Abstract: The audio reproduction system amplifies and reproduces both a digital audio signal and an analog audio signal. After delta sigma modulation by a ?? modulator, the digital audio signal is pulse width modulated by a first PWM converter and supplied to a selector. The analog audio signal is compared with a PWM carrier signal by a second PWM converter, converted to a PWM signal, and supplied to the selector. A signal selected by the selector is then amplified by a class D amplifier.

Abstract: The present invention provides a vertically or horizontally placeable combinative array speaker. The vertically or horizontally placeable combinative array speaker includes a microprocessor, an orientation sensor coupled to the microprocessor to sense condition changes of the combinative array speaker, a sound field reconstructing unit formed within or outside of the combinative array speaker, wherein the sound field reconstructing unit is coupled to the microprocessor to simulate surround sounds, and array speakers coupled to the sound field reconstructing unit through an amplifier.

Abstract: An amplifier controller for controlling a plurality of amplifiers connected therewith is provided. Each of said amplifiers is provided with one or more audio output channels. The amplifier controller operates in two modes of solo mode and normal mode. When the solo mode is initiated, the amplifier controller instructs all of the amplifiers to turn off output of all audio output channels provided in the amplifiers, and only in the solo mode, according to selection of an output channel for which solo output is to be performed, the amplifier controller instructs the amplifier provided with the selected channel to turn on output of the channel, and instructs each of the amplifiers provided with an audio output channel other than the selected channel to turn off output of the audio output channel.

Abstract: A system and method of improving the efficiency in the power consumption of an audio system. In essence, the technique is to adjust the power delivered from the power supply to the analog section, such as the power amplifier, in response to the volume level indicated by the volume control module and/or in response to the detected characteristic of the input audio signal. Thus, in this manner, the analog section is operated in a manner that is related to the level of the signal it is processing. Additionally, the system and method also relate to a technique of adjusting the dynamic ranges of the digital signal and the analog signal to improve the overall dynamic range of the system without needing to consume additional power.

Abstract: Systems and methods for synchronizing multiple digital audio controller chips, wherein one of the chips is designated as a master and the other chips are designated as slaves. A common line connects all of the chips and is used to transmit synchronization signals from the master to the slaves. Each of the chips listens for an appropriate signal and, when the signal is detected, all of the chips simultaneously begin operation. In one embodiment, the synchronization signal comprises a transition on the shared line to an active state. The transition is repeated at fixed intervals and maintained in the active state for a fixed period in order to enable the chips to determine whether synchronization is being maintained. The signal may be sampled and/or filtered to improve reliability. The chips may be able to drive the shared line active to indicate that synchronization has been lost.

Abstract: A tone alert amplifier includes a pickup coil, a filter unit, a converting unit, a micro-control unit, an amplifier, and a loud speaker unit. The pickup coil senses a magnetic signal to induce an input signal, and the filter unit performs a specific filtering operation upon the input signal to generate a filtered input signal. Next, the converting unit converts the filtered input signal into the digital signal, and the micro-control unit receives the digital signal to generate at least one output signal. Then the amplifier amplifies the output signal to generate an audio signal, and finally, the speaker unit outputs the audio signal.

Abstract: To provide a wireless microphone device that enables a circuit board, which is to be provided with an oscillation circuit, to be decreased in size without deteriorating radiation characteristics. The wireless microphone device is configured to include: a circuit board 5 that is sectioned into circuit areas 11a and 11b and makes the respective circuit areas function as antenna elements of a dipole antenna; an oscillation circuit 21 that is arranged in the circuit area 11b and generates a high frequency signal on the basis of a voice signal from a microphone 2a; a feeding path for feeding the high frequency signal to an electrically conductive layer 11 in the circuit area 11b through a feeding point positioned on the circuit area 11a side distant from the oscillation circuit 21; and a high frequency shield covering at least a part of the feeding path.

Abstract: An audio amplifier having a variably configurable housing, which may be mounted to an interior surface of a motor vehicle. The housing is formed in two complementing housing sections mutually joined by a hinge, tether, or other connector. A power supply is contained in one housing section and an audio output module is contained in the other housing section. The power supply and audio output module may be connected by flexible signal conductors to accommodate pivot of the two housing sections relative to one another. A heat sink comprising cooling fins and communications and power terminals may be disposed on the exterior of the housing sections to enable conventional connection to an associated audio system. The hinge may incorporate a fixing element which releasably holds the two housing sections at a selected degree of pivot.

Abstract: A signal transfer arrangement is provided for conveying a signal from a first location to a second location. The signal transfer arrangement includes an articulated support structure rotatably mounted on a base located on a support surface. The support structure has a mobile collection device for receiving an input signal from at least one input emission device at the first location positioned on the support surface without contact between the collection device and the emission device, and transferring the input signal to the second location.

Abstract: In a full digital amplifier for an audio amplifier or the like, it is possible to suppress the concentration of an electromagnetic noise emission spectrum at a specific frequency. A sampling period variation type digital filter is realized by varying the coefficient of a noise shaping filter for the delta-sigma modulator of the full digital amplifier depending on a sampling period. This allows the variation in the carrier frequency of the pulse width modulation.

Abstract: A sound signal transmitter-receiver includes a differential microphone for receiving sounds respectively at first and second points to convert the receiving sounds into a transmission sound signal; a transmission-reception unit for receiving an incoming signal as a reception sound signal; an addition unit for adding the reception sound signal from the transmission-reception unit and the transmission sound signal to produce an addition signal; and a speaker outputting sound based on the addition signal.

Abstract: A two channel surround sound audio circuit (surround sound circuit) includes a first amplifier, a second amplifier, two polarized input capacitors, and two polarized output capacitors. A first input line is coupled through one polarized input capacitor to a positive terminal of the second amplifier and to a negative terminal of the first amplifier. A second input line is coupled through the other polarized input capacitor to a positive terminal of the first amplifier and to a negative terminal of the second amplifier. The output of the first and second amplifier are connected to the first and second polarized output capacitors, respectively. A second embodiment of the surround sound circuit includes two amplifiers, two inverting amplifiers, and two balancing potentiometers. The output of a single amplifier is balanced with the output of a single inverting amplifier with a single balancing potentiometer.

Abstract: The invention concerns an audio power amplifier apparatus capable of providing at low manufacturing cost extremely low non-linear distortion, even lower than ?120 dB, comprising a main power amplifying section the output of which is series connected to a secondary of a coupling transformer T1, in turn connected to the apparatus output, the apparatus being characterized in that the amplifying section provides an output signal Vma having a negative feed-back loop non-inverting gain, and in that it further comprises a cascade of one or more sections, the inputs of which are connected to the output of the input section and to the output of the amplifying section, and the output of which is constituted of a secondary winding of the transformer T1, the cascade being capable to very accurately extract the error signal Ve with respect to the amplified signal Vi from the signal at the output of the amplifying section and to to provide to its output an exact, but anti-phase, copy thereof in a predetermined very wide fr

Abstract: The present invention provides a headphone amplifier circuit capable of canceling the influence of a parasitic resistance developed thereinside thereby to improve channel separation and increase output amplitude thereof. When audio signals respectively inputted to minus input terminals via resistors are amplified by inverting amplifiers each having a negative feedback circuit including a resistor and thereafter applied to input ends of left and right headphones, and the voltage of a preset potential is applied to each of output terminals of the headphones by an amplifier, a center output terminal of the amplifier and plus input terminals of the inverting amplifiers are connected to one another via resistors, and the plus input terminals of the inverting amplifiers are grounded via resistors respectively.

Abstract: A disclosed embodiment is a programmable integrated circuit such as an audio processor or a base band processor for generating a low noise and programmable microphone bias voltage or current. The programmable integrated circuit generates a programmable reference input, where the reference input is programmably generated from at least one power source, such as a on-chip audio power supply, an on-chip power supply, or an off-chip power supply, for use by a regulator. The regulator in the programmable integrated circuit receives a bias input and the programmable reference input and generates a programmable output for biasing a microphone. The bias input for the regulator can be provided by an off-chip power supply or an on-chip power supply. The reference input provided to the regulator can be appropriately filtered to reduce noise. In one embodiment, the programmable reference input and the programmable output are programmed by first and second potentiometers, respectively.

Abstract: Systems and methods for implementing over-current protection in amplifiers are provided, including systems, methods and devices for specifying a clip level at which to clip an audio signal in response to an over-current condition being detected. In an embodiment, the clip level is reduced while the over-current condition is being detected. Once the over-current condition is no longer detected, the clip level is maintained for a specified period before allowing the clip level to be increased. In an embodiment, the specified period, for which the clip level is maintained before the clip level is allowed to be increased, starts when the over-current condition is no longer detected, and ends when each of N immediately preceding sample(s) of the audio signal are not clipped to the clip level, where N is an integer, and N?1.

Abstract: An audio playback apparatus is disclosed. The audio playback apparatus processes an audio signal and provides at least one output signal to at least one speaker or an earphone connected to a phone-jack. The audio playback apparatus comprises a clock generating module, a processing module, an amplifier module, and a detecting module. The processing module is connected to the clock generating module and processes the audio signal to generate a processed signal according to a clock signal generated by the clock generating module. The amplifier module amplifies the processed signal to generate an output signal. The detecting module detects whether the earphone is plugged in the phone-jack. If the earphone is plugged in the phone-jack, the amplifier module provides the output signal to the earphone. If not, the amplifier module provides the output signal to the speaker.

Abstract: An audio module used for a display device is disclosed. The display device has a display substrate. The audio module has a filter, an amplifier, and at least one output unit. The filter receives and filters an audio signal to generate a filtered signal. The amplifier is coupled to the filter and amplifies the filtered signal to generate an amplified signal. At least one output unit is coupled to the amplifier and plays the amplified signal in a predetermined way.

Abstract: A signal amplifying circuit and associated methods and apparatuses, the circuit comprising: a signal path extending from an input terminal to an output terminal, a gain controller arranged to control the gain applied along the signal path in response to a control signal; an output stage within the signal path for generating the output signal, the output stage having a gain that is substantially independent of its supply voltage, and a variable voltage power supply comprising a charge pump for providing positive and negative output voltages, the charge pump comprising a network of switches that is operable in a number of different states and a controller for operating the switches in a sequence of the states so as to generate positive and negative output voltages together spanning a voltage approximately equal to the input voltage.

Abstract: A loudspeaker system including a plurality of sonic converters fixed in or to the rear of sound passage openings of a carrier plate is disclosed. The carrier plate is configured in the form of a wall plate for interior spaces or outside facades of buildings and the sonic converters are integrated into the carrier plate. The loudspeaker system or loudspeaker wall plate, respectively, permit the realization of an optimum acoustic irradiation of a space without aesthetically annoying loudspeaker boxes.

Abstract: An acoustic processing device, includes an inputting section which receives a first audio signal and a second audio signal, a first input signal amplifying section which amplifies the first audio signal at an amplification factor, a second input signal amplifying section which amplifies the second audio signal at an amplification factor, a first initial delayed amplifying section, a first adding section which adds the first audio signal amplified by the first amplifying portion and the first audio signal amplified by the first input signal amplifying section, a second adding section which adds the first audio signal amplified by the second amplifying portion and the second audio signal amplified by the second input signal amplifying section, a first supplying section which supplies an audio signal output from the first adding section to a first sound emitting section, and a second supplying section which supplies an audio signal output from the second adding section to a second sound emitting section differen

Abstract: The DC magnetization of a transformer core is prevented without increasing the size of an output transformer in a condenser microphone which is operated by a phantom power source, uses a vacuum tube as an impedance converter, and outputs a vacuum tube signal via the output transformer. The condenser microphone includes a condenser microphone capsule MC, a vacuum tube V01 used as an impedance converter, and an output transformer TRS having a primary winding F connected to the plate and screen grid of the vacuum tube V01 and a secondary winding S connected to the phantom power source via an output connector, wherein the primary winding F has a center tap CF and both ends of the secondary winding S are connected to the center tap CF via constant current diodes D04 and D05, respectively.

Abstract: A system and a method are provided for receiving analog and digital audio input via a single audio input connector. The method includes receiving an input signal from a single audio input connector, splitting the received input signal into a first input signal and a second input signal, filtering the first input signal to pass a digital signal, filtering the second input signal to pass an analog signal, digitizing the filtered analog signal, and multiplexing the filtered digital signal and the filtered digitized analog signal.

Abstract: A method and apparatus for identifying running vehicles in an area to be monitored using acoustic signature recognition. The apparatus includes an input sensor for capturing an acoustic waveform produced by a vehicle source, and a processing system. The waveform is digitized and divided into frames. Each frame is filtered into a plurality of gammatone filtered signals. At least one spectral feature vector is computed for each frame. The vectors are integrated across a plurality of frames to create a spectro-temporal representation of the vehicle waveform. In a training mode, values from the spectro-temporal representation are used as inputs to a Nonlinear Hebbian learning function to extract acoustic signatures and synaptic weights. In an active mode, the synaptic weights and acoustic signatures are used as patterns in a supervised associative network to identify whether a vehicle is present in the area to be monitored. In response to a vehicle being present, the class of vehicle is identified.

Abstract: A Wireless Acoustic SPeaker mount, or WASP, is disclosed that serves as both a wireless speaker adapter and a speaker mount. Some embodiments include a separate transmitter that obtains wired acoustic signals from an acoustic source and transmits them wirelessly to the WASP. WASP's can include a digital and/or analog wireless receiver, digital-to-analog converter, amplifier, and/or equalizer or other sound quality adjuster. WASP's can rest on a horizontal surface or be mounted to or embedded within a wall, ceiling, or other structure. Speakers can rest on or attach to a WASP or be mounted inside of a WASP. In various embodiments the horizontal and/or vertical positioning of the speaker is adjustable, WASP's can be used outdoors, WASP's can extend a wireless transmission range by relaying signals to other WASP's, and the transmitter and WASP's can send on/off and other command signals to each other.

Abstract: An electronic device having a unique audio sensing method that senses the event of no audio for a predetermined period of time. The sensed information is used by a microprocessor to bring the device into a low-power mode. The same method may be used to bring a device into active mode from a low-power mode.

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

Abstract: An electronic circuit for adding the effects of reverberation to a high impedance signal produced from an external audio source such as a guitar pickup or a high impedance microphone.

Abstract: The invention provides a switching audio power amplifier with de-noise function, including a first comparator, a second comparator, a logic control unit, a de-noise circuit, and a bridge circuit. The first comparator and the second comparator respectively generate the first PWM signal and the second PWM signal, and then the logic control unit performs logic operation to generate a third PWM signal and a fourth PWM signal. If the pulse width of the third PWM signal (or the fourth PWM signal) is lower than a threshold, the de-noise circuit increases the pulse width of the third PWM signal or the fourth PWM signal and outputs the fifth PWM signal and the sixth PWM signal to drive the bridge circuit. Next, the bridge circuit conducts a driving current alternately flowing to and from a load according to the firth PWM signal and the sixth PWM signal.

Abstract: A speaker device employing a diaphragm structure for providing high quality sound characteristics. In particular, a separate speaker unit is additionally provided so as to improve a resonator characteristic produced at the rear side of an existing speaker. As such, the rear sound arriving at an end of the resonator is dampened by the sound outputted from the additional speaker unit, thereby improving characteristics, such as clearness, total harmonic distortion, etc.

Abstract: An audio signal processing apparatus is provided. The audio signal processing apparatus comprises a clock generator, a processing module, an amplifying module and an output module. The clock generator is used for generating a clock signal. The processing module is coupled to the clock generator for processing the clock signal and generating a processing signal. The amplifying module is coupled to the processing module for amplifying the processing signal and generating an amplifying signal. The output module is coupled to the amplifying module for outputting the amplifying signal.

Abstract: An amplifier is provided using digital potentiometer integrated circuits to control the tone of a vacuum tube preamplifier allowing digital control of the analog signal path of the amplifier. Using digital potentiometer integrated circuits to control the tone of a vacuum tube preamplifier results in an amplifier that preserves the unique tone quality of a vacuum tube amplifier that offers the flexibility, versatility, and user-friendly features of a digitally controlled amplifier, such as the ability to save and recall amplifier settings. The amplifier of the present invention is especially applicable for use with musical instruments such as for example, electric guitars.

Abstract: A controller, either a microprocessor or finite state machine, is used to generate a pulse train whose frequency and duty cycle can be varied to alter the frequency and amplitude of the output of a driven audio transducer. The ability to control both frequency and amplitude allows programmatic synthesis of many audio effects such as steady tones, warbles, beeps, sirens and chimes with no hardware or circuit changes. The transducer can be a piezoelectric bender or a speaker. The output of the controller controls a switch that builds current in an inductor when the switch is on. When the switch is turned off, the energy stored in the inductor is dumped into the audio transducer, either directly or through intermediate capacitor storage. This allows the generation of voltages across the transducer many times the supply voltage.

Abstract: Systems and methods for “shadowing” a target codec to provide additional features that are not available in the target codec. In one embodiment, an audio amplification system includes a High Definition Audio (HDA) bus, and an HDA controller, a conventional HDA codec and a shadow HDA codec coupled to the HDA bus. The conventional codec receives audio data and commands from the HDA controller via the bus and processes them to generate an output audio signal. The shadow codec snoops the audio data and commands on the HDA bus that are targeted to the conventional codec. The shadow codec processes the snooped audio data and commands to generate a second audio output. The shadow codec does not communicate with the HDA controller and is transparent to the controller. The shadow codec does not request enumeration from the HDA controller and does not receive an address from the HDA controller.

Abstract: A vehicle audio system that includes a source of audio signals, which may include both entertainment audio signals and announcement audio signals, speakers for radiating audio signals, and spatial enhancement circuitry comprising circuitry to avoid applying spatial enhancement processing to the announcement audio signals.

Abstract: A stereo headphone includes a first audio element and a second audio element to be positioned against sides of a user's head in which each of the first and second audio elements is configured to transmit audio signals through bone to the auditory system of the user.

Abstract: An audio system includes an audio enabled device, a transmitter and at least one receiver. The audio enabled device has a school and office product and an amplifier integrated with the school and office product. The audio enabled device is configured such that when the amplifier receives an electronic audio signal the amplifier and the school and office product cooperate to provide an audible audio output. The transmitter is connectable to the amplifier and configured to wirelessly transmit the electronic audio signal. Each receiver is connectable to the input port of an amplifier, and each such receiver is configured to receive the electronic audio signal transmitted by the transmitter.

Abstract: Systems and methods for controlling the capabilities of an High Definition Audio (HDA) system, wherein the system determines whether an optional component such as a plug-in card is connected to the system and then configures itself in a baseline configuration if the optional component is not connected or configures itself in a different, alternative configuration if the optional component is connected. In one embodiment, a codec of the system includes a programmable processor configured to read configuration authorization information and also read configuration information from the optional component if it is connected to the system. The processor also controls the configuration of the HDA system and the operation of the codec based on the authorization and configuration information. The system can thereby provide different features and functionality using the same hardware.

Abstract: An audio circuit arranged in a display includes an audio input connector configured to connect to an audio output connector of a computer to receive audio signals therefrom, an audio input circuit receiving the audio signals, an audio amplifier circuit connected to the audio input circuit to amplify the audio signals, an audio output circuit outputting the amplified audio signals, a first output connector connected to the audio output circuit, a volume adjusting circuit, a micro control unit (MCU) of a motherboard of the display connected to the volume adjusting circuit, and a speaker connected to the first output connector. The volume adjusting circuit receives a control signal from the MCU to control the volume adjusting circuit to adjust the audio signals, and the speaker receives the adjusted audio signals.

Abstract: An electrostatic loudspeaker driver includes a class-D amplifier and a demodulator circuit. The class-D amplifier is operated with a PWM signal, creating an amplified digital signal according to an input signal. A low-pass filter in the demodulator circuit filters out the PWM carrier frequency in the digital signal and retrieves an audio signal therefrom. The efficiency is improved significantly and heat sink is no longer needed.

Abstract: An amplification system of the invention can decrease power consumption in a power amplification section if the power amplification section need not be used. The power consumption in the power amplification section can be decreased by shutting off power feed into a voltage amplification stage by a power control section, and the power feed state into a power amplification stage from a power supply section is not changed. Thus, power feed into the voltage amplification stage of the circuit wherein a large current does not flow needs only to be controlled using limiter means also used for a different application, so that the power consumption of the power amplification section can be decreased without the need for enlarging the circuit scale, with saved space, and simply.

Abstract: A headset used as an external louder speaker and a method for adjusting an output of the speaker transducers are disclosed. The headset includes a signal receiver, speaker parts, hinge parts, and amplifiers. The speaker parts change their direction through the hinge parts. The output of speaker transducers is adjusted according to the direction of the speaker parts. When the output of speaker transducers is increased, the speaker parts of the headset are used as an external speaker.

Abstract: A serializer/deserializer interfaces a microprocessor/controller with I/O devices over a flexible hinging cable. The I/O devices have parallel interfaces as does the controller but the serializer/deserializer reduces the number of signal that traverse the flexible hinging cable. LCD displays, cameras, keypads and audio signals handled by the invention.

Abstract: A power supply for limited power sources and an audio amplifier using the power supply comprising power sources to provide an output power signal that can be used by load with a high peak to average power requirement ratio. When such power sources are used to power devices that have a high peak to average power consumption, the average power output of the device is severely limited if the peak power is kept below the power supply limits of the limited power source.

Abstract: A loudspeaker system with three loudspeakers (LF, LR, LB), includes a first and a second amplifier (BF, BR), each of which amplifies a channel of an audio signal. The outputs of the amplifiers (FDA, FIA; RDA, RIA) are in phase opposition, wherein the outputs of the amplifiers (RDA, FIA; RDA, FIA) are each connected to the inputs of the first and second loudspeakers (LF, LR). The outputs of the amplifiers (RDA, FIA; RDA, FIA) are also connected to the inputs of the third loudspeaker (LB). A high-pass filter (HP) and a low-pass filter (TP), which are used to partition the audio signal, are connected in parallel. As the amplifiers, bridge output stages (BF, BR) are provided. The output of the high-pass filter (HPA) is connected to the inputs of the two bridge output stages (BF, BR). An inverter (IF, IR) is provided in each case between the output of the high-pass filter (HPA) and one of the inputs of the bridge output stages (BF, BR).

Abstract: In an audio signal amplifying circuit, a main amplifier and a sub amplifier amplify an audio signal. The sub amplifier is disposed in parallel with the main amplifier and also is set to have a lower driving capability than the main amplifier. A control unit controls the on and off of the main amplifier. The control unit turns the main amplifier off when it is determined that the audio signal is in a mute state. An audio signal amplified by the main amplifier and the sub amplifier passes through a low-pass filter to be converted into an analog signal and is output to a speaker.

Abstract: A circuit (FIGS. 2A-2D) and method of providing an auto-on and/or auto-off capability for an audio device, of a type having an audio plug (14) which mates with the output jack of an audio source. The portable transmitter (10) modulates audio signals from the audio source onto a carrier and transmits them to a receiver. The auto-on and auto-off capability is provided to prolong battery life and degradation of the transmitter circuit and comprises pinching off a FET (Q2) when the circuit is in an “off” state. This occurs when a pre-determined threshold in a capacitor is reached by not discharging that capacitor. The capacitor (C29) is discharged by dropping a comparator input below a pre-determined threshold limit when presented with an audio peak and wherein the drop in value causes the comparator output to go low, causing the capacitor to discharge and causing the FET (Q2) to supply power to the regulator.

Abstract: A headphone driver amplifier operative without an external negative voltage power supply, coupled directly to the headphone speakers without the need for DC coupling capacitors used for preventing DC reaching the headphones. An onboard power supply generates a negative voltage rail which powers the output amplifiers, allowing driver amplifier operation from both positive and negative rails. Since the amplifiers can be biased at ground potential (O volts), no significant DC voltage exists across the speaker load and the need for DC coupling capacitors is eliminated.

Abstract: A multi-mode amplifier with configurable DC-coupled or AC-coupled output is described. In one design, the multi-mode amplifier includes an amplifier and at least one DC level shifting circuit. The amplifier receives and amplifies an input signal and provides an output signal that is suitable for DC coupling to a load in a DC-coupled mode and for AC coupling to the load in an AC-coupled mode. The at least one DC level shifting circuit performs DC level shifting for at least one (e.g., input and/or output) common-mode voltage of the amplifier and is controlled based on whether the amplifier is operating in the DC-coupled or AC-coupled mode. The amplifier operates between VDD and VNEG supplies in the DC-coupled mode and between VDD and VSS supplies in the AC-coupled mode. The amplifier may include at least one gain stage, an internal DC level shifting circuit, and an output stage.

Abstract: A direct digital drive audio system and method system and method are presented. The direct digital drive system and method utilizes a digital signal to directly drive the speakers. In one exemplary implementation, an audio system includes a sample register, an convergence adjustment component, an accumulated error register, a digital driver and a speaker. The sample register is coupled to the convergence adjustment component which is coupled to the accumulated error register and the digital driver which in turn is coupled to the speaker. The sample register holds an audio sample. The convergence adjustment component calculates the error for each sample. The accumulated error register stores an accumulated error. The digital driver determines whether to drive on a positive digital value, drive on a negative digital value or not drive. The speaker creates audio sounds based upon a signal from the digital driver.