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: A semiconductor circuit including an input terminal, an impedance converting portion configured to receive an input signal from the input terminal and to output an output signal corresponding to the input signal, an input impedance of the semiconductor circuit being higher than an output impedance of the semiconductor circuit, a detecting portion connected to a node between the input terminal and the impedance converting portion, and configured to detect whether the input signal is higher than a predetermined threshold, and a variable impedance connected to a reference voltage and the node, an impedance of the variable impedance configured to decrease after the input signal is detected as higher than the predetermined threshold.

Abstract: A phantom power circuit has a detection circuit and a limiting circuit, the detection circuit detecting a pulse current generated in association with connection or disconnection of a condenser microphone, the limiting circuit limiting the output of the condenser microphone. The detection circuit detects a pulse current generated between input terminals of the condenser microphone. The limiting circuit reduces the output from the condenser microphone when the detection circuit detects the pulse current.

Abstract: The invention provides an integrated circuit. The integrated circuit receives a first signal from a microphone via a first node. In one embodiment, the integrated circuit comprises a biasing circuit and a buffering circuit. The biasing circuit is coupled between the first node and a second node, drives the microphone with a first voltage source, and filters the first signal to generate a second signal at the second node. In one embodiment, the biasing circuit comprises a first resistor, a first capacitor, and a load element. The first resistor is coupled between the first voltage source and the first node. The first capacitor is coupled between the first node and the second node. The load element is coupled between the second node and a second voltage source. The buffering circuit is coupled between the second node and a third node and buffers the second signal to generate a third signal at the third node.

Abstract: A microphone system has a base coupled with first and second microphone apparatuses. The first microphone apparatus is capable of producing a first output signal having a noise component, while the second microphone apparatus is capable of producing a second output signal. The system also has combining logic operatively coupled with the first microphone apparatus and the second microphone apparatus. The combining logic uses the second output signal to remove at least a portion of the noise component from the first output signal.

Abstract: A condenser microphone comprising: a mic capsule in which a capacitor is composed of a diaphragm and a counter electrode, and which effects electroacoustic conversion; a FET for impedance-converting audio signals output from the mic capsule; and a CR circuit composed of a resistor and a capacitor, and connected to the FET to adjust a signal level in a low frequency range, and in the condenser microphone, an output terminal may be drawn out from a drain of the FET; and the CR circuit may be connected in between a source of the FET and the ground, furthermore, in the condenser microphone, there may be provided a changeover switch for switching a mode in which the CR circuit is connected in between the source of the FET and the ground into another mode in which the CR circuit is short-circuited to connect the source of the FET to the ground.

Abstract: An apparatus and method for making a microphone that is not susceptible to RF noise and that can be fabricated to be very thin. The microphone includes a light transmitter configured to generate light, a waveguide having optically aligned transmit, vibrating and receive sections, and a receiver. Light from the transmitter is configured to be transmitted through the transmit section, vibrating section and the receive section of the waveguide, and to the receiver. The vibrating section of the waveguide is configured to vibrate in response to received acoustic energy, so that the light received by the receive section is modulated in proportion to the acoustic energy. In response, the receiver converts the modulated light to an electrical signal that is indicative of the received acoustic energy. Since the microphone of the present invention uses a thin waveguide to modulate the acoustic energy, it is not susceptible to RF noise, and it can be made to have a very thin profile.

Abstract: A range-sensitive wireless-microphone method includes receiving an audio input, converting the received audio input into digital data, buffering the digital data, and transmitting the buffered digital data. The method also includes determining whether the transmitted buffered data was successfully received, responsive to a determination that the transmitted buffered data was successfully received deleting the transmitted buffered data, and, responsive to a determination that the transmitted buffered data was not successfully received, retaining the transmitted buffered data and repeating the transmitting step. This Abstract is provided to comply with rules requiring an Abstract that allows a searcher or other reader to quickly ascertain subject matter of the technical disclosure. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: Disclosed is a condenser microphone chip, comprising: a substrate (21); a diaphragm (26) spaced from the substrate; a curved beam (27) connected with the diaphragm (26) to anchor the diaphragm (26) to the substrate (21); a curved beam connecting part (29) having a shape of a substantially circular plate. The curved beam (27) is arranged in the diaphragm (26). The curved beam (27) includes a plurality of sub beams, each of the plurality of sub beams including a first sub beam portion extending in a substantially radial direction from a circumference of the curved beam connecting part (29); a second sub beam portion extending in a substantially circumferential direction from an end of the first sub beam portion away from the circumference of the curved beam connecting part (29) and having a shape of a substantial arc; and a third sub beam portion extending in the radial direction from an end of the second sub beam portion away from the first sub beam portion and connected to the diaphragm (26).

Abstract: A semiconductor integrated circuit for a condenser microphone according to one exemplary aspect of the present invention includes a first resistor, a second resistor, a power supply terminal, a first capacitor, and a first diode. The first resistor and the second resistor are connected between a drain of an output transistor and an output terminal in series. The power supply terminal is connected to a source of the output transistor. The first capacitor is arranged between the power supply terminal and a connection point of the first resistor and the second resistor. The first diode is connected in parallel with the first capacitor.

Abstract: A microelectromechanical system (MEMS) device includes a diaphragm capacitor, connected between a capacitor biasing voltage source and a ground. A source follower circuit is coupled to the diaphragm capacitor. An amplifier is coupled to the source follower circuit to amplify the voltage signal as an output voltage signal. A programmable trimming circuit is implemented with the amplifier to trim a gain or implemented with the capacitor biasing voltage source to trim voltage applied on the diaphragm capacitor. Whereby, the output voltage signal has a target sensitivity.

Abstract: The present invention discloses a microphone comprising a first electrode, a second electrode, a printed circuit board and a shielding layer. The microphone is configured into a mobile communication device. The shielding layer located on the printed circuit board is disposed on the microphone. When the mobile communication device charges with an AC power supply and communicates with others simultaneously, the shielding layer can diminish the 50˜60 Hz noise produced by the AC power supply. Owing to the shielding layer reduces the EMI effect; the talking quality of the mobile communication device is thereby enormously improved.

Abstract: The invention relates to electroacoustic engineering, in particular to methods for converting electric signals into acoustic oscillations and to electroacoustic transducers. The method for converting electric signals into acoustic oscillations comprises exposing an oscillating system that is a gas medium pre-structured by a static electric field to an electric/electromagnetic field modulated in strength by an alternating electric signal in accordance with the shape and frequency of the modulating signal, and converting the energy of the field into acoustic energy to be released thereupon into the ambient. An electric gas-kinetic transducer developed to perform this method comprises a dielectric working element and at least two current-conducting plates that can be connected to the pole terminals of a direct voltage source and to a source of alternating electric signals.

Abstract: A battery compartment for a condenser microphone includes a battery space configured to hold a battery; a battery outlet open to a portion of a peripheral wall of the battery space and allowing removal of the battery in the battery space; a lid covering the battery outlet; and a ribbon having one end portion fixed to an internal wall of the battery space and the other end portion disposed to be pulled out from the battery outlet and wrapping around an external periphery of the battery. The ribbon is conductive and the fixed end portion is grounded.

Abstract: A passive processing device (D) is adapted to be interfaced in a full integrated way on at least a first audio signal path defined between a first audio signal source and an audio signal processing means of an electronic device, such as a mobile communication device. This device (D) comprises a first protection means (DE11; DE12) for rejecting electrostatic discharges on the first path, a first rejection means (CR11, R11; CR12) for rejecting radio signals at least in a chosen frequency band on the first path, and a first AC-coupling means (CC1) for interfacing voltage levels between the first audio signal source and the audio signal processing means.

Abstract: The coupling of an electret microphone is detected and identifying whether there is monaural or stereo speakers coupled to the USB connector is accomplished by coupling a current source to the USB ID terminal and detecting the voltage on the ID terminal. If the voltage on the ID line is substantially below the voltage associated with any other accessory when an electret microphone is coupled between the ID terminal and the ground terminal, and a microphone bias resistor is coupled to the ID line. On detection of an electret microphone being coupled between the ID terminal and the ground terminal, whether there is a monaural or stereo speakers coupled to the USB connector is determined by detecting the impedance on the one of the D+ and D? terminals to which a monaural speaker would not be coupled. An open circuit indicates a monaural speaker, otherwise stereo speakers are connected. An alternate embodiment is disclosed.

Abstract: A microphone bias circuit is disclosed. A current source provides a first current. A voltage buffer provides a first reference voltage. A microphone coupled between the current source and the first reference voltage receives acoustic waves and converts the received acoustic waves to a second current. A loading device coupled between the current source and a second reference voltage lower than the first reference voltage outputs an output voltage according to the first current and the second current.

Abstract: The invention provides an interfacing circuit for a removable microphone. In one embodiment, the interfacing circuit comprises a jack for receiving the removable microphone and an integrated circuit comprising a biasing circuit, a buffer amplifier, and an insertion detecting circuit. The jack comprises a first terminal receiving an output voltage of the removable microphone and a second terminal coupling the removable microphone to a ground voltage source. The integrated circuit is coupled to the first terminal of the jack via a first node. The biasing circuit, coupled between the first node and a second node, biases the removable microphone and passes only an alternative current (AC) portion of the output voltage of the removable microphone to the second node. The buffer amplifier, coupled to the second node, buffers the AC portion to generate a voltage signal.

Abstract: An audio processing system is provided. The audio processing system comprises a transducer, a gain stage, a capacitor network, and a preamplifier. The transducer transduces a sound signal to a voltage signal. The gain stage comprises an input coupled to the transducer and an output. The capacitor network, coupled between the output of the gain stage and the transducer, provides an equivalent capacitance. The preamplifier coupled to the transducer amplifies the voltage signal.

Abstract: An exemplary audio signal transmission circuit includes a codec to provide analog and digital audio signals; an amplifier connected to the codec to receive the analog audio signals; a control circuit connected to the codec to receive the digital audio signals and connected to the amplifier to selectively turn off the amplifier; a front audio port connected to the amplifier to receive amplified analog audio signals generated by the amplifier; and a rear audio port connected to the amplifier and the control circuit to selectively receive the amplified analog audio signals or the digital audio signals. The control circuit and the front audio port are turned off when the rear audio port is connected to an analog system, and the amplifier and the front audio port are turned off when the rear audio port is connected to a digital system.

Abstract: A voltage supply circuit comprises a voltage control circuit for outputting a bias voltage control signal according to a set value based on a bias voltage of a sensor and a voltage generation circuit for generating the bias voltage to be applied to the sensor based on the bias voltage control signal.

Abstract: A MEMS microphone comprising a MEMS transducer having a back plate and a diaphragm as well as controllable bias voltage generator providing a DC bias voltage between the back plate and the diaphragm. The microphone also has an amplifier with a controllable gain, and a memory for storing information for determining a bias voltage to be provided by the bias voltage generator and the gain of the amplifier.

Abstract: A microphone in which a core of an output transformer can be grounded without soldering and degradation of magnetic properties of the core can be prevented by preventing mechanical damage to the output transformer even if an impact force of the microphone is applied is obtained. A grounding pattern is formed in an output transformer mounting location of a circuit board incorporated in the microphone, a conductive fabric is put on the grounding pattern, a core of the output transformer is stacked and arranged on the conductive fabric, and the core of the output transformer is grounded through the conductive fabric. A second conductive fabric that covers the output transformer and is in contact with an inner circumferential surface of a microphone case may be provided and the microphone case may be grounded by bringing the second conductive fabric into contact with the core of the output transformer.

Abstract: A multi-voltage biasing system with over voltage protection has an amplifier with a stage including at least one output device and one cascode protection device having a predetermined maximum recommended voltage; a biasing network is selectively responsive to a plurality of different supply voltages at least one of which is higher than the maximum recommended voltage for providing to the stage a bias voltage to operate the cascode device and output device below their maximum recommended voltages.

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: The present invention discloses a Micro-Electro-Mechanical Systems (MEMS) capacitive sensing circuit wherein two input nodes of a fully differential amplifier are separately connected to a MEMS capacitive sensing device and a matching capacitor, which both contain similar capacity value and connect to a bias node, and two resistors separately connect the MEMS capacitive sensing device and the matching capacitor to ground (zero voltage). Thus, the present invention could effectively eliminate the bias noise in the circuit without any discrete capacitor and capable for designer to integrate all circuit devices into an IC.

Abstract: A microphone circuit includes an amplifier for amplifying an electric signal output from an electroacoustic transducing module, an external power supply circuit capable of supplying power for driving at least the amplifier from the outside, a light source that is turned on when an external power is supplied through the external power supply circuit, and a photo relay having contacts that are turned on and off in response to blinking of the light source. The contacts of the photo relay are connected so as to output an output signal of the amplifier as a microphone output when the light source is turned on and output an output signal of the electroacoustic transducing module as the microphone output when the light source is turned off.

Abstract: An apparatus having a microphone and a mute circuit (not shown in detail here) operable to be actuated by a rotating door assembly. The apparatus provides a mute circuit suitable to mute the audio microphone when the rotating door assembly is in a closed position and unmute the audio microphone when the rotating door assembly is not in the closed position. Additionally, the mute circuit is impervious to generating audible disturbances in the microphone signal when the rotating assembly door is rotated between open and closed positions. This advantageously allows for the microphone to essentially transition to off when the rotating door assembly is closed and transition to on when the rotating door assembly is open and do so without additional audio disturbance.

Abstract: An alternative sensing circuit for a micro-electro-mechanical system (MEMS) microphone and a sensing method thereof are provided. The sensing circuit reads out output signals of an MEMS electret microphone or an MEMS condenser microphone. In considering different operating requirements of the different MEMS microphones, for example, low power consumption for the MEMS electret condenser microphone or high sensitivity for the MEMS condenser microphone, the manner of using two kinds of MEMS microphone sensing components in one circuit can significantly increase the flexibility of using the MEMS microphone and can be applied to the application or design of a condenser sensing component.

Abstract: A differential microphone having a perimeter slit formed around the microphone diaphragm that replaces the backside hole previously required in conventional silicon, micromachined microphones. The differential microphone is formed using silicon fabrication techniques applied only to a single, front face of a silicon wafer. The backside holes of prior art microphones typically require that a secondary machining operation be performed on the rear surface of the silicon wafer during fabrication. This secondary operation adds complexity and cost to the micromachined microphones so fabricated. Comb fingers forming a portion of a capacitive arrangement may be fabricated as part of the differential microphone diaphragm.

Abstract: The invention provides a microphone. The microphone receives a first sound signal and at least one second electrical signal and outputs a third electrical signal. In one embodiment, the microphone comprises a transducer and a signal processor. The transducer converts the first sound signal to a first electrical signal. The signal processor has a first input terminal receiving the first electrical signal and at least one second input terminal receiving the at least one second electrical signal, and derives the third electrical signal from the first electrical signal and the second electrical signal. In one embodiment, the at least one second electrical signal is derived from a t least one second sound signal by at least one second microphone located in the vicinity of the microphone. In another embodiment, the at least one second electrical signal comprises a wind noise signal derived from wind pressure by a pressure sensor located in the vicinity of the microphone.

Abstract: A circuit includes a differential amplifier having a first input for coupling to a first terminal of a microphone and a second input for coupling to a first terminal of a component having an impedance value that is substantially equal to an impedance value of the microphone, where a second terminal of the microphone and a second terminal of the component are coupled to circuit ground. The circuit further includes a first resistance having a first node coupled to a source of microphone bias voltage and a second node coupled to the first terminal of the microphone; and a second resistance having a first node coupled to the source of microphone bias voltage and a second node coupled to the first terminal of the component. Operation of the differential amplifier results in attenuating or suppressing common mode noise and interference present in the microphone bias voltage and in the common potential.

Abstract: A condenser microphone is obtained, in which the bias of a current amplifier circuit in emitter-follower connection immediately after an impedance converter automatically changes in accordance with the switching of phantom power supply voltages and the maximum output level and the maximum permissible input sound pressure level are increased at any power supply voltage. The condenser microphone comprising a transistor Q2 in emitter-follower connection immediately after an FET 2 that constitutes an impedance converter Q1 has a constant current diode D2 connected to an output transformer TRS that also serves as a transformer for phantom power source supply and resistors R0 and R1 that divide the voltage on the cathode side of the constant current diode D2 into a bias voltage that causes the transistor Q2 to operate.

Abstract: The invention provides an audio interface device and method to acquire audio signal from either an analog or digital microphone through a common connector. The audio interface comprises a connector, electrically connected with a microphone plugged thereinto, an analog readout circuit, acquiring an analog audio signal from an analog microphone, a digital readout circuit, acquiring a digital audio signal from a digital microphone, and a decision circuit, selectively connecting the analog or digital readout circuit to the connector to acquire the analog or digital audio signal respectively according to whether the microphone plugged into the connector is analog or digital.

Abstract: A mobile terminal having a dual display unit, a dual speaker and a dual microphone, and a method of controlling the dual speaker and the dual microphone thereof are provided. The method of controlling a dual speaker and a dual microphone of a mobile terminal having a dual display unit including a first body having a first display unit and first speaker on a front surface and a second display unit and second speaker on a rear surface, a second body having a first and a second microphone, and a hinge module for rotatably connecting the first body and the second body, includes determining which of the first and second display units is activated; activating, if the first display unit is activated, the first speaker; and activating, if the second display unit is activated, the second speaker.

Abstract: A synchronous detection and calibration system is provided for expedient calibration of differential acoustic sensors in a manufacturing and testing environment. By processing a series of sequentially received tones, respective portions of a system using differential acoustic sensors are tuned for optimum individual operation, following which corresponding control data are generated and stored for use in selecting among predetermined calibration vectors which establish and maintain optimum system operation.

Abstract: A microphone including a connector with a plurality of electrical contacts. The microphone interfaces with a computer system via a digital bus. The microphone can transmit data to the computer system via the connector that is related to at least one of the following: the microphone manufacturer, the microphone manufacture date, the microphone model number, the microphone serial number, the microphone frequency response, whether the microphone uses phantom power, the desired pre-amplifier gain, and the microphone dynamic response.

Abstract: A voltage supply circuit includes a power supply booster, an amplifier operating with a voltage generated by the power supply booster as a power supply voltage and supplying a bias voltage to a sensor, and an output voltage setting part including a feedback resistor for the amplifier. The feedback resistor has resistance determined according to a set value of a bias voltage of the sensor.

Abstract: An oscillator device having an oscillating member, a resilient support and a supporting member is produced. The oscillating member is supported by the resilient support for oscillation about an oscillation axis. The oscillating member is formed with a movable element having protrusions for adjusting its mass, the protrusions extending from the movable element parallel to the oscillation axis and being formed in pairs disposed at positions symmetrical with respect to the oscillation axis. A sectional area of each protrusion along a plane perpendicular to the oscillation axis is constant in the oscillation axis direction. A laser beam is projected to a cutting position of protrusions, so as to partly remove the protrusion. The protrusions are cut based on adjusting the cutting position. The sum of the lengths removed from the protrusions by the cutting becomes equal to a predetermined length to thereby adjust an inertia moment of the oscillating member.

Abstract: The present invention provides a stable and excellent electro-acoustic transducer having simple constitution with which a vibration pole does not contact with stator poles by a repulsive force acting between the vibration pole and the stator poles and the vibration pole can be stably positioned in place between the two stator poles. A vibration pole is disposed between two stator poles, and surfaces of the vibration pole and the two stator poles facing to each other have electrostatically same polarity to generate an electrostatic repulsive force as a restorative force acting between the vibration pole and the stator poles, so that the vibration pole is positioned in place and electro-acoustic conversion is performed by the vibration displacement of the vibration pole with respect to the stator poles. Whereby, the vibration pole does not contact substantially with the stator poles and the vibration pole is stably positioned in place.

Abstract: A microphone having: a first bidirectional microphone unit formed by connecting two unidirectional microphone units, each of which has a vibrating section on a front side thereof, back to back; and a second bidirectional microphone unit formed by connecting two unidirectional microphone units, each of which has a vibrating section on a front side thereof, back to back, and a directional axis of the second bidirectional microphone unit is arranged to be shifted by 90 degrees with respect to a directional axis of the first bidirectional microphone unit.

Abstract: A condenser microphone employs a wide band stop filter, having improved resistance to electrostatic discharge. This includes providing a condenser microphone used for a multi-band by comprising a wide band stop filter capable of efficiently blocking a wide band signal including low frequency and radio frequency used in a mobile communication. A condenser microphone includes: an acoustic module for converting sound pressure into an electric signal; an FET for amplifying the electric signal; and a wide band stop filter for blocking a wide band signal including low frequency and radio frequency output from the FET. The filter is realized by resistors and/or capacitors which are connected selectively according to the radio frequency band between the drain and the source of the FET. The range capable of removing EM noise is widened, an excellent filtering effect of noise is obtained, and resistance of electrostatic discharge applied from outside is improved.

Abstract: A condenser microphone having a capsule with a cardioid pattern diaphragm on opposite sides of a back plate wherein each diaphragm is selectively activated via a switch to complete the audio circuit. The microphone employs two different diaphragm materials to produce two different sound reproduction characteristics. A first diaphragm produces a “warm and lush” sound output, while the second diaphragm produces a “bright and airy” sound output. The microphone includes the use of a pair of light emitting diodes located behind the grill indicating which capsule diaphragm is activated. The dual diaphragm arrangement is mounted on a standard microphone body and includes conventional electronics for connection to an associated piece of audio equipment producing phantom power.

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 voltage supply circuit includes a booster outputting a voltage boosted from a power supply voltage and an amplifier operating with a voltage output from the booster as a power supply and supplying a bias voltage to a sensor. An output voltage value of the booster that generates a power supply voltage of the amplifier is set according to a signal for specifying a sensitivity of the sensor.

Abstract: A switch control circuit monitors a signal produced by a MEMS or other capacitor microphone. When a criterion is met, for example when the amplitude of the monitored signal exceeds a threshold or the monitored signal has been clipped or analysis of the monitored signal indicates clipping is imminent or likely, the switch control circuit operates one or more switches so as to selectively connect one or more capacitors to a signal line from the microphone, i.e., so as to connect a selected capacitance to the signal line to attenuate the signal from the microphone and, therefore, avoid clipping. The switches may be MOSFET, MEMS or other types of switches co-located with the microphone in a common semiconductor package. Similarly, the capacitors, a circuit that processes the signals from the microphone and/or the switch control circuit may be co-located with the microphone in a common semiconductor package.

Abstract: To operate from any of phantom power sources of 12 V, 24 V and 48 V and secure a maximum output level according to each of the power sources. A condenser microphone including a microphone unit MU containing a diaphragm and a fixed pole, an FET Q1 of a built-in bias circuit type for operating as an impedance converter of the microphone unit MU and an output transformer TRS connected to a phantom power source with a midpoint of a primary winding of the output transformer TRS connected to a drain of the FET Q1 via a constant current diode D2, and a transistor Q2 of an emitter follower for current amplification connected between a source of the FET Q1 and a secondary winding of the output transformer TRS, wherein a diode D3 is connected between the source of the FET Q1 and a base of the transistor Q2 to have an anode thereof on the source side of the FET Q1 so as to provide forward voltage generated by the diode D3 to the base of the transistor Q2.

Abstract: A microphone system includes a microphone capsule, an audio amplifier and microphone electronics. A phantom power supply provides power to the audio amplifier and the microphone electronics through cable conductors. The microphone system includes a power supply that provides a supply voltage to the microphone electronics, a polarization voltage to the microphone capsule and a supply voltage to the audio amplifier. The power supply includes a constant current generator. The constant current generator operates as a constant current sink for the phantom power supply.

Abstract: The occurrence of noise caused by external electromagnetic waves is prevented and a high voltage is prevented in a microphone case, so that the possibility of an electrical shock is eliminated. A condenser microphone, comprising a microphone case (shield case) 10 including a circuit board 11 having a ground circuit 13 and an electronic circuit 12 for a condenser microphone unit MU, and a 3-pin output connector 20 which is mounted on the microphone case 10 and connected to a microphone cable 30 from an external power unit (for example, a phantom power source), the output connector 20 including a first grounding pin connected to the ground circuit 13 and the microphone case 10, wherein the ground circuit 13 and the microphone case 10 are electrically connected at multiple points via conductive connecting means 40, which can be brought into surface contact, to prevent a ground loop current path caused by a stray capacitance between the ground circuit 13 and the microphone case 10.

Abstract: A low power high dynamic range microphone amplification system is disclosed. The system includes a current sensing amplifier for receiving an input current signal representative of auditory information and for providing an amplifier output signal. The current sensing amplifier includes a DC bias network that includes a cascode filter.