Abstract: An audio device incorporates a first acoustic driver having a first direction of maximum acoustic radiation and a second acoustic driver having a second direction of maximum acoustic radiation, where the first and second directions of maximum acoustic radiation are not in parallel, and where the audio device employs the first acoustic driver or the second acoustic driver in acoustically outputting a sound of a predetermined range of frequencies in response to the orientation of the casing of the audio device relative to the direction of the force of gravity.

Abstract: A noise level of an output signal is maintained low. An adjacent interference detecting unit compares a signal level of a wide band signal which is a desired station signal of a relatively wide band and a signal level of a narrow band signal which is a desired station signal of a relatively narrow band, and judges that adjacent interference has occurred when the signal level of the narrow band signal is less than or equal to a predetermined level even though the signal level of the wide band signal is greater than or equal to a predetermined level. A variable amplifier (36) attenuates an L?R signal and forms a monophonic signal when the signal level of the narrow band signal is lower than a predetermined level. With this process, when there is adjacent interference, a signal level of the narrow band signal at which the attenuating unit starts attenuating the L?R signal is changed to a relatively high value.

Abstract: The invention relates to a circuit (100) for use with a loudspeaker (104) having a first differential input terminal (t1) and a second differential input terminal (t2), the circuit (100) comprising: a differential power amplifier (103) having a first differential output terminal (t3) operatively connected to the first differential input terminal (t1) of the loudspeaker (104) and a second differential output terminal (t4) operatively connected to the second differential input terminal (t2) of the loudspeaker (104);—a first resistor (RS1) disposed between the first differential output terminal (t3) of the differential power amplifier (103) and the first differential input terminal (t1) of the loudspeaker (104); a second resistor (RS2) disposed between the second differential output terminal (t4) of the differential power amplifier (103) and the second differential input terminal (t2) of the loudspeaker (104).

Abstract: While level of the inputted analog signal is adjusted according to a set analog gain value and then analog-digital converted and outputted, when an automatic compensation is on and a difference of the analog gain value and a target value is compensated by level adjustment in a digital amplifier, the analog gain value is displayed by a gain knob, and in response to an operation to turn on the automatic compensation, a present value of the analog gain value at that time is displayed as a target gain value by a mark near the analog gain value, and in response to an operation to turn off the automatic compensation, display of the target gain value is erased.

Abstract: An apparatus allowing the recording and storage of data with a programmable timer alarm/alert. This data that can be either retrieved manually or automatically via audio playback or computer link. For certain embodiments, the audio device is configured for mounting on a consumable item. In a further embodiment the audio device may include and collect information regarding the consumer item on which it is mounted. In yet another embodiment the audio device contains a timing device and an alarm function coupled to an actuator that can be set at predetermined intervals.

Abstract: Techniques for controlling one or more audio amplifiers in or associated with a device coupled on a local area network are disclosed. An example playback device includes a processor, an amplifier, a network interface, and a memory. The memory includes a software module that, when executed by the processor, causes the playback device to: operate in a first power mode in which the amplifier consumes a first amount of power while operating in the first power mode, determine that a defined time has passed since receiving, via the network interface, a specified type of data packet; and based on determining that the defined time has passed since receiving the specified type of data packet, transition from operating in the first power mode to operate in a second power mode in which the amplifier consumes a second amount of power, wherein the first amount of power is greater than the second amount of power.

Abstract: An apparatus for providing an audio signal to drive a speaker system includes first and second audio channels. The first audio channel has a first class-D amplifier for receiving an input signal, and a first reconstruction filter for receiving an output from the first class-D amplifier and reconstructing therefrom an output audio signal for driving the speaker system. The second audio channel has a second class-D amplifier for receiving an input audio signal, and a second reconstruction filter for receiving an output from the second class-D amplifier and reconstructing therefrom an output audio signal for driving the speaker system. The first and second reconstruction filters have corresponding first and second planar inductors, with the second planer inductor being magnetically coupled to the first planar inductor.

Abstract: With a hearing aid device, the problem arises of having to match the output power and/or the frequency response of the hearing aid device to the level of hearing impairment of the patient as precisely as possible. In such cases allowance must be made for the noise level, which is a function of the technology used, to be kept as low as possible and for the signal-to-noise level to be as great as possible. A switching arrangement and/or a hearing aid device and method are provided in which the power amplifier is embodied with at least two output stages. The outputs of the individual output stages can be connected in parallel by means of a controllable switching facility. A simple adjustment of the output power and/or frequency response can be achieved in this way by simply connecting a corresponding number of output stages in parallel.

Abstract: The power amplifying apparatus includes a first comparator that compares the first detection signal and the fourth detection signal and outputs a first comparison signal depending on whether or not a difference between the first current and the fourth current is equal to or greater than a first predetermined value. The power amplifying apparatus includes a second comparator that compares the second detection signal and the third detection signal and outputs a second comparison signal depending on whether or not a difference between the second current and the third current is equal to or greater than a second predetermined value.

Abstract: An amplifier includes a differential input with a positive and a negative input and an analog integrator with a differential integrator input and a differential integrator output. The analog integrator further includes an operational amplifier with a positive operational amplifier input, a negative operational amplifier input, a positive operational amplifier output and a negative operational amplifier output. The differential integrator input is coupled to the differential input. A ternary pulse width modulator includes two modulator inputs coupled to the differential integrator output and two modulator outputs. A first feedback path is coupled between a first of the two modulator outputs and the positive operational amplifier input and a second feedback path is coupled between a second of the two modulator outputs and the negative operational amplifier input. A first divert capacitor is coupled between the positive operational amplifier input and a constant voltage reference.

Abstract: An end-of-branch (EOB) module system for an audio signal distribution system having a wired trunk and a plurality of wired branches extending communicatively from such trunk, the EOB module system including: a plurality of EOB modules including one EOB module electronically coupled at each distal end of each branch and trunk of the audio signal distribution system, where each EOB module of the plurality of EOB modules has a unique address together forming a plurality of unique addresses; a test system able to send a test carrier signal encoded with any one unique address of the plurality of unique addresses at a time onto the trunk; and a switch within each EOB module, responsive to its unique address to place an end-of-line (EOL) load on its respective branch or trunk, and where power for operation of each EOB module is provided by rectification of the test signal.

Abstract: A noise control circuit includes a filter, a rectifier and a switch. The filter receives audio signals and obtains a noise signal portion of the received audio signals. The rectifier converts the noise signal portion to a current signal. The switch controls output of the audio signals according to an intensity of the current signals.

Abstract: A microphone amplifier comprises an input terminal (E100) for applying an input signal (IN), an output terminal (A100a) for outputting an output signal (OUT), and an additional output terminal (A100b) for outputting an additional output signal (VBIAS). The microphone amplifier also contains an amplifying circuit (10) for generating the output signal (OUT) by amplifying the input signal (IN), wherein the amplifying circuit (10) is connected between the input terminal (E100) and the output terminal (A100a), and a voltage generator (30) for generating the additional output signal (VBIAS). A supply voltage terminal (V30) of the voltage generator (30) is connected to the output terminal (A100a) of the microphone amplifier. Since the amplifying circuit (10) makes available a supply voltage (V) for the voltage generator (30), the microphone amplifier can be operated without a separate supply voltage terminal.

Abstract: An apparatus is provided that includes first and second ICs configured to communicate using a plurality of differential signal lines. The apparatus includes a common mode suppression circuit having a plurality of common mode voltage adjustment circuits, each configured to provide a low impedance path for common mode signals and a high impedance path for differential AC signaling, thereby suppressing the effect of common mode transients between the voltage domains. The plurality of common mode voltage adjustment circuits each have components that are impedance matched up to an impedance-tolerance specification. The common mode suppression circuit also includes an AC coupling circuit configured to be less dependent on impedance mismatch, beyond the impedance-tolerance specification, by cross coupling the impedance differentials from each of the differential signal lines through the AC coupling circuit and to one of the common mode voltage adjustment circuits.

Abstract: An electronic amplifier for driving a capacitive load may include first and second differential input terminals to receive an input signal, and first and second differential output terminals to provide a differential output signal. The amplifier may further include a first operational device having first and second differential inputs connected to the first and second differential input terminals, respectively, and an output connected to the first differential output terminal, and a second operational device having first and second differential inputs connected to the first and second differential input terminals, respectively, and an output connected to the second differential output terminal. The first and second operational devices may be operatively configured so that both the first and the second output terminals are at a same reference potential during periods in which a magnitude of differential output signal amplitude decreases.

Abstract: A controller for controlling an amplification gain of an amplifier for amplifying a high dynamic range signal for an analog to digital converter comprises an input interface adapted to receive a representation of the high dynamic range signal and a signal compressor adapted to provide a low amplitude representation of the high dynamic range signal, the low amplitude representation having a lower signal amplitude than the high dynamic range signal. A comparator is adapted to compare the signal amplitude of the low amplitude representation with a predetermined threshold and an output interface is adapted to provide a control signal to the amplifier, the control signal being adapted to control the amplification gain of the amplifier such that the amplification gain is lowered when the signal amplitude of the low amplitude representation exceeds the predetermined threshold.

Abstract: A multichannel input device with automatic number-of-channels detection includes an automatic channel and bit depth detector, a digital audio interface (DAI), an analog device, and a digital-to-analog converter (DAC) coupling the DAI to the analog device. The automatic number-of-channels and bit depth detector has a BCLK input, a LRCLK input, a number of channels NCHAN output, and a bit depth B output. The DAI has a data DIN input, the BCLK input, the LRCLK input, an NCHAN input and a B input and has an output including data associated with an assigned channel.

Abstract: An audio amplifier receiving a digital input audio signal and generating an output audio signal for driving a speaker includes a digital input class D amplifier configured to receive the digital input audio signal and to generate the output audio signal. The digital input class D amplifier includes a first modulator configured to receive the digital input audio signal and to generate a quasi-digital signal in n-bit, and a class D modulator configured to receive the n-bit quasi-digital signal and to generate the output audio signal, the class D modulator implementing an analog feedback loop. In some embodiments, the class D modulator is implemented using a PWM modulator. In other embodiments, the PWM modulator incorporates enhanced features to improve the output noise characteristics.

Abstract: An amplifier has a dual bridge design with two bridge amplifiers. A mode switch enables them to be configured in a series amplification mode. The switching of the mode switch is dynamic and enables re-use of signal current thereby improving overall system efficiency. A delay to the mode switch closure is provided in the event of clipping of one of the amplifier outputs. This prevents large cross currents from flowing.

Abstract: A home use sound reproduction system for Hi-fi, with digital signal transfer from a playback unit via a control unit to one or more active loudspeakers, each including or arranged beside an amplifier unit. The control unit is arranged to control sound parameters and send both a digital sound information signal and a power signal for powering the amplifier units, and to superimpose the single ended or differential digital signal together with the power signal on at least one common lead in a cable.

Abstract: Techniques for providing multiple power supplies in electronic devices are disclosed. According to one aspect of the present invention, an appropriate power supply is provided only to accommodate a volume setting. In other words, there are at least two power supplies, one with a low voltage and the other with a high voltage. The high voltage power supply is only applied when there is a need to accommodate a volume setting. Thus the power consumption of the amplifiers is well controlled. As a result, the designs of the device and heat dissipation therein can be simplified and lowered in cost.

Abstract: In an audio processing apparatus of the present invention, one or two audio signals selected from a surround rear left audio signal, a left outer audio signal and a left upper audio signal is (are) amplified to be outputted from a speaker terminal(s) corresponding to this (these) channel(s) without necessity to provide amplifiers of all channels. When the surround rear left audio signal is included, a switch S13a is turned ON to supply the surround rear left audio signal amplified by an amplifier 12a to a SP terminal 14a. When the left outer audio signal is included, a switch 13b is turned ON to supply the left outer audio signal amplified by the amplifier 12a to a SP terminal 14b, or a switch 13c is turned ON to supply the left outer audio signal amplified by an amplifier 12b to the SP terminal 14b. When the left upper audio signal is included, a switch 13d is turned ON to supply the left upper audio signal amplified by the amplifier 12b to a SP terminal 14c.

Abstract: An audio output circuit includes an on-chip left channel amplifier module, an on-chip center channel amplifier module, and an on-chip right channel amplifier module. A left channel IC pin is operably coupled to an output of the on-chip left channel amplifier module. A right channel IC pin is operably coupled to an output of the on-chip right channel amplifier module. A center channel IC pin is operably coupled to an output of the on-chip center channel amplifier module. A center channel feedback IC pin is operably coupled to an input of the on-chip center channel amplifier module to provide a feedback loop. A left jack connection is operably coupled to the left channel IC pin. A right jack connection is operably coupled to the right channel IC pin. A jack return connection coupled to the center feedback IC pin. An inductor has a first node coupled to the jack return connection and a second node coupled to the center channel IC pin.

Abstract: A speaker and stereo system for a watercraft are disclosed. The stereo system includes an amplifier sized and adapted to fit within an internal compartment of the watercraft, and having a power input that connects to a battery of the watercraft for power. The amplifier further includes a control input, a signal amplifier, at least two audio outputs connected to the signal amplifier, and an audio input for receiving a digital audio signal from a digital music player to be amplified by the signal amplifier. The speaker for use with the stereo system includes a speaker housing having a flattened bottom, an opening at a front face, and an enclosure that tapers and extends to a substantially pointed terminal end.

Abstract: Disclosed is a class D amplifier comprising a modulation stage having a first input for receiving an input signal and an output for producing a modulated version of the input signal; a plurality of power stages, each power stage being responsive to said modulation stage and comprising a first switch and a second switch coupled in series between a first voltage source and a second voltage source, each power stage comprising an output node between the first switch and the second switch; and a power stage control circuit for measuring the input signal level and enabling a selected number of the power stages as a function of the measured input signal level. A method for controlling such a class D amplifier is also disclosed.

Abstract: An audio splitter receiving an incoming electrical signal defining an audio signal. The audio splitter receives an incoming signal and creates at least two identical channels having the same incoming signal. Each channel has a manually controlled amplifier. By manipulating the manually controlled amplifier, the operator is able to selectively magnifying the electrical signal within the channel. This allows the operator to adjust the intensity or “loudness” of the signal being generated as output within the channel.

Abstract: The invention is provided with a first class-D amplifying unit for amplifying an inputted audio signal and supplying the amplified signal to a positive side of an audio output terminal, a second class-D amplifying unit for amplifying an inputted audio signal inverted in an inverting unit and supplying the amplified signal to a negative side of the audio output terminal, wherein, in a first mode, the first and second class-D amplifying units are activated and outputs of the first and second class-D amplifying units are kept equal to or less than a first current value, and wherein, in a second mode, the first class-D amplifying unit is activated, the second class-D amplifying unit is inactivated, the negative side of the audio output terminal is grounded, and output of the first class-D amplifying unit is kept equal to or less than a second current value larger than the first current value.

Abstract: A signal processing method for enhancing the dynamic range of a signal is disclosed. The method comprises: a) forming an attenuated signal from an input signal; b) filtering each of the input and the attenuated signals such that the sum of their bandwidths is less than or equal to the bandwidth of a transmission channel; c) modulating a first one of the filtered input signal and the filtered attenuated signal, whereby the filtered input signal and the filtered attenuated signal occupy respective non-overlapping frequency ranges within the bandwidth of the transmission channel; and d) combining the modulated signal with the second one of the filtered input signal and the filtered attenuated signal to form a composite output signal.

Abstract: The present invention relates to an audio amplification circuit comprising a first preamplifier for receipt of an audio input signal and a second preamplifier comprising a first differential input for receipt of an attenuated audio input signal. The attenuated audio input signal is generated by an attenuator coupled to the audio input signal. A non-linear element is coupled to a first input of the first preamplifier thereby distorting the audio input signal at the first input at large signal levels. A distortion compensation network is adapted to supply a distortion compensation signal from the first input of the first preamplifier to a second differential input of the second preamplifier such that distortion in the output signal of the second preamplifier is cancelled or attenuated. The invention further relates to a corresponding method of compensating an audio amplification circuit for distortion induced by a non-linear element.

Abstract: An original loudness level of an audio signal is maintained for a mobile device while maintaining sound quality as good as possible and protecting the loudspeaker used in the mobile device. The loudness of an audio (e.g., speech) signal may be maximized while controlling the excursion of the diaphragm of the loudspeaker (in a mobile device) to stay within the allowed range. In an implementation, the peak excursion is predicted (e.g., estimated) using the input signal and an excursion transfer function. The signal may then be modified to limit the excursion and to maximize loudness.

Abstract: An audio amplifier is to transition between a power-down mode and an active mode, based on assertion and deassertion of a power down signal. A power down control module is to selectively assert and deassert the power down signal to the audio amplifier. The power down control module may identify at least one of a digital detection signal and an analog detection signal. The digital detection signal indicates the availability of a digital audio signal to be amplified, and the analog detection signal indicates the availability of an analog audio signal to be amplified.

Abstract: In at least one embodiment, an audio amplifier apparatus including a connector is provided. The apparatus includes a connector having a plurality of first openings. Each first opening being arranged to receive a first fastening mechanism to couple the connector to a first side of an audio amplifier. The connector further includes a plurality of second openings to enable access to a plurality of second fastening mechanisms which provide an electrical output from the audio amplifier. The connector further includes a plurality of terminal channels being angularly offset from the plurality of second openings. Each terminal channel being configured to receive a connection terminal to connect to a corresponding second fastening mechanism to electrically couple the connection terminal to the audio amplifier.

Abstract: An output-stage circuit is disclosed. The output-stage circuit includes high-side output driver, first body selector, low-side output driver, second body selector and inductance. When output current is larger than current threshold value so as to make the low-side output driver generate overcurrent, the low-side output driver controlled by second control signal is disabled, and the high-side output driver controlled by first control signal is enabled so as to create first current channel. When output current is larger than current threshold value so as to make the high-side output driver generate overcurrent, the high-side output driver controlled by the first control signal is disabled, and the low-side output driver controlled by the second control signal is enabled so as to create second current channel to avoid current flowing through low-side output driver's body, and thus reduce the output current and voltage spiking of the output voltage.

Abstract: An asymmetric modulation scheme may be used to drive two output nodes coupled to a load. The asymmetric modulation scheme may be one-sided such that the switching rate of a first output node is lower than the switching rate of a second output node. The first output node may be switched only to change a direction of current between the first output node and the second output node, while the second output node is switched to convey the information of an input signal. The asymmetric modulation scheme may be used to drive a speaker to reduce noise at the first output node to improve accuracy of current monitoring through the speaker by a current monitor coupled at the first output node.

Abstract: The present technology relates generally to a closed-loop power stage and audio amplifier circuits comprising the same. The present technology further provides a method for controlling an amplifier circuit. The closed-loop power stage is configured to receive a PWM input signal having a first frequency and a first duty cycle, a power supply voltage, and a bias signal related to the power supply voltage, and to output a square-wave signal having a second frequency and a second duty cycle. The closed-loop power stage comprises a feedback loop which is configured to regulate the second duty cycle of the square-wave signal in response to a variation in the power supply voltage. The audio amplifier circuit comprising the closed-loop power stage may have a stable output voltage and thus have good power supply rejection performance.

Abstract: A low powered guitar amplifier is disclosed that can generate the overdriven tones of much larger class ab push-pull amplifiers and attenuate them further with an attenuator that leaves the tone and feel intact. This amplifier uses a cathode follower output stage FIG. 1. 12 to generate these powerful tones and a non intrusive attenuation circuit FIG. 2. 46 that benefits from the unique properties of the cathode follower output stage regardless of configuration or topology. These benefits are the ability to drive any impedance above the selected output impedance and no need to maintain a constant impedance therefore utilizing a simple series attenuation circuit whereby substantially all the current is seen in the speaker load and therefore the output stage interaction between the amp and musician is left intact.

Abstract: A low-noise pre-amplifier with an active load element is integrated into a microphone. The microphone has an acoustic sensor coupled to the intrinsic pre-amplifier. A controllable current source is coupled to the intrinsic pre-amplifier and supplies a pre-amplifier bias current. A current source controller is coupled to the current source and controls the amplitude of the pre-amplifier bias current to maintain the intrinsic pre-amplifier at a bias point at which the intrinsic pre-amplifier amplifies microphone signals produced by the acoustic sensor. The intrinsic pre-amplifier may be actively regulated at the pre-determined bias point using negative feedback. Alternatively, the intrinsic pre-amplifier may be set to the pre-determined bias point by sweeping the pre-amplifier bias current for the intrinsic pre-amplifier over a range of currents.

Abstract: Technology for grouping, consolidating, and pairing individual playback devices with network capability (players) to stimulate a multi-channel listening environment is disclosed. Particularly, the embodiments described herein enable two or more playback devices to be paired, such that multi-channel audio is achieved. Such embodiments may be used to produce stereo and multi-channel audio environments for television and movies.

Abstract: Techniques for controlling one or more audio amplifiers in or associated with a device coupled on a local area network are disclosed. The device receives at least one selected source from other devices also coupled on the network According to one aspect of the techniques, an automatic shutdown control module is provided in the device to power down the audio amplifiers when there is no audio data flow coming to the device or power up the audio amplifiers when there is audio data flow coming to the device. In one embodiment, the procedure to power down or power up the amplifiers is in accordance with a hysteresis, wherein the hysteresis, being lagging of an effect behind its cause, protects the amplifiers and makes the powering-down or powering-up procedure unnoticeable to a user.

Abstract: A sound volume control circuit includes: a first operational amplifier; a variable resistor circuit connected between an output and an inverting input of the first operational amplifier and having a plurality of resistance values; an R-2R ladder circuit connected between a voltage source of an input voltage; and a control circuit controlling the variable resistor circuit and the R-2R ladder circuit; wherein when changing a resistance value of the variable resistor circuit from a first resistance value to a second resistance value, so as to change the output voltage in a step size where a difference between the output voltage corresponding to the first resistance value and the output voltage corresponding to the second resistance value is further segmented, the control circuit changes the magnitude of the electric current flowing to the variable resistor circuit by use of the R-2R ladder circuit.

Abstract: An apparatus and method for outputting a sound with Hearing Aids Compatibility (HAC) in a mobile terminal. The sound output apparatus includes a modem chip including a first amplifier amplifying and transferring an electric signal to a switch, a switch that selectively connects an output line of the first amplifier to a receiver or a second amplifier, a second amplifier connected with the receiver and the switch and that amplifies and transfers an electric signal received from the first amplifier to the receiver when the switch connects the output line of the first amplifier to the second amplifier, and a receiver connected with the switch and the second amplifier and that converts and outputs an electric signal received from the first amplifier or the second amplifier into a sound. This allows for the stable transfer of a sound to hearing handicapped persons with HAC without distortion of the sound quality.

Abstract: Embodiments consistent with the present disclosure provide a multifunctional LED device and a multifunctional speaker system. The multifunctional LED device includes a power supply unit configured to supply power; a control unit configured to process audio signals and control signals; a speaker configured to play audio signals, an audio power amplifier configured to drive the speaker, a wireless transceiver configured to receive and send data, and an LED lighting unit. Further, the wireless transceiver may communicate with both remote smart terminals and other multifunctional LED devices. The multifunctional speaker system may include several multifunctional LED devices and a smart terminal. The smart terminal may communicate with all the multifunctional LED devices. The multifunctional LED devices may communicate with each other. Two of the multifunctional LED devices may form a 2.0-channel speaker system. Other speaker systems such as 2.1-channel, 5.1-channel, 7.1-channel, speaker systems etc.

Abstract: A method and an amplifier for amplifying audio signals include a signal processor for processing incoming audio samples in preparation for amplification by an electronic amplifier circuit. A voltage is received from a power supply. Before the signal processor completes processing the incoming audio samples, an input level is estimated based on the incoming audio samples. In response to a comparison between the estimated input level and a threshold value, it is determined whether to boost the voltage received from the power supply. After the signal processor completes processing the incoming audio samples, an output level is estimated based on the processed audio samples. A determination is made, in response to the estimated output level, whether to adjust the threshold value used to determine whether to boost the voltage received from the power supply.

Abstract: A method and an amplifier for amplifying audio signals receive and process an incoming audio sample in preparation for amplification by an electronic amplifier circuit. A boost supply circuit receives a voltage from a power supply. A processor system determines whether amplification of the incoming audio sample warrants more voltage than the voltage received from the power supply. Before completing the processing of the incoming audio sample, the processor system sends a signal to the boost supply circuit to boost the voltage received from the power supply and to supply the boosted voltage to the electronic amplifier circuit if the incoming audio sample warrants more voltage than the voltage received from the power supply. Otherwise, the boost supply circuit passes the voltage received from the power supply to the electronic amplifier circuit.

Abstract: Methods and system are described for cancelling interference in a microphone system. A positive bias voltage is applied to a first microphone diaphragm and a negative bias voltage is applied to a second microphone diaphragm. The diaphragms are configured to exhibit substantially the same mechanical deflection in response to acoustic pressures received by the microphone system. A differential output signal is produced by combining a positively-biased output signal from the first microphone diaphragm and a negatively-biased output signal from the second microphone diaphragm. This combining cancels common-mode interferences that are exhibited in both the positively-biased output signal and the negatively-biased output signal.

Abstract: A portable electronic device having a speaker module is provided. The speaker module includes: a speaker unit; a back chamber; a channel coupled between the speaker unit and the back chamber; and a porous material filled inside at least a portion of the front chamber, the back chamber, and/or the channel, for improving and extending bass performance and relieving a channel effect caused by the channel. Moreover, the portable electronic device is advantageously able to compensate a resonance degradation caused by the porous material.

Abstract: A microphone structure has a lid forming an interior chamber. The lid includes a permanent magnet for forming a permanent magnetic field. The microphone structure includes an aperture for permitting acoustic access to the interior of the chamber and thus, the MEMS microphone. The MEMS microphone structure includes a substrate mechanically coupled to an electrically conductive diaphragm. The electrically conductive diaphragm has a first side defining a plane and the diaphragm moves through a range of motion perpendicular the plane of the first side. The permanent magnetic field is perpendicular to the direction of motion of the diaphragm and linear within the range of motion, such that a current will be generated and sensed by sensors within an electric circuit loop that includes the diaphragm.

Abstract: An audio amplification circuit may include an input terminal for receipt of an input signal from a transducer. A signal processor may be coupled to the input terminal for receipt and processing of the input signal to generate a processed digital audio signal in accordance with a programmable configuration setting of the signal processor. A serial data transmission interface is configured for receipt of the processed digital audio signal and supply of a corresponding digital audio stream at an output terminal of the integrated audio amplification circuit. A serial data receipt interface may be coupled to an externally accessible configuration terminal of the integrated audio amplification circuit and a controller is configured to adjust one of the programmable configuration setting of the signal processor and a format of a digital audio stream in accordance with first configuration data received through the serial data receipt interface.

Abstract: An operation-mode conversion apparatus for an image display compound device includes a power-state detector which detects a power state of the compound device, an operation-mode determination unit which determines a present operation mode of the compound device, and an operation-mode controller which converts the operation mode of the compound device based on the power state, the present operation mode, and whether one of an optical storage medium and a movable memory is detected by the compound device, in response to a user input signal, regardless of the preset operation mode.

Abstract: An apparatus comprises an integrated circuit (IC) and a resistor external to the IC. The IC includes a current output digital-to-analog converter (IDAC) circuit configured to provide an adjustable specified current to a resistor external to the apparatus, a voltage sensing circuit configured to sense the voltage of the external resistor, and an automatic gain control (AGC) circuit configured to receive threshold information using the adjustable specified current.