coefficient with a plurality of second bit-wise shift operations and at least one addition operation.

Filter and method with multiplication operation approximation capability

A crossover circuit, disposed within a sound producing device including a first sound producing cell driven by a first driving signal and a second sound producing cell driven by a second driving signal, includes a first filter receiving an input signal at an input terminal of the first filter, a first subtraction circuit, and a second filter coupled between the output terminal of the first filter and the second input terminal of the first subtraction circuit. A first input terminal of the first subtraction circuit is coupled to the input terminal of the first filter; a second input terminal of the first subtraction circuit is coupled to an output terminal of the first filter. The crossover circuit produces the first driving signal and the second driving signal according to a first output signal of the first subtraction circuit and a second output signal of the first filter respectively.

Crossover circuit

A signal density modulation (SDM) encoder includes a first subtractor, a sigma circuit and a multi-bit quantizer. The first subtractor is used for receiving an input signal. The sigma circuit is coupled to the first subtractor. The multi-bit quantizer, coupled to the first subtractor and the sigma circuit, is configured to generate an output signal. The sigma circuit or the multi-bit quantizer produces a first feedback signal to the first subtractor. The first subtractor performs a subtraction operation according to the first feedback signal and the input signal, and generates a delta signal. The sigma circuit performs an operation on the delta signal, such that the SDM encoder has a noise transfer function having a high pass filtering effect. The noise transfer function is a ratio of a quantization error brought by the multi-bit quantizer with respect to the input signal. The output signal has more than two levels.

SDM encoder and related signal processing system

A system, disposed within a wearable hearing device, includes a sound producing device (SPD) driven by a driving voltage, a first sound sensing device, and a subtraction circuit. The first sound sensing device is configured to sense a combined sound pressure produced at least by the SPD and generate a sensed signal accordingly. The subtraction circuit has a first input terminal, a second input terminal, and a first output terminal. The first input terminal is coupled to the first sound sensing device, and the first output terminal is coupled to the SPD. A first phase delay between the driving voltage and the sensed signal is less than 60&#xb0;.

System and method thereof

A sound producing device includes a first sound producing cell, driven by a first driving signal and configured to produce a first acoustic sound on a first audio band, and a second sound producing cell, driven by a second driving signal and configured to produce a second acoustic sound on a second audio band different from the first audio band. A first membrane of the first sound producing cell and a second membrane of the second sound producing cell are Micro Electro Mechanical System fabricated membranes. The first audio band is upper bounded by a first maximum frequency; the second audio band is upper bounded by a second maximum frequency. A first resonance frequency of the first membrane is higher than the first maximum frequency of the first driving signal. A second resonance frequency of the second membrane is higher than the second maximum frequency of the second driving signal.

Sound producing device

A system to process a signal sequence is described. A hybrid block matching and transform based N-Dimensional signal sequence encoder and decoder is disclosed. The encoder includes encoder side block matching predictor, which includes entropy based cost function which can be estimated from certain energy measure of the block matching difference; a fast block matching search method to learn the results from neighboring blocks and to perform large range search with only a small number of points to visit.

Apparatus for adaptive multiple-dimentional signal sequences encoding/decoding

An apparatus for detecting the video mode of a video data, the apparatus capable of receiving a plurality of synchronous signals along with the transmission of the video data, comprises: a first counter stage capable of receiving the synchronous signals and generating a first counter stage output signal that represents the number of total lines in a frame of the video data; a second counter stage capable of receiving an active line indicator signal that indicates an active line in the video data, the second counter stage capable of generating a second counter stage output signal that represents the number of active lines in a frame of the video data; and a logic circuit coupled to the first counter stage and to the second counter stage, the logic circuit capable of detecting the video mode of the video data based upon the values of the first counter stage output signal and the second counter stage output signal.

Growing community of inventors

Fremont, CA, United States of America

Hsi-Sheng Chen