Abstract: The present disclosure provides a detailed description of techniques for implementing a linear amplifier with extended linear output range. More specifically, the present disclosure discloses techniques for extending the output signal range of a linear amplifier with a minimum increase in power consumption and die area consumption. Some embodiments facilitate coupling boost amplifiers with adjustable independent biasing to a main amplifier to boost the output signal near the non-linear regions of the transfer curve to extend the linear range. Certain embodiments comprise a first boost amplifier biased to contribute to the output signal when the input signal is near a negative threshold voltage, and a second boost amplifier biased to contribute to the output signal when the input signal is near a positive threshold voltage. In certain embodiments, the threshold voltages and/or the bias currents can be controlled to adjust certain amplifier attributes.

Abstract: The present disclosure relates to methods and systems for LNAs with high linearity and low noise for wideband receivers that receive high dynamic range signals. A multi-stage multipath LNA is disclosed in which outputs from various stages are amplified with variable gains and combined in parallel. A smart gain control unit evaluates the noise and non-linearity characteristics associated with each gain stage to configure the variable gains for the various stages to generate an overall LNA gain that minimizes the overall noise and/or non-linearity characteristics of the LNA while ensuring that the overall gain for the LNA satisfies the desired gain. The variable gains may be configured to change smoothly over the dynamic range of the input signal. Noise is minimized by reducing additional gain stages and by the smooth change in gain when switching between stages. High linearity performance is maintained by minimizing the number of gain stages combined.

Abstract: A low noise amplifier includes: first and seventh transistors configured to respectively receive first and second input signals; second, third, and fifth transistors connected to the first transistor; eighth, ninth, and eleventh transistors connected to the seventh transistor; a third resistive element; fourth and tenth transistors respectively connected to the third and ninth transistors; sixth and twelfth transistors respectively connected to second and first output terminals; and first and second resistive elements.

Abstract: In an embodiment, an electronic device includes a first amplifier having a non-inverting input configured to receive a reference voltage and an inverting input coupled to a first output node, where the first amplifier is configured to produce a first output voltage at the first output node. The electronic device also includes a second amplifier having a non-inverting input coupled to a ground reference level, and an inverting input coupled to the first output node via a first resistor and to a second output node via a second resistor, where the second amplifier is configured to produce a second output voltage at the second output node.

Abstract: An analog differential amplifier circuit, such as an operational transconductance amplifier (OTA), with input offset correction capability. First and second analog floating gate (AFG) devices each include a trim transistor connected in parallel with a series transistor in first and second input legs, respectively, of the amplifier. Floating gate electrodes in the AFG devices are differentially programmed to correct for error in the output signal in response to zero input differential voltage at its inputs. Temperature stability is attained by programming the floating gate electrodes to gate voltages above the floating gate transistors. In one embodiment, the AFG devices each include a second trim transistor sharing the same floating gate electrode; the sum of the currents conducted by the second trim transistors is added, by way of a current mirror, to the tail current applied to the first and second input legs.

Abstract: Methods and systems for an analog-to-digital converter (ADC) with constant common mode voltage may include in an ADC comprising a sampling switch on a first input line to the ADC, a sampling switch on a second input line to the ADC, N switched capacitor pairs and M single switched capacitors on the first input line, and N switched capacitor pairs and M single switched capacitors on the second input line: sampling an input voltage by closing the sampling switches, opening the sampling switches and comparing voltage levels between the input lines, iteratively switching the switched capacitor pairs between a reference voltage (Vref) and ground based on the compared voltage levels, and iteratively switching the single switched capacitors between ground and voltages that are a fraction of Vref, which may equal Vref/2x where x ranges from 0 to m?1 and m is a number of single switched capacitors per input line.

Abstract: An instrumentation amplifier includes first and second resistors for gain setting. The operational amplifiers within the instrumentation amplifier include selectively enabled current drive sources coupled to the amplifier output. The first and second resistors have variable resistances. A control circuit is configured to select the variable resistances of the first and second resistors to implement a fixed gain for the instrumentation amplifier and further selectively enable the current drive sources. The control circuit receives an indication of a downstream programmable gain (for example, from a downstream programmable gain amplifier). The variable resistances of the first and second resistors are selected to be scaled inversely with respect to the downstream programmable gain and the current drive sources are enabled proportionately with respect to the downstream programmable gain.

Abstract: Some embodiments relate to a method and circuit for gain compensation. The method includes detecting a strength of an output signal generated by a power amplifier of a transmitter in response to a commanded transmission signal. The method also includes comparing the detected strength of the output signal to a delayed version of a detected strength of the commanded transmission signal to obtain an error signal. The method further includes compensating for gain drop of the output signal by adjusting a gain of the transmitter based on the error signal.

Abstract: A system has a baseband gain stage to receive incoming in-phase and quadrature voltage signals and output in-phase and quadrature current signals, a mixer core arranged to receive the in-phase and quadrature current signals and output radio frequency signals, and a variable gain amplifier to receive the radio frequency signals and produce a broadband radio signal.

Abstract: A system that utilizes an amplified signal is disclosed that includes a plurality of first switches coupled to a plurality of first impedances. A plurality of second switches coupled to a plurality of second impedances. An amplifier having a first input coupled to the plurality of first switches and a second input coupled to the plurality of second switches. A leakage current offset source coupled to the first input of the amplifier, wherein the leakage current offset source cancels a leakage current component of a first current provided from the plurality of first switches to the first input.

Abstract: Gain variations during a packet can lead to significant performance degradation in communications systems that use high order quadrature amplitude modulation (QAM). A method and the associated apparatus track such variations in an OFDM system and completely eliminate any performance degradation. Gain estimation and compensation is employed with the use of pilot subcarriers in the payload of an OFDM data packet. Estimated pilot magnitude ratios are averaged, throughout the processing life of a packet, to yield accurate gain estimations. A gain compensation factor is used to adjust data carriers. An exclusion method is also employed to eliminate pilot carriers which contribute to noise.

Abstract: Provided is an emphasis circuit capable of obtaining a desired emphasis amount with which waveform deterioration of an output signal in a high frequency band (high frequency band deterioration) is suppressed without increasing power consumption (current consumption). In the emphasis circuit, a baseband amplifier section and a peaking amplifier section are connected in parallel to each other, and respective drive current setting sections are adjusted to adjust respective drive current values thereof so that the sum of the drive current value of the baseband amplifier section and the drive current value of the peaking amplifier section may be constant.

Abstract: A power device temperature monitor is provided. The power device temperature monitor includes a power device having a control terminal and an output terminal, where the output terminal is configured to output a current as directed by a voltage of the control terminal. The power device temperature monitor includes an inductor coupled to the output terminal of the power device and an amplifier coupled to the inductor. The power device temperature monitor includes a computing device that receives an output of the amplifier, the computing device is configured to derive a temperature of the power device based upon the output of the amplifier.

Abstract: Provided is a power amplifier installed in wireless communication terminals and systems. According to one aspect of the present invention, a reconfigurable power amplifier capable of selecting a wide band frequency is provided. The reconfigurable power amplifier includes input transistors receiving a radio frequency (RF) signal and a reconfigurable adaptive power cell configured to select the wide band frequency by applying a common-gate bias voltage to a plurality of common-gate transistors with a plurality of separate common gates to amplify the RF signal.

Abstract: A reconfigurable operational amplifier includes: a first signal input terminal; a second signal input terminal; an output terminal; an operational amplifier having a non-inverting input, an inverting input, and an output; a negative feedback circuit path from the output of the operational amplifier to the inverting input of the operational amplifier; a first input circuit path from the first signal input terminal to the non-inverting input of the operational amplifier; a second input circuit path from the second signal input terminal to the inverting input of the operational amplifier; an output circuit path from the output of the operational amplifier to the output terminal; and logic units, wherein one or more of the logic units are provided in at least one of the negative feedback circuit path, the first input circuit path, the second input circuit path, and the output circuit path.

Abstract: A differential signal is input to a pair of gates of a differential pair, a differential signal generated by a load circuit connected to drains of the differential pair is amplified by a differential amplifier stage, and the amplified differential signal is fed back to a pair of sources of the differential pair via a feedback circuit. It is possible to maintain a high input impedance in the pair of gates of the differential pair while not being influenced by a gain of negative feedback of an amplifier circuit, and it is possible to perform amplification in an input stage by using a pair of a first transistor and a second transistor of the differential pair. Therefore, compared with the related art, it is possible to decrease the number of transistors in the input stage and to reduce a flicker noise.

Abstract: A circuit includes an electrical gain element, a variable reactance element, and a controller. The electrical gain element is arranged to receive and change an amplitude of a signal over a set frequency range. The variable reactance element is connected to the electrical gain element. The controller is configured to control the variable reactance element to have a reactance such that the electrical gain element has a set gain slope as a function of signal frequency over the set frequency range.

Abstract: A power amplifier module includes an amplifier transistor and a bias circuit. A first power supply voltage based on a first operation mode or a second power supply voltage based on a second operation mode is supplied to the amplifier transistor. The amplifier transistor receives a first signal and outputs a second signal obtained by amplifying the first signal. The bias circuit supplies a bias current to the amplifier transistor. The bias circuit includes first and second resistors and first and second transistors. The first transistor is connected in series with the first resistor and is turned ON by a first bias control voltage which is supplied when the first operation mode is used. The second transistor is connected in series with the second resistor and is turned ON by a second bias control voltage which is supplied when the second operation mode is used.

Abstract: An amplifier includes a differential amplifier and a compensator. A differential amplifier includes a current source and paired transistors. The paired transistors generate an output signal by dividing a source current supplied by the current source into emitter currents of the paired transistors in response to a difference between an input signal and a reference signal. A compensator includes an amplifying transistor and a feedback circuit that feeds a collector current output from a collector of the amplifying transistor back to a base of the amplifying transistor therethrough. The compensator generates the reference signal at a base of the amplifying transistor. The compensator decreases power consumption of the amplifying transistor when the collector current increases, and increases the power consumption of the amplifying transistor when the collector current decreases. The compensator suppresses a peaking of gain in a low frequency band.

Abstract: Apparatuses and methods are described where input signals are supplied to a translinear mesh. In some embodiments an output of the translinear mesh is regulated to a desired value.

Abstract: A circuit may include a signal converter configured to convert a differential signal to a single-ended signal. The circuit may also include a biasing circuit configured to set a bias of the signal converter based on a feedback of the single-ended signal such that a voltage level of the single-ended signal is at a target voltage level.

Abstract: Disclosed examples include a programmable attenuator circuit providing selective cross coupling of impedance components between circuit input nodes and output nodes according to control signals to set or adjust an attenuation value of the attenuator circuit. The attenuator circuit includes a plurality of attenuator impedance components, and a switching circuit to selectively connect at least a first attenuator impedance component between the first input node and the second output node, to selectively connect at least a second attenuator impedance component between the second input node and the first output node, to selectively connect a third attenuator impedance component between the first input node and the first output node, and to selectively connect a fourth attenuator impedance component between the second input node and the second output node.

Abstract: An input buffer circuit comprising: a first current source; a first differential control circuit, configured to generate a first bias voltage at the first couple terminal according to the input signals, and configured to generate first control signals according to the input signals; a second current source; a second differential control circuit, configured to generate a second bias voltage at the second couple terminal according to the input signals, and configured to generate second control signals according to the input signals; a third current source, configured to provide a first current according to the second bias voltage; a first differential output circuit, configured to receive the first control signals to generate output signals; a fourth current source, configured to drain a second current according to the first bias voltage; and a second differential output circuit, configured to receive the second control signals to generate the output signal.

Abstract: A control signal is generated for mechanical loudspeaker protection, or for other signal pre-processing functions. The procedure contains the following steps: perform a non-linearity analysis based on current and voltage measurements; use the results of the non-linearity analysis, and the voltage and current measurements to control audio processing for the loudspeaker thereby to implement loudspeaker protection and/or acoustic signal processing.

Abstract: An integrated circuit includes a motor current input voltage-to-current (VI) converter that receives a motor current sensor voltage from a motor and a reference voltage to generate an output current related to a motor's current. A motor current calibration VI converter compensates for errors in the motor current input VI converter and generates a calibration output current based on the reference voltage, wherein the output current and the calibration output current are combined to form an estimate of the motor's current.

Abstract: There is provided an output stage comprising: a phase splitter for receiving an input signal and for generating first and second drive signals of opposite phase in dependence thereon; a DC offset signal generator for generating a DC offset signal; an adder for adding the DC offset signal to the first drive signal to provide a first modified drive signal; a subtractor for subtracting the DC offset signal from the second drive signal to provide a second modified drive signal; a first drive transistor associated with a first power supply voltage, for generating a first output signal in dependence on the first modified drive signal; a second drive transistor associated with a second power supply voltage, for generating a second output signal in dependence on the second modified drive signal; and a combiner for combining the first and second output signals to generate a phase combined output signal.

Abstract: A differential amplifier includes a differential circuit section, a gain circuit section amplifying the output of the differential circuit section and outputting the amplified output, and an offset voltage adjusting circuit section carrying out an adjustment so that a voltage equal to the offset voltage of the differential circuit section is added to the input voltage applied across a pair of input terminals and giving the adjusted voltage to the differential circuit section. The offset voltage adjusting circuit section includes a differential pair formed of a pair of MOS-FETs, a MOS-FET forming the load of the differential pair, and two resistor elements each corresponding to one of the MOS-FETs of the differential pair and the load, and giving a voltage equal to the offset voltage to the differential pair. This provides a differential amplifier suitable for detecting the output current of the zero-phase current transformer in an earth leakage breaker.

Abstract: The differential amplifying circuit includes a first bias resistor having a variable resistance and connected between the first input terminal and the reference voltage node. The differential amplifying circuit includes a second bias resistor having a variable resistance and connected between the second input terminal and the reference voltage node. The differential amplifying circuit includes a controlling circuit that controls the resistance of the first bias resistor and the resistance of the second bias resistor in synchronization with each other.

Abstract: An amplifier circuit outputs a control signal for controlling a control target circuit and receives input of a feedback signal from the control target circuit. The amplifier circuit and the control target circuit constitute a feedback loop that includes a plurality of poles. A semiconductor capacitive element is provided for phase compensation in the feedback loop. The amplifier circuit includes an output branch that includes a first transistor having a first current terminal from which the control signal is output and a second current terminal connected to a power supply potential, and a branch that is connected in parallel to the output branch and includes a cascode circuit. The cascode circuit includes a second transistor having third and fourth current terminals, and a third transistor having fifth and sixth current terminals. The fourth and fifth current terminals are connected to each other.

Abstract: Embodiments of variable gain transimpedance amplifiers are described. In an embodiment, the variable gain transimpedance amplifier may include an amplifier coupled to an adjustable gain feedback network, the adjustable gain feedback network including a selectable set of Resistor-Capacitor (RC) branches, each RC branch having one or more unit RC elements, each unit RC element being comprised of a unit resistor and a unit capacitor arranged in parallel.

Abstract: An apparatus includes a first bias circuit configured to generate a first current that varies with temperature according to a first slope. The apparatus also includes a second bias circuit configured to generate a second current that varies with temperature according to a second slope. The apparatus further includes a low noise amplifier including a transconductance stage that is responsive to an output of the first bias circuit. The apparatus also includes a load coupled to an output of the low noise amplifier and responsive to an output of the second bias circuit.

Abstract: A switching regulator comprising a droop amplifier responsive to a reference voltage and a feedback voltage to generate a droop voltage. The droop amplifier includes a boost circuit configurable to increase a transconductance of the droop amplifier during an upward transition of the reference voltage. The switching regulator further includes a comparator responsive to the droop voltage and a current sense signal. The comparator is configured to initiate switching in the switching regulator.

Abstract: There is provided a variable gain multistage amplifier including: an input terminal to which the input signal is input; multistage amplifiers amplify the input signal, the multistage amplifiers being connected in series; and an output terminal that outputs the amplified signal, and the multistage amplifiers include one or more successive cascode amplifiers, one of which is in final stage.

Abstract: A transconductance gain stage including a pair of gain transistors, each gain transistor having a base and an emitter, the emitter of each gain transistor electrically coupled to a degenerating resistor, and the emitter of each gain transistor connected to a gain resistor.

Abstract: The present document relates to multi-stage amplifiers, such as linear regulators or linear voltage regulators (e.g. low-dropout regulators) configured to provide a constant output voltage subject to load transients. A multi-stage amplifier is described. The multi-stage amplifier comprises a first amplification stage configured to provide a stage output voltage at a stage output node. Furthermore, the amplifier comprises an intermediate amplification stage comprising an amplifier current source configured to provide an amplifier current and an amplifier transistor arranged in series with the amplifier current source. A gate of the amplifier transistor is coupled to the stage output node of the first amplification stage. The intermediate amplification stage is configured to provide an amplified or attenuated stage output voltage at a midpoint between the amplifier current source and the amplifier transistor.

Abstract: A method, computer program, device and system are provided for determining channel state information for use in a wireless communications network. The channel state information includes a rank indicator (RI), precoding matrix index (PMI) and channel quality indicator (CQI). The RI, PMI or CQI can be determined based on channel covariance estimation and the Taylor series approximation of its inverse. Further, the RI and PMI can be determined separately.

Abstract: A device comprising a clock circuit, a control circuit, and a current mode logic (CML) circuit is disclosed. The clock circuit provides a first differential clock signal and the control circuit generates a control signal based at least in part on the frequency of the first differential clock signal. The CML circuit generates a second differential clock signal based at least in part on the first differential clock signal. The CML circuit operates in one of a plurality of different frequency modes based at least in part on the control signal and includes a number of variable resistors that are responsive to the control signal.

Abstract: A protection circuit includes a transformer (11), wherein a terminal (11a) of the transformer (11) is connected to a terminal part (1) of a radio IC, a terminal (11b) thereof is connected to a grounding point, a terminal (11c) thereof is connected to an input or output of an on-chip circuit (7), and a terminal (11d) thereof is connected to a bias power supply circuit (18). A signal is transmitted between a terminal-side inductor (11f) and a circuit-side inductor (11g) due to magnetic coupling therebetween. The terminal-side inductor and the circuit-side inductor are insulated to each other from a standpoint of DC and hence isolated completely to each other. Thus, different voltages can be applied to the terminal part (1) and the input or output of the on-chip circuit (7), respectively.

Abstract: A multi-mode OPAMP-based circuit is provided. An input amplifying stage amplifies a pair of input differential signals to provide a pair of intermediate differential signals. An output amplifying stage amplifies the pair of intermediate differential signals to provide a pair of output differential signals. A first capacitor is disposed in a first negative feedback loop of the output amplifying stage. A second capacitor is disposed in a second negative feedback loop of the output amplifying stage. A third capacitor is selectively disposed in a first positive feedback loop of the output amplifying stage or coupled to the first capacitor in parallel according to a control signal. A fourth capacitor is selectively disposed in a second positive feedback loop of the output amplifying stage or coupled to the second capacitor in parallel according to the control signal.

Abstract: A method may include applying an input differential voltage to input terminals of an amplifier, a first input terminal coupled to a gate of a first transistor and a second input terminal coupled to a gate of a second transistor. The method may also include varying a gain of the amplifier by varying at least one of: a resistance of a first resistor, the first resistor coupled between a source of the first transistor and a source of the second transistor; and a resistance of a second resistor, the second resistor coupled between a source of a third transistor and a source of a fourth transistor; wherein: the third transistor is coupled at its drain to the drain of the first transistor; and the fourth transistor is coupled at its drain to the drain of the second transistor and a gate of the third transistor and coupled at its gate to the drain of the third transistor.

Abstract: An instrumentation amplifier includes first and second resistors for gain setting. The operational amplifiers within the instrumentation amplifier include selectively enabled current drive sources coupled to the amplifier output. The first and second resistors have variable resistances. A control circuit is configured to select the variable resistances of the first and second resistors to implement a fixed gain for the instrumentation amplifier and further selectively enable the current drive sources. The control circuit receives an indication of a downstream programmable gain (for example, from a downstream programmable gain amplifier). The variable resistances of the first and second resistors are selected to be scaled inversely with respect to the downstream programmable gain and the current drive sources are enabled proportionately with respect to the downstream programmable gain.

Abstract: An integrated circuit having transceiver circuitry is provided. The transceiver circuitry may include an equalization circuit such as a decision feedback equalizer (DFE). The DFE may include a variable gain amplifier (VGA) that is coupled to a summation node circuit and a digital sampler. The DFE may also include an operational amplifier that is coupled in a negative feedback loop and that provides a controlled power supply voltage to the VGA so that the VGA is able to provide a stable common mode output voltage to the digital sampler. The operational amplifier may be a self-biased operational amplifier with an output stage that includes miller compensation circuitry for enhanced stability.

Abstract: First and second transconductance amplifier input stages having first and second gain characteristics, respectively, are combined. The resulting combined input stage has a third gain characteristic with a linear range that is larger than a linear range of either of the first and second gain characteristics.

Abstract: Disclosed herein is a signal processor including: a plurality of parallel-connected variable gain amplification sections with variable gains; and a control section adapted to control the potentials of control terminals of each of the variable gain amplification sections and make transitions in the control terminal potentials according to different input signal levels.

Abstract: Receiver circuits that can be reconfigured to generate test signals in a wireless device are disclosed. In an exemplary design, an apparatus includes a mixer and an amplifier. The mixer downconverts an input radio frequency (RF) signal based on a local oscillator (LO) signal in a first mode. The amplifier, which is formed by at least a portion of the mixer, amplifies the LO signal and provides an amplified LO signal in a second mode. In another exemplary design, an apparatus includes an amplifier and an attenuator. The amplifier receives and amplifies an input RF signal in a first mode. The attenuator, which is formed by at least a portion of the amplifier, receives and passes an LO signal in a second mode.

Abstract: An amplifier, including a voltage-to-current converter (V2I) to control an output current based on an input voltage, resistive degeneration circuitry to reduce baseband gain of the voltage-to-current converter, capacitive degeneration circuitry to increase passband gain of the voltage-to-current converter, and impedance control circuitry to compensate for negative input impedance of the capacitive degeneration circuitry. The V2I may include series-connected complimentary V2Is. The impedance control circuitry may include resistive negative feedback to provide a real part of input impedance, which may increase a frequency range for which the amplifier is linear. Capacitive degeneration and associated phase compensation may increase a frequency range for which the resistive feedback is negative. The amplifier may be configured as a single-input/single-output system and/or as a differential system.

Abstract: According to one embodiment, a compact low-power receiver comprises first and second analog circuits connected by a digitally controlled interface circuit. The first analog circuit has a first direct-current (DC) offset and a first common mode voltage at an output, and the second analog circuit has a second DC offset and a second common mode voltage at an input. The digitally controlled interface circuit connects the output to the input, and is configured to match the first and second DC offsets and to match the first and second common mode voltages. In one embodiment, the first analog circuit is a variable gain control transimpedance amplifier (TIA) implemented using a current mode buffer, the second analog circuit is a second-order adjustable low-pass filter, whereby a three-pole adjustable low-pass filter in the compact low-power receiver is effectively produced.

Abstract: An amplifier biasing circuit that reduces gain variation in short channel amplifiers, an amplifier biasing circuit that produces a constant Gm biasing signal for short channel amplifiers, and a multistage amplifier that advantageously incorporates embodiment of both types of amplifier biasing circuits are described. Both amplifier biasing circuit approaches use an operational amplifier to equalize internal bias circuit voltages. The constant Gm biasing circuit produces a Gm of 1/R, where R is the value of a trim variable resistor value. The biasing circuit that reduces gain variation produces a Gm of approximately 1/R, where R is the value of a trim variable resistor value, however, the biasing circuit is configurable to adjust the bias circuit Gm to mitigate the impact of a wide range of circuit specific characteristics and a wide range of changes in the operational environment in which the circuit can be used, such as changes in temperature.

Abstract: A receiver circuit includes a first differential amplification unit including a variable load section, and configured to receive first and second input signals, and to generate first and second output signals, which are amplified based on an impedance value of the variable load section and a voltage difference between the first and second input signals, a second differential amplification unit configured to receive the first and second output signals and to generate a third output signal based on a voltage difference between the first and second output signals, and a signal generating unit configured to generate an equalization signal for controlling the variable load section based on the third output signal.

Abstract: A circuit is provided for both boosting output current and providing short circuit protection in an integrated circuit such as an operational amplifier. In an embodiment, a current-boosting output stage with short-circuit protection includes six current sources and six transistors, where the the boosting of output current is achieved using positive feedback and the short circuit protection is achieved using negative feedback.