Abstract: A microphone and a method for calibrating a microphone are disclosed. In one embodiment the method for calibrating a microphone comprises operating a MEMS device based on a first AC bias voltage, measuring a pull-in voltage, calculating a second AC bias voltage or a DC bias voltage, and operating the MEMS device based the second AC bias voltage or the DC bias voltage.

Abstract: A power supply circuit including a voltage regulator and a headphone driving circuit employing the same are disclosed. In accordance with the present invention, the power supply circuit may provide stable power supply to the amplifier since the power supply circuit generates the constant voltage +Vreg and the constant voltage ?Vreg from +VDD robust to stronger than a power noise, and the balanced signal path for isolating the noise of the input signal to be amplified is not required, thereby simplifying the constitution of the circuit.

Abstract: Disclosed is an audio amplification circuit comprising: an input terminal for receipt of an audio input signal; a first preamplifier having an input operatively coupled to the input terminal and operable to provide a first amplified audio signal with a first signal amplification; a second preamplifier having an input operatively coupled to the input terminal and operable to provide a second amplified audio signal with a second signal amplification, smaller than the first signal amplification; a switch having a first input operatively coupled to the first preamplifier, a second input operatively coupled to the second preamplifier, and an output; an analogue-to-digital converter operatively coupled to the output of the switch and operable to provide a digital audio signal; a signal selection circuit operable to control the switch to selectively provide one of the first and second amplified audio signals on the output of the switch.

Abstract: A semiconductor die with an integrated electronic circuit, configured so as to be mounted in a housing with a capacitive transducer e.g. a microphone. A first circuit is configured to receive an input signal from the transducer at an input node and to provide an output signal at a pad of the semiconductor die. The integrated electronic circuit comprises an active switch device with a control input, coupled to a pad of the semiconductor die, to operatively engage or disengage a second circuit interconnected with the first circuit so as to operate the integrated electronic circuit in a mode selected by the control input. That is, a programmable or controllable transducer. The second circuit is interconnected with the first circuit so as to be separate from the input node. Thereby less noise is induced, a more precise control of the circuit is obtainable and more advanced control options are possible.

Abstract: Audio amplifiers, particularly those employed with headphones, use snubbers to suppress or snub signals within a particular frequency range. Conventional resistive and resistor-capacitor (RC) type snubbers have a number of drawbacks (i.e., require external components and high power consumption). Here, an active snubber is provided that allows for suppression in a desired frequency range without the need for external components and with relatively small footprint and a relatively small power increase.

Abstract: A digital/analog conversion apparatus for converting a digital signal into an analog signal. The digital/analog conversion apparatus can generate a high-quality analog signal, even when elements configuring the digital/analog conversion apparatus have variance, with high resolution and a small circuit size. The data conversion apparatus is provided with a first data converter for reducing the number of bits of an input signal, a second data converter for converting the format of the first output signal, and a third data converter for conversion into a code which corresponds to the history of the output from the second data converter.

Abstract: In a source sound separator, first and second target sound predominant spectra are generated respectively by first and second processing operations for linear combination for emphasizing the target sound, using received sound signals of two microphones arrayed at a distance from each other. A target sound suppressed spectrum is generated by processing for linear combination for suppression of the target sound, using the two received sound signals. Further, a phase signal containing a larger amount of signal components of the target sound and exhibiting directivity in the direction of the target sound is generated by processing of linear combination, using the two received sound signals. The target sound and the interfering sound are separated from each other using the first and second target sound predominant spectra, the target sound suppressed spectrum, and the phase signal.

Abstract: The present invention has: a condenser microphone unit which performs electroacoustic conversion according to a change in an electrostatic capacitance between a diaphragm and a fixed pole; a non-inverting amplifier which is connected to one of the diaphragm and the fixed pole, and which has an impedance converter which converts an output impedance of the microphone unit into a low impedance; an inverting amplifier which receives an input of an output signal of the non-inverting amplifier through an input resistance, and which has a feedback resistance; and a variable resistor which is connected between an output of the non-inverting amplifier and an output of the inverting amplifier, and in which a wiper is connected to the diaphragm or the fixed pole, whichever is not connected to the non-inverting amplifier, and the sensitivity changes according to the position of the wiper of the variable resistor.

Abstract: A circuit electrically connects a MEMS microphone with a single line transmitting both a DC power signal and an AC information signal. The MEMS microphone has a power interface for receiving the power signal, and an information interface for delivering the information signal. In such embodiments, the circuit includes a pair of lines that separate the power and information signals. To that end, the circuit has an information line configured to connect with the information interface of the MEMS microphone, and a power line configured to connect with the power interface of the MEMS microphone.

Abstract: A method of optimizing a parametric emitter system having a pot core transformer coupled between an amplifier and an emitter, the method comprising: selecting a number of turns required in a primary winding of the pot core transformer to achieve an optimal level of load impedance experienced by the amplifier; and selecting a number of turns required in a secondary winding of the pot core transformer to achieve electrical resonance between the secondary winding and the emitter.

Abstract: A semiconductor device is disclosed. The semiconductor device includes a digital audio circuit which converts an input digital signal into an analog audio signal, a DC-DC converter having a switching power source circuit, and an audible frequency determining circuit. In order that a difference between a frequency of a first clock signal for digital to analog conversion which is used in the digital audio circuit and a frequency of a second clock signal for switching control which is used in a DC-DC converter exceeds a maximum audible frequency, a frequency comparing circuit in the audible frequency determining circuit outputs a signal to a frequency changing circuit in the DC-DC converter. The frequency changing circuit causes a second oscillating circuit to change the second frequency.

Abstract: There is provided a condenser microphone in which even if strong electromagnetic waves are applied from a cellular phone or the like, the balance between a filter circuit for a No. 2 pin on the hot side and a filter circuit for a No. 3 pin on the cold side is maintained. The condenser microphone includes a printed wiring board 200 housed in a microphone casing and a three-pin type output connector, and is configured so that a No. 1 pin of the output connector is connected directly to the microphone casing and is connected to a ground electrode of the printed wiring board 200 via a high-frequency choke coil IL; on the printed wiring board, a first filter circuit 401 connected to the No. 2 pin on the hot side and a second filter circuit 501 connected to the No.

Abstract: According to an embodiment, a method includes amplifying a signal provided by a capacitive signal source to form an amplified signal, detecting a peak voltage of the amplified signal, and adjusting a controllable impedance coupled to an output of the capacitive signal source in response to detecting the peak voltage. The controllable impedance is adjusted to a value inversely proportional to the detected peak voltage.

Abstract: A microphone circuit includes a condenser microphone and a charge pump. The condenser microphone is configured to receive sound energy and responsively convert the sound energy into a microphone output voltage. The charge pump is implemented in a low voltage CMOS process. It is coupled to the microphone and is configured to supply a bias voltage to the microphone allowing the microphone to operate. By using a proper circuit topology, whose maximum output voltage is limited by the breakdown voltage between the NWELL and the substrate, and by blocking the formation of the PWELL around the NWELL at a predetermined distance so that the NWELL is surrounded by a very lightly doped substrate from all sides, the maximum output voltage of the charge pump is increased significantly.

Abstract: A microelectromechanical (MEMS) microphone includes a MEMS motor and a gain adjustment apparatus. The MEMS motor includes at least a diaphragm and a charge plate and is configured to receive sound energy and transform the sound energy into an electrical signal. The gain adjustment apparatus has an input and an output and is coupled to the MEMS motor. The gain adjustment apparatus is configured to receive the electrical signal from the MEMS motor at the input and adjust the gain of the electrical signal as measured from the output of the gain adjustment apparatus. The amount of gain is selected so as to obtain a favorable sensitivity for the microphone.

Abstract: A dual backplate microphone is provided that utilizes either an electret condenser or a MEMS condenser configuration and in which an op-amp IC is electrically connected to both backplates and the conductive layer of the diaphragm.

Abstract: A sound collector includes a first microphone unit and a second microphone unit having a single directivity and being pivotally supported in a manner that directions of directional axes of the units are changeable in an identical flat plane and a switch to be controlled in conjunction with the rotations of the first and the second microphone units. Output signals of the first and the second microphone units are outputted with channels of the signals being exchanged or non-exchanged by the switch in accordance with an angle formed by the directional axes.

Abstract: A silicon based capacitive microphone includes a first printed circuit board, a second printed circuit board far away from the first printed circuit board, a transducer electrically mounted on the first printed circuit board, a controlling chip electrically mounted on the second printed circuit board, a connecting member located between the first and second printed circuit boards.

Abstract: An electronic device includes a capacitance electro-acoustic transducer and an audio driver. The audio driver is coupled to the capacitance electro-acoustic transducer. The audio driver includes a high-voltage amplifier for receiving an input audio signal and for transforming the input audio signal into an output audio signal to drive the capacitance electro-acoustic transducer, wherein an absolute voltage value of the input audio signal is smaller than an absolute voltage value of the output audio signal. The output bandwidth of the capacitance electro-acoustic transducer is controlled by the magnitude of the output current of the audio driver. The capacitance electro-acoustic transducer of the present invention can meet different bandwidth requirements and thus achieve saving power, which cannot be achieved by a traditional dynamic electro-acoustic transducer.

Abstract: In an amplifier circuit of a capacitor microphone, when a too high input signal from the capacitor microphone is inputted, the levels of output signals of the amplifier circuit are limited. A first feedback capacitor of an operational amplifier is formed using a changeable capacitance type MOS capacitor element, and has a characteristic of increasing the capacitance value CAf1 according to the amplitude of an input signal generated by a capacitor increases. Therefore, CAf (=CAf1+CAF2) increases according to the amplitude of the input signal increases, and accordingly the gain of the operational amplifier decreases, thereby limiting the output signals of the operational amplifier. This realizes the appropriate limitation of the output signals of the operational amplifier, even when the amplitude of the input signal becomes too high.

Abstract: An audio reproducing apparatus includes the following elements: an output circuit operable to generate audio signals to be supplied to first and second speakers placed near the ears of a listener; and a detector operable to detect the presence of sound output from other speakers placed at positions further away from the listener than the first and second speakers. When it is determined that there is no sound output from the other speakers on the basis of a detection result obtained by the detector, the output circuit performs a control operation so that audio signals to be supplied to the other speakers are supplied to the first and second speakers.

Abstract: An audio host device has an electrical interface having a speaker contact, a microphone contact, and a reference contact. The reference contact is shared by a microphone and a speaker. The reference contact is also directly coupled to a power return plane of the audio host device. A difference amplifier is provided, having a cold input and a hot input. The hot input is coupled to the microphone contact. A switched attenuator circuit is also provided that has first and second states. In the first state, the attenuator circuit couples a sense point of the reference contact to the cold input, while in the second state the cold input is isolated from the reference sense point. Other embodiments are also described and claimed.

Abstract: A system and method for processing close talking differential microphone array (CTDMA) signals in which incoming microphone signals are transformed from time domain signals to frequency domain signals having separable magnitude and phase information. Processing of the frequency domain signals is performed using the magnitude information, following which phase information is reintroduced using phase information of one of the original frequency domain signals. As a result, high pass filtering effects of conventional differential signal processing of CTDMA signals are substantially avoided.

Abstract: In some embodiments, a method for processing output of at least one microphone of a device (e.g., a headset) to identify at least one touch gesture exerted by a user on the device, including by distinguishing the gesture from input to the microphone other than a touch gesture intended by the user, and by distinguishing between a tap exerted by the user on the device and at least one dynamic gesture exerted by the user on the device, where the output of the at least one microphone is also indicative of ambient sound (e.g., voice utterences). Other embodiments are systems for detecting ambient sound (e.g., voice utterences) and touch gestures, each including a device including at least one microphone and a processor coupled and configured to process output of each microphone to identify at least one touch gesture exerted by a user on the device.

Abstract: An audio host device has a connector having a speaker contact, a microphone contact, and a reference contact. The reference contact is shared by a microphone and a speaker. The reference contact is also directly coupled to a power return plane of the audio host device. A difference amplifier is provided, having a first cold input, a second cold input, and hot input. The first cold input is coupled to an output of the speaker amplifier, while the second cold input is coupled a sense point for the reference contact. The hot input is coupled to the microphone contact. Other embodiments are also described and claimed.

Abstract: An audio host device has an electrical interface having a speaker contact, a microphone contact, and a reference contact. The reference contact is shared by a microphone and a speaker. The reference contact is also directly coupled to a power return plane of the audio host device. A difference amplifier is provided, having a cold input and a hot input. The hot input is coupled to the microphone contact. A variable attenuator circuit is also provided having an input coupled to receive a signal from a sense point for the reference contact, and an output coupled to the cold input of the difference amplifier. A controller has an output coupled to control the variable attenuator. Other embodiments are also described and claimed.

Abstract: A self-tuning MEMS microphone. The microphone includes a capacitive sensor, an amplifier, a signal converter, a frequency generator, a micro-speaker, and a controller. The capacitive sensor is configured to detected a sound wave and output an electric signal based on the sound wave. The amplifier is coupled to the capacitive sensor, and configured to amplify the electric signal. The signal converter is coupled to the amplifier, and configured to adjust a frequency response of the amplified electric signal. The frequency generator is configured to output an AC electric signal. The micro-speaker is coupled to the frequency generator, and configured to convert the AC electric signal into a sound wave. The controller is coupled to the signal converter and the frequency generator. The controller is configured to direct the frequency generator to output the AC electric signal at a predetermined frequency and to detect an amplified electric signal generated by the capacitive sensor based on the AC electric signal.

Abstract: Electric power is provided to a two-way communications headset by creating a differential DC voltage potential between a ground conductor associated with a microphone of that headset and a ground conductor associated with an acoustic driver of that headset, thereby enabling that headset to refrain from drawing electric power from a more limited local power source.

Abstract: Microphone assemblies may be provided that have microelectromechanical systems microphones and associated application-specific integrated circuits mounted to printed circuit boards. The application-specific integrated circuits may contain amplifier circuitry for amplifying microphone signals from the microphone. One or more though-silicon vias may be formed in the application-specific integrated circuit that serve as an acoustic port through which sound may pass. The application-specific integrated circuit may be embedded in the printed circuit board and the microphone may be mounted to the upper surface of the printed circuit board, the application-specific integrated circuit and microphone may be stacked on the upper surface of the printed circuit board, or the microphone and application-specific integrated circuit may be mounted to the printed circuit board so that the microphone is received within an opening in the printed circuit board.

Abstract: A micro-speaker. The micro-speaker includes a first plate, a second plate, and a diaphragm. The first plate is biased to a first voltage. The second plate is biased to a second voltage. The diaphragm is positioned between the first plate and the second plate and is configured to receive a digital signal. The digital signal causes the diaphragm to cycle between fully displaced toward the first plate and fully displaced toward the second plate, creating air pressure pulses that mimic the digital signal.

Abstract: An amplifier circuit for thermoacoustic device includes a peak hold circuit, an add-subtract circuit, and a power amplifier. The peak hold circuit is configured to accept an audio signal and output a peak hold signal. The add-subtract circuit is configured to accept the audio signal and the peak hold signal, and output a modulated signal after a comparison operation of the audio signal and the peak hold signal. The power amplifier is configured to accept the modulated signal, amplify the modulated signal, and output an amplified voltage signal.

Abstract: A USB ribbon microphone includes a ribbon diaphragm assembly, an amplification circuitry connected to the ribbon diaphragm assembly, an A/D converter connected to the amplification circuitry, and a USB output port connected to the A/D converter for selective connection with a USB input.

Abstract: A method of amplifying an output signal from a microphone or audio transducer so as to introduce a controllable degree of distortion for inputs having a wide dynamic range, comprising the steps of: receiving a differential input signal from a microphone or audio transducer, applying said differential signal to a differential amplifier, said differential amplifier having a negative feedback path to control the gain of said amplifier; and providing non-linear circuitry in said feedback path so as to introduce distortion, such that the degree of distortion present is related to the level of the output signal and not to the level of the input signal.

Abstract: An infrared light emitting diode circuit and related methods are disclosed. Exemplary features of embodiments comprise circuitry for controlling the voltage delivered to infrared light emitting diodes and for reducing the power consumption of the circuitry in the absence of audio signals to be transmitted.

Abstract: A digital sound system suitable for a digital speaker device for directly converting analog sound by a circuit using a ?? modulator and a mismatch shaping filter circuit to output a plurality of digital signals and a plurality of speakers driven by the plurality of digital signals. A digital speaker driving device includes a ?? modulator, a post filter, s driving circuits, and a power supply circuit to supply power to the ?? modulator, the post filter and the s driving elements and the s driving circuits are adapted to s digital signal terminals.

Abstract: Provided is a read-out circuit that is connected to a microphone and configured to linearly amplify a current signal generated by the microphone and output the amplified current signal. The read-out circuit includes an amplification unit and a feedback resistor. The amplification unit has an amplification gain between 0 and 1. The feedback resistor is connected between input and output terminals of the amplification unit. As the amplification gain of the amplification unit becomes closer to 1, an input impedance becomes higher. A preamp of the read-out circuit can have a high input impedance due to the amplification gain, and the read-out circuit can be manufactured using a CMOS process.

Abstract: An integrated circuit configured to provide a microphone output signal, comprising: a preamplifier coupled to receive an input signal, generated by either a first microphone member or a second microphone member, where one of the members is movable relative to the other microphone member; a voltage pump to output a pumped voltage; and a low-pass filter coupled to filter the pumped voltage from the voltage pump and to provide a bias voltage to either microphone member.

Abstract: In an example embodiment a headset includes a phone jack, a speaker connected to the phone jack, a microphone coupled to the phone jack and a resistive switch string coupled to the phone jack to the same ring of the phone jack as the microphone. In another example an integrated circuit device includes a charge pump, a multi-voltage LDO having an input which is capable of being coupled to an output of the charge pump, an ADC; and a pull-up resistor coupled between an output of the LDO and an input of the ADC. In another example embodiment, a method for headset signal multiplexing includes providing a headset with a plurality of signal sources and voltage division multiplexing the plurality of signal sources on a common wire.

Abstract: A system that models a microphone may include capsules that receive individual signals. The signals may be combined and modified based on a weighting factor. Directivity patterns of a converted signal may be modified or controlled based on the weighting of the signals.

Abstract: A mobile communication terminal includes a receiver converting an audio signal outputted from the mobile communication terminal into an audible sound; a coupler dividing the audio signal outputted from the receiver into first and second audio signals which are different in phase from each other; an audio signal amplifier amplifying the second audio signal outputted from the coupler according to a predetermined amplification gain; a receiver port to which the receiver is detachably connected and which includes a first output port transmitting the first audio signal outputted from the coupler to the receiver and a second output port transmitting the second audio signal amplified by the audio signal amplifier to the receiver; and a controller controlling the mobile communication terminal and the amplification gain of the audio signal amplifier.

Abstract: A transducer assembly utilizing at least two MEMS transducers is provided, the transducer assembly preferably defining either an omnidirectional or directional microphone. In addition to at least first and second MEMS transducers, the assembly includes a signal processing circuit electrically connected to the MEMS transducers, a plurality of terminal pads electrically connected to the signal processing circuit, and a transducer enclosure housing the first and second MEMS transducers. The MEMS transducers may be electrically connected to the signal processing circuit using either wire bonds or a flip-chip design. The signal processing circuit may be comprised of either a discrete circuit or an integrated circuit. The first and second MEMS transducers may be electrically connected in series or in parallel to the signal processing circuit. The first and second MEMS transducers may be acoustically coupled in series or in parallel.

Abstract: A processing chip for a digital microphone and related input circuit and a digital microphone are described herein. In one aspect, the input circuit for a processing chip of a digital microphone includes: a PMOS transistor, a resistor, a current source, and a low-pass filter. The described processing chip possesses high anti high-frequency interference capabilities and the described input circuit possesses high high-frequency power supply rejection ratio.

Abstract: An apparatus comprises a substantially horn shaped structure configured to amplify sound from a speaker of a device wherein the apparatus comprises packaging of the device.

Abstract: An audio host device has a headset electrical interface in which a reference contact is shared by a microphone and a speaker. A variable or programmable gain amplifier, PGA, has a signal input coupled to a sense point for the reference contact. A first difference amplifier has its inputs coupled to a microphone contact and the PGA through a first gain stage; a second difference amplifier has its inputs coupled to the microphone contact and to the output of the PGA, through a second gain stage having a different gain than the first gain stage; a third difference amplifier has its inputs coupled to the microphone contact and the output of the PGA through a third gain stage having a gain in between that of the first and second gain stages. A controller monitors outputs of the first and second difference amplifiers and changes a gain setting of the PGA. Other embodiments are also described and claimed.

Abstract: Provided is a digital microphone having a power supply. In this case the power supply is configured so as to provide a P48 V phantom power.

Abstract: A method for driving a condenser microphone is provided. The condenser microphone comprises a membrane and an electrode constituting a capacity. A polarization voltage is applied between the membrane and the electrode. According to the method, an electrical signal generated by the condenser microphone based on a received acoustic signal causing a deflection of the membrane is detected, and the polarization voltage is varied in response to the detected electrical signal.

Abstract: A mobile computing device comprises a printed circuit board, a processing circuit, a surface mount microphone, and a vibration attenuation portion. The processing circuit is disposed on a first portion of the printed circuit board. The surface mount microphone is disposed on a second portion of the printed circuit board. The vibration attenuation portion of the board is configured to attenuate vibrations from the first to the second portion of the printed circuit board.

Abstract: An integrated circuit for providing programmable microphone interface includes an input terminal for receiving an input signal and an output terminal for providing an output audio signal. In an embodiment, the integrated circuit includes a bias circuit, an amplifier circuit and two feedback circuits. The amplifier circuit includes a first input, a second input, and an output. The first input receives either the input signal or a feedback signal, depending upon mode control signals. The second input receives either the feedback signal or the input signal depending upon the mode control signals. The first feedback circuit is in communication with the output and the first input of the amplifier and includes a first resistor and a first capacitor connected in parallel. The second feedback circuit includes an integrator circuit and provides the feedback signal. The mode control signals can be set in a programmable mode control register.

Abstract: The present invention provides a receiver for making an earphone cord of an earphone function as an earphone antenna. The receiver includes a receiver circuit for receiving a broadcast wave signal received at the earphone code of the earphone and outputting an audio signal, an earphone jack into which a earphone plug is inserted, a first detector circuit for detecting whether the earphone is one of stereo and monaural functionalities, and a second detector circuit for the earphone is connected to the receiver. The earphone jack has an antenna terminal, left channel audio terminal and right channel audio terminal, a first detection terminal and a second detection terminal, and a ground terminal.

Abstract: An audio output control device includes: display means for displaying two screens; speaker output control means for recognizing whether a main screen or a sub screen is being selected on the display means that is displaying the two screens and performing a control process to output a main or sub sound of the selected main or sub screen through a speaker; and headphone output control means for, before a headphone is connected, performing a control process to supply to a headphone terminal of the headphone the sub or main sound of the sub or main screen that is not being selected.