Abstract: A buffer circuit and a multiplexer using the buffer are provided. The buffer may selectively operate at a first mode or a second mode. The buffer includes a first signal input terminal, a first signal output terminal, and a path circuit coupled between the first signal input terminal and the first signal output terminal. The path circuit has a voltage source terminal. In response to the buffer operating at the first mode, a first signal transmission path is formed in the path circuit and between the first signal input terminal and the first signal output terminal. The first signal transmission path is disconnected from the voltage source terminal.

Abstract: A power amplifier includes a power switching circuit, a driver circuit, and an amplifier circuit. The power switching circuit is configured to receive a first voltage and a second voltage, and provide the first voltage or the second voltage according to an operation mode of the power amplifier. The driver circuit is coupled to the power switching circuit. The driver circuit is configured to operate according to the first voltage or the second voltage and generate a driving signal according to an input signal. The amplifier circuit is coupled to the power switching circuit and the driver circuit. The amplifier circuit is configured to operate according to the first voltage or the second voltage and generate an output signal according to the driving signal.

Abstract: Described are concepts, circuits, systems and techniques directed toward N-phase control techniques useful in the design and control of supply generators configured for use in a wide variety of power management applications including, but not limited to mobile applications.

Abstract: A method of operating a power amplifier supplying power to an antenna, supplying switched power to the power amplifier comprises in a first mode of operation via a driver circuit and one or more switches to switch the supply of power to the power amplifier on and off periodically; and calibrating the power amplifier in a second mode of operation. The calibrating comprises supplying voltage to the power amplifier via the same driver circuit and one or more switches for a calibration pulse duration longer than the on/off period. A power supply and an RF front end comprising the power supply are also disclosed.

Abstract: The present document describes a power converter configured to convert electrical power at an input voltage at an input of the power converter to electrical power at an output voltage at an output of the power converter. The power converter comprises a first upper capacitor and a first lower capacitor, which are coupled with one another via a first mid node; a second upper capacitor and a second lower capacitor, which are coupled with one another via a second mid node; an inductor; and a set of power switches. In addition, the power converter comprises a control unit which is configured to control the set of power switches such that during an operation cycle the power converter is operated in a first main state and in a second main state in a mutually exclusive manner.

Abstract: An electronic control system provides selectable path operation, such as linear and pulse-width modulated (PWM) operation and provides path transition management to improve operation. The system supplies a current or a voltage to a load in response to an input signal or value and includes an output driver, and multiple selectable control paths. The system includes a control circuit that selects between the first control path and the second control path in response to a path selection indication to drive the output driver. The system may include an evaluator that determines the path selection indication in conformity with an amplitude and a slew rate of the input. One or all of the control paths may have a response time to changes in the input signal or value, and the control circuit may delay switching from the second control path to the first control path to compensate for the response time.

Abstract: An error amplifier includes an output pin coupled to a pulse width modulation (PWM) comparator of a buck-boost converter. A first transconductance amplifier adjusts an output current at the output pin and operates in a constant voltage mode. The first transconductance amplifier includes a first positive input to receive a first voltage reference and a first negative input coupled to a tap point of a voltage divider coupled between a voltage bus and a ground of the buck-boost converter. A second transconductance amplifier also adjusts the output current at the output pin and operates in a constant current mode. The second transconductance amplifier includes a second positive input to receive a second voltage reference and a second negative input coupled to a current sense amplifier, the current sense amplifier being coupled to a sense resistor positioned inline along the voltage bus.

Abstract: Apparatus and methods for adaptive power amplifier biasing are provided. In certain embodiments, a power amplifier system includes a power amplifier that provides amplification to a radio frequency (RF) signal, and a power amplifier bias control circuit that generates a bias signal of the power amplifier based on a bandwidth signal indicating a bandwidth of the RF signal. The power amplifier bias control circuit has a bandwidth that adapts to the bandwidth of the RF signal as indicated by the bandwidth signal.

Abstract: Cascode power amplifier bias circuits suitable for operating across multiple power supply domains are provided. In certain embodiments, a power amplifier system includes a cascode power amplifier and a multi-domain bias circuit that generates at least a first cascode bias voltage for the cascode power amplifier. The multi-domain bias circuit includes a coarse regulator that generates a regulated voltage based on a power supply voltage that is operable with multiple voltage levels associated with different power supply domains, a bandgap reference circuit that is powered by the regulated voltage and outputs a bandgap reference voltage, a bias voltage generator that generates multiple selectable bias voltages based on the bandgap reference voltage, and a bias voltage selector that chooses the first cascode bias voltage from amongst the selectable bias voltages.

Abstract: A power supply unit using intellectual pre-regulator which includes an input port connected to a power source realized as battery or generator (hereinafter, it is called as ‘battery’), an output port connected to an electronic device, a voltage dropping part connected between said input port and said output port to drop the input voltage to match it to the voltage required by said electronic device, and a detection-control part to detect the voltage required by said electronic device connected to said output port and to transfer it to said voltage dropping part.

Abstract: Described is a system for modulating power to one or more radio frequency (RF) amplifiers to suppress undesired output signal components, improve linearity and reduce noise. The described systems and techniques enable shaping of spectral components introduced via an amplifier bias voltage owing to transitions among bias discrete states. The systems and techniques facilitate operation of multilevel, RF amplifiers under a wider range of operating conditions. In embodiments, the system includes modulators coupled to a supply terminal port of each of the one or more amplifiers to modulate the voltage levels supplied to the one or more amplifiers. The outputs of the modulators may be combined to provide a combined signal coupled to the amplifiers. A delay circuit delays switching of at least one of the power modulators relative to other modulator, by a variable time delay. This results in suppression of undesired output signal components of the amplifier output.

Abstract: An amplifier includes an amplification circuit, a power supplying circuit and an input circuit. A first end of the amplification circuit is connected with a first end of the input circuit; a second end of the amplification circuit is connected with the power supplying circuit; and a third end of the amplification circuit is connected with a second end of the input circuit. The power supplying circuit is at least configured to supply power to the amplification circuit so that the amplification circuit operates in an amplification region. The input circuit is at least configured to receive an input signal; the amplification circuit is configured to obtain an amplification gain in case of operating in the amplification region, and amplify the input signal by using the obtained amplification gain.

Abstract: An adaptive DC-DC boost converter arrangement and an electronic circuit including such an arrangement are provided. The arrangement includes a circuit board with a plurality of electronic components mounted thereon, implementing an adaptive DC-DC boost converter circuit and a boost decoupling capacitor. The adaptive DC-DC boost converter circuit comprises a DC-DC boost converter having a converter set value input, a boost supply input, and a boost voltage output, and an adaptive DC-DC boost control unit having a control input and a control output. An acoustical noise suppression filter is present having a filter input connected to the control output of the adaptive DC-DC boost control unit and a filter output connected to the converter set value input of the DC-DC boost converter.

Abstract: A power amplifier circuit includes a power amplification circuit and a diode assembly. The diode assembly is connected in series with a transistor amplification circuit of the power amplification circuit, and the transistor amplification circuit is configured to, when load of power amplifier is mismatched, turn the diode assembly on, so as to divide current voltage to at least two electrodes of the transistor amplification circuit.

Abstract: Techniques are described for using valley detection for supply voltage modulation in power amplifier circuits. Embodiments operate in context of a power amplifier circuit configured to be driven by a supply voltage generated by a supply modulator and to receive an amplitude-modulated (AM) signal at its input. The output of the power amplifier circuit can be fed to a valley detector that can detect a valley level corresponding to the bottom of the envelope of the AM signal. The detected valley level can be fed back to the supply modulator and compared to a constant reference. In response to the comparison, the supply modulator can vary the supply voltage to the power amplifier circuit in a manner that effectively tracking the envelope of the power amplifier circuit's output signal, thereby effectively seeking a flat valley for the output signal's envelope.

Abstract: A semiconductor device includes a first transistor that flows a load current to an external load; a current generation circuit that outputs a current corresponding to a power consumption generated in an overheat detection target when the load current flows the overheat detection target; a resistor-capacitor-network comprising a resistor and a capacitor corresponding to a thermal resistance and a thermal capacitance of the overheat detection target, and having one end coupled to the current generation circuit; an overheat detection circuit coupled to a connection point of the current generation circuit and the resistor-capacitor-network; and a voltage source that sets a voltage of the connection point of the current generation circuit and the resistor-capacitor-network to a predetermined voltage.

Abstract: An apparatus is disclosed for waveform-tailored average power tracking. In an example aspect, the apparatus includes an amplifier, a power converter, and an average power tracking module. The amplifier is configured to amplify radio-frequency signals using a supply voltage. The radio-frequency signals have different waveforms. The power converter is coupled to the amplifier and configured to provide the supply voltage. The average power tracking module is coupled to the power converter and configured to adjust the supply voltage according to the different waveforms to cause the supply voltage to vary across at least two waveforms of the different waveforms for related average output powers.

Abstract: Methods and devices addressing power tracking of transmission systems using antenna arrays are disclosed. The disclosed teachings may be implemented on a channel element to channel element basis, are adaptive and can be implemented on short time durations such as time slots. Power efficiency can be improved when applying the described methods to the design of systems with antenna arrays.

Abstract: A supply voltage conditioning circuit comprises a differential amplifier, a comparator, a sample and hold (S/H) circuit, and a delay circuit. The differential amplifier receives an input supply voltage and a reference voltage, and outputs a difference signal. The comparator receives the difference signal and a value representative of a noise margin, and outputs a control signal indicative of whether the difference signal is greater than the value representative of the noise margin. The S/H circuit samples the input supply voltage in response to the control signal indicating the difference signal is greater than the noise margin, and outputs a substantially noise free supply voltage. This allows the output supply voltage to track underlying changes in the input supply voltage but filter out noise in the input supply voltage. The delay circuit receives and delays the output supply voltage to generate the reference voltage.

Abstract: A system includes a current-mode switcher configured to provide a direct current (DC) voltage for a noise sensitive load, and a linear amplifier connected to an output of the current-mode switcher, the linear amplifier configured to draw a reduced supply voltage through at least one power conversion device that is coupled between a power source and the linear amplifier.

Abstract: An amplifying apparatus is provided, which includes a power-source main line, a plurality of amplifying control devices which include an amplifier, a power-source branch line, an over current protector. The amplifier amplifies a high-frequency signal. The power-source branch line is branched from the power-source main line. The over current protector disposed for the power-source branch line is connected to the amplifier and configured to disconnect the power-source branch line based on drive current flowing through the amplifier from the power-source branch line. The power-source main line is common to the plurality of amplifying control devices.

Abstract: A tracker circuit configured to provide a variable supply voltage to a power amplifier (PA) circuit is disclosed. The tracker circuit includes a state machine circuit comprising a plurality of states mapped in accordance with transitions associated with a mapping scheme. In some embodiments, the plurality of states of the state machine circuit identify one or more operational modes associated with the tracker circuit, wherein at least one operational mode comprises one or more voltage levels respectively associated therewith. In some embodiments, the one or more operational modes includes at least two active operational modes. In some embodiments, a transition between the one or more operational modes of the tracker circuit is controlled by a digital selection signal received from a digital communication interface associated therewith.

Abstract: In a discrete supply modulation system, a circuit includes a multi-stage pulse shaping network (PSN) having a first PSN stage having an input configured to receive variable bias supply signals from a power management circuit (PMC) and having an output coupled to one or more second PSN stages with each of the one or more second PSN stages having an output configured to be coupled to a supply (or bias) terminal of a respective one of one or more radio frequency amplifiers. Such an arrangement is suitable for use with transmit systems in mobile handsets operating in accordance with 5th generation (5G) communications and other connectivity protocols such as 802.11 a/b/g/n/ac/ax/ad/ay and is suitable for use with multiple simultaneous transmit systems including multiple-input, multiple-output (MIMO), uplink carrier aggregation (ULCA) and beamforming.

Abstract: An average power tracking (APT) power management integrated circuit (PMIC) is provided. The APT PMIC is configured to generate an APT voltage to a power amplifier for amplifying a high modulation bandwidth (e.g., ?200 MHz) radio frequency (RF) signal. The APT PMIC includes a voltage amplifier configured to generate an initial APT voltage and an offset capacitor configured to raise the initial APT voltage by a modulated offset voltage. The APT PMIC can be configured to modulate the initial APT voltage and the modulated offset voltage concurrently based on a time-variant APT target voltage. As a result, the APT PMIC can adapt the APT voltage very quickly between different voltage levels, thus making it possible to amplify a high modulation bandwidth radio frequency (RF) signal for transmission in a fifth-generation (5G) communication system.

Abstract: A device including a III-N material is described. In an example, the device has a terminal structure with a central body and a first plurality of fins, and a second plurality of fins, opposite the first plurality of fins. A polarization charge inducing layer including a III-N material in the terminal structure. A gate electrode is disposed above and on a portion of the polarization charge inducing layer. A source structure is on the polarization charge inducing layer and on sidewalls of the first plurality of fins. A drain structure is on the polarization charge inducing layer and on sidewalls of the second plurality of fins. The device further includes a source structure and a drain structure on opposite sides of the gate electrode and a source contact on the source structure and a drain contact on the drain structure.

Abstract: Disclosed is envelope tracking circuitry having an envelope tracking integrated circuit (ETIC) coupled to a power supply to provide an envelope tracked power signal to a power amplifier (PA) with a filter equalizer configured to inject an error-correcting signal into the ETIC in response to equalizer settings. Further included is PA resistance estimator circuitry having a first peak detector circuit configured to capture within a window first peaks associated with a sense current generated by the ETIC, a second peak detector circuit configured to capture within the window second peaks associated with a scaled supply voltage corresponding to the envelope tracked power signal, comparator circuitry configured to receive the first peaks and receive the second peaks and generate an estimation of PA resistance, and an equalizer settings correction circuit configured to receive the estimation of PA resistance and update the equalizer settings in response to the estimation of PA resistance.

Abstract: A switching system is connected to the power amplifier of an RF system. The switching system can switch the DC supply voltage to the power amplifier while handling the high DC current and the nanosecond switching speed requirements that are mandatory for most RF systems. The embodiments can rapidly control DC voltages but not interfere with the optimized operation of the RF transistor. The embodiments provide a desired sharp turn-on leading edge for an RF pulse while eliminating the extremely long and undesirable ramp down that typically occurs beyond the desired RF pulse period.

Abstract: Apparatus and methods for power amplifier bias modulation for low bandwidth envelope tracking are provided herein. In certain embodiments, a power amplifier system for a mobile device includes a power amplifier that amplifies an RF signal and a low bandwidth envelope tracker that generates a power amplifier supply voltage for the power amplifier based on an envelope of the RF signal. The envelope tracking system further includes a bias modulation circuit that modulates a bias signal of the power amplifier based on a voltage level of the power amplifier supply voltage.

Abstract: Envelope tracking systems with modeling for power amplifier supply voltage filtering are provided herein. In certain embodiments, an envelope tracking system includes a supply voltage filter, a power amplifier that receives a power amplifier supply voltage through the supply voltage filter, and an envelope tracker that generates the power amplifier supply voltage. The power amplifier provides amplification to a radio frequency (RF) signal that is generated based on digital signal data, and the envelope tracker generates the power amplifier supply voltage based on an envelope signal corresponding to an envelope of the RF signal. The envelope tracking system further includes digital modeling circuitry that models the supply voltage filter and operates to digitally compensate the digital signal data for effects of the supply voltage filter, such as distortion.

Abstract: A power amplifier circuit includes a lower transistor having a first terminal, a second terminal connected to ground, and a third terminal, wherein a first power supply voltage is supplied to the first terminal, and an input signal is supplied to the third terminal; a first capacitor; an upper transistor having a first terminal, a second terminal connected to the first terminal of the lower transistor via the first capacitor, and a third terminal, wherein a second power supply voltage is supplied to the first terminal, an amplified signal is outputted to an output terminal from the first terminal, and a driving voltage is supplied to the third terminal; a first inductor that connects the second terminal of the upper transistor to ground; a voltage regulator circuit; and at least one termination circuit that short-circuits an even-order harmonic or odd-order harmonic of the amplified signal to ground potential.

Abstract: Multi-level envelope trackers with an analog interface are provided herein. In certain embodiments, an envelope tracking system for generating a power amplifier supply voltage for a power amplifier is provided. The envelope tracking system includes a multi-level supply (MLS) DC-to-DC converter that outputs multiple regulated voltages, and an MLS modulator that controls selection of the regulated voltages over time based on an analog envelope signal corresponding to an envelope of the RF signal amplified by the power amplifier.

Abstract: A supply voltage circuit for reducing in-rush battery current in an envelope tracking (ET) integrated circuit (ETIC) is provided. The ETIC includes an ET voltage circuit configured to generate a time-variant ET voltage, which includes an offset voltage, in multiple time intervals based on a supply voltage. In some cases, the offset voltage and the supply voltage may both need to be increased or decreased as the time-variant ET voltage increases or decreases. As the offset voltage and the supply voltage increase or decrease, an excessive in-rush battery current may result in a reduced battery life. In this regard, a supply voltage circuit is configured to help the ETIC to adapt the supply voltage on a per-symbol basis. As a result, it is possible to reduce the in-rush battery current in the ETIC while still allowing the time-variant ET voltage to change in a timely manner.

Abstract: Methods and apparatus for implementing a power efficient amplifier device through the use of a main (primary) and auxiliary (secondary) power amplifier are described. The primary and secondary amplifiers operate as current sources providing current to the load. Capacitance coupling is used to couple the primary and secondary amplifier outputs. In some embodiments the combination of primary and secondary amplifiers achieve high average efficiency over the operating range of the device in which the primary and secondary amplifiers are used in combination as an amplifier device. The amplifier device is well suited for implementation using CMOS technology, e.g., N-MOSFETs, and can be implemented in an integrated circuit space efficient manner that is well suited for supporting RF transmissions in the GHz frequency range, e.g., 30 GHz frequency range. The primary amplifier in some embodiments is a CLASS-AB or B amplifier and the secondary amplifier is a CLASS-C amplifier.

Abstract: A DC/DC power converter comprises three or more capacitors connected in series between an output terminal and a ground terminal, the three or more capacitors being connected in series by means of two or more capacitor connection points, and an input voltage switching unit configured to connect an input terminal to one of a group of switching connection points, the group of switching connection points comprising the two or more capacitor connection points and the output terminal. With such a DC/DC power converter it is possible, for example, to convert a variable DC voltage at the input into a variable DC voltage at the output, wherein the voltage range of the output voltage is smaller than the voltage range of the input voltage.

Abstract: The present invention provides a circuitry applied to multiple power domains, wherein the circuitry includes a first circuit block and second circuit block, the first circuit block is powered by a first supply voltage of a first power domain, and the second circuit block is powered by a second supply voltage of a second power domain. The first circuit block includes a first amplifier and a switching circuit. The first amplifier is configured to receive an input signal to generate a processed input signal. When the second circuit block is powered by the second supply voltage, the switching circuit is configured to forward the processed input signal to the second circuit block; and when the second circuit block is not powered by the second supply voltage, the switching circuit disconnects a path between the first amplifier and the second circuit block.

Abstract: Disclosed is a system and method for providing stable and reliable power to components on the top of a cell tower. The system performs a device discovery process to determine with Power Supply Units are connected to which Remote Radio Heads on the tower. It also provides several ways of characterizing the power cables and input capacitance to the Remote Radio Heads to provide optimal power to the Remote Radio Heads, including situations in which the power demand for the Remote Radio Heads increases, while obviating the need to replace the power cables with those of greater current capacity. Further, the system provides for stable power even in the presence of sensor instabilities and data dropouts.

Abstract: A current-averaging audio amplifier for vehicles. The current averaging audio amplifier is connectable to a DC power source and a load, and may generally comprise a power input to receive a DC electrical power from the DC power source. The system may further include a voltage converter, such as a boost converter, connected to the power input, such that the voltage converter can receive electrical power from the DC power source. The system also includes a rechargeable battery coupled to the voltage converter, such that the voltage converter charges the rechargeable battery. An audio amplifier can be powered by the rechargeable battery and connectable to supply power to the load, wherein the average power supplied by the rechargeable battery to the audio amplifier in a finite time interval differs from the average power supplied by the DC power source to the voltage converter.

Abstract: An envelope tracking (ET) power amplifier apparatus is provided. The ET power amplifier apparatus includes an amplifier circuit configured to amplify a radio frequency (RF) signal based on an ET voltage and a tracker circuit configured to generate the ET voltage based on an ET target voltage. The ET power amplifier apparatus also includes a control circuit. The control circuit is configured to dynamically determine a voltage standing wave ratio (VSWR) change at a voltage output relative to a nominal VSWR and cause an adjustment to the ET voltage. By dynamically determining the VSWR change and adjusting the ET voltage in response to the VSWR change, the amplifier circuit can operate under a required EVM threshold across all phase angles of the RF signal.

Abstract: A voltage regulation circuit includes a switching output terminal, a high-side output transistor, a low-side output transistor, a high-side replica transistor, a low-side replica transistor, and a comparator circuit. The high-side output transistor is configured to drive the switching output terminal. The low-side output transistor is configured to drive the switching output terminal. The high-side replica transistor is coupled to the high-side output transistor. The low-side replica transistor is coupled to the high-side replica transistor and the low-side output transistor. The comparator circuit is coupled to the high-side replica transistor and the low-side replica transistor, and is configured to compare a signal received from both the high-side replica transistor and the low-side replica transistor to a ramp signal.

Abstract: A fast-switching average power tracking (APT) power management integrated circuit (PMIC) is provided. The fast-switching APT PMIC includes a voltage amplifier(s) and an offset capacitor(s) having a small capacitance (e.g., between 10 nF and 200 nF). The voltage amplifier(s) is configured to generate an initial APT voltage(s) based on an APT target voltage(s) and the offset capacitor(s) is configured to raise the initial APT voltage(s) by an offset voltage(s) to generate an APT voltage(s). In embodiments disclosed herein, the offset voltage(s) is modulated based on the APT target voltage(s). Given the small capacitance of the offset capacitor(s), it is possible to adapt the offset voltage(s) fast enough to thereby change the APT voltage(s) within a predetermined temporal limit (e.g., 0.5 ?s). As a result, the fast-switch APT PMIC can enable a power amplifier(s) to support dynamic power control with improved linearity and efficiency.

Abstract: Fast envelope tracking systems are provided herein. In certain embodiments, an envelope tracking system for a power amplifier includes a switching regulator and a differential error amplifier configured to operate in combination with one another to generate a power amplifier supply voltage for the power amplifier based on an envelope of a radio frequency (RF) signal amplified by the power amplifier. The envelope tracking system further includes a differential envelope amplifier configured to amplify a differential envelope signal to generate a single-ended envelope signal that changes in relation to the envelope of the RF signal. Additionally, the differential error amplifier generates an output current operable to adjust a voltage level of the power amplifier supply voltage based on comparing the single-ended envelope signal to a reference signal.

Abstract: A cartridge memory is a cartridge memory used in a recording medium cartridge and includes an antenna section that induces an induced voltage by means of electromagnetic induction, a load modulation section including a load whose magnitude is variable, and a control section that measures the induced voltage and controls the load modulation section on the basis of the measured induced voltage.

Abstract: An audio riser active electrical supervision system includes a high-voltage audio alert system connected to a riser circuit. The high-voltage audio alert system disconnects a high-voltage analog signal from the riser circuit when the audio riser active electrical supervision system operates in a standby mode, and connects the high-voltage analog signal to the riser circuit when the audio riser active electrical supervision system operates in an active alert mode. A plurality of isolator modules operate in a closed state that connects a circuit node to the riser circuit and an open state that disconnects the respective circuit node from the riser circuit. A riser supervision circuit is connected to at least one isolator module to detect a circuit fault on the riser circuit when the audio riser active electrical supervision system operates in the standby mode and the active alert mode.

Abstract: An envelope tracking (ET) integrated circuit (ETIC) supporting multiple types of power amplifiers. The ETIC includes a pair of tracker circuits configured to generate a pair of low-frequency currents at a pair of output nodes, respectively. The ETIC also includes a pair of ET voltage circuits configured to generate a pair of ET voltages at the output nodes, respectively. In various embodiments disclosed herein, the ETIC can be configured to generate the low-frequency currents independent of what type of power amplifier is coupled to the output nodes. Concurrently, the ETIC can also generate the ET voltages in accordance with the type of power amplifier coupled to the output nodes. As such, it is possible to support multiple types of power amplifiers based on a single ETIC, thus helping to reduce footprint, power consumption, and heat dissipation in an electronic device employing the ETIC and the multiple types of power amplifiers.

Abstract: A peak current limiter for an audio system comprising at least two audio amplifiers is described. The peak current limiter comprises at least two audio inputs; at least two audio outputs, each audio output being coupled to a respective one of the at least two audio inputs and configured to be coupled to a respective one of the at least two audio amplifiers. The peak current limiter is configured to receive an audio signal on each of the respective audio inputs. The peak current limiter determines a current value required by each of at least two audio amplifiers. An audio characteristic of at least one of the received audio signals is modified to limit the total current supplied to the at least two amplifiers below a predefined maximum current value.

Abstract: A power supply for a radio-frequency power amplifier includes: first and second linear circuits, configured to linearly amplify a low-power signal and a high-power signal in a first envelope signal respectively and provide first and second voltages to the radio-frequency power amplifier respectively, wherein the low-power signal is a signal with a power ratio less than or equal to 30% in the envelope signal, and the high-power signal other than the low-power signal is a signal with a power ratio greater than or equal to 70% in the envelope signal; and a third circuit, configured to detect the linearly-amplified high-power signal and work in a constant on time control mode having a constant on time or a constant off time control mode having a constant off time so as to provide a third electric current to the radio-frequency power amplifier according to the detected linearly-amplified high-power signal.

Abstract: In accordance with embodiments of the present disclosure, a system may include a circuit having a power converter and an amplifier, wherein the power converter is configured to generate an intermediate voltage, provide the intermediate voltage as an amplifier supply voltage to the amplifier, and share the intermediate voltage with one or more additional circuits external to the circuit, wherein at least one of the one or more additional circuits is configured to generate the intermediate voltage.

Abstract: A flyback power converter circuit includes: a power transformer, a primary side switch and a conversion control circuit. In a DCM, during a dead time, the conversion control circuit calculates an upper limit frequency corresponding to output current according to a frequency upper limit function, and obtains a frequency upper limit masking period according to a reciprocal of the upper limit frequency, wherein the frequency upper limit masking period is a period starting from when the primary side switch is turned ON. During an upper limit selection period, the conversion control circuit selects a valley among one or more valleys in a ringing signal related to a voltage across the primary side switch as an upper limit locked valley, so that the conversion control circuit once again turns ON the primary side switch at a beginning time point of the upper limit locked valley.

Abstract: Systems and methods include a digital control module that receives and processes audio data for output through a loudspeaker. An analog block receives the audio data and the power control signal and amplifies the audio data for output. A first processing path includes a buffer to delay the audio data, a first component to combine the buffered audio data and anti-noise. A second processing path includes an absolute value block to receive the audio data and an envelope detector to receive the absolute value data and generate a maximum value for the envelope. An anti-noise path includes an absolute value block configured to determine an anti-noise absolute value which is combined with the absolute value anti-noise data. A power generator receives the output from the envelope detector and updates a power level to approximate a minimum powered needed to process the audio signal.

Abstract: A multi-mode voltage pump may be configured to select an operational mode based on a temperature of a semiconductor device. The selected mode for a range of temperature values may be determined based on process variations and operational differences caused by temperature changes. The different selected modes of operation of the multi-mode voltage pump may provide pumped voltage having different voltage magnitudes. For example, the multi-mode voltage pump may operate in a first mode that uses two stages to provide a first VPP voltage, a second mode that uses a single stage to provide a second VPP voltage, or a third mode that uses a mixture of a single stage and two stages to provide a third VPP voltage. The third VPP voltage may be between the first and second VPP voltages, with the first VPP voltage having the greatest magnitude. Control signal timing of circuitry of the multi-mode voltage pump may be based on an oscillator signal.