Abstract: A DC-coupled audio out unit is provided, including at least one regulator and at least one audio amplifier. The regulator is coupled to at least one power terminal of the audio amplifier.

Abstract: A power supply for providing a modulated output voltage to a load is disclosed. According to various embodiments, the power supply comprises a plurality of parallel-connected switch-mode power modules and a controller. The controller is connected to each of the power modules and is for controlling the duty cycles of the respective power modules such that the power modules have a common duty cycle in steady state, but in a phase-shifted or “interleaved” manner. In addition, the controller is for controlling the output voltage of the power converter by controlling the ratio of power modules in the forward state at a time to the total number of power modules. In this way, by providing a sufficiently large number of power modules, arbitrarily low output voltage amplitudes and intra-level oscillations can be achieved. Further, the rate of modulation of the output voltage can exceed the switching frequency (f=1/T, where T is the switching period) of the power modules.

Abstract: An amplifying circuit includes: a waveform modifying unit which changes the signal value in the second section in such a manner so as to reduce the difference between the signal strength of a DC component of the input signal and the limit value that limits the variation range of the signal value in the first section; a DC component removing unit which removes the DC component of the input signal after the input signal has been modified by the waveform modifying unit; and an amplifying unit which amplifies the input signal whose DC component has been removed.

Abstract: A supply voltage control device for an amplifier that controls a supply voltage for the amplifier has been improved.

Abstract: A receiver particularly suited for an M-BUS is described. During transmission, the receiver is disabled. After each transmission, nodes and states in the receiver are set to prepare the receiver to receive a signal. Once data is sensed, a feedback loop clips the input signal to the receiver to limit the swing of the input signal. The line of the power supply at the lower potential is modulated, rather than modulating the line at the higher potential, for the transmission of data.

Abstract: A power amplifying circuit includes a first field effect transistor and a second field effect transistor that are connected in series, are interposed between a high potential power line and a low potential power line, and drive a load; a predriver that generates, in response to an input signal, gate voltages applied to the first field effect transistor and the second field effect transistor respectively; and a variable power source that supplies source voltages to the high potential power line and the low potential power line respectively, and is configured to control the source voltages.

Abstract: A power amplifier is provided with an AD converter pulse modulating an envelope signal extracted from a high frequency modulation signal; a switching amplifier amplifying an output signal from the AD converter; a low-pass filter removing high frequency noise from an output signal from the switching amplifier; a voltage control device controlling a power supply voltage of the switching amplifier; and a high frequency amplifier amplifying a phase-modulated signal having a constant envelope and having output from the low-pass filter as a power supply. The average power of the envelope signal to be inputted to the AD converter is permitted to be constant so that an input dynamic range of the AD converter can be most efficiently used. In addition the average power of the output signal from the power amplifier is adjusted by a power supply voltage to be supplied to the switching amplifier.

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: An apparatus for amplifying a signal. The apparatus includes an amplifier powered by a power supply, a monitor that monitors an output signal of the amplifier and a controller operative to adjust the power supply if distortion is detected in the output signal of the amplifier by the monitor.

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: When overdriving a first power supply voltage supplied to a sense amplifier, a line for the first power supply voltage and a line for a second power supply voltage which is higher than the first power supply voltage are connected to each other by a first transistor, thereby boosting the first power supply voltage. When the first power supply voltage drops upon activation of the sense amplifier, the line for the first power supply voltage and the line for the second power supply voltage are connected to each other by a second transistor, thereby increasing the current supply capability. The first transistor and the second transistor are fully driven to operate as switches.

Abstract: A class G headphone amplifier circuit with improved power efficiency and low EMI. It may use an automatic signal level detector to detect the signal level of incoming signals and determine positive and negative power supplies for headphone amplifiers accordingly. A voltage generator may generate pairs of differential output voltages at a plurality of amplitude steps, and supply to headphone amplifiers the pair with the amplitude determined by the automatic signal level detector. As a result, headphone amplifiers are biased according to the input signal level, and the multiple voltage rails may improve power efficiency and avoid clipping.

Abstract: Voltage Enhancement Circuitry (VEC) for amplifiers, suitable of being implemented as an Integrated Circuit (IC), that comprises a VEC driver with a low output resistance (Rdson) while being in its inactive mode and a linearly increasing resistance that is changing linearly with the input control signal, while entering into its active mode, above a determined threshold; external contacts in the VEC, for connecting, whenever required, external feedback elements across the contacts; an external feedback loop connected to an input of the VEC driver, for sensing changes in the enhancement power; a threshold programming module, for externally programming and determining a threshold level for the input signal, above which enhancement is provided shaping the amplified video envelope pulse; an I-Boost module for sampling the amplitude of the video envelope input current and for amplifying the input current up to a pre-defined level; and a current controlled bias circuit for shifting, whenever required, the bias of the

Abstract: A switching transistor has its drain and source respectively connected to a gate and a source of an output transistor for supplying output current to a load, and its gate connected to an internal grounding wire GW to be connected to a grounding terminal GND. A resistance element R1 connects the gate to the source of the switching transistor. When a voltage not smaller than a predetermined value is generated across the resistance element R1 at turn-on, due to a parasitic capacitance existing between a power supply terminal. Vcc and the internal grounding wire GW, the switching transistor can be turned on to turn off the output transistor.

Abstract: A radio frequency power amplifier has first and second amplifier stages coupled in series, one of which is operated in class F and the other is operated in inverse class F; an envelope detector adapted to detect an envelope of the input signal; a power supply coupled to supply an electrical supply voltage to the first and second amplifier stages, wherein the electrical supply voltage is controlled to follow the envelope of the input signal. Such amplifier makes it possible to maintain class F and inverse class F operation, respectively, of the first and second amplifier stages independent on the input signal. Preferably, this is done by controlling the electrical supply voltage so that the saturation levels of the first and second amplifier stages follow the envelope of the input signal.

Abstract: A power amplifier is provided that includes a plurality of stages. Each of the stages is capable of being controlled by a first supply voltage or a second supply voltage. The first supply voltage is provided by a linear amplifier, and the second supply voltage is provided by a switching converter. A first stage is capable of being controlled by the first supply voltage, and a second stage is capable of being controlled by the second supply voltage.

Abstract: An output power detection circuit including a detection circuit is disclosed. The output power detection circuit further includes a summing network, wherein a first voltage input of the summing network is capable of receiving a voltage that is proportional with a current flowing through an output stage of an RF amplifier circuit, a second voltage input is coupled with the detection circuit, and an output is capable of providing a summing voltage.

Abstract: A system and method for dynamic adjustment of drain or collector voltage of a power amplifier (PA), including a PA having a voltage input, a temperature sensor measuring ambient temperature of the PA, and an adaptive PA control processor that dynamically changes the input voltage based on the ambient temperature, achieving a desired peak power when the system is subjected to high temperatures. In a further embodiment, a power sensor measures output power of the PA, and the control processor dynamically changes the voltage based on output power when the system serves a large cell in a mobile communication infrastructure employing high power. In a further embodiment, a multistage PA and method include amplifier stages having drain or collector voltage inputs, wherein a voltage applied to the inputs are set so as to be proportional to the peak power requirements of each stage, enhancing overall efficiency.

Abstract: Systems and method to compress digital video based on human factors expressed as a desirability score are provided. A particular method includes passing a digital input signal through a pulse-width modulator and passing an output of the pulse-width modulator through a power switching device. An output of the power switching device has a plurality of pulses. The method includes receiving the output of the power switching device at a first input of a comparator and receiving a reference voltage at a second input of the comparator. The method includes determining a net signal based on an output of the comparator and determining a timing error signal based on the net signal and the digital input signal. The method also includes adjusting the digital input signal to compensate for harmonic distortion based at least in part on the timing error signal.

Abstract: An amplifier device including an amplifier having an input for receiving an audio input signal and an output for sending an output signal to a load. A boosted-rail circuit is connected to a power source and has a single boosted rail connected to the BTL amplifier. Also, a common-mode circuit is coupled to the boosted-rail circuit and the BTL amplifier. The common-mode circuit sends a common-mode signal to the BTL amplifier that will dynamically track the output voltage supplied from the boosted-rail circuit to the BTL amplifier. In operation, the boosted-rail circuit reacts to the BTL amplifier and switches from a non-boost mode to a boost mode to increase the output voltage supplied to the BTL when the BTL amplifier requires additional voltage.

Abstract: Ground skimming output stages that are designed to drive wideband signals with the ability to provide a high quality output signal all the way to the low supply rail are provided. In accordance with an embodiment of the present invention, the output stage of the present invention includes a translinear current controller, an output transistor and a current mirror. While not limited thereto, embodiments of the present invention only require a single positive power supply, consistent with the recent trend toward integrated circuits that only require a single low voltage power supply.

Abstract: A solution is provided for correcting distortions on a radio frequency output signal of a power amplifier. There is provided an apparatus, comprising: a processor configured to determine at least one correction factor for a distortion on a radio frequency output signal of a power amplifier on the basis of estimated characteristics of a distorted time-varying supply voltage from a power supply to a power amplifier and an interface configured to feed the at least one correction factor to an input signal of the power amplifier.

Abstract: An analog error amplifier includes an amplifier circuit and a replica bias circuit that together produce an output signal representing a difference between an input signal and a reference signal. The amplifier circuit produces the output signal in response to the input signal and a bias signal provided by the replica bias circuit. The bias signal may establish a reference threshold of a basic amplifier in the amplifier circuit. The replica bias circuit produces the bias signal in response to the reference signal and drives the bias signal to be equal to the reference signal. The replica bias circuit may include a plurality of amplifier stages. The bias signal produced by a single replica bias circuit may be provided to a plurality of amplifier circuits to provide a plurality of error amplifiers for a single reference signal.

Abstract: A dynamic power supply for N amplifiers includes first and second power boost circuits which temporarily boost the positive or negative power supply rail, respectively. A control circuit monitors amplifier output signal levels and provides power boost control signals to the power boost circuits, which temporarily raise the positive supply voltage above the nominal voltage level in tandem with the highest output signal from the N amplifiers and lower the negative supply voltage below the nominal voltage level in tandem with the lowest output signal level from the N amplifiers. The power boost circuits each may be coupled to a reservoir capacitor from which current is drawn to provide the power boost. When inactive, the reservoir capacitors charge up from the respective power supply rails. The dynamic power supply is well suited for audio amplification systems.

Abstract: The RF power amplifier apparatus has an RF power amplifier and a power-supply circuit. The power-supply circuit controls the level of a source voltage supplied to the RF power amplifier in response to the level of a power-control signal. A sensing resistance produces a sense signal Vsen corresponding to a source current with respect to a source voltage. The current-control unit controls the source current ILDO in response to the sense signal Vsen. When Vsen coincides with an allowable sense signal level Vsh corresponding to a source current allowable level ILDO(Max), the current-control unit controls the source current ILDO to a limit current smaller than the allowable level ILDO(Max). Preferably, the limit current is a shutdown current when a shutdown switch is in an OFF state. Thus, the draining of the battery of a mobile-phone terminal can be reduced even when an impedance mismatch condition lasts for a long time.

Abstract: A class G headphone amplifier circuit with improved power efficiency and low EMI. It may use an automatic signal level detector to detect the signal level of incoming signals and determine positive and negative power supplies for headphone amplifiers accordingly. A voltage generator may generate pairs of differential output voltages at a plurality of amplitude steps, and supply to headphone amplifiers the pair with the amplitude determined by the automatic signal level detector. As a result, headphone amplifiers are biased according to the input signal level, and the multiple voltage rails may improve power efficiency and avoid clipping.

Abstract: A broad power band transmitter utilizing a duty cycle modulator achieves 80dB of power range for 3G signals. The present invention greatly improves the efficiency of transmitters used in mobile phones, for example, by using the duty cycle modulator during medium and low power levels of the transmitting power amplifier. The power amplifier operates in three different modes based upon the amplifier power level selected. The power amplifier operates in an EER mode during high power levels, in a DCM ERR mode during medium power levels, and in a DCM mode during low power levels.

Abstract: A circuit, system and method determine the control voltage for a DC-DC converter. A control module determines a raw battery voltage and an operating temperature. It references a look up table to determine a voltage regulator control voltage based on the battery voltage and the operating temperature during normal operation. In some cases, the control module also uses a level of interference to determine the control voltage.

Abstract: A regulator with decreased leakage and low loss for a power amplifier is described. Switching circuitry is used to connect the regulator input bias to a bias control voltage when the power amplifier is to be operated in an on condition or to a voltage generator when the power amplifier is to be operated in an off condition.

Abstract: A power supply includes: a switching amplifier including an input and an output, the amplifier input being adapted to be powered by an electrical power source; a transformer including a primary and a secondary winding on a magnetic core, the number of winding turns being chosen to limit magnetization levels to avoid magnetic saturation while maximizing winding spacing, the transformer primary winding being in communication with the amplifier output; a rectification system in communication with the transformer secondary winding, the rectification system providing a DC power output; and a controller. The controller monitors the DC power output and adjusts the switching amplifier in response to the monitoring to provide a desired power output characteristic.

Abstract: Disclosed is an apparatus and method for operating a microwave amplifier with improved efficiency and reduced harmonic emissions. The disclosed amplifier includes a variable rail voltage supply and a variable input drive stage. A controller continually monitors the amplifier output and adjusts the rail voltage and input drive signal to achieve high efficiency and low harmonic emissions. The amplifier may include a dynamic bias controller configured to operate the gain elements outside the linear region. Efficiencies of over 70% may be achieved by the disclosed amplifier.

Abstract: A highly accurate current detection apparatus is realized in a one-chip LSI. An end of a current detector is connected to an analog power supply (VACC) or a virtual analog ground potential (VAG) of a voltage amplifier and an A/D converter, and a predetermined voltage is supplied between the voltage amplifier and the virtual ground potential (VAG) by a power supply.

Abstract: Embodiments of circuits, systems, and methods relating to a power amplifier with a reconfigurable direct current coupling are disclosed. Other embodiments may be described and claimed.

Abstract: 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.

Abstract: The present invention is a tunable multi-element network for providing impedance transformation. The network may include a first switched capacitor power load modulator circuit and a second switched capacitor power load modulator circuit. The network may further include a series inductive component configured for connecting to at least one of the first power load modulator circuit and the second power load modulator circuit. The network may be further configured for connection to a transmit antenna and a power amplifier. The network may be further configured for receiving an arbitrary impedance from the antenna. The network may be further configured for synthesizing an arbitrary capacitive reactance based on a dynamically controllable phase angle between a switch drive signal provided by the network and an incident Radio Frequency (RF) signal. The network may be further configured for matching the antenna impedance to the power amplifier via the arbitrary capacitive reactance.

Abstract: An apparatus comprising an input, a control signal generator coupled to the input and having a control signal generator output, and an amplifier coupled to the control signal generator output, wherein a voltage supplied to the amplifier is switched based on the control signal generator output, and wherein the control signal generator output is based on a data signal in the input. Also included is an apparatus comprising circuitry configured to implement a method comprising detecting an incoming signal, calculating a derivative of the incoming signal, estimating a future incoming signal based on the derivative of the incoming signal and a time step, and providing the estimated future incoming signal to switch between a first supply voltage and a second supply voltage prior to or concurrent with an arrival of the future incoming signal at the switch, wherein the incoming signal and the future incoming signal are analog signals.

Abstract: A method of controlling power supply voltage of an audio amplifier delays an input audio signal; estimates, with a digital signal processor, an audio output level of the delayed input audio signal based on correlations between the delayed input audio signal level and audio level change factors; sets a value of power supply voltage supplied to a power switching circuit unit in correspondence with the estimated audio output level prior to outputting the delayed input audio signal on which the estimated audio output level is based; and amplifies the delayed audio input signal to provide an audio output signal by variably controlling the power supply voltage supplied to the power switching circuit unit according to the set value of power supply voltage.

Abstract: A power amplifier is provided with a signal generating circuit, a plurality of control signal amplifiers and an RF amplifier. The signal generating circuit outputs the amplitude modulation components of an input signal by dividing the components into a plurality of control signals, and outputs a modulation wave signal or the phase modulation components of the modulation wave signal. The control signal amplifier is provided with a pulse modulator, which performs pulse modulation of a control signal; a switching amplifier, which performs current amplification of a rectangular wave signal outputted from the pulse modulator; and a low-pass filter, which removes spurious components from the signal outputted from the switching amplifier. The RF amplifier amplifies the inputted signal, performs amplitude modulation with the signal outputted from the low-pass filter and outputs the amplitude-modulated signal.

Abstract: The invention relates to a switching amplifier comprising at least one pulse modulator arranged for modulating at least one input utility signal into at least one pulse modulated signal and at least one switching power stage arranged to establish at least one amplified utility signal on the basis of said at least one pulse modulated signal and a power signal, said power signal being delivered by a tracking power supply at least partly controlled by said at least one input utility signal, characterized in that said switching amplifier is arranged to process said at least one input utility signal according to a correction signal established by a correction signal estimator on the basis of a supply information signal derived from said tracking power supply. According to the present invention an advantageous switching amplifier enabling use of a tracking power supply is provided. Thereby the many benefits of switching amplifiers can now be obtained together with the benefits of utilizing a tracking power supply.

Abstract: A high efficiency precision amplifier which comprises a linear amplifier stage, a class D amplifier stage and a set of switches is provided. Both amplifier stages receive the same input signal. The load is driven by the output of the linear amplifier stage. The set of switches connect the output of the class D amplifier stage to either of the positive and negative supply terminals of the linear amplifier stage and the other of the positive and negative supply terminals of the linear amplifier stage to a negative or positive supply, depending on the polarity of the signal being amplified.

Abstract: A method and apparatus for power conversion in a class D amplifier is provided. The power conversion is achieved using synchronous rectifiers in a regulated half bridge power supply, taking the sum of the positive and negative rails as feedback, in order facilitate energy transfer between positive and negative output rails. This minimizes the effects of off side charging and rail sag, as well as achieving good line regulation, while allowing use of very small, low value output capacitors.

Abstract: The RF power amplifier apparatus has an RF power amplifier and a power-supply circuit. The power-supply circuit controls the level of a source voltage supplied to the RF power amplifier in response to the level of a power-control signal. A sensing resistance produces a sense signal Vsen corresponding to a source current with respect to a source voltage. The current-control unit controls the source current ILDO in response to the sense signal Vsen. When Vsen coincides with an allowable sense signal level Vsh corresponding to a source current allowable level ILDO(Max), the current-control unit controls the source current ILDO to a limit current smaller than the allowable level ILDO(Max). Preferably, the limit current is a shutdown current when a shutdown switch is in an OFF state. Thus, the draining of the battery of a mobile-phone terminal can be reduced even when an impedance mismatch condition lasts for a long time.

Abstract: The present invention relates to an electronic device for power efficient linear amplification. The electronic device includes an amplifier (RF-PA) for amplifying a phase modulated signal (PM). The amplifier (RF-PA) is adapted to be controlled by a first modulating signal (AM high) for modulating the amplitude of the phase modulated signal (PM) above a predetermined amplitude value. The electronic device is further adapted to attenuate an output signal of the amplifier (RF-PA) for providing amplitude modulation below the predetermined amplitude value.

Abstract: A method for obtaining field strength information from a received electromagnetic signal by a receiver unit, in which an input voltage is generated for an operational amplifier from the received signal in the receiver unit by an input resistance and an output voltage is generated by the operational amplifier by a fixed amplification factor.

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

Abstract: 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.

Abstract: A dynamic power supply for N amplifiers includes first and second power boost circuits which temporarily boost the positive or negative power supply rail, respectively. A control circuit monitors amplifier output signal levels and provides power boost control signals to the power boost circuits, which temporarily raise the positive supply voltage above the nominal voltage level in tandem with the highest output signal from the N amplifiers and lower the negative supply voltage below the nominal voltage level in tandem with the lowest output signal level from the N amplifiers. The power boost circuits each may be coupled to a reservoir capacitor from which current is drawn to provide the power boost. When inactive, the reservoir capacitors charge up from the respective power supply rails. The dynamic power supply is well suited for audio amplification systems.

Abstract: A charge pump power supply for a consumer device audio power stage has an efficiency selected according to signal level. The frequency of operation of the charge pump and/or the effective size of a switching transistor bank is adjusted based upon a volume (gain) setting, or a detected signal level, so that internal power consumption of the charge pump is reduced when high output current is not required from the audio power stage and consequently from the charge pump. Operating modes of the charge pump are selected by the signal level indication and include at least a high power and a high efficiency mode selected by setting the charge pump operating frequency and/or enabling or disabling switching of one or more of multiple parallel transistors used to implement each switching element of the charge pump, thereby setting the level of gate capacitance being charged/discharged by the gate driver circuit(s).

Abstract: The present invention discloses a circuit providing a power for a sense amplifier that stabilizes a power voltage supplied to the sense amplifier by compensating a noise generated in the power voltage when the sense amplifier operates with an selectively generated decoupling noise. The circuit providing a power for a sense amplifier includes a sense amplifying circuit sensing and amplifying data loaded on a bit line with a first power. A power supplying unit provides the first power to the sense amplifying circuit. A decoupling unit generates a decoupling noise with a second power and provides the decoupling noise to the first power voltage. The decoupling noise is maintained for a period including a time point of an operation of the sense amplifying circuit and a predetermined time thereafter.

Abstract: An amplifying circuit includes: a waveform modifying unit which changes the signal value in the second section in such a manner so as to reduce the difference between the signal strength of a DC component of the input signal and the limit value that limits the variation range of the signal value in the first section; a DC component removing unit which removes the DC component of the input signal after the input signal has been modified by the waveform modifying unit; and an amplifying unit which amplifies the input signal whose DC component has been removed.