Abstract: A multi-channel audio playback apparatus including a channel interface, a first switching amplifier and a second switching amplifier is provided. The channel interface is used to receive multi-channel digital data and generate first channel digital data and second channel digital data. The first switching amplifier is used to convert the first channel digital data into a first pulse width modulation (PWM) signal according to a first reference signal with a first frequency. The second switching amplifier is used to convert the second channel digital data into a second PWM signal according to a second reference signal with a second frequency. The second frequency is different from the first frequency.

Abstract: A digital microphone is provided, comprising a transducer for converting sound pressure into an analog electrical signal, an analog-to-digital converter for converting the analog electrical signal into a digital signal according to a clock signal, and a clock buffer circuit coupled between the analog-to-digital converter and a clock source for deducting a high frequency component from the clock signal received from the clock source.

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.

Abstract: A microphone array comprises a circuit board, a first microphone, and a second microphone. The circuit board comprises a first layer, a third layer, and a second layer sandwiched between the first and third layers. The first layer comprises a first shielding part with a fixed electric potential. The third layer comprises a second shielding part with the fixed electric potential. The second layer comprises an electrically conductive part running between the first and second shielding parts. The first microphone is attached to the first layer of the circuit board. The second microphone is attached to the first layer of the circuit board and electrically connected to the first microphone through the electrically conductive part of the second layer of the circuit board.

Abstract: An MEMS microphone package includes a circuit board and an MEMS microphone chip. The MEMS microphone chip, mounted on the circuit board, includes a substrate, an MEMS transducer formed on the substrate, and a readout circuit also formed on the substrate. The MEMS transducer generates a sound signal according to sound pressure variations. The readout circuit reads the sound signal from the MEMS transducer.

Abstract: A switching audio amplifier adapted in a digital speaking device for driving a speaker is provided. An audio amplification method implemented for the switching audio amplifier is also provided. In the switching audio amplifier, a comparison stage compares an audio input signal with a saw-tooth signal to generate a Pulse Width Modulation (PWM) signal. A driver stage buffers the PWM signal to drive the speaker. A detector detects amplitude of the input signal to generate a control signal, and a saw-tooth generator adjusts a transition rate of the saw-tooth signal based on the control signal.

Abstract: A microphone module. The module comprises a carrier having a first side and an opposing second side and comprising a through hole. A microphone is disposed on the first side of the carrier and corresponding to the through hole. A processing chip is disposed on the first side of the carrier and coupled to the microphone. An encapsulant is disposed on the first side of the carrier to encapsulate the microphone and the processing chip.

Abstract: An array microphone system of compensating phase drift of input signals and a method thereof. The microphone system comprises a speaker, first and second microphones, a delay estimator, and a memory. The speaker outputs an acoustic signal. The first and second microphones, spaced by a predetermined distance, receive the acoustic signal to generate first and second input signals. The delay estimator, coupled to the first and second microphones, computes a time difference between the first and second input signals. The memory, coupled to the delay estimator, stores the time difference.

Abstract: A micro-electro-mechanical-system microphone package includes a substrate, a micro-electro-mechanical-system microphone chip mounted on the substrate, and a cover attached to the substrate to cover the micro-electro-mechanical-system microphone chip. The cover is provided with a sound inlet through which the micro-electro-mechanical-system microphone receives external sound. The micro-electro-mechanical-system microphone chip includes a conductive base connected to a constant voltage, a shielding layer supported by the conductive base and connected to the constant voltage, a diaphragm disposed between the conductive base and the shielding layer, and a back plate also disposed between the conductive base and the shielding layer.

Abstract: An electronic device includes a housing, a plurality of microphones, and a plurality of guide tubes. The plurality of microphones are disposed in the housing. The plurality of guide tubes extend from the housing toward the plurality of microphones, whereby the plurality of microphones in the housing are capable of receiving external sound via the guide tubes.

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: 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: 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 audio codec is provided, comprising an analog to digital converter (ADC) operable to receive an analog input signal for producing a first digital signal, and a first decimator down samples the first digital signal to generate a first intermediate signal. A second decimator receives a second digital signal from a digital microphone and down sample the second digital signal to generate a second intermediate signal. A multiplexer selects either the first intermediate signal or the second intermediate signal as a selected signal based on a control signal. A third decimator down samples the selected signal to generate a down sampled signal. A data formatter produces a digital output signal based on the down sampled signal.

Abstract: An electronic device includes a display, a plurality of chambers, and a microphone array. The display includes a front cover and a rear cover affixed to the front cover. The plurality of chambers is formed on the rear cover. The microphone array includes a plurality of microphones disposed in the chambers.

Abstract: A microphone module includes a cabinet, a sensor, an integrated circuit chip, a first substrate, and a second substrate. The first substrate carries the integrated circuit chip and includes a first top surface, a first bottom surface, and a first shielding part with a fixed electric potential extending from the first top surface to the first bottom surface. The second substrate includes a second top surface contacting the first bottom surface, a second bottom surface, and a second shielding part with the fixed electric potential on the second bottom surface, wherein the second shielding part is arranged in such a way that no electromagnetic waves can pass between the first shielding part and the second shielding part.

Abstract: The invention provides a method for analog-to-digital conversion in a microphone circuit. First, a first gain is determined. A first analog signal is then amplified according to the first gain to obtain a second analog signal. The second analog signal is then converted from analog to digital to obtain a first digital signal. A second gain is then determined according to the first gain so that a product of the first gain and the second gain is kept constant. The first digital signal is then amplified according to the second gain to obtain a second digital signal.

Abstract: An audio processing method used in a microphone is provided. Firstly, a sound signal is received. Next, the sound signal is transduced to a first voltage signal. The first voltage signal is interfered with by a second voltage signal resulting from electromagnetic wave penetrating into the microphone. Next, the second voltage signal is filtered out from the interfered first voltage signal. Finally, the filtered first voltage signal is amplified.

Abstract: The invention provides a microphone circuit. In one embodiment, the microphone circuit comprises a microphone, a self-biased amplifier with a finite gain, and a feedback capacitor. The microphone coupled between a ground and a first node generates a first voltage at the first node according to sound pressure. The self-biased amplifier has a positive input terminal coupled to the ground and a negative input terminal coupled to the first node and amplifies the first voltage according to the finite gain to generate a second voltage at a second node. The feedback capacitor coupled between the first node and the second node feeds back the second voltage to the first node. The second voltage is then output to a following module subsequent to the microphone circuit.

Abstract: An electronic device includes a front cover, a circuit board, a plurality of flexible boots, a plurality of microphones, and an abutting mechanism. The front cover includes a plurality of wall portions, a plurality of storage spaces encircled by the wall portions, and a plurality of acoustic openings connecting to the storage spaces. The flexible boots are disposed in the storage spaces. The microphones are mounted on the circuit board and disposed in the boots. The abutting mechanism pushes the circuit board toward the front cover to squeeze the flexible boot.