Abstract: To suppress the transverse displacement of a ribbon due to an impact to a level smaller than that achieved by electromagnetic damping. The switch 150 breaks a path between the piezoelectric element 140 and the secondary winding 132 so as to be non-conductive when a power plug is connected (the microphone is in use), and completes a path between the piezoelectric element 140 and the secondary winding 132 so as to be conductive when a power plug is not connected (the microphone is not in use), in order to generate a driving force in the direction opposite to the displacement direction of the ribbon 10 by causing a current corresponding to power generated in the piezoelectric element 140 to flow in the ribbon 10.

Abstract: Illustrative acoustic transducers are provided. A monolithic semiconductor layer defines a plate, two or more flexible extensions and at least a portion of a support structure. Acoustic pressure transferred to the plate results in tensile strain of the flexible extensions. The flexible extensions exhibit varying electrical characteristics responsive to the tensile strain. An electric signal corresponding to the acoustic pressure can be derived from the varying electrical characteristics and processed for further use.

Abstract: The present invention relates to an integrated circuit voltage pump with temperature compensation circuitry providing improved DC output voltage accuracy over an operational temperature range. The compensation circuitry is operative to eliminate or reduce temperature induced changes of voltage drops across semiconductor diodes of the integrated circuit voltage pump.

Abstract: The invention relates an electrostatic speaker system comprising—a high voltage switching power amplifier,—an extraction filter having an input coupled to an output of the high voltage switching amplifier, and—an electrostatic speaker element having a capacitive load and an input coupled to an output of the extraction filter. The combination of the extraction filter and capacitive load form a filter circuitry having at least a first filter stage and a second filter stage. The first filter stage comprising a RLC circuit having a resonant frequency ?O and a quality factor Q>½ and wherein the second filter stage being a low pass filter comprises at least one electrical element for damping a signal component at the resonant frequency of the RLC circuit at the output of the extraction filter.

Abstract: A capacitive microphone and method of fabricating the same are provided. One or more holes can be formed in a first printed circuit board (PCB). A diaphragm can be surface micro-machined onto an interior surface of the first PCB at a region having the one or more holes. Interface electronics can also be interconnected to the interior surface of the PCB. One or more spacer PCBs can be attached to a second PCB to the first PCB, such that appropriate interconnections between interconnect vias are made. The second PCB and first PCB with spacers in between can be attached so as to create a cavity in which the diaphragm and interface electronics are located.

Abstract: An apparatus comprising a capacitive transducer, for example a MEMS microphone. A first voltage generator is connected to receive a first voltage (VDD*) and generate a second voltage (VCP) for biasing the capacitive transducer. A control circuit is adapted to, in use, control the first voltage (VDD*) based on a calibration value, wherein a different calibration value would lead to a different first voltage level and the calibration value is set such that an input signal of known amplitude produces an output signal of predetermined amplitude.

Abstract: The present invention relates to a condenser microphone assembly comprising an electro-acoustic transducer element comprising a diaphragm and a back plate, signal processing circuitry operatively connected to the transducer element so as to process signals generated by the transducer element, and a mode-setting circuitry for selectively setting the condenser microphone assembly in a test mode or an operational mode. The electro-acoustic sensitivity of the condenser microphone assembly, when operated in the test mode, is at least 40 dB lower than the corresponding electro-acoustic sensitivity of the assembly when operated in the operational mode. The present invention further relates to a method for determining a performance parameter of a signal processing circuitry mounted inside a housing of an assembled condenser microphone assembly.

Abstract: A MEMS microphone includes a cover, a housing engaging with the cover for forming a cavity, at least one transducer accommodated in the cavity, and a conductive case covering the cover and the sidewall of the housing. The housing includes a cover and a sidewall extending from the base. The conductive case defines a first part covering the cover, a second part extending from the first part for covering the sidewall and a third part perpendicularly extending from the second part for covering a periphery part of the base, the third part forming an opening.

Abstract: The present invention relates to a condenser microphone assembly comprising a capacitive electro-acoustic transducer element comprising a diaphragm and a back-plate operatively connected to a DC bias voltage, a fast charge pump adapted to generate the DC bias voltage, and a controllable or programmable current source operatively connected to the DC bias voltage to draw a predetermined DC current there from. The controllable or programmable current source is responsive to a difference between a representative of a detected DC bias voltage and a DC reference voltage.

Abstract: The present invention relates to a microphone assembly comprising a microphone assembly casing having a sound inlet port and a transducer for receiving acoustic waves through the sound inlet port. The transducer converts the received acoustic waves to analog audio signals. The assembly according to the present invention further comprises an electronic circuit positioned within the microphone assembly casing, said electronic circuit comprising a pre-amplifier and an analog-to-digital converter preferably in form of a sigma-delta modulator so as to convert amplified analog audio signals to digital audio signals.

Abstract: The invention provides an audio interface device and method utilizing a single audio jack connector for plugging into a three-wire analog microphone or a three-wire digital microphone, thereby reducing dimensions and production costs thereof and an electronic system using the same. The audio interface comprises an audio jack connector, having first to third contacts electronically connected with the three-wire microphone plugged thereinto; and an audio processing device, detecting a type of the three-wire microphone plugged into the audio jack connector, outputting a clock signal to the three-wire microphone and receiving a digital audio signal from the three-wire microphone when the type is digital; or receiving analog audio signals from the three-wire microphone when the type is analog.

Abstract: A sound processing device includes: a plurality of sound input units; a detecting unit for detecting a frequency component of each sound input to the plurality of sound signal unit, the each sound arriving from a direction approximately perpendicular to a line determined by arrangement positions of two sound input units among the plurality of sound input units; a correction coefficient unit for obtaining a correction coefficient for correcting a level of at least one of the sound signals generated from the input sounds by the two sound input units so as to match the levels of the sound signals with each other based on the sound of the detected frequency component; a correcting unit for correcting the level of at least one of the sound signals using the obtained correction coefficient; and a processing unit for performing a sound process based on the sound signal with the corrected level.

Abstract: Electronic devices and accessories such as headsets for electronic devices are provided. A microphone may be included in an accessory to capture sound for an associated electronic device. Buttons and other user interfaces may be included in the accessories. An accessory may have an audio plug that connects to a mating audio jack in an electronic device, thereby establishing a wired communications link between the accessory and the electronic device. The electronic device may include power supply circuitry for applying bias voltages to the accessory. The bias voltages may bias a microphone and may adjust settings in the accessory such as settings related to operating modes. User input information may be conveyed between the accessory and the electronic device using ultrasonic tone transmission. The electronic device may also gather input from the accessory using a voltage detector coupled to lines in the communications path.

Abstract: A dual backplate MEMS microphone system including a flexible diaphragm sandwiched between two single-crystal silicon backplates may be formed by fabricating each backplate in a separate wafer, and then transferring one backplate from its wafer to the other wafer, to form two separate capacitors with the diaphragm.

Abstract: There is disclosed a microphone, a circuit, and a method. A microphone capsule may include an electret microphone and a field effect transistor (FET). A floating DC voltage source may have a first end connected to a drain terminal of the electret microphone capsule and a second end. A load resistor may be connected between the second end of the floating DC voltage source and a source terminal of the electret microphone capsule. A voltage follower may have an output connected to the source terminal of the electret microphone capsule and the first end of the floating DC voltage source. A coupling capacitor may couple an audio signal from the source terminal of the electret microphone capsule to an input of the voltage follower.

Abstract: A driving interface device adaptive to a flat speaker is introduced herein. The driving interface device is coupled with an external sound source for receiving sound signals, and boosts voltage levels of the sound signals to drive the thin flat speaker without using an external power source. In one embodiment, an impedance component is provided in the driving interface device for coupling to the external sound source, so as to drive the flat speaker.

Abstract: Described herein is a preamplifier circuit for a capacitive acoustic transducer provided with a MEMS detection structure that generates a capacitive variation as a function of an acoustic signal to be detected, starting from a capacitance at rest; the preamplifier circuit is provided with an amplification stage that generates a differential output signal correlated to the capacitive variation. In particular, the amplification stage is an input stage of the preamplifier circuit and has a fully differential amplifier having a first differential input (INP) directly connected to the MEMS detection structure and a second differential input (INN) connected to a reference capacitive element, which has a value of capacitance equal to the capacitance at rest of the MEMS detection structure and fixed with respect to the acoustic signal to be detected; the fully differential amplifier amplifies the capacitive variation and generates the differential output signal.

Abstract: In accordance with an embodiment, a method of operating a charge pump includes providing a first programmable voltage to a plurality of clock generators having outputs coupled to first nodes of corresponding groups of charge pump capacitors, and selecting a second node of one capacitor from one of the corresponding groups of charge pump capacitors. The clock generators produce a plurality of clock signals having amplitudes proportional to the first programmable voltage.

Abstract: A stereo capacitor microphone unit includes: two unidirectional microphone units integrally formed with respective fixed electrodes of the unidirectional microphone units facing each other; and an insulating spacer that is interposed between the fixed electrodes and provided with a gap formed at a portion of an outer periphery towards radial direction. The gap communicates fixed electrode rear spaces of the respective unidirectional microphone units with an external space to serve as a common rear acoustic terminal for the unidirectional microphone units.

Abstract: The invention is directed to echo cancellation for a microphone system. An exemplary microphone system comprises a first transistor, wherein a gate terminal of the first transistor is connected to a ground terminal via a microphone electret element, the microphone electret element being associated with a capacitance and a voltage, the microphone electret element reverse biasing the first transistor; and a second transistor in parallel with the first transistor, wherein a gate terminal of the second transistor is connected to the ground terminal via a capacitor, the capacitance of the capacitor being selected to suppress at least a portion of a common mode signal, and wherein the gate terminal of the second transistor is not connected to the microphone electret element. The common mode signal comprises the echo, which may be the output of a speaker system that is received as input to the microphone system.

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: Systems and methods for a noise canceling microphone and microphone system are disclosed. The system generally includes a housing with a printed circuit board forming a surface of the housing. Electrical terminals are located on an exterior side of the printed circuit board. A diaphragm is disposed within the housing. A first port in the housing remote from the printed circuit board provides access to one face of the diaphragm first face and a second port disposed in the housing remote from the printed circuit board provides access to a second face of the diaphragm.

Abstract: A system and method for sensing acoustic sounds is provided having at least one directional sensor, each directional sensor including at least two compliant membranes for moving in reaction to an excitation acoustic signal and at least one compliant bridge. Each bridge is coupled to at least a respective first and second membrane of the at least two membranes for moving in response to movement of the membranes it is coupled to for causing movement of the first membrane to be related to movement of the second membrane when either of the first and second membranes moves in response to excitation by the excitation signal. The directional sensor is controllably rotated to locate a source of the excitation signal, including determining a turning angle based on a linear relationship between the directionality information and sound source position described in experimentally calibrated data.

Abstract: A capacitor microphone includes: a capacitor microphone unit including a diaphragm that vibrates upon receiving sound waves and a fixed electrode arranged opposite to the diaphragm with a space therebetween; and a polarization voltage generating circuit that generates polarization voltage to be applied across the diaphragm and the fixed electrode. The polarization voltage generating circuit includes an oscillating circuit that alternately turns on and off DC power, coils to boost the voltage of the power alternately turned on and off, and a DC boosting circuit including a rectifying circuit that rectifies the boosted voltage. The coils are formed of two inductors that are electromagnetically coupled and are provided with an electromagnetic coupling adjusting unit with which the level of electromagnetic coupling between the two inductors is adjusted to adjust the polarization voltage.

Abstract: An integrated circuit includes at least one output cell including a first output cell having a ground pin connected to a ground rail, a first power supply pin connected to a first power rail, a second power supply pin connected to a second power rail, a data pin, at least one voltage select pin, and an output pin wired to the first output pad. The first output cell is configured to operate according to a first mode wherein the output pin has a first voltage amplitude, and according to a second mode wherein the output pin has a second voltage amplitude larger than the first voltage amplitude depending on a control signal applied to the at least one voltage select pin.

Abstract: A biasing circuit for an acoustic transducer is provided with: a voltage-booster stage, which supplies, on a biasing terminal, a boosted voltage for biasing a first terminal of the acoustic transducer; and filtering elements, set between the biasing terminal and the acoustic transducer, for filtering disturbances on the boosted voltage. The biasing circuit is further provided with switches, which can be actuated so as to connect the first terminal to the biasing terminal of the voltage-booster stage, directly during a start-up step of the biasing circuit, and through the filtering elements at the end of the start-up step.

Abstract: A micro-electromechanical (MEMS) based directional sound sensor includes a two sensor wings attached to a surrounding support structure by two legs. The support structure is hollow beneath the sensor wings allowing the sensor wings to vibrate in response to sound excitation. In one embodiment, interdigitated comb finger capacitors attached on the sensor wing edges and the support structure enable an electrostatic (capacitive) readout related to the vibrations of the sensor which allows determination of the sound direction.

Abstract: To provide a condenser microphone having a removable head unit on the microphone body, wherein the head unit can be attached and detached to and from the microphone body through one connection at a low impedance. A second pin 22h and a third pin 22c of a microphone body 20, which has a 3-pole output connector, is connected with current regulative diodes D2 and D3 as a feed circuit for the drain D of the FET Q1. A first AC coupling electrolytic capacitor C3 is connected to one of the current regulative diodes, D2, and a series circuit of a second AC coupling electrolytic capacitor C4 and a resistive element R3 is connected between the anode of the other current regulative diode D3 and a ground line L3. The resistive element R3 has substantially the same impedance as an output impedance of the transistor Q2.

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: 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: 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 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: Vacuum tubes that receive output signals from microphone units through grids and with which the signals are output as outputs from cathode followers; FETs in cascade connection with the corresponding vacuum tubes and that define currents flowing in the vacuum tubes; and bias circuits that apply a bias voltage to the grids of the corresponding vacuum tubes are included. Pairs of such vacuum tubes, FETs, and fixed bias circuits are each symmetrically connected so that a balanced signal can be output from two cathode followers, and an adjuster is provided between the pair of fixed bias circuits, the adjuster adjusts currents flowing in the pair of vacuum tubes to achieve a balanced output.

Abstract: An impedance converter for a capacitor microphone includes: a vacuum tube that receives an output signal from a capacitor microphone unit through a grid and with which the signal is output as an output from a cathode follower; an FET in cascade connection with the vacuum tube and that defines a current flowing in the vacuum tube; and a bias circuit that applies a bias voltage to the grid of the vacuum tube. The bias circuit includes: a first diode and a second diode that apply the bias voltage to the grid of the vacuum tube; the first diode and the second diode being connected in inverse parallel; and a bias resistor for applying the bias voltage at a constant level to the grid of the vacuum tube via the first diode or the second diode.

Abstract: Methods are provided for production of pre-collapsed capacitive micro-machined ultrasonic transducers (cMUTs). Methods disclosed generally include the steps of obtaining a nearly completed traditional cMUT structure prior to etching and sealing the membrane, defining holes through the membrane of the cMUT structure for each electrode ring fixed relative to the top face of the membrane, applying a bias voltage across the membrane and substrate of the cMUT structure so as to collapse the areas of the membrane proximate to the holes to or toward the substrate, fixing and sealing the collapsed areas of the membrane to the substrate by applying an encasing layer, and discontinuing or reducing the bias voltage. CMUT assemblies are provided, including packaged assemblies, integrated assemblies with an integrated circuit/chip (e.g., a beam-steering chip) and a cMUT/lens assembly. Advantageous cMUT-based applications utilizing the disclosed pre-collapsed cMUTs are also provided, e.g.

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: 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: A method of forming a miniature, surface micromachined, differential microphone, comprising depositing a sacrificial layer on a surface of a silicon wafer; depositing a diaphragm material on a surface of the sacrificial layer; etching the diaphragm material layer to isolate a diaphragm; and removing a portion of the sacrificial layer beneath the defined diaphragm. A diaphragm formed in the diaphragm material layer is supported by a hinge and otherwise isolated from a remaining portion of the diaphragm material layer by a slit adjacent a perimeter of the diaphragm. An enclosed back volume beneath the diaphragm has a depth defined by a thickness of the sacrificial layer, and communicates with an external region via the slit. A transducer may be provided for producing an electrical signal responsive to a displacement of the diaphragm.

Abstract: A microphone system has a primary microphone for producing a primary signal, a secondary microphone for producing a secondary signal, and a selector operatively coupled with both the primary microphone and the secondary microphone. The system also has an output for delivering an output audible signal principally produced by one of the to microphones. The selector selectively permits either 1) at least a portion of the primary signal and/or 2) at least a portion of the secondary signal to be forwarded to the output as a function of the noise in the primary signal.

Abstract: A microphone assembly is provided that includes a condenser transducer element having a displaceable diaphragm and a back-plate. The displaceable diaphragm and the back-plate are arranged to form a capacitor in combination. A preamplifier circuit has an input stage, the input stage comprising a P-type field effect transistor. The displaceable diaphragm and the back-plate are operatively connected between a source input and a gate input of the P-type field effect transistor.

Abstract: An autobias vehicular microphone system (300) includes a microphone (301) uses an amplifier (306) for amplifying an output of the microphone. A first feedback path (308) provides an amplifier output signal to the amplifier input for providing amplifier linearity and a second feedback path (305) is used for providing bias to an voltage reference (303). The voltage reference (303) operates to provide an autobias to the amplifier (306) based upon amplifier loading. Thus, a DC feedback loop works as an average voltage sensing circuit operating to center the amplifier (306) to an operating point near one half its supply voltage. By allowing the bias point to vary, a constant clip level can be maintained depending on varying load conditions of electronic devices (307, 309, 311) using the microphone (301).

Abstract: A microphone assembly is provided that includes a condenser transducer element having a displaceable diaphragm and a back-plate. The displaceable diaphragm and the back-plate are arranged to form a capacitor in combination. A preamplifier circuit has an input stage, the input stage comprising a P-type field effect transistor. The displaceable diaphragm and the back-plate are operatively connected between a source input and a gate input of the P-type field effect transistor.

Abstract: A microelectromechanical system microphone structure including a substrate, a first device and at least one second device is provided. The first device is disposed on the substrate and including a first upper electrode and a first lower electrode disposed between the first upper electrode and the substrate. The second device is disposed on the substrate, surrounding the first device and including a second upper electrode and a second lower electrode disposed between the second upper electrode and the substrate. The second upper electrode includes a plurality of first conductive layers and first plugs. The first conductive layers are arranged in steps, and the first plug is disposed between the adjacent first conductive layers. The second lower electrode includes a plurality of second conductive layers and a plurality of second plugs. The second conductive layers are arranged in steps, and the second plug is disposed between the adjacent second conductive layers.

Abstract: In a condenser microphone having a battery holder and a battery cover therefor, one part is used as a member for grounding the battery cover and as a member for preventing the battery cover from coming off.

Abstract: There is provided a condenser microphone in which electromagnetic shielding in the connecting part of a microphone capsule and a microphone main body is made more reliable.

Abstract: There is provided a condenser microphone unit incorporating a FET (impedance converter) in a unit case, in which the electromagnetic shield on the rear surface side of the unit case is assured, sound waves do not leak, and a steady internal stress is applied to incorporated parts almost uniformly.

Abstract: A microphone circuit includes a signal generating module, a filtering module, a transmitting module and a switch module. The signal generating module transforms audio signals into electronic signals. The filtering module is connected to the signal generating module to filter the electronic signals sent from the signal generating module. The transmitting module is connected to the filtering module to transmit the signals sent from the filtering module. The switch module is connected to the signal generating module to selectively regulate the microphone circuit to function as a differential microphone circuit or a single-ended microphone circuit.

Abstract: An apparatus comprising: a first member including a plurality of portions separated from one another by electrical insulator material; a second member configured to form capacitors with the plurality of portions of the first member; and wherein one of the first member and the second member are configured to vibrate in response to sound waves, and a first portion of the plurality of portions is configured to provide a first output signal representative of the sound waves and a second portion of the plurality of portions is configured to provide a second output signal representative of the sound waves.

Abstract: The invention provides an integrated circuit attached to a microphone. In one embodiment, the integrated circuit comprises a buffer, a gain stage, an analog-to-digital converter (ADC), and a memory module. The buffer buffers a first signal generated by the microphone, and outputs the first signal as a second signal. The gain stage amplifies the second signal according to an adjustable gain to obtain a third signal. The analog-to-digital converter converts the third signal from analog to digital to obtain a fourth signal as an output of the integrated circuit. The memory module stores the adjustable gain and outputs the adjustable gain to the gain stage for controlling amplification of the gain stage.