Abstract: A selectable current limiter circuit to limit the current an amplifier with a load. The limiter circuit limits the current of an amplifier by comparing a voltage reference that follows the output swing of the amplifier to voltage drop across a current limiting resistor coupled to the output of the amplifier. The limiter circuits are operatively coupled to buffer and switch circuits that delay the current limiting until the limiter circuits are activated.

Abstract: A communication device includes a pulse width modulator that is provided with an oscillator signal at a communication carrier frequency. The pulse width modulator input is an amplified reference voltage that is regulated by a feedback loop. A modulation control provides the data signal to be transmitted. The modulation control may either be provided to the amplifier mixed with the reference voltage or may be provided to the pulse width modulator. A power transistor receives the pulse width modulator output and generates a chip output signal. An external filter is connected at the chip output to filter the signal that is provided to the communication antenna and produce a carrier sinusoid with an amplitude proportional to the pulse width modulated by voltage regulation and by the modulating data input. The power source is connected to the external filter.

Abstract: Envelope tracking power converter circuitry is configured to receive a supply voltage and simultaneously provide a first envelope tracking power supply signal for amplifying a first RF input signal and a second envelope tracking signal for amplifying a second RF input signal.

Abstract: Provided is a power supply circuit for a wireless mobile device having a plurality of power amplification components. The power supply circuit includes: a first DC-DC converter, for providing at least one constant output voltage (which is provided to the power amplification components) and/or at least one DC intermediate voltage; a second DC-DC converter, for providing a DC component of at least one time-varying output voltage; and at least one linear amplifier. When the at least one linear amplifier receives the at least one DC intermediate voltage from the first DC-DC converter, the at least one linear amplifier provides at least one AC component of the at least one time-varying output voltage. The DC component and the at least one AC component of the at least one time-varying output voltage are combined into the at least one time-varying output voltage and provided to the power amplification components.

Abstract: Provided is a technique for effectively implementing DC removal during switching of transmission scheme or transmission data in a wireless apparatus equipped with a function for supplying a voltage to a power amplifier by ET control. When the ET control is not carried out in a power supply unit, more specifically, when an IQ signal is not present, a control unit outputs a pulse width modulation (PWM) signal for a fixed voltage via a switch unit. In other words, the switch unit selectively supplies a PWM signal for ET and a PWM signal for the fixed voltage to a switching amplifier. The switching amplifier is controlled by a predetermined control signal from the control unit.

Abstract: According to some implementations, a voltage supply system includes a boost converter including a bypass core. The voltage supply system also includes a buck converter configured to receive an input voltage and generate a buck voltage. The voltage supply system further includes a routing circuit configured to provide the buck voltage as an input to the boost converter.

Abstract: Provided herein are a single-inductor dual-output (SIDO) power converter operable in a discontinuous conduction mode and a control method thereof. The SIDO power converter is operable to switch between a boost mode and a buck-boost mode. The SIDO power converter dynamically adjusts output timings of clock signals with respect to the loads according to a load difference therebetween to lower the power consumption with a light load when the inductor current is zero to achieve optimal power distribution.

Abstract: A method of characterizing an envelope tracking amplification stage, the method comprising: generating an input test waveform which is representative of an input waveform under normal operating conditions of the amplification stage; applying a respective one of a plurality of different shaping functions, each comprising a non-linear transfer function, to the input signal envelope in each of a plurality of test periods during the period in which the input test waveform is applied as the input signal to generate the input to the envelope tracking modulated supply voltage; measuring parameters of the amplification stage during the period in which the input test waveform is applied in order to allow determination of the gain, phase and efficiency characteristics of the amplifier; and for each of the gain, phase and efficiency characteristics, generating a three dimensional plot of the characteristic with respect to input power and supply voltage applied to the amplifier.

Abstract: Systems and methods are provided for a crystal (xtal) oscillator with high interference immunity. Generated reference signals may be processed to mitigate effects of interference. The processing may comprise filtering, particularly at harmonic positions, to remove or greatly reduce interference signals.

Abstract: An active electronically scanned array (AESA) includes a plurality of power amplifiers including first power amplifiers and second power amplifiers. The first power amplifiers are biased by a first drain voltage. The second power amplifiers are biased by a second drain voltage. The second drain voltage is different from the first drain voltage.

Abstract: An integrated circuit for use in remote keyless entry (RKE) applications is disclosed that integrates two drivers with a shared dual mode antenna. The drivers may be integrated on a single integrated circuit chip using high voltage (HV) complementary metal-oxide-semiconductor (CMOS) processes. In immobilizer mode of operation, an immobilizer driver coupled to the dual mode antenna is configured to drive the dual mode antenna, while an LF mode driver coupled to the dual mode antenna is configured to be idle. In LF mode of operation, the LF mode driver is configured to drive the dual mode antenna, while the immobilizer driver is configured to be idle. In some implementations, the drivers are coupled to a common node coupled to the dual mode antenna and are selectively biased with different supply voltages based on the current mode of operation to prevent current leakage and component damage.

Abstract: A cordless phone apparatus is provided, which includes one or more slave devices and a master device. The master device includes: i) a LAN transmitter configured to transmit slave device information to a wireless IP terminal via a wireless LAN, wherein the slave device information includes identification information of each slave device registered to the master device, ii) a receiver configured to receive from the wireless IP terminal selection of the identification information of a destination slave device and selection of transfer data including at least one of ringtone data, wallpaper data, and phone book data, iii) a transfer data converter configured to convert at least one of the ringtone data, wallpaper data, and phone book data included in the transfer data into a data format usable in the destination slave device, and iv) a cordless phone transmitter configured to transmit the converted transfer data to the destination slave device.

Abstract: A power detector is described herein that detects a true power provided by power amplifier of an RF transmitter. The power detector may include a plurality of voltage detectors that determine one or more voltages of a power amplifier included in the RF transmitter and/or a transformer included in the RF transmitter. At least one of the voltage detectors may be coupled to a sense inductor that senses one or more magnetic fields emitted by the transformer. The at least one voltage detector coupled to the sense inductor determines the voltage induced across the sense inductor as a result of the sensed magnetic field(s). The determined voltage(s) may be used to determine the load impedance of an antenna of the RF transmitter that transmits the RF signals. The load impedance may be used to accurately measure the power regardless of any impedance mismatches between the power amplifier and the antenna.

Abstract: A power amplifier without transformer includes an audio isolator, a phase detector, a power protection controller, a rectifier and an amplifier. The audio isolator is used to isolate audio-source input end and the amplifier for making the amplifier directly connected to utility power via the rectifier without transformer to increase transformation efficiency and decrease weight and bulk of the power amplifier substantially. The phase detector is used to detect utility power phase whether correct. The power protection controller is used to determine utility power whether supply to the amplifier for preventing the amplifier from broken caused by excessive current.

Abstract: A power amplifier having a stack structure comprises a first driver stage that receives a power voltage from a power supply and receives and amplifies an input signal; a second driver stage that receives the power voltage from the power supply, has an input terminal connected with an output terminal of the first driver stage, and receives and amplifies an output signal from the first driver stage; and a power stage that has a power input terminal connected with a ground terminal of the first driver stage and a ground terminal of the second driver stage and receives a virtual ground voltage, and has an input terminal connected with an output terminal of the second driver stage and receives and amplifies an output signal from the second driver stage.

Abstract: An amplifier cell apparatus has an RF input node, a first power transistor in communication with the input node through a first input impedance matching network, a second power transistor in communication with the input node through a second input impedance matching network, and an RF output node in communication with the first and second power transistors through a single output impedance matching network so that the first and second input impedance matching networks are disposed on an RF input side of the amplifier cell.

Abstract: A tracking power supply for one or more amplifiers includes one or more cascaded sets of power boost circuits to temporarily boost the positive and/or negative power supply rail, respectively. Each power boost circuit may include a gain element and an energy source such as a capacitor or battery, and the power boost circuits are linked to provide a greater degree of voltage boost when needed. An optional control circuit monitors amplifier output signal levels, or separately amplified input signal levels, and provides power boost control signals to the power boost circuits, which temporarily raise or lower the positive and/or negative supply voltages above or below the nominal voltage rails in tandem with the highest and lowest output signals, respectively, from the amplifier(s).

Abstract: A differential audio amplifier system and a related system to generate an output signal free or with only very limited clipping are disclosed. It provides a solution to solve the problem of limited electrical speaker amplifier output power available (e.g. inside battery driver applications). A differential speaker amplifier has positive and negative supply rails. In a first embodiment of the disclosure the negative supply rail is connected to the output of an inverting buck-boost converter and the positive supply rail is directly connected to VSS voltage. In a second embodiment of the disclosure the positive supply rail is connected to the output of a buck-boost converter and the negative supply rail is directly connected to a positive battery voltage.

Abstract: Disclosed boost amplifiers are used with a BTL amplifier that outputs balanced audio signals and that has an output current capacity and a dynamic power capacity. Disclosed amplifiers include an audio amplifier with a dynamic power capacity and that amplifies the balanced audio signals and applies them to a load, at least one diode that receives audio signals and produces single-ended input power signals, and at least one regulator that converts the single-ended input power signal into a regulated power signal of a higher magnitude. The boost regulator presenting a variable input impedance to the BTL amplifier such that the output current capacity of the BTL amplifier is not exceeded. Disclosed amplifiers also include a DC power reservoir that stores power from the regulated power signal and supplies sufficient power that the dynamic output power capacity of the audio amplifier exceeds the dynamic power capacity of the BTL amplifier.

Abstract: A multi-mode bias modulator operating in envelope tracking mode or average power tracking mode and an envelope tracking power amplifier using the same are disclosed. The envelope tracking power amplifier includes a multi-mode bias modulator and a power amplifier. The multi-mode bias modulator generates a variable bias voltage using a linear amplifier and a switching amplifier operating in envelope tracking mode or average power tracking mode in accordance with an operation mode control signal that determines any one of envelope tracking mode and average power tracking mode. The power amplifier is biased in response to the variable bias voltage, power-amplifies a radio frequency (RF) signal, and outputs the amplified RF signal to an antenna.

Abstract: A capacitance sensing apparatus includes: a driving circuit unit applying a driving signal of a first period to a node capacitor; a first integrating circuit unit integrating voltage charged in the node capacitor to generate output voltage of which a voltage level is changed twice during a second period; a buffer capacitor charged or discharged by the output voltage of the first integrating circuit unit; a second integrating circuit unit integrating voltage charged in the buffer capacitor to generate output voltage of which a voltage level is changed twice during the first period; and an amplifying unit differentially amplifying non-inverted output voltage and inverted output voltage of the second integrating circuit unit, wherein the amplifying unit amplifies voltage corresponding to a difference between the non-inverted output voltage and the inverted output voltage during a reset section of the second integrating circuit unit to generate offset information.

Abstract: A power amplifying apparatus and a method for effectively controlling a bias voltage of a power amplifier are provided. An electronic device includes a baseband signal processor configured to convert a baseband signal to an envelope signal, a power amplifier configured to amplify a Radio Frequency (RF) signal based on the baseband signal, a power modulator configured to modulate an input voltage to a bias voltage of the power amplifier based on the envelope signal, and a power controller configured to control an operation of the power modulator according to a characteristic of the baseband signal.

Abstract: Adaptive rail power amplifier technology processes an audio signal by feeding the audio signal to the power amplifier to produce an output signal, applying positive and negative power supply voltages centered with respect to the audio signal to the positive and negative power supply rails of the power amplifier, comparing the output signal with the positive and negative power supply rail voltages to produce dynamically varying positive and negative control signals, feeding the positive and negative control signals to positive and negative high current charge pumps and adding supplemental positive and negative voltages from the positive and negative charge pumps to the positive and negative power supply rails to produce a linear adaptive rail voltage which tracks the output signal.

Abstract: A device may be associated with a power source. The device may include a charge pump configured to output a pulse-width modulated voltage based upon an input voltage from the power source, with the pulse-width modulated voltage varying between a first voltage and a second voltage. The device may also include a low-pass filter comprising an output capacitor, with the output capacitor being configured to average the pulsed-width modulated voltage and to output a filtered voltage having a value different than that of the input voltage. The device may further include a controller configured to selectively decouple the charge pump from the power source when a load imposed on the low-pass filter is below a threshold load.

Abstract: RF PA circuitry and a DC-DC converter, which includes an RF PA envelope power supply and DC-DC control circuitry, are disclosed. The PA envelope power supply provides an envelope power supply signal to the RF PA circuitry. The DC-DC control circuitry has a DC-DC look-up table (LUT) structure, which has at least a first DC-DC LUT. The DC-DC control circuitry uses DC-DC LUT index information as an index to the DC-DC LUT structure to obtain DC-DC converter operational control parameters. The DC-DC control circuitry then configures the PA envelope power supply using the DC-DC converter operational control parameters. Using the DC-DC LUT structure provides flexibility in configuring the DC-DC converter for different applications, for multiple static operating conditions, for multiple dynamic operating conditions, or any combination thereof.

Abstract: A bias circuit may include an envelope detecting unit detecting an envelope of an input signal, a source voltage generating unit generating a source voltage using a power supply voltage, and an envelope amplifying unit receiving the power supply voltage and the source voltage as a driving voltage and amplifying an envelope signal detected by the envelope detecting unit to generate a first bias voltage.

Abstract: An adaptive voltage divider for measuring a high voltage between a ground terminal (GND) and a measurement terminal (U). It comprises a first branch comprising a first set of impedance elements (Z, R) forming a voltage divider circuit connected between the ground terminals (GND) and the measurement terminal (U) and a voltage meter (AD2) configured to measure voltage on one of the impedance elements (Z, R) of the first branch. Furthermore, it comprises a second branch comprising a second set of impedance elements (Q, P) connected between the ground terminal (GND) and the measurement terminal (U) and switchable between a plurality of configurations, wherein in at least one configuration the second set of impedance elements (Q, P) forms a voltage divider circuit, and voltage meters (AD1, AD3) configured to measure voltage on at least one of the impedance elements (Q, P) of the second branch.

Abstract: In one embodiment, a method of verifying a component coupled to an output of a power supply includes measuring a frequency response from a control input of the power supply to the output of the power supply. The method also includes comparing the frequency response to a predetermined metric based on the measuring. The component is determined to be valid if the frequency response falls within the predetermined metric.

Abstract: A system for circuit for generating an output signal with a dynamically adjustable slew rate includes a sampler, an envelope detector, an envelope comparison and control circuit, and a voltage-driver circuit that includes output buffers for generating the output signal. The sampler generates a sampled signal indicative of the slew rate of the output signal. The envelope detector generates an envelope detection signal indicative of a peak value of the sampled signal. The envelope comparison and control circuit compares a voltage level of the envelope detection signal with various threshold voltage levels, and generates control signals. The voltage-driver circuit controls the operation states of the output buffers based on the control signals to dynamically adjust the slew rate of the output signal.

Abstract: A power supply system includes a high-speed power supply providing a first output, operating in conjunction with an externally supplied DC source or low frequency power supply which provides a second output. A frequency blocking power combiner circuit combines the first and second outputs to generate a third output in order to drive a load, while providing frequency-selective isolation between the first and second outputs. A feedback circuit coupled to the combined, third output compares this combined, third output with a predetermined control signal and generates a control signal for controlling the high-speed power supply, based on a difference between the third output and the predetermined control signal. The feedback circuit does not control the DC source or the low frequency power supply, but controls only the high-speed power supply.

Abstract: Apparatus and methods for capacitive load reduction are disclosed. In one embodiment, a power amplifier system includes a plurality of power amplifiers and an envelope tracking module for generating a supply voltage for the power amplifiers. The power amplifier system further includes a switch and a decoupling capacitor operatively associated with a first power amplifier of the system. The switch is configured to electrically float an end of the decoupling capacitor when the first power amplifier is disabled so as to reduce capacitive loading of the envelope tracker and to operate as a dampening resistor when the power amplifier is enabled so as to improve the stability of the system.

Abstract: Method and apparatus for controlling a programmable power converter are provided. The method and apparatus generate a first power source and a second power source. The voltage level of the second power source is lower than the voltage level of the first power source. The first power source and the second power source provide a power supply for a control circuit. The control circuit will use the first power source as its power supply when the first power source is low. The control circuit will use the second power source as its power supply for saving the power when the first power source is high.

Abstract: Electronic devices may provide microphone bias voltages to accessories. The accessories may include circuitry powered from the microphone bias voltages. The output impedances and the voltages of the microphone bias voltages may be adjusted during operation of the electronic devices. An electronic device may provide a bias voltage to an accessory, may lower the output impedance of the bias voltage, and may increase the voltage of the bias voltage during operation of the electronic device. Accessories that received bias voltages with lowered impedances or raised voltage levels may exhibit greater tolerance to faults such as moisture-based shorts and may be able to continue operating even in the presence of some faults.

Abstract: A front end radio architecture (FERA) with power management is disclosed. The FERA includes a first power amplifier (PA) block having a first-first PA for amplifying first-first signals and a first-second PA for amplifying first-second signals. Also included is a second PA block having a second-first PA for amplifying second-first signals and a second-second PA for amplifying second-second signals. At least one power supply is adapted to selectively supply power to the first-first PA and the second-second PA through a first path. The power supply is also adapted to selectively supply power to the first-second PA and the second-first PA through a second path. A control system is adapted to selectively enable and disable the first-first PA, the first-second PA, the second-first PA, and the second-second PA.

Abstract: An apparatus comprises an amplifier having an input coupled to a radio frequency signal through a digital-to-analog circuit, an adaptive power supply having an output coupled to a bias voltage of the amplifier, wherein the output of the adaptive power supply is configured to have a shape similar to an envelope of the radio frequency signal and a feedback circuit comprising a sensing circuit and a mapping circuit, wherein the sensing circuit is configured to sense a current flowing from the adaptive power supply to the amplifier and sense the bias voltage of the amplifier, and wherein the mapping circuit is configured to sense the bias voltage of the amplifier, and wherein the mapping circuit is configured to generate a control signal for dynamically adjusting parameters of a low pass filter so as to stabilize the adaptive power supply.

Abstract: Embodiments disclosed in the detailed description relate to a pseudo-envelope follower power management system used to manage the power delivered to a linear RF power amplifier.

Abstract: Aspects of the disclosure process an amplifier circuit. The amplifier circuit includes an input stage, an intermediate stage, an output stage and a detecting and controlling circuit. The input stage is configured to receive an electrical signal for amplification. The intermediate stage is configured to amplify with an adjustable gain. The output stage is configured to drive an audio output device in response to the amplified electrical signal. The detecting and controlling circuit is configured to detect a current for driving the audio output device, and adjust the gain of the intermediate stage based on the current to compensate for a pole change of the amplifier circuit due to a change of the current.

Abstract: A damping circuit having an input terminal and an output terminal is described. The damping circuit comprises a driver having an input and an output; an RC circuit coupled between the input terminal and the output; and a resistor coupled between the output and the output terminal, wherein the RC circuit delays passing a signal from the output terminal to the input terminal and a low impedance associated with the driver generally reduces ringing.

Abstract: Circuits and methods for performing multilevel power amplification using multiple different supply voltages or states are disclosed. In some embodiments, power amplifiers are provided that switch between three or more supply voltages or states.

Abstract: A method and an amplifier for amplifying audio signals receive and process an incoming audio sample in preparation for amplification by an electronic amplifier circuit. A boost supply circuit receives a voltage from a power supply. A processor system determines whether amplification of the incoming audio sample warrants more voltage than the voltage received from the power supply. Before completing the processing of the incoming audio sample, the processor system sends a signal to the boost supply circuit to boost the voltage received from the power supply and to supply the boosted voltage to the electronic amplifier circuit if the incoming audio sample warrants more voltage than the voltage received from the power supply. Otherwise, the boost supply circuit passes the voltage received from the power supply to the electronic amplifier circuit.

Abstract: A voltage converter can be switched among two or more modes to produce an output voltage tracking a reference voltage that can be of an intermediate level between discrete levels corresponding to the modes. One or more voltages generated from a power supply voltage, such as a battery voltage, can be compared with the reference voltage to determine whether to adjust the mode. The reference voltage can be independent of the power supply voltage.

Abstract: A multi-level amplifier including a converter circuit being supplied with a supply voltage and operable to generate at least two output voltages, a voltage comparator circuit adapted to compare each of the output voltages with the supply voltage to generate a driving signal, and an amplifier circuit being supplied with an analog input signal, the amplifier circuit including an analog-to-digital converter coupled to a power stage driver and power stage, wherein the power stage driver receives the driving signal from the voltage comparator.

Abstract: Apparatus and methods for envelope tracking are disclosed. In one embodiment, a power amplifier system including a power amplifier and an envelope tracker is provided. The power amplifier is configured to amplify a radio frequency (RF) signal, and the envelope tracker is configured to control a supply voltage of the power amplifier using an envelope of the RF signal. The envelope tracker includes a buck converter for generating a buck voltage from a battery voltage and a digital-to-analog conversion (DAC) module for adjusting the buck voltage based on the envelope of the RF signal to generate the supply voltage for the power amplifier.

Abstract: A voltage converter can be switched among two or more modes to produce an output voltage tracking a reference voltage that can be of an intermediate level between discrete levels corresponding to the modes. One or more voltages generated from a power supply voltage, such as a battery voltage, can be compared with the reference voltage to determine whether to adjust the mode. The reference voltage can be independent of the power supply voltage.

Abstract: Apparatus and methods are disclosed, such as those involving a receiver device. One such apparatus includes an equalizer configured to process an input signal transmitted over a channel. The equalizer can include a programmable gain amplifier (PGA) block which includes an input node configured to receive the input signal; an output node; and a programmable gain amplifier (PGA). The PGA amplifies the input signal with an adjustable gain. The PGA block also includes a gain control block having an input electrically coupled to the input node. The gain control block is configured to adjust the gain of the PGA at least partly in response to the input signal from the input node such that the PGA generates an output signal with a substantially constant amplitude envelope to the output node.

Abstract: Apparatus and methods for reducing capacitive loading of an envelope tracker are disclosed. In one embodiment, a wireless device comprises an envelope tracker including an output configured to generate a power amplifier supply voltage, a plurality of power amplifiers, and a power supply network configured to provide the power amplifier supply voltage to the plurality of power amplifiers. The power amplifier supply network includes a first inductor electrically connected between a supply input of a first power amplifier and the output of the envelope tracker, and a second inductor electrically connected between a supply input of a second power amplifier and the output of the envelope tracker. The first inductor resonates with a distributed capacitance of the power supply network at a frequency greater than the envelope tracker's modulation bandwidth of, and the second inductor resonates with the distributed capacitance at a frequency greater than the envelope tracker's modulation bandwidth.

Abstract: A radio frequency (RF) power amplifier circuit with spur cancellation for GSM/GPRS/EDGE transceivers is disclosed. There is a power amplifier with an RF input, an RF output, and a voltage supply input. Additionally, there is an adjustable DC-DC converter with an input connected to a battery, an output connected to the voltage supply input of the power amplifier with a DC supply voltage signal generated thereby. A spur compensator generates an error control signal responsive to spurs in the DC supply voltage signal. The error control signal is applied to the RF input of the power amplifier.

Abstract: An apparatus for driving speakers includes user-configurable amplifier cells for driving selected speakers, a synchronous rectifier circuit, and a control system. Each cell connects between power rails. The rectifier circuit provides current on the rails for consumption by the cells. The current depends on the configuration. The control system implements a model of the rectifier circuit and cells and uses it to control an audio input signal in response to information concerning electrical outputs of the amplifier cells. This indirectly limits current drawn from the synchronous rectifier circuit.

Abstract: A power amplifier may include a first amplifying unit receiving a first bias signal to amplify a power level of an input signal; an envelope detecting unit detecting an envelope of the input signal; a comparing circuit unit comparing a peak value of the detected envelope with a preset reference voltage; and a second amplifying unit amplifying the power level of the input signal according to a second bias signal set depending on a comparison result of the comparing circuit unit.

Abstract: Peak information about an envelope of a high frequency signal extracted from an output of a high frequency power amplifier (101) and information about a power supply voltage applied to the high frequency power amplifier (101) are detected. In order to suppress HCI degradation based on an additional value that is calculated by addition of the information a controller (10) controls a power supply voltage regulation circuit (125) and a current regulation circuit (126), thereby automatically regulating a power supply voltage and an operating current for the high frequency power amplifier (101). Even when an output voltage exceeds the power supply voltage, a maximum value of a voltage applied to a transistor can be identified, so that HCI degradation can be suppressed.