Class / Patent application number | Description | Number of patent applications / Date published |
330010000 | MODULATOR-DEMODULATOR-TYPE AMPLIFIER | 72 |
20080204132 | Class-D Amplifier - The present invention relates to a class-D amplifier having a pre-processing unit ( | 08-28-2008 |
20080218258 | DIGITAL ISOLATOR - A signal isolator comprises an isolation barrier, a transmitter, a differentiator, and a recovery circuit. The transmitter is coupled to a first side of the isolation barrier and is configured to receive and convert an information signal to a differential signal that encodes information in the information signal in a single transition edge. The differentiator is coupled to a second side that is isolated from the first side of the isolation harrier and differentiates the differential signal. The recovery circuit is coupled to the differentiator and operates to recover an output information signal based on the information in the single transition edge. | 09-11-2008 |
20080224769 | POWER SUPPLY PROVIDING ULTRAFAST MODULATION OF OUTPUT VOLTAGE - A circuit for use with a power amplifier that amplifies an input signal. The circuit may comprise an amplitude correction circuit and an open-loop switching regulator. The amplitude correction circuit may be configured to generate a corrected envelope signal from an input envelope signal that represents an envelope of the input signal. The open-loop switching regulator may be connected to the amplitude correction circuit and may be for powering the power amplifier based on the corrected envelope signal. According to various embodiments, the corrected envelope signal generated by the amplitude correction circuit is a function of the input envelope signal and an error voltage of the open-loop switching regulator. | 09-18-2008 |
20080238540 | POWER AMPLIFIER WITH NOISE SHAPING - A power amplifier with noise shaping is disclosed. The power amplifier with noise shaping is able to minimize the noise interference a regular power amplifier encounters. The power amplifier includes a differential-mode integrator, a driving unit, and a low pass filter and integration unit. The differential-mode integrator receives a differential-mode input signal and a differential-mode feedback signal and performs integration operations to output a differential-mode intermediate signal. The driving unit outputs a differential-mode output signal and drives a load according to the differential-mode intermediate signal. The low pass filter and integration unit performs a filtering operation on the differential-mode output signal and integration operations to output the differential-mode feedback signal to the differential-mode integrator. | 10-02-2008 |
20080278230 | Systems and Methods for Correcting Errors Resulting from Component Mismatch in a Feedback Path - Systems and methods for minimizing performance degradation due to component mismatch in the feedback path of a digital PWM amplifier feedback loop. One embodiment comprises a digital pulse width modulated (PWM) amplifier with feedback. The amplification subsystem receives a digital audio signal and produces an analog output signal. The feedback loop produces a feedback signal based on the filtered analog output signal and modifies the digital audio signal based on the feedback signal. The feedback loop includes a filter configured to filter the analog output signal and correction circuitry configured to correct component mismatch errors introduced by the filter. In one embodiment, the correction circuitry receives a measurement of a power supply voltage, multiplies the measured voltage by a gain and adds the scaled measurement to the feedback signal to correct for the component mismatch errors. | 11-13-2008 |
20080284508 | OUTPUT CIRCUITS WITH CLASS D AMPLIFIER - Output circuits using pulse width modulation (PWM) and/or pulse density modulation (PDM) are described. In one aspect, a PWM output circuit includes a PWM modulator that operates based on a square wave signal instead of a sawtooth or triangular wave signal. In another aspect, a PDM output circuit includes a PDM modulator that uses variable reference voltages to reduce variations in switching frequency. In yet another aspect, a dual-mode output circuit supports both PWM and PDM and includes a pulse modulator and a class D amplifier. The pulse modulator performs PWM on an input signal if a PWM mode is selected and performs PDM on the input signal if a PDM mode is selected. The class D amplifier receives a driver signal from the pulse modulator and generates an output signal. | 11-20-2008 |
20080297244 | PWM Loop Filter with Minimum Aliasing Error - One embodiment of an apparatus for filtering an electrical signal includes a loop filter with an input and an output that applies a transfer function to a signal at the input. The transfer function has substantially no real part. The loop filter has a dominant pole placed substantially at or above an upper frequency in the frequency range of interest for the loop filter. | 12-04-2008 |
20080315945 | Arrangement for Amplifying a Pwm Input Signal - A pulse-width modulation (PWM) amplifier comprises a feedback loop for reshaping the pulses of the PWM input signal to correct timing and amplitude errors in the class D output stage of the amplifier by means of an error correction signal. In such an amplifier the feedback loop gives a substantial amount of base-band noise when the pulse-period of the PWM input signal is not constant, which is especially the case when the PWM signal originates from a noise shaper. The invention reduces this noise by modifying the reshaping gain of the amplifier with a pulse-period proportional signal. | 12-25-2008 |
20090027117 | Low-Noise, Low-Distortion Digital PWM Amplifier - Systems and methods for performance improvements in digital switching amplifiers using low-pass filtering to reduce noise and distortion. In one embodiment, a digital pulse width modulation (PWM) amplifier includes a signal processing plant configured to receive and process an input audio signal. The amplifier also includes a low-pass filter configured to filter audio signals output by the plant. The filtered output of the plant is added to the input audio signal as feedback. The plant may consist of a modulator and power switch, a noise shaper, or any other type of plant. An analog-to-digital converter (ADC) may be provided to convert the output audio signal to a digital signal. Filtering may be implemented before or after the ADC, and a decimator may be placed after the ADC if it is an oversampling ADC. | 01-29-2009 |
20090027118 | Digital PWM Amplifier Having a Low Delay Corrector - Systems and methods for performance improvements in digital switching amplifiers using a low delay corrector. In one embodiment, a digital pulse width modulation (PWM) amplifier includes a signal processing plant configured to receive and process an input audio signal. The amplifier also includes a low delay corrector configured to receive signals output by the plant. The output of the low delay corrector is added to the input audio signal as feedback. The plant may consist of a modulator and power switch, a noise shaper, or any other type of plant. An analog-to-digital converter (ADC) may be provided to convert the output audio signal to a digital signal. Filtering may be implemented before or after the ADC, and a decimator may be placed after the ADC if it is an oversampling ADC. | 01-29-2009 |
20090039957 | POWER AMPLIFIER AND METHOD FOR REDUCING COMMON NOISE OF POWER AMPLIFIER - A power amplifier including a delta-sigma modulation module, a differential programmable dead-time-control module, and an output stage module is provided. The delta-sigma modulation module integrates and quantizes an error between a differential-mode input signal and an output signal to generate a first and a second mean signal. The differential programmable dead-time-control module includes a first and a second dead-time-control module which respectively generate a first and a second signal corresponding to the first mean signal and a third and a fourth signals corresponding to the second mean signal through logic calculations. The differential programmable dead-time-control module determines a dead time between the first signal and the second signal according to a first control signal and a dead time between the third signal and the fourth signal according to a second control signal. The output stage module generates the output signal according to the first, second, third, and fourth signal. | 02-12-2009 |
20090051423 | DIGITAL AUDIO AMPLIFIERS, ELECTRONIC SYSTEMS, AND METHODS - An embodiment of an electronic system includes a digital audio amplifier having a continuous time modulator adapted to generate a difference signal between an audio bitstream and a feedback signal, and to perform a modulation process on the difference signal to generate an input pulse modulated signal, a class D output stage adapted to receive, quantize, and amplify the input pulse modulated signal to generate an output pulse modulated signal, and a feedback path adapted to provide the output pulse modulated signal as the feedback signal to the continuous time modulator. Another embodiment includes a class AB output stage adapted to receive and amplify an input digital audio signal to generate an analog output signal, and circuitry adapted to enable the digital audio amplifier to be configured to enable the class AB output stage and to disable the class D output stage. | 02-26-2009 |
20090066412 | CLASS-D AMPLIFIER CIRCUIT - A class-D amplifier circuit of one aspect includes a gain controller, a pulse-width modulator, an output driver, and a drive controller. The gain controller selectively amplifies an analog input signal according to a level control signal, and outputs a corresponding gain-adjusted analog input signal. The pulse-width modulator converts the gain-adjusted analog input signal into a pulse signal. The output driver includes a plurality of output driver circuits which generate an amplified pulse signal corresponding to the pulse signal output by the pulse-width modulator. The drive controller selectively disables a subset of the plurality of output driver circuits according to the level control signal. | 03-12-2009 |
20090072897 | Sigma-delta class-D amplifier and control method for a sigma-delta class-D amplifier - A sigma-delta class-D amplifier includes a quantizer to quantize an input to produce a digital signal, and an output stage to produce an output according to the digital signal. The quantizer has a smaller step size so that the digital signal has at least five logical levels, and the sigma-delta class-D amplifier is thus improved to have wider stable modulation range and less switching loss. | 03-19-2009 |
20090091382 | AUDIO SIGNAL PROCESSING SYSTEM AND METHOD - An audio signal processing system and method is disclosed. In a particular embodiment, the audio signal processing system includes a first electrical path responsive to a power supply of an audio amplifier. The first electrical path can include a low pass filter to filter a direct current (DC) component of the power supply and a first analog-to-digital converter (ADC) responsive to the low pass filter. The audio signal processing system also includes a second electrical path responsive to the power supply. The second electrical path can include a high pass filter to filter an alternating current (AC) component of the power supply and a second ADC responsive to an output of the high pass filter. The audio signal processing system includes compensation logic to modify an audio signal based on a first signal generated from the first electrical path and a second signal generated from the second electrical path. | 04-09-2009 |
20090102549 | DIGITAL PULSE WIDTH MODULATED FEEDBACK SYSTEM FOR A SWITCHING AMPLIFIER AND METHOD THEREFOR - A switching amplifier includes a power stage, a low pass filter, a combining circuit, and a feedback correction circuit. The power stage has an input terminal and an output terminal. The low pass filter has an input terminal coupled to the output terminal of the power stage, and an output terminal for providing a filtered pulse width modulated signal. The combining circuit has a first input terminal coupled to the output terminal of the power stage, a second input terminal coupled to the output terminal of the low pass filter, and an output terminal. The feedback correction circuit has a first input terminal for receiving a reference pulse width modulated signal, a second input terminal coupled to the output terminal of the combining circuit, and an output terminal coupled to the input terminal of the power stage. | 04-23-2009 |
20090102550 | AUDIO SIGNAL AMPLIFIER CIRCUIT WITH A MUTE FUNCTION - An integrator generates analog voltage in a manner that in an active state a duty ratio of an output signal of an class D amplifier is brought close to a duty ratio defined by an analog audio signal. A first mute circuit forcibly turns on the class D amplifier in an active state. In an active state, A voltage-fixing circuit fixes an output terminal of the class D amplifier to a predetermined fixed potential of Vdd/2. A second mute circuit is provided between an output terminal of a filter and ground, and connects the output terminal of the filter to ground in an active state. A mute control unit controls the integrator, the first mute circuit, the voltage-fixing circuit and the second mute circuit, respectively. As a result, the noise at the time of start and stop can be optimally reduced. | 04-23-2009 |
20090115508 | SWITCHING AMPLIFIER AND ITS MODULATION PROCESS - The present invention discloses a switching amplifier and its modulations process, which belongs to the field of non-filters-type switching amplifier. The switching amplifier comprises; pulse-width modulation with dual comparator, multiple-loop feedback structure, only one integrating amplifier with dual-ends output needed for each loop, no less than two feedback loops set between the integrating amplifier and H-bridge, in addition, no any low-pass filters needed adding to the feedback path. Multiple feedback loops are adopted in the present invention, which can low the distortion of the switching amplifier to the extent. Furthermore, no any extra low-pass filters are needed adding to the feedback path, which making the products a higher cost effectiveness. | 05-07-2009 |
20090115509 | Systems and Methods for Isolating an Analog Signal - An accurate linear equivalent of an analog signal may be produced across an isolation barrier by driving a primary transformer winding with a drive amplifier and compensation amplifier, where the compensation operational amplifier amplifies a difference between a signal produced on a sense winding of the transformer and a combination of the input analog signal and output of the drive amplifier. The system may be stabilized by a lead-lag network between the sense winding, input signal, and operational amplifier. The transformer may comprise an isolation barrier to isolate the input analog signal from a signal winding. The primary winding of the transformer, driven by the operational amplifier and driver amplifier circuit, may produce a linear equivalent of the input analog signal across the isolation barrier on a signal winding of the transformer. The transformer may comprise power supply windings connected to a power supply bridge rectifier and regulator circuit to control and supply power to the circuit components across the isolation barrier. The operational amplifier and drive amplifier circuit may be active for only a portion of each analog signal sampling period. The control signals may provide power during the rest of the sampling cycle. | 05-07-2009 |
20090115510 | DEVICE FOR AMPLIFYING A VOLTAGE REPRESENTING AN AUDIOPHONIC INFORMATION - The invention concerns a device ( | 05-07-2009 |
20090153242 | METHOD AND APPARATUS FOR DIRECT DIGITAL TO RADIO FREQUENCY CONVERSION - A method and apparatus for direct conversion of digital data to high power RF signals, known as DDRF. The method and apparatus receive a digital signal, create a digital modulated signal therefrom, and amplify the modulated signal with an H-bridge Power Amplifier for transmission. DDRF uses a multi-level H-bridge amplification circuit to establish a more power efficient digital transmitter. | 06-18-2009 |
20090160547 | METHOD AND SYSTEM FOR TRANSITIONING BETWEEN OPERATION STATES IN AN OUTPUT SYSTEM - A closed loop amplifier system comprising a modulator that provides a pulse-width modulated (PWM) output signal based on an input signal, the modulator having a variable closed loop transfer function. The system also comprises a ramp generator that provides a ramp signal to the modulator, the variable closed loop transfer function of the modulator varying as a function of the ramp signal. The system further comprises a controller that controls the ramp generator to provide the ramp signal to adjust the variable closed loop transfer function during transitions between operating states of the amplifier system. | 06-25-2009 |
20090167431 | Class D Amplifier Having PWM Circuit with Look-up Table - A class D amplifier includes a noise-shaping modulator, a pulse width modulator, and a pulse amplifier. The noise-shaping modulator receive a pulse code modulated (PCM) signal and produces an oversampled PCM signal. The pulse width modulator produce a pulse width modulated (PWM) signal from the oversampled PCM signal. The pulse amplifier amplifies the PWM signal to produce an amplified PWM signal. The PWM uses a lookup table to convert from PCM to PWM. A compensation circuit optimizes amplifier performance. An optional demodulator filter converts the amplified PWM signal to an analog signal. The amplifier is ideal for integrated audio applications. | 07-02-2009 |
20090174472 | Apparatus and method for improving the feedback linearity of a 1.5-bit sigma-delta class-D amplifier - A conversion circuit is provided for a 1.5-bit Σ-Δ class-D amplifier to improve the feedback linearity of the class-D amplifier, by periodically inverting and mixing a first positive feedback signal and a first negative feedback signal from the power stage of the class-D amplifier to generate a second positive feedback signal and a second negative feedback signal with better linearity for feedback control in the class-D amplifier. | 07-09-2009 |
20090174473 | Systems, Methods, and Apparatuses for Linear Envelope Elimination and Restoration Transmitters - Systems, methods, and apparatuses are provided for linear envelope elimination and restoration transmitters that are based on the polar modulation operating in conjunction with the orthogonal recursive predistortion technique. The polar modulation technique enhances the battery life by dynamically adjusting the bias level. Further, the analog orthogonal recursive predistortion efficiently corrects amplitude and phase errors in radio frequency (RF) power amplifiers (PA) and enhances the PA output capability. Additionally, even-order distortion components are used to predistort the input signal in a multiplicative manner so that the effective correction bandwidth is greatly enhanced. Also, the predistortion scheme, which uses instantaneously feed-backed envelope distortion signals, allows for correction of any distortion that may occur within the correction loop bandwidth, including envelope memory effects. | 07-09-2009 |
20090179697 | AMPLIFIER HAVING A VIRTUAL GROUND AND METHOD THEREOF - An amplifier comprises first, second, and third modulators. The first modulator includes an input for receiving a first input signal, and an output for providing a first modulated output signal corresponding to the first input signal. The second modulator includes an input for receiving a second input signal, and an output for providing a second modulated output signal corresponding to the second input signal. The third modulator has an input for receiving a third input signal, and an output for providing a third modulated output signal corresponding to the third input signal and for providing a virtual ground. A first amplifier circuit is coupled to the outputs of the first and third modulators for driving a first load. A second amplifier circuit is coupled to the outputs of the second and third modulators for driving a second load. | 07-16-2009 |
20090184761 | AMPLIFIER MODULATION METHOD AND APPARATUS - One embodiment relates to a power amplifier that includes a switched mode power amplification stage. The power amplification stage has an output configured to provide an amplified output voltage as a function of a drive signal, where the drive signal fluctuates during a first time and is inactive during a second time. The power amplifier also includes impedance compensation circuitry coupled to the output of the power amplification stage. The impedance compensation circuitry can selectively alter an output impedance of the power amplification stage as a function of a control signal that is continuously de-asserted during the first time and continuously asserted during the second time. Other embodiments are also disclosed. | 07-23-2009 |
20090189689 | Power supply processing for power amplifiers - The present invention, generally speaking, uses multiple selectable power supply paths, a saturation detector, or combinations of the same to achieve efficient power supply processing. In one aspect of the invention, a power supply processing circuit includes a first switched converter stage and a second linear stage. Depending on the power supply desired, the first stage may be bypassed to avoid conversion losses. In another aspect of the invention, a saturation detector is used to control the first stage such that the second stage operates efficiently just short of saturation, thereby avoiding distortion. | 07-30-2009 |
20090201083 | AMPLIFIER DEVICE AND SYSTEM USING THE DEVICE - A device comprising: an input for an electric signal; an integrator stage connected to said input to provide an integrated signal; an amplifier stage electrically coupled to the integrator stage to receive said integrated signal and to provide an output signal. The device being characterized in that the integrator stage is such that the integrated signal is obtained by an individual signal integration operation. | 08-13-2009 |
20090231030 | AUDIO POWER AMPLIFIER AND A PRE-AMPLIFIER THEREOF - An audio power amplifier includes a pre-amplifier, an error amplifier, a comparator, a bridge circuit, and a feedback circuit, in which the gain of the pre-amplifier gradually increases when the audio power amplifier is powered on. The comparator generates a PWM signal by comparing a reference signal and an amplified audio signal. The bridge circuit has switches controlled according to the PWM signal such that a driving current alternately flows to and from a load. The feedback circuit generates the feedback signal indicating a condition of the load. | 09-17-2009 |
20090243717 | Compact high-speed modulator driver method and apparatus - Modulator driver for driving an electro-optical modulator in a high-speed optical communications system. In accordance with aspects of the present invention, a modulator driver is presented comprising an input differential limiting amplifier which is coupled to a distributed differential current-switch configuration, where one set of outputs of the distributed differential current-switch configuration are grounded and the other set of outputs are connected to an artificial transmission line structure generating forward traveling and reverse traveling signals, with the reverse traveling signal termination bias inductively coupled to a separately adjustable positive bias voltage, whereby the circuit architecture reduces the number of components and transitions in the high-speed signal path and is compatible with compact, monolithic fabrication requiring a minimal amount of external components for operation. Other methods and apparatus are presented. | 10-01-2009 |
20090243718 | High-speed modulator driver circuit with enhanced drive capability - Modulator driver for driving an electro-optical modulator in a high-speed optical communications system. In accordance with aspects of the present invention, a modulator driver is presented comprising an input differential limiting amplifier providing differential outputs coupled to a distributed enhanced drive output stage configuration, wherein said distributed enhanced drive output stage configuration comprises a plurality of inductively coupled enhanced drive differential amplifiers, each of said enhanced drive differential amplifiers comprising a plurality of transistors in a cascode configuration whereby the control electrode of the upper transistor in said cascode configuration is biased by a voltage having a modulation component derived from either an input signal to or output signal from said enhanced drive differential amplifier, for the purpose of providing an enhanced output voltage swing capability that exceeds the breakdown voltage of a single transistor. Other methods and apparatus are presented. | 10-01-2009 |
20090273396 | Pulse Area Modulation and High-Efficiency Linear Power Amplifier System Using the Same - A linear power amplifier system using pulse area modulation includes: an envelop/phase decomposer for decomposing an input signal into an envelop signal and a phase signal; a pulse area modulator for modulating the envelop signal such that an area of the modulated envelop signal is proportional to an amplitude of the envelop signal; a control signal generator for converting the modulated envelop signal into a control signal; an automatic gain adjuster for equalizing pulse height of the modulated envelop signal; a mixer for mixing the phase signal with the output of the automatic gain adjustor to produce a RF pulse train; a power amplifier for amplifying the RF pulse train, to generate an amplified RF pulse train; and a band pass filter for restoring the original input signal from the amplified RF pulse train. The output level of the power amplifier is controlled by the control signal. | 11-05-2009 |
20090284313 | AUDIO AMPLIFIER - An audio amplifier, amplifying the audio signal, includes a first filtering circuit, and a second filtering circuit. The first filtering circuit generates an inverting driving voltage to drive a load according to the audio signal. The second filtering circuit generates a non-inverting driving voltage to drive the load according to the inverting driving voltage. The first filtering circuit and the second filtering circuit filter out signals with frequencies greater than a pre-determined frequency. | 11-19-2009 |
20090284314 | AUDIO AMPLIFIER - An audio amplifier includes a timing control circuit, an amplifying circuit, and a bias control circuit. The timing control circuit generates a first power down signal and a second power down signal, in which the first power down signal is asserted before the second power down signal is asserted. The amplifying circuit receives a bias voltage to amplify an audio signal and is deactivated when the first power down signal is asserted. The bias control circuit provides the bias voltage for the amplifying circuit and is deactivated when the second power down signal is asserted. | 11-19-2009 |
20090289704 | AMPLIFICATION CIRCUIT FOR DRIVING A DIFFUSER - An amplification circuit for driving an audio signal diffuser that includes a generation circuit of a first pre-charging signal, the generation circuit including an amplifier provided with an input terminal for receiving the first pre-charging signal and provided with an output terminal for providing a second pre-charging signal as a function of the first pre-charging signal, and a decoupling capacitor of the amplifier from the diffuser, the capacitor connected to the output terminal for charging by the second pre-charging signal. | 11-26-2009 |
20090289705 | PULSE MODULATION TYPE ELECTRIC POWER AMPLIFIER - A pulse modulation type electric power amplifier includes a pulse modulator that receives as input a clock and an input signal, and converts the input signal to a pulse train, an output control circuit that receives as input the pulse train output by the pulse modulator, and controls output of the pulse train, an output circuit that performs switching according to the pulse train output by the output control circuit, a comparator that converts an output terminal voltage of the output circuit to a high or a low digital value, and a short-circuit determination circuit that determines whether an output short circuit has occurred based on a state of an output signal of the comparator, and outputs an output prohibition signal to the output control circuit when an output short circuit is detected. The output control circuit controls output of the pulse train when the output prohibition signal is input, so that the output circuit stops the switching operation. An output short-circuit protection circuit can thereby be configured simply with little circuitry, and is thus small, low power, and integrated easily. | 11-26-2009 |
20090302937 | AMPLIFIER USING SIGMA-DELTA MODULATION AND METHOD FOR ADJUSTING ERRORS OF THE AMPLIFIER THEREOF - An amplifier includes a sigma-delta modulating circuit, a power stage circuit, two feedback components, an error suppressing circuit, and a selecting circuit. The sigma-delta modulating circuit generates two input voltages according to two input signals or one single-ended signal. The power stage circuit provides two output voltages according to the two input voltages or an error adjusting voltage. The two feedback components are respectively coupled to two output terminals of the power stage circuit and two input terminals of the sigma-delta modulating circuits. The error suppressing circuit is used for providing the error adjusting voltage according to the two input voltages. The selecting circuit selects outputs depending on whether the two input voltages corresponding to different logic levels or an identical logic level for adjusting the power stage circuit to suppress a mismatch error between the two feedback components. | 12-10-2009 |
20090302938 | LOW DELAY CORRECTOR - A low delay corrector (LDC) unit includes a non-linear function generator and a filter. The nonlinear function generator receives a first signal and outputs a second signal in dependence on the first signal and a transfer function of the nonlinear function generator. The filter is fed in dependence on the second signal output by the nonlinear function generator. The first signal received by the nonlinear function generator is derived in dependence on an input signal provided to an input of the LDC unit and an output of the filter. An output of the LDC unit is derived in dependence on the first signal received by the nonlinear function generator and the second signal output by the nonlinear function generator. | 12-10-2009 |
20090309654 | SYSTEM AND METHOD OF ALTERING A PWM CARRIER POWER SPECTRUM - In a particular embodiment, a circuit device includes an input to receive a pulse-width modulated (PWM) signal and an output to send a modulated PWM signal. The circuit device further includes a pulse edge control circuit coupled between the input and the output. The pulse edge control circuit receives the PWM signal via the input and includes a control input to receive a modulation control signal. The pulse edge control circuit is adapted to modify the PWM signal to provide the modulated PWM signal with suppressed carrier power and associated harmonics to the output based on the modulation control signal. The circuit device further includes a modulation sequence controller adapted to provide the modulation control signal via the control input. The modulation control signal selectively controls a sequence of the modification of the PWM signal to selectively alter an output power spectrum of the modulated PWM signal. | 12-17-2009 |
20090315620 | POWER AMPLIFIER - A power amplifier based on EER technology or ET technology extracts an amplitude-modulated component from a modulated signal as an input signal which includes the amplitude-modulated component and a phase-modulated component, and decomposes the amplitude-modulated component into two control signals whose product is proportional to the amplitude-modulated component. One of the control signals is amplified by a highly efficient amplifier, and thereafter is used to amplitude-modulate an output from an RF amplifier. The other control signal is converted by a pulse modulator into a rectangular-wave signal, which is then mixed with the phase-modulated component or the modulated signal and input to the RF amplifier. | 12-24-2009 |
20100001793 | HIGH EFFICIENCY MODULATING RF AMPLIFIER - A high efficiency modulating RF amplifier ( | 01-07-2010 |
20100001794 | METHOD AND SYSTEM FOR INCREASING SAMPLING FREQUENCY FOR SWITCHING AMPLIFIERS - The present invention is directed toward providing a system and method of reducing RF interference in switching amplifiers without degrading performance. In one embodiment, the sampling rate of coarse high voltage modulated pulsewidths are increased relative to the sampling rate of fine lower voltage modulated pulsewidths. This increase in the sampling rate of coarse high voltage modulated pulsewidths results in a reduction in EMI. | 01-07-2010 |
20100007410 | Switch method for switching class amplifiers - In accordance with one the present disclosure, systems and methods are disclosed that include transmitting a binary signal from a signal source into a switch where the switch is in series between the signal source and a first circuit element. In addition, the switch is operating substantially in a switched mode and creates a switched output signal and the switch is controlled by the binary signal. Also disclosed in this method is detecting a negative voltage in a signal from a second circuit element. In this method the first circuit element is in series between the second circuit element and the switch, and upon detecting the negative voltage from the second circuit element the first circuit element creates high impedance in the first circuit element. | 01-14-2010 |
20100013554 | SWITCHING POWER AMPLIFIER AND METHOD OF CONTROLLING THE SAME - A switching power amplifier having a pulse width modulation (PWM) signal generation unit that converts an input audio signal into a PWM signal with a predetermined carrier frequency, a correction unit that corrects the difference between an audio signal included in the PWM signal and a negative feedback output audio signal to generate a corrected PWM signal, a low pass filter that removes a high-frequency component from the corrected PWM signal, a frequency modulation unit that modulates the corrected PWM signal so that the corrected PWM signal has a switching frequency different from the carrier frequency of the input PWM signal to generate a modulated PWM signal, and a power amplification unit that amplifies a power of the modulated PWM signal. | 01-21-2010 |
20100097136 | A/D CONVERTER AND A/D CONVERSION METHOD - In an A/D converter provided with an A/D converter circuit | 04-22-2010 |
20100109767 | DIGITAL PULSE WIDTH MODULATION FOR HALF BRIDGE AMPLIFIERS - A switching amplifier drives a load or audio transducer. A digital integral noise shaping circuit converts a digital input such as audio content to an output digital pulse width modulated signal using an integrator. The integrator integrates the digital input, a variable frequency reference pulse width modulated signal and an inverse of the output digital pulse width modulated signal. A half bridge amplifier receives the output digital pulse width modulated signal and drives the load or audio transducer. A variable frequency generator generates the variable frequency reference pulse width modulated signal with an approximately equal duty ratio or alternatively varies the variable frequency pulse width modulated signal above and below about a fifty percent duty ratio. | 05-06-2010 |
20100109768 | METHOD AND APPARATUS FOR HIGH PERFORMANCE CLASS D AUDIO AMPLIFIERS - The present disclosure provides a method and apparatus for high performance class D audio amplifier circuit that includes: a modulator circuit for receiving a PWM input signal and generating a control signal, a driver control circuit, a switching circuit, and a feedback circuit. The driver control circuit is adapted to generate a drive signal for the switching circuit. The driving signal provides compensation for noise and distortions in a PWM output signal at each cycle by selecting either a first pulse signal or a second pulse signal based on the information of the control signal. | 05-06-2010 |
20100123518 | POWER AMPLIFIER AND MODULATOR THEREOF - A power amplifier including a loop filter, a frequency generator, a quantizer, and an output stage module is provided. The frequency generator outputs a signal with a reference frequency to the loop filter, and includes a logic circuit, a current array, and a dummy load. The dummy load representing a load circuit in the loop filter is coupled to the current array. An equivalent impedance of the dummy load is proportioned to an equivalent impedance of the load circuit. The current array outputs the signal and a dummy signal to the loop filter and the dummy load, respectively, according to a logic signal. By using the frequency generator to modulate the frequency automatically, an impact on the power amplifier caused by passive devices therein due to process variationscan be reduced. | 05-20-2010 |
20100156527 | SPREAD SPECTRUM PULSE WIDTH MODULATION METHOD AND APPARATUS - A circuit includes a variable frequency generator circuit and a quantization circuit. The variable frequency generator circuit provides a discontinuous switching frequency signal. The variable frequency generator circuit varies the discontinuous switching frequency signal between a first and second frequency while avoiding at least one frequency band between the first and second frequency. The quantization circuit provides a plurality discrete switching signals each separated by a second frequency band that vary in accordance with the discontinuous switching frequency signal, wherein the avoided frequency band of the discontinuous switching frequency signal is greater than the second frequency band. | 06-24-2010 |
20110012674 | QUIET POWER UP AND POWER DOWN OF CLOSED LOOP DIGITAL PWM MODULATORS - A switching audio amplifier circuit drives a switching audio amplifier stage using a digital PWM signal from an audio source. A PWM duty ratio modifier modifies an edge timing of the digital PWM signal to produce a modified digital PWM signal. A mode switch switches between the digital PWM signal and the modified digital PWM signal in a way that masks audible noise such as clicks and pops at power-up and power-down of the switching audio amplifier. An integrating error amplifier compares a difference between the digital PWM signal and an amplified PWM signal and integrates the difference to control the edge timing modified by the PWM duty ratio modifier. A mode controller can apply an offset signal to the integrating error amplifier and can control the switching of the mode switch. | 01-20-2011 |
20110068861 | CHOPPER-STABILIZED INSTRUMENTATION AMPLIFIER - This disclosure describes a chopper stabilized instrumentation amplifier. The amplifier is configured to achieve stable measurements at low frequency with very low power consumption. The instrumentation amplifier uses a differential architecture and a mixer amplifier to substantially eliminate noise and offset from an output signal produced by the amplifier. Dynamic limitations, i.e., glitching, that result from chopper stabilization at low power are substantially eliminated through a combination of chopping at low impedance nodes within the mixer amplifier and feedback. The signal path of the amplifier operates as a continuous time system, providing minimal aliasing of noise or external signals entering the signal pathway at the chop frequency or its harmonics. The amplifier can be used in a low power system, such as an implantable medical device, to provide a stable, low-noise output signal. | 03-24-2011 |
20120044018 | SYSTEMS AND METHODS FOR IMPROVED OVER-CURRENT CLIPPING - Systems and methods for implementing over-current protection include reducing a clip level while an 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 ≧1. After an over-current condition is no longer detected, and after the clip level has been maintained for the specified period, the clip level can be increased if an over-current condition is not detected for a sample and the clip level is below a specified maximum clip level. | 02-23-2012 |
20120161864 | AMPLIFIER STRUCTURE AND AMPLIFICATION METHOD THEREOF - Provided is an amplifier structure. The amplifier structure includes a delta-sigma modulator, an up converter, a power amplifier, and a band-pass filter. The delta-sigma modulator receives an IF signal to delta-sigma modulate the IF signal. The up converter up-converts a frequency of the delta-sigma modulated signal with an LO signal. The power amplifier amplifies a power of the up-converted signal. The band-pass filter filters the amplified signal of a selected band. The amplifier structure performs the delta-sigma modulation operation on an IF input signal, and thus can considerably decrease a delta-sigma modulation operation speed compared to a typical amplifier structure and moderate the specification in implementing a power amplifier. | 06-28-2012 |
20130049856 | Self Oscillating Modulator - There is described a self oscillating modulator circuit comprising at least two coupled self oscillating loop modules, that achieved a good efficiency and a good linearity. | 02-28-2013 |
20130169356 | SWITCHING POWER AMPLIFIER AND METHOD OF CONTROLLING THE SAME - A switching power amplifier having a pulse width modulation (PWM) signal generation unit that converts an input audio signal into a PWM signal with a predetermined carrier frequency, a correction unit that corrects the difference between an audio signal included in the PWM signal and a negative feedback output audio signal to generate a corrected PWM signal, a low pass filter that removes a high-frequency component from the corrected PWM signal, a frequency modulation unit that modulates the corrected PWM signal so that the corrected PWM signal has a switching frequency different from the carrier frequency of the input PWM signal to generate a modulated PWM signal, and a power amplification unit that amplifies a power of the modulated PWM signal. | 07-04-2013 |
20130200948 | DIGITAL PRE-DISTORTION DEVICE AND METHOD FOR A BROADBAND POWER AMPLIFIER - According to the present invention, a digital pre-distortion device and method for use in a dynamic spectrum allocation system, which uses a breadband frequency range, such as a cognitive radio (CR) system, are implemented. Also, while as conventional pre-distortion device only enable the linearization of a signal of a fundamental frequency band, the digital pre-distortion device and method according to the present invention enable not only the linearization of a basic signal on frequency f | 08-08-2013 |
20130328624 | SYSTEMS, AND METHODS OF RF POWER TRANSMISSION, MODULATION, AND AMPLIFICATION, INCLUDING EMBODIMENTS FOR OUTPUT STAGE PROTECTION - Methods and systems for vector combining power amplification are disclosed herein. In one embodiment, a plurality of signals are individually amplified, then summed to form a desired time-varying complex envelope signal. Phase and/or frequency characteristics of one or more of the signals are controlled to provide the desired phase, frequency, and/or amplitude characteristics of the desired time-varying complex envelope signal. In another embodiment, a time-varying complex envelope signal is decomposed into a plurality of constant envelope constituent signals. The constituent signals are amplified equally or substantially equally, and then summed to construct an amplified version of the original time-varying envelope signal. Embodiments also perform frequency up-conversion. | 12-12-2013 |
20130328625 | AMPLIFIER AND AUDIO DEVICE PROVIDED WITH AMPLIFIER - Because of input of a digital signal, PWM-input, separately excited, class-D amplifier systems are less prone to be affected by noise than in the conventional case that an analog signal is input. Since a ramp wave that is synchronized with a PWM signal is used as a comparison clock, no beats occur between a PWM clock and a reference clock, making is possible to provide a class-D amplifier system which exhibits a large S/N ratio. Furthermore, the fact that an external clock can be varied provides another advantage that no beat noise occurs even in a set that is disposed close to a radio receiver. | 12-12-2013 |
20130335140 | AMPLIFICATION DEVICE AND AMPLIFICATION METHOD - An amplification device includes a first filter configured to pass a predetermined frequency component of a first digital signal phase-modulated with a constant amplitude; a first distortion compensator configured to compensate the signal output from the first filter in advance for distortion occurring in an amplified signal, based on a first distortion compensation coefficient dependent on an amplitude of the signal output from the first filter; a first converter configured to convert the signal compensated by the first distortion compensator into a first analog signal; and a first amplifier configured to amplify the first analog signal. | 12-19-2013 |
20140159809 | SINGLE STAGE SWITCHING POWER AMPLIFIER WITH BIDIRECTIONAL ENERGY FLOW - A switching amplifier realizes bidirectional energy flow and combines switching and power amplification into one single stage so as to increase system efficiency. The modulator circuit of the amplifier receives and modulates an input signal, and generates and outputs modulated driver signals, which are used by the power driver circuit to generate signals to drive switching transformers of an amplifier circuit of the amplifier, and control signals, which are used to control an output generator circuit so as to allow individual inductors across the load by enabling current flowing through the load to have a path to ground. The amplifier circuit comprises switching transformers as well as circuitries configured to capture energy returned from the load and enable the captured energy to flow back to a power supply circuit of the amplifier through an energy flow-back circuit of the amplifier. | 06-12-2014 |
20140184323 | Hybrid Digital/Analog Power Amplifier - The invention may be embodied in radio frequency power amplifier (RF-PA) predriver circuits employing a hybrid analog/digital RF architecture including a resynchronizing digital-to-analog convertor to drive an efficient high-power output stage suitable for driving standard high power amplifier (HPA) output devices. The hybrid analog/digital RF architecture retains the advantages of high digital content integration found in conventional Class-S architecture, while relaxing the performance requirements on the output transistors and on the bitstream generator. The resulting predriver circuit combines the VLSI integration benefits of digital designs with the extensibility to arbitrary output power levels characteristic of analog designs. The hybrid analog/digital driving circuit is well suited for use with analog and Class-S HPAs used in wireless communication systems, such as the Doherty type HPA. | 07-03-2014 |
20140218103 | LOCK-IN AMPLIFIER WITH PHASE-SYNCHRONOUS PROCESSING - The presented device is the combination of a lock-in amplifier unit ( | 08-07-2014 |
20140218104 | POWER AMPLIFICATION DEVICE - An object of the present invention is to provide a power amplification device having high power efficiency for an input signal even in a power region in a large back-off. | 08-07-2014 |
20140285257 | APPARATUS AND METHOD FOR AMPLIFYING SIGNAL - An apparatus that amplifies a signal, includes an amplifier configured to amplify the signal. The apparatus further includes a current supplier configured to supply a periodically variable current to the amplifier. | 09-25-2014 |
20140285258 | SILENT START CLASS-D AMPLIFIER - A Class-D amplifier includes a pre-amplifier having an input configured to receive an amplifier reference voltage signal which is ramped at start-up at a fast rate. An integrator has a first input configured to receive an input signal from the pre-amplifier and a second input configured to receive an integrator reference voltage signal which is ramped at start-up at a slower rate. A modulator has an input coupled to an output of the integrator. The modulator generates a pulse width modulated output signal. Operation of the Class-D amplifier is controlled at start-up by applying a slow ramped signal as the integrator reference voltage signal and a fast ramped signal as the amplifier reference voltage so that the pulse width modulated output signal exhibits an increasing change in duty cycle in response to an increasing voltage of the integrator reference voltage signal, and no “pop” is introduced at start-up. | 09-25-2014 |
20140312968 | DIFFERENTIAL OUTPUT INDUCTOR FOR CLASS D AMPLIFIER - A circuit includes a first input terminal for receiving a first pulsed voltage and a second input terminal for receiving a second pulsed voltage. The circuit further includes a load and an LC filter. The LC filter includes a coupled inductor pair that includes a first winding and a second winding magnetically coupled to each other. The first winding is coupled between the first input terminal and the load, and the second winding is coupled between the second input terminal and the load. A frequency of a first current flowing through the first winding is increased by the second pulsed voltage applied to the second winding. | 10-23-2014 |
20140354352 | SELF-OSCILLATING CLASS-D AMPLIFIER AND SELF-OSCILLATING FREQUENCY CONTROL METHOD FOR SELF-OSCILLATING CLASS-D AMPLIFIER - A self-oscillation frequency varying element for varying the self-oscillation frequency of a self-oscillation loop of a self-oscillating class-D amplifier is placed in the self-oscillation loop. Frequency comparison, cycle comparison, or phase comparison is performed between a self-oscillation signal of the self-oscillating class-D amplifier or a signal corresponding to the self-oscillation signal and a reference frequency signal having a prescribed reference frequency. Alternatively, information corresponding to a frequency or a cycle of a self-oscillation signal of the self-oscillating class-D amplifier or a signal corresponding to the self-oscillation signal is compared with information corresponding to a prescribed reference frequency or reference cycle. The self-oscillation frequency varying element is controlled in accordance with a result of the comparison, whereby the frequency of the self-oscillation signal or the signal corresponding to the self-oscillation signal is caused to follow the frequency of the reference frequency signal. | 12-04-2014 |
20140354353 | DEVICE HAVING A DELTA-SIGMA MODULATOR AND A SWITCHING AMPLIFIER CONNECTED THERETO - A delta-sigma modulator for a switching amplifier, which achieves a high signal-to-noise ratio (SNR) in the multi-MHz range and keeps the noise-transfer function over the useful frequency range as low and as flat as possible. A series connection of a parallel-serial converter and a downstream swap element for the serial output signal y | 12-04-2014 |
20150054577 | AMPLIFICATION SYSTEMS AND METHODS WITH ONE OR MORE CHANNELS - Systems and methods are provided for amplifying multiple input signals to generate multiple output signals. An example system includes a first channel, a second channel, and a third channel. The first channel is configured to receive one or more first input signals, process information associated with the one or more first input signals and a first ramp signal, and generate one or more first output signals. The second channel is configured to receive one or more second input signals, process information associated with the one or more second input signals and a second ramp signal, and generate one or more second output signals. The first ramp signal corresponds to a first phase. The second ramp signal corresponds to a second phase. The first phase and the second phase are different. | 02-26-2015 |
20150054578 | AMPLIFICATION SYSTEMS AND METHODS WITH ONE OR MORE CHANNELS - Systems and methods are provided for amplifying multiple input signals to generate multiple output signals. An example system includes a first channel, a second channel, and a third channel. The first channel is configured to receive one or more first input signals, process information associated with the one or more first input signals and a first ramp signal, and generate one or more first output signals. The second channel is configured to receive one or more second input signals, process information associated with the one or more second input signals and a second ramp signal, and generate one or more second output signals. The first ramp signal corresponds to a first phase. The second ramp signal corresponds to a second phase. The first phase and the second phase are different. | 02-26-2015 |
20160094188 | POWER AMPLIFYING APPARATUS AND POWER AMPLIFYING METHOD - A power amplifying apparatus includes an amplifier configured to amplify an input signal and supply a load with the amplified input signal, a current detecting circuit, disposed at an output stage of the amplifier, configured to detect a current of an output signal from the amplifier, a current feedback circuit configured to provide feedback of the detected current of a certain feedback amount, a voltage feedback circuit configured to provide feedback of a voltage of the output signal of a certain feedback amount, and an adjuster configured to adjust the input signal using the feedback current and the feedback voltage. | 03-31-2016 |