Abstract: An information handling system includes a management controller that may determine average power consumption of a processor, and determine average power measurement at a power supply unit. If the average power consumption of the processor does not match the average power measurement at the power supply unit, then the system may calibrate the average power consumption of the processor to match the average power measurement at the power supply unit.

Abstract: This application relates to circuitry for monitoring for instability of an amplifier. The amplifier (100) has a first signal path between an amplifier input (INN) and an amplifier output (VOUT) and a feedback path from the output to form a feedback loop with at least part of the first signal path. A comparator (212) has a first input configured to receive a first signal (INN) derived from a first amplifier node which is part of said feedback loop and a second input configured to receive a second signal (INP) derived from a second amplifier node which varies with the signal at the amplifier input but does not form part of said feedback loop. The comparator is configured to compare the first signal to the second signal and generate a comparison signal (COMP), wherein in the event of amplifier instability the comparison signal comprises a characteristic indicative of amplifier instability.

Abstract: This application relates to circuitry for monitoring for instability of an amplifier. The amplifier (100) has a first signal path between an amplifier input (INN) and an amplifier output (VOUT) and a feedback path from the output to form a feedback loop with at least part of the first signal path. A comparator (212) has a first input configured to receive a first signal (INN) derived from a first amplifier node which is part of said feedback loop and a second input configured to receive a second signal (INP) derived from a second amplifier node which varies with the signal at the amplifier input but does not form part of said feedback loop. The comparator is configured to compare the first signal to the second signal and generate a comparison signal (COMP), wherein in the event of amplifier instability the comparison signal comprises a characteristic indicative of amplifier instability.

Abstract: RF transistor amplifiers are provided that include a submount and an RF transistor amplifier die that is mounted on top of the submount. A multi-layer encapsulation is formed that at least partially covers the RF transistor amplifier die. The multi-layer encapsulation includes a first dielectric layer and a first conductive layer, where the first dielectric layer is between a top surface of the RF transistor amplifier die and the first conductive layer.

Abstract: Systems and apparatuses are disclosed that include an RF generator configured to generate RF signals having a wavelength. Amplifiers are configured to receive and amplify the RF signals from the RF generator and are separated from each other by a separation distance in a range between about 0.2 times the wavelength and about 10.0 times the wavelength. A power management system is configured to control one or more of the amplifiers based on information received that is associated with the RF signals.

Abstract: A method of controlling bandwidth and peaking over gain in a variable gain amplifier (VGA) device and structure therefor. The device includes at least three differential transistor pairs configured as a cross-coupled differential amplifier with differential input nodes, differential bias nodes, differential output nodes, a current source node, and two cross-coupling nodes. The cross-coupled differential amplifier includes a load resistor coupled to each of the differential output nodes and one of the cross-coupling nodes, and a load inductor coupled to the each of the cross-coupling nodes and a power supply rail. A current source is electrically coupled to the current source node. The cross-coupling configuration with the load resistance and inductance results in a lower bandwidth and lowered peaking at low gain compared to high gain. Further, the tap point into the inductor can be chosen as another variable to “tune” the bandwidth and peaking in a communication system.

Abstract: A multi-stage amplifier with a high signal-to-noise ratio is introduced. Multiple amplification stages are cascaded between an input terminal and an output terminal of the amplifier. A controller switches the output stage among the multiple amplification stages from a normal mode to an attenuation mode in response to the amplifier input being lower than the threshold. In the attenuation mode, the output stage provides an attenuation resistor coupled in series with the load resistor of the amplifier. Noise is successfully attenuated by the attenuation-mode output stage.

Abstract: A radio frequency signal transmission circuit includes a direct current blocking unit, a biasing impedance circuit, and a radio frequency element. The direct current blocking unit has a first terminal for receiving an input signal, and a second terminal coupled to a first bias voltage terminal. The biasing impedance circuit has a first terminal coupled to the first bias voltage terminal for providing a first bias voltage, and a second terminal coupled to a second bias voltage terminal for receiving a second bias voltage. The radio frequency element is coupled to the first bias voltage terminal, and receives and processes the input signal. When the biasing impedance circuit operates in a first mode, the biasing impedance circuit provides a first impedance. When the biasing impedance circuit operates in a second mode, the biasing impedance circuit provides a second impedance greater than the first impedance.

Abstract: A contactless integrated circuit (IC) card reader configured to communicate with a contactless IC card includes an antenna circuit, a variable amplifier that amplifies a carrier signal at an amplification gain and outputs the amplified carrier signal to the antenna circuit as a transmit signal, a variable attenuator that attenuates a receive signal received through the antenna circuit at an attenuation ratio, and a controller that controls the amplification gain and the attenuation ratio based on the attenuated receive signal.

Abstract: A switch IC includes first, second and third switch units, and an amplifier. The first switch unit and the third switch unit are adjacent to each other. The third switch unit and the amplifier are adjacent to each other. The amplifier and the second switch unit are adjacent to each other. The first, second and third switch units, and the amplifier are disposed on a straight line in an order in which a signal passes through the first switch unit, the second switch unit, the third switch unit, and the amplifier.

Abstract: Multi-level envelope tracking systems with adjusted voltage steps are provided. 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, an MLS modulator that controls selection of the regulated voltages over time based on an envelope signal corresponding to an envelope of a radio frequency (RF) signal amplified by the power amplifier, and a modulator output filter coupled between an output of the MLS modulator and the power amplifier supply voltage. The envelope tracking system further includes a switching point adaptation circuit configured to control the voltage level of the regulated voltages outputted by the MLS DC-to-DC converter based on a power level of the RF signal.

Abstract: A method for diagnosing errors in the correct operation of a sensor system. A positive signal amplifier saturation threshold value and a negative signal amplifier saturation threshold value less than the positive signal amplifier saturation threshold value are provided, and at least one signal comparator threshold value. A current value of a first amplified input signal at a first time is provided and a current value of a second amplified input signal obtained at a second time later than the first time, but in the same measurement cycle. The measured values of the first and second amplified input signal are compared to the current signal comparator threshold value. A new output state is determined via the measured first and second amplified input signals. From a previous comparison of the first and second amplified input signal a current output state is provided, from which an expected new output state is determined.

Abstract: Apparatus and methods for true power detection are provided herein. In certain embodiments, a power amplifier system includes an antenna, a directional coupler, and a power amplifier electrically connected to the antenna by way of a through line of the directional coupler. The power amplifier system further includes a combiner that combines a first coupled signal from a first end of the directional coupler's coupled line with a second coupled signal from a second end of the directional coupler's coupled line.

Abstract: A wireless communication device includes: a receiving unit that receives a first signal storing first information with which precision or accuracy of transmission power is recognized; and a transmission unit that transmits a second signal regarding permission of multiple access that allows simultaneous communication with at least one first wireless communication device identified on the basis of the first information. A wireless communication device includes: a transmission unit that transmits a first signal storing first information with which precision or accuracy of transmission power is recognized; a receiving unit that receives a second signal regarding permission of multiple access that allows simultaneous communication after the transmission of the first signal; and a control unit that controls transmission of a third signal on the basis of the second signal.

Abstract: A semiconductor device includes a base, a first switching unit disposed on the base, the first switching unit having a substantially rectangular shape and including plural first switches, and an amplifier unit disposed on the base, the amplifier unit including plural amplifier circuits to which a radio-frequency signal is inputted after passing through the first switching unit. In plan view of the base, the first switching unit has four edges including a first edge, a second edge orthogonal to the first edge, and a third edge parallel to the first edge and orthogonal to the second edge, the amplifier unit includes a first region extending along the first edge, a second region extending along the second region, and a third region extending along the third edge, and at least one of the plural amplifier circuits is disposed in each of the first region, the second region, and the third region.

Abstract: A device for digital envelope tracking with dynamically changing voltage levels for a radio frequency (RF) power amplifier is disclosed. A power management unit generates a set of supply voltages for a power amplifier based on a control signal. A setpoint generator in the power management integrated circuit gradually increases or decreases a target voltage such that the set of supply voltages output from the voltage converter gradually increase or decrease in response to a gradual transition of the target voltage. A transceiver includes digital models for replicating a behavior of the setpoint generator and a voltage regulator in the voltage converter such that a signal pre-distortion unit may use an instantaneous voltage level for signal predistortion.

Abstract: The invention relates to a method for operating a class-D amplifier (2) for an audio signal (4), which class-D amplifier contains an output stage (10) and a signal-processing unit (12) in a signal path (6), wherein a voltage (U) of at least two magnitudes (U1, U2) is provided for the output stage (10), a voltage requirement (B) of the output stage (10) for the audio signal (4) is predictively determined from the audio signal (4) at a measurement location (14) before the signal-processing unit (12), a magnitude (U1, U2) that is minimally sufficient for the voltage requirement (B) is selected on the basis of the voltage requirement (B) and said magnitude is applied to the output stage (10) before the amplification.

Abstract: Described herein are systems and methods that can adjust the performance of a transimpedance amplifier (TIA) in order to compensate for changing environmental and/or manufacturing conditions. In some embodiments, the changing environmental and/or manufacturing conditions may cause a reduction in beta of a bipolar junction transistor (BJT) in the TIA. A low beta may result in a high base current for the BJT causing the output voltage of the TIA to be formatted as an unusable signal output. To compensate for the low beta, the TIA generates an intermediate signal voltage, based on the base current and beta that is compared with the PN junction bias voltage on another BJT. Based on the comparison, the state of a digital state machine may be incremented, and a threshold base current is determined. This threshold base current may decide whether to compensate the operation of the TIA, or discard the chip.

Abstract: In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may include a memory and at least one processor coupled to the memory. The at least one processor may be configured to determine a retransmission rate associated with retransmission of one or more packets by the communications device. The at least one processor may be configured to determine a measurement associated with antenna gain of at least one antenna of the apparatus. The at least one processor may be configured to adjust a transmission power of the apparatus based on the retransmission rate and based on the measurement.

Abstract: At least one embodiment relates to a radio-frequency (RF) power amplifier system for amplifying a first RF signal. The RF power amplifier system includes a RF power amplifier being configured to amplify a second RF signal. The RF power amplifier system also includes a control loop for controlling a power level of the second RF signal. The control loop includes a RF output power determining unit for determining a power level of the amplified second RF signal. The control loop also includes a gain determining unit for determining an actual large signal gain based on the determined power level of the amplified second RF signal and a power level of the second RF signal. Further, the control loop includes an attenuator for attenuating the first RF signal and for providing the attenuated first RF signal to the RF power amplifier as the second RF signal.

Abstract: A device for measuring a reflection coefficient of an antenna by using a radio frequency (RF) feedback signal provided by a coupler based on an RF transmission signal provided to the antenna includes a feedback circuit configured to generate a baseband feedback signal by down-converting and filtering the RF feedback signal, and a signal processing device configured to control the down-converting, based on a target frequency band, process a baseband transmission signal and the baseband feedback signal to have the target frequency band, and calculate a reflection coefficient of the antenna corresponding to the target frequency band. The RF transmission signal is generated from the baseband transmission signal.

Abstract: A method and a device for adjusting an audio signal, and an audio system are provided. The method includes: obtaining a candidate audio signal (S1); obtaining a current noise signal in an environment (S2); calculating a first plurality of difference values in loudness between the candidate audio signal and the current noise signal (S3); modifying the first plurality of difference values with a plurality of target factors, where the plurality of target factors are obtained based on a plurality of test noise signals and a corresponding plurality of test audio signals (S4); and modifying the candidate audio signal with the modified first plurality of difference values to obtain a target audio signal (S5). Therefore, loudness loss of the audio signal perceived due to the noise signal can be compensated, and an overcompensation issue can be solved.

Abstract: A class-E power oscillator (PO) is disclosed. The class-E PO includes a first inductor, a switch, a first capacitor, a resonant circuit, and a feedback network. The first inductor is coupled in series to a first power supply. The switch is connected between the first inductor and a primary common node. The first capacitor is connected between the first inductor and the primary common node. The resonant circuit includes a second inductor, a second capacitor, and a resistor. The second inductor is connected between the first inductor and the primary common node. The second capacitor is connected between the first inductor and the primary common node, and is coupled in series to the second inductor. The resistor is connected between the first inductor and the primary common node, and is coupled in series to the second inductor. The feedback network is connected between the switch and a feedback node. The feedback node is located between the second inductor and the second capacitor.

Abstract: Systems, methods, and circuitries are provided for generating supply voltages for a power amplifier in a digital envelope tracking system. In one example, a voltage generation circuitry converts a source voltage into a supply voltage based on a target voltage. The voltage regulation circuitry includes an adjustable boost circuitry that multiplies the source voltage to generate an input voltage having a voltage equal to or greater than the source voltage and a step-down regulator circuitry that regulates the input voltage to generate a regulated output voltage having a voltage that is less than or equal to the input voltage. A voltage splitter circuitry is coupled to the regulated output voltage and is configured to generate at least one derived output voltage from the regulated output voltage. A supply modulator provides a selected one of the at least one derived output voltage to a power amplifier.

Abstract: A power amplifier (20) for a transmitter circuit (10) is disclosed. The power amplifier (20) comprises at least one field-effect transistor (100, 100n, 100p) having a gate terminal (110, 110n, 110p) and a bulk terminal (120, 120n, 120p), wherein the at least one field-effect transistor (100, 100n, 100n) is configured to receive an input voltage at the gate terminal (110, 110p, 110n) and a dynamic bias voltage at the bulk terminal (120, 120n, 120p). Furthermore, the power amplifier (20) comprises a bias-voltage generation circuit (130). The input voltage is a linear function of an input signal. The bias-voltage generation circuit (130) is configured to generate the dynamic bias voltage as a nonlinear function of an envelope of the input signal.

Abstract: Provided is an AD conversion unit that includes a comparator to compare an electric signal with a reference signal having a variable level, and performs AD conversion of the electric signal by using a result of the comparison between the electric signal and the reference signal by the comparator. An attenuation unit attenuates the electric signal supplied to the comparator with the amplitude of the electric signal.

Abstract: A transistor circuit includes a transistor having a gate terminal and first and second conduction terminals, a first circuit configured to convert an AC input signal of the transistor circuit to a gate bias voltage and to apply the gate bias voltage to the gate terminal of the transistor, a second circuit configured to convert the AC input signal of the transistor circuit to a control voltage, and a switching circuit configured to apply a first voltage to the first conduction terminal of the transistor in response to the control voltage.

Abstract: The specification and drawings present a new method, apparatus and software related product (e.g., a computer readable memory or a storage device) for automatically stabilizing a volume of different audio streams/contents to predefined boundary levels which may be requested by a user. According to an embodiment, an automated volume control feature may allow a user to set the highest level of volume for any audio stream played on a user's device for automatically adjusting the incoming audio content volume of audio streams not to exceed at least the highest level of volume set as the maximum threshold volume.

Abstract: In accordance with embodiments of the present disclosure, a system may include an impedance estimator configured to estimate an impedance of a load and generate a target current based at least on an input voltage and the impedance, a voltage feedback loop responsive to a difference between the input voltage and an output voltage of the load, and a current controller configured to, responsive to the voltage feedback loop, the impedance estimator, and the input voltage, generate an output current to the load.

Abstract: A device for detecting proximity to an active alternating current (AC) voltage source is provided. The device includes a housing, at least one antenna configured to generate a signal in response to exposure to electromagnetic radiation, signal processing circuitry configured to process the signal generated by the at least one antenna, a microprocessor configured to determine, from the processed signal, whether the alert device is proximate to the active AC voltage source, a communication device configured to generate a signal in response to a determination that the alert device is proximate the active AC voltage source, and an interference reduction device configured to discharge an accumulated charge on the alert device to reduce electromagnetic interference from sources other than the active AC voltage source.

Abstract: Apparatus and methods for power amplifiers with positive envelope feedback are provided herein. In certain implementations, a power amplifier system includes a power amplification stage that amplifies a radio frequency signal, at least one envelope detector that generates one or more detection signals indicating an output signal envelope of the power amplification stage, and a wideband feedback circuit that provides positive envelope feedback to a bias of the power amplification stage based on the one or more detection signals. The power amplifier system further includes a supply modulator that controls a voltage level of a supply voltage of the power amplification stage based on the one or more detection signals such that the supply voltage is modulated with the output signal envelope through positive envelope feedback.

Abstract: A band selection switch circuit for an amplifier with an impedance matching circuit includes a band selection switch and an impedance compensation circuit. The band selection switch includes a signal port switch configured to selectively connect to one of a common transmit port, transmit and receive (TxRx) ports, and receive ports, and an impedance port switch configured to selectively connect the common transmit port and one of the receive ports and an impedance port. The impedance compensation circuit includes an impedance element connected to the impedance port.

Abstract: An electronic device may include a feedback circuit that may determine an error of a first signal to be transmitted to a second electronic device. The electronic device may also include a transceiver that may adjust the first signal based on the error and send the adjusted first signal to the second electronic device. The electronic device may also include a coupler circuitry configured to route a second signal received from the second electronic device or a third electronic device to the feedback circuit, such that the feedback circuit may determine one or more properties associated with the second signal.

Abstract: The invention relates to an amplification circuit (100), comprising: a VGA (2), an AGC loop (10) for automatically controlling the gain of the VGA (2), a switching circuit (14) for switching between an AGC mode, in which the gain of the VGA (2) is automatically controlled by an output signal of the AGC loop (10) and a manual gain control, MGC, mode, in which the gain of the VGA (2) can be manually controlled by an input signal, and a read/write circuit (30) with a contact (31) for connection to a peripheral system, wherein the read/write circuit (30) is configured, in the MGC mode, to provide the input signal from the contact (31) via a write-mode path (32) to the VGA (2), and, in the AGC mode, to provide the output signal of the AGC loop (10) via a read-mode path (33) on the contact (31).

Abstract: High bandwidth envelope trackers are provided herein. In certain embodiments, an envelope tracking system for a power amplifier includes a switching regulator that operates in combination with a high bandwidth amplifier 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 high bandwidth amplifier includes an output that generates an output current for adjusting the power amplifier supply voltage, a first input that receives a reference signal, and a second input that receives an envelope signal indicating the envelope of the RF signal. The second input has lower input impedance than the first input to provide a rapid transient response and high envelope tracking bandwidth.

Abstract: A power distribution and control module includes a digital data processor and associated memory module operating an energy management program or schema and a battery charging manager program thereon. The energy management schema is operable to determine an instantaneous configuration of the power and distribution and control module, to determine total instantaneous input power available, total instantaneous power demand by connected power loads and to allocate a portion of the input power to power the loads. Thereafter any unallocated power is allocated to charge rechargeable batteries using allocation criteria that are situationally variable.

Abstract: A transistor circuit includes a transistor having a gate terminal and first and second conduction terminals, a first circuit configured to convert an AC input signal of the transistor circuit to a gate bias voltage and to apply the gate bias voltage to the gate terminal of the transistor, a second circuit configured to convert the AC input signal of the transistor circuit to a control voltage, and a switching circuit configured to apply a first voltage to the first conduction terminal of the transistor in response to the control voltage.

Abstract: Embodiments of the disclosure relate to calibrating a power amplifier. The power amplifier calibration circuit is configured to provide a plurality of bias signal combinations each including a respective first bias signal and a respective second bias signal to the power amplifier. Power amplifier performance parameters for each of the bias signal combinations can be measured and provided to a control circuit in the power amplifier calibration circuit. The control circuit is configured to rank the measured power amplifier performance parameters based on predefined ranking criteria and determines a selected bias signal combination that can optimize the power amplifier performance parameters of the power amplifier. As such, it is possible to calibrate the power amplifier to operate at a balanced performance level, thus helping to improve radio frequency (RF) coverage and performance of the remote unit in a wireless distribution system (WDS).

Abstract: Audio content in a single-bit audio stream can be reproduced at a transducer by mapping the single-bit audio stream to symbols in a multi-bit audio stream. Volume control may be implemented, in part, in the digital domain and, in part, in the analog domain. In the digital domain, when converting the single-bit audio stream to a plurality of symbols, the plurality of symbols is selected based, at least in part, on audio content of the single-bit audio stream and a desired volume level. In the analog domain, when converting an analog current signal output from a current-steering DAC processing the plurality of symbols to an analog voltage signal, an analog gain value may be selected based, at least in part, on the desired volume level.

Abstract: A signal processing device according to an embodiment includes a plurality of signal processing units and a pseudo signal generating unit. The plurality of signal processing units are provided in a plurality of reception antennas which receive reflection signals of a transmission signal reflected on an object, and perform signal processing in parallel on beat signals which are generated based on the transmission signal and the reflections signals. The pseudo signal generating unit generates a pseudo signal imitating the beat signal, and inputs the pseudo signal as a target of the signal processing into the plurality of signal processing units in parallel.

Abstract: A transmission unit includes: a power amplification module that amplifies the power of an input signal and outputs an amplified signal; and a power supply module that supplies a power supply voltage to the power amplification module on the basis of a first control signal corresponding to the band width of the input signal. On the basis of the first control signal, the power supply module varies the power supply voltage in accordance with the amplitude level of the input signal in the case where the band width of the input signal is a first band width and varies the power supply voltage in accordance with the average output power of the power amplification module in the case where the band width of the input signal is a second band width that is larger than the first band width.

Abstract: A multimode voltage tracker circuit is provided. The multimode voltage tracker circuit is configured to generate a modulated voltage for amplifying a radio frequency (RF) signal(s), which may be modulated in a wide range of modulation bandwidth. In one non-limiting example, the multimode voltage tracker circuit can be configured to operate in a low modulation bandwidth (LMB) mode to generate an average power tracking (APT) modulated voltage for amplifying the RF signal(s) when the RF signal(s) is modulated in a lower modulation bandwidth (e.g., <50 KHz). As such, the multimode voltage tracker circuit can be adapted to support lower bandwidth communications in an Internet-of-Things (IoT) network with improved efficiency, stability, and performance.

Abstract: An integrated circuit includes a first high-pass filter having an input coupled to receive a first signal and an output coupled to a first input of a first differential pair of transistors. A second high-pass filter includes an input coupled to receive a second signal and an output coupled to a second input of the first differential pair of transistors. The second signal may be a complementary signal of the first signal. A second differential pair of transistors includes control electrodes coupled to a first voltage supply terminal. A boost circuit is coupled between the second differential pair of transistors and the first voltage supply terminal. A low-pass filter is coupled between the first differential pair of transistors and the second differential pair of transistors.

Abstract: A mobile terminal, a housing component and a manufacturing method thereof are provided. The housing component of the mobile terminal includes a conductive housing and at least one conductive component. The conductive housing is provided with at least one slot. The at least one slot is configured to divide the conductive housing into a plurality of regions, and is filled with an insulating layer. The at least one conductive component is attached to the conductive housing and across the at least one slot, so as to electrically connect the plurality of regions together. The housing component of the mobile terminal realizes grounding and conduction of an antenna through electrically connecting the plurality of regions of the conductive housing using the at least one conductive component.

Abstract: A method for controlling a supply voltage of a power amplifier, and an electronic device are provided. The method includes acquiring a state of an envelope of a to-be-amplified signal, where the state of the envelope includes a rising edge and a falling edge; acquiring a first voltage corresponding to the envelope when the state of the envelope is the falling edge, and controlling the supply voltage of the power amplifier according to the first voltage. The method also includes acquiring a second voltage corresponding to a maximum peak value of the to-be-amplified signal in a first preset time when the state of the envelope is the rising edge, and controlling, according to the second voltage, the supply voltage of the power amplifier in the first preset time.

Abstract: A Cartesian loop circuit includes a reference signal amplifier, a forward path coupled to the reference signal amplifier, a feedback path coupled to the forward path, and a controller. The forward path includes an up-mixer to up mix a forward path signal to a radio frequency signal. The feedback path includes a down-mixer to down mix a feedback signal to a frequency of a baseband reference signal inputted to the forward path. The feedback path provides the down-mixed feedback signal to the forward path. The controller is to perform power control at a low power by controlling a gain of the reference signal amplifier and is to perform power control at a high power by controlling a gain of the down-mixer. At the high power, the controller may perform power control by further controlling the gain of the up-mixer.

Abstract: A power distribution and control module includes a digital data processor and associated memory module operating an energy management program or schema and a battery charging manager program thereon. The energy management schema is operable to determine an instantaneous configuration of the power and distribution and control module, to determine total instantaneous input power available, total instantaneous power demand by connected power loads and to allocate a portion of the input power to power the loads. Thereafter any unallocated power is allocated to charge rechargeable batteries using allocation criteria that are situationally variable.

Abstract: The present disclosure discloses a protective circuit for an output terminal capacitor of a light-emitting diode (LED) driver, and a method for providing the protective circuit. The protective circuit is connected to two ends of the output terminal capacitor and includes a switching element, a voltage dividing unit and a one-way conduction unit. The switching element is in parallel connection with the output terminal capacitor, the one-way conduction unit is connected between the switching element and the output terminal capacitor, the switching element is switched on when a voltage exceeds a threshold so as to establish a short circuit between two ends of the output terminal capacitor and prevent an excessively large voltage from being applied to the output terminal capacitor, and the one-way conduction unit allows a current to flow across the output terminal capacitor from the protective circuit by a one-way conduction.

Abstract: A Cartesian loop circuit includes a reference signal amplifier, a forward path coupled to the reference signal amplifier, a feedback path coupled to the forward path, and a controller. The forward path includes an up-mixer to up mix a forward path signal to a radio frequency signal. The feedback path includes a down-mixer to down mix a feedback signal to a frequency of a baseband reference signal inputted to the forward path. The feedback path provides the down-mixed feedback signal to the forward path. The controller is to perform power control at a low power by controlling a gain of the reference signal amplifier and is to perform power control at a high power by controlling a gain of the down-mixer. At the high power, the controller may perform power control by further controlling the gain of the up-mixer.

Abstract: In accordance with an embodiment, method for generating an output signal of an amplifier having an increased signal to noise ratio includes receiving a first signal at an input terminal of the amplifier that is not part of a differential input. The input terminal of the amplifier is a sole input terminal of the amplifier. The first signal has an externally received portion and a feedback portion. A first amplified signal is generated at an output of the amplifier. High frequency components of the first amplified signal may be filtered. A feedback signal is generated at the sole input terminal of the amplifier in response to the first output signal.