Abstract: A compensated amplifier for use in a power converter controller. The compensated amplifier comprises a first amplifier, a second amplifier, an integrator, and an arithmetic operator. The first amplifier coupled to receive a sensed signal and a reference signal and configured to generate a first error signal in response to the sensed signal and the reference signal. The second amplifier coupled to the first amplifier and configured to generate a second error signal in response to the sensed signal and the reference signal. The integrator coupled to the first amplifier and configured to generate an integrated error signal in response to the first error signal. The arithmetic operator coupled to the integrator and to the second amplifier, wherein the arithmetic operator is configured to generate a control signal in response to the integrated error signal and the second error signal.

Abstract: A communication device includes a power amplifier that generates power signals according to one or more operating bands of communication data, with the amplitude being driven and generated in output stages of the power amplifier. The final stage can include an output passive network that suppresses suppress an amplitude modulation-to-phase modulation (AM-PM) distortion. During a back-off power mode a bias of a capacitive unit of the output power network component can be adjusted to minimize an overall capacitance variation. An output passive network can further generate a flat-phase response between dual resonances of operation.

Abstract: Enhanced operational amplifier trim circuitry and techniques are presented herein. In one implementation, a circuit includes a reference circuit configured to produce a set of reference voltages, and a digital-to-analog conversion (DAC) circuit. The DAC circuit comprises a plurality of transistor pairs, where each pair among the plurality of transistor pairs is configured to provide portions of adjustment currents for an operational amplifier based at least on the set of reference voltages and sizing among transistors of each pair. The circuit also includes drain switching elements coupled to drain terminals of the transistors of each pair and configured to selectively couple one or more of the portions of the adjustment currents to the operational amplifier in accordance with digital trim codes.

Abstract: A distributed power management circuit is provided. In embodiments disclosed herein, the distributed power management circuit can achieve multiple performance enhancing objectives simultaneously. More specifically, the distributed power management circuit can be configured to switch a modulated voltage from one voltage level to another within a very short switching window, reduce in-rush current required for switching the modulated voltage, and minimize a ripple in the modulated voltage, all at same time. As a result, the distributed power management circuit can be provided in a wireless device (e.g., smartphone) to enable very fast voltage switching across a wide modulation bandwidth (e.g., 400 MHz) with reduced power consumption and voltage distortion.

Abstract: A power amplifier includes: a power amplification circuit and a linearity compensation circuit; and herein the linearity compensation circuit is connected between a transistor amplification circuit and a biasing circuit of the power amplification circuit, to linearly compensate a nonlinear distortion of the power amplification circuit.

Abstract: A circuit includes an operational amplifier having: a positive input; a negative input; an operational amplifier output; a differential front end; a positive channel (PCH) input stage; a negative channel (NCH) input stage; and an output stage. The operational amplifier also includes a current limit circuit coupled to an output of the output stage and including: an output current sense voltage circuit having an output configured to provide an output current sense voltage; an indirect current feedback circuit coupled to the output of the output current sense voltage circuit, the indirect current feedback circuit having an output configured to provide an output current feedback sense voltage responsive to the output current sense voltage; and control circuitry coupled to the indirect current feedback circuit and configured vary a resistance between the output stage output and ground responsive to a difference between the output current feedback sense voltage and a reference voltage.

Abstract: Differential input circuits employ protection transistors and feedback paths to limit the differential voltage applied to input transistors. In an example arrangement, a differential input voltage is applied to terminals of the protection transistors, and current paths couple the respective protection transistors to control terminals of the input transistors, respectively. A control terminal drive voltage source is coupled to the control terminals of the input protection transistors to control the drive voltage applied to those terminals. Feedback paths, one for each of the input transistors, control voltages applied to the control terminals of the input transistors, maintaining the input differential voltage at a relatively low level and defined by the product of a specified current value and a specified resistance value.

Abstract: Provided is an output amplifier having: a push-pull output-stage formed by first and second output-stage transistors; and a detection circuit detecting an abnormal output current output by the output amplifier and including: a coupling circuit, generating first and second currents mirroring current flowing in the first output-stage transistor and third and fourth currents mirroring current flowing in the second output-stage transistor, coupling the first and third currents at a first output node, outputting a first voltage at the first output node, coupling the second and fourth currents at a second output node, and outputting a second voltage at the second output node; and a determination circuit, outputting a determination signal indicating normality of an output current based on the first and second voltages. The coupling circuit generates the first to fourth currents. In the reference state, the third current >the first current, the second current >the fourth current.

Abstract: An active electrode has an electrode for sensing an electric potential and generating an input signal, and a shield placed near the electrode but being electric insulated from the electrode. An integrated amplifier (10) has an input connected to the at least one electrode for receiving the input signal, and providing a buffered path outputting a buffered output signal. The shield being connected to the output of the integrated amplifier to actively drive the electrical potential of the shield, thereby providing an active shielding of the electrode. The buffered path includes a first mixer (11) in front of the integrated amplifier for frequency shifting the input signal from a basic frequency range to a higher frequency range, and a second mixer (12) on the output of the integrated amplifier for frequency shifting the amplified signal from the higher frequency range back to the basic frequency range. The active electrode may be used for recording EEG signals.

Abstract: An amplifier circuit includes a voltage-to-current conversion circuit and a current-to-voltage conversion circuit. The voltage-to-current conversion circuit generates a current signal according to an input voltage signal, and includes an operational transconductance amplifier (OTA) used to output the current signal at an output port of the OTA. The current-to-voltage conversion circuit generates an output voltage signal according to the current signal, and includes a linear amplifier (LA), wherein an input port of the LA is coupled to the output port of the OTA, and the output voltage signal is derived from an output signal at an output port of the LA.

Abstract: Aspects of the present disclosure provide a method for regulating an integration current of a sensing amplifier. The sensing amplifier includes a first input transistor and a second input transistor, wherein a source of the first input transistor and a source of the second input transistor are coupled to a source node. The method includes pulling a current from or sourcing the current to the source node, measuring the integration current, comparing the measured integration current with a reference signal, and adjusting the current pulled from or sourced to the source node based on the comparison.

Abstract: A compact ADC circuit can include one or more comparators, and a serial DAC (Digital-to-Analog) circuit that provides a signal to the comparator (or comparators). In addition, the ADC circuit can include a serial DAC redistribution sequencer that can provide a plurality of signals as input to the serial DAC circuit and is subject to a redistribution cycle and which receives as input a signal from a data multiplexer whose input connects electronically to an output of the comparator. The circuit can further include an ADC code register that provides an ADC output that connects electronically to the output of the comparator and the input to the data multiplexer. Shared logic circuitry for sharing common logic between pixels can be included, wherein the shared logic circuitry connects electronically to the data multiplexer and the ADC code register, wherein the shared logic circuitry promotes area and power savings for the pixel detector circuit.

Abstract: A method of temperature compensation in an optical-fingerprint detection system includes acquiring a first reading associated with one or more pixels of an array. The first reading is a baseline reading. The method further includes acquiring a second reading associated with the one or more pixels of the array. The second reading includes the baseline plus a signal. Producing a temperature compensated signal reading by subtracting the first reading from the second reading. The array is an optical-fingerprint array, and each pixel of the array is coupled to a readout circuit via a pixel switch. The method includes row-based and frame-based schemes and a blind pixel scheme. Readout circuit improvements including multiplexed analog front-end (AFE), charge magnifier with column charge offset compensation and a low-noise gate driver circuit are provided.

Abstract: An electronic amplification-interface circuit includes a differential-current reading circuit having a first input terminal and a second input terminal. The differential-current reading circuit includes a continuous-time sigma-delta conversion circuit formed by an integrator-and-adder module generating an output signal that is coupled to an input of a multilevel-quantizer circuit configured to output a multilevel quantized signal. The integrator-and-adder module includes a differential current-integrator circuit configured to output a voltage proportional to an integral of a difference between currents received at the first and second input terminals. A digital-to-analog converter, driven by a respective reference current, receives and converts the multilevel quantized signal into a differential analog feedback signal. The integrator-and-adder module adds the differential analog feedback signal to the differential signal formed at the first and second input terminals.

Abstract: Systems and methods for magnitude and phase trimming are provided. In one aspect, a radio frequency (RF) trimmer circuit includes an input terminal configured to receive an RF signal, an output terminal configured to output the RF signal, a control input configured to receive a control signal, at least one impedance element, and at least one transistor configured to selectively connect the impedance element onto a path between the input and output terminals. The selectively connecting the impedance element controls at least one of a magnitude trim and a phase trim of the RF signal.

Abstract: An active load stage converts a first input current and a second input current into a first voltage and a second voltage. A driver amplifier operates upon receiving the first voltage and the second voltage from the active load stage, and outputs a current to an output terminal. The driver amplifier has a first transistor and a second transistor connected in series between a first reference potential terminal and a second reference potential terminal. The first transistor receives the first voltage at a gate and passes a first current, and the second transistor receives the second voltage at a gate and passes a second current. A minimum selector provides feedback to the first voltage and the second voltage such that an absolute value of each of the first current and the second current becomes more than or equal to a quiescent current of the driver amplifier.

Abstract: A method for use in an analog circuit having a plurality of differential pairs of elements, wherein for each pair of the plurality of differential pairs of elements, the elements of the pair are designed to match but may have mismatch that induces error. The method includes, for each pair of at least two pairs of the plurality of differential pairs of elements: spectrally separating the mismatch-induced error of the pair from mismatch-induced error of a remainder of the plurality of differential pairs of elements, monitoring, by an analog-to-digital converter (ADC), an output of the analog circuit, and analyzing the monitored output to measure the mismatch-induced error of the pair.

Abstract: A differential amplifier circuit generates a first current and a second current having a current difference obtained by amplifying a voltage difference between an input voltage and a reference voltage. An output stage supplies current proportional to the first current to an output node. A current conversion circuit discharges current proportional to the second current from the output node. After connecting the output node to a ground node in response to a reset signal, a latch circuit disconnects the output node from the ground node after reset cancellation. Thereafter, when voltage at the output node rises from the ground voltage in a case where a level relationship between the input voltage and the reference voltage is reversed from a reset cancellation time point, the latch circuit fixes the voltage at the output node to a power supply voltage by a positive feedback latch operation.

Abstract: A receiver includes an amplifier that receives a transmission signal and amplifies a first voltage difference between the transmission signal and a reference signal to generate a first output signal and a second output signal at a first node and a second node. An equalizer is provided, which is connected to the first node and the second node and receives the transmission signal. The equalizer compensates a common-mode offset between the first output signal and the second output signal based on a second voltage difference between an average voltage level of the transmission signal and the reference signal.

Abstract: A circuit including an amplifier having an input and an output. The circuit also includes a current-to-voltage amplifier having an input. The circuit further includes a current mirror coupled between the output of the amplifier and the input of the current-to-voltage amplifier. The current mirror is configured to chop current flowing through the first current mirror.

Abstract: Power amplifier apparatuses and techniques for optimizing the design of power amplifiers are disclosed. In one aspect, a method for optimizing a power amplifier includes selecting a circuit topology for the power amplifier. The circuit topology includes one or more photoconductive switches and an impedance matching network including one or more parameter values representative of the impedance matching network or the photoconductive switches that can be adjusted. The method further includes selecting one or more optimization goals for the impedance matching network and the one or more photoconductive switches, and adjusting the one or more parameter values according to the one or more optimization goals. The one or more optimization goals include an efficiency at a particular power output.

Abstract: According to an embodiment of the disclosure, a series or source feedback is provided to a solid-state power amplifier to achieve improved amplifier output power, good impedance match, and low voltage standing wave ratio (VSWR). In an embodiment, an inductive element is coupled to the source of the power amplifier transistor to serve as a series or source feedback for the transistor. In an embodiment, a high-impedance microstrip is provided as an inductive element coupled to the source of the transistor. In an embodiment, a series or source feedback is provided to each amplifier in a multistage amplifier circuit. In an embodiment, a greater series or source feedback is provided at a later stage of a multistage amplifier circuit, whereas a smaller series or source feedback is provided at an earlier stage of the multistage amplifier circuit.

Abstract: An apparatus includes a comparator. The comparator includes first and second pregain stages, and a switch network coupled to the first and second pregain stages. A plurality of switches in the switch network are operable to provide a feedback path around at least one of the first and second pregain stages. The comparator further includes a latch coupled to the second pregain stage.

Abstract: A differential residue amplifier fits between Analog-to-Digital Converter (ADC) stages. Switched-Capacitor Common-Mode Feedback circuits determine voltage shifts. An AC-coupled input network uses switched capacitors to shift upward voltages of the differential inputs to the residue amplifier to apply to an upper pair of p-channel differential transistors with sources connected to the power supply. The AC-coupled input network also shifts downward in voltage the differential inputs to the residue amplifier to apply to a lower pair of n-channel differential transistors with grounded sources. The drains of the p-channel differential transistors connect to differential outputs through p-channel cascode transistors. N-channel cascode transistors connect the drains of the n-channel differential transistors to the differential outputs. The drains of differential transistors can be input to differential amplifiers to drive the gates of the cascode transistors for gain boosting.

Abstract: A voltage-to-current converter circuit comprises an amplifier, a resistor, first and second feedback circuits, and an output circuit. The amplifier is configured to receive a differential input voltage signal. The resistor is coupled between first and second nodes of the amplifier. The first feedback circuit is coupled to a third node of the amplifier, provides feedback to the first and second nodes when the value of the input voltage signal is in a first range, and is turned off otherwise. The second feedback circuit is coupled to a fourth node of the amplifier, provides feedback to the first and second nodes when the value of the input voltage signal is in a second range different from the first range, and is turned off otherwise. The output circuit produces a differential current output signal having a value according to the value of the input voltage signal.

Abstract: Certain aspects of the present disclosure provide an amplifier. The amplifier generally includes an amplifier core circuit configured to amplify a radio frequency signal and having a first output and a second output; a transformer coupled to the amplifier core circuit, the transformer having a primary winding and a secondary winding, the primary winding being coupled to the first output and the second output of the amplifier core circuit, the secondary winding being coupled to an output node of the amplifier; and a variable resistance circuit coupled in parallel with the primary winding.

Abstract: Class-D amplifier circuits provide operation with low-distortion zero crossings outside of a unipolar power supply voltage range. The amplifiers include a first H-bridge driver circuit and a second H-bridge driver circuit. The class-D amplifier circuits also include a control circuit having an input for receiving an input signal to be reproduced by the class-D amplifier circuit. The control circuit has outputs coupled to inputs of the first and second H-bridge drivers, and includes one or more modulators. The control circuit selects between actively operating a selected one of the driver circuits or both, according to the signal to be reproduced, while setting an unselected driver circuit to turn either a high-side switch or a low-side switch of the unselected one of the first driver circuit or the second driver circuit fully on for at least some cycles of the one or more modulators.

Abstract: Described herein is a fully-differential preamplifier comprising an input differential pair, an output current load, and a current source. The current source is coupled between the input differential pair and a low voltage rail and configured to control whether the fully-differential preamplifier is operating in a first mode or a second mode, wherein the preamplifier draws more current when operating in the second mode compared to when operating in the first mode. The input differential pair is coupled between the output current load and the current source. The output current load is coupled between a high voltage rail and the input differential pair. The input differential pair comprise positive and negative inputs of the fully-differential preamplifier. Nodes where the input differential pair and the output current load are coupled to one another comprise positive and negative outputs of the fully-differential preamplifier.

Abstract: According to one aspect, an ambient-light sensor includes a photodiode configured to generate an electrical signal according to an ambient light, a capacitive-feedback transimpedance amplifier connected at its input to the photodiode for receiving a signal generated by the photodiode and for generating as an output an amplified signal from the signal generated by the photodiode, and an auto-zero switch at the input of the capacitive-feedback transimpedance amplifier. The ambient-light sensor further includes a control circuit including a bootstrap circuit configured to receive an initial positive- or zero-voltage logic control signal, and then generate, from this initial logic control signal, an adapted logic control signal having a first positive voltage level and a second negative voltage control level for controlling the auto-zero switch.

Abstract: A high-speed buffer amplifier includes an input stage including a first channel coupled to receive differential inputs and a second channel coupled to receive the differential inputs; a middle stage including a first current source coupled to receive outputs of the second channel and electrically connected to power, a second current source coupled to receive outputs of the first channel and electrically connected to ground, and a floating current source electrically connected between the first current source and the second current source; and an output stage coupled to the middle stage to generate an output voltage. A shunt circuit is electrically connected between the first current source and the second current source, and configured to bypass the floating current source.

Abstract: A serial receiver combines continuous-time equalization, analog interleaving, and discrete-time gain for rapid, efficient data reception and quantization of a serial, continuous-time signal. A continuous-time equalizer equalizes a received signal. A number N of time-interleaved analog samplers sample the equalized continuous-time signal to provide N streams of analog samples transitioning at rate reduced by 1/N relative to the received signal. A set of N discrete-time variable-gain amplifiers amplify respective streams of analog samples. A quantizer then quantizes the amplified streams of analog samples to produce a digital signal.

Abstract: A bidirectional isolated communication circuit and method for a differential signal. The circuit comprises a first detection circuit used for receiving a first differential pair from a first direction, converting the first differential pair into a first level signal, and inhibiting common-mode interference; a second detection circuit used for receiving a second differential pair from a second direction, converting the second differential pair into a second level signal, and inhibiting common-mode interference; an isolation adjustment circuit used for being provided between the first detection circuit and the second detection circuit and performing communication isolation; and a watchdog circuit used for being awoken according to the first differential pair and/or the second differential pair, and enabling the bidirectional isolated communication circuit to enter from a small current working mode to a normal working mode to perform communication isolation.

Abstract: A circuit which reuses current to synthesize a negative impedance includes a current source circuit, a differential circuit, and a negative impedance conversion circuit. The current source circuit is arranged to provide at least one predetermined current, wherein the current source circuit has a first connection port and a second connection port, and the first connection port of the current source is coupled to a first reference voltage. The differential circuit is coupled between the second connection port of the current source circuit and a second reference voltage, and is arranged to receive a differential input pair and generate a differential output pair, wherein the differential circuit has a differential output port. The negative impedance conversion circuit is coupled between the differential output port and a third reference voltage, wherein the third reference voltage is different from the first reference voltage.

Abstract: A circuit (e.g., implemented as part of a controller area network (CAN) bus receiver includes a pre-amplifier stage having first and second outputs. The circuit also includes a comparator having first and second inputs. The first input is coupled to the first output of the pre-amplifier stage, and the second input is coupled to the second output of the pre-amplifier stage. The comparator includes an input differential transistor pair, a second pair of transistors coupled to the input differential transistor pair in a cascode configuration, and a push-pull output stage coupled to the second pair of transistors.

Abstract: A variable-current trans-impedance amplifier (TIA) for an ultrasound device is described. The TIA may be coupled to an ultrasonic transducer to amplify an output signal of the ultrasonic transducer representing an ultrasound signal received by the ultrasonic transducer. During acquisition of the ultrasound signal by the ultrasonic transducer, one or more current sources in the TIA may be varied. The variable-current trans-impedance amplifier may include multiple stages, including a first stage having N-P transistor pairs configured to receive an input signal and produce a single-ended amplified signal.

Abstract: The present disclosure relates to Class D amplifier circuitry comprising a mode controller configured to dynamically adjust an operational switching mode of the Class D amplifier over a range between a Class AD mode and a Class BD mode.

Abstract: A semiconductor device includes an equalizer for receiving a first signal and outputting a second signal that has been adjusted to compensate for attenuation of the first signal. A filter is connected to the output terminal of the equalizer. A cancellation circuit operates to cancel a DC offset in the output of the equalizer. A processing circuit is configured to control the cancellation circuit to cancel the DC offset according to an output from the filter. The processing circuit sets a time constant for the filter to a first value to permit the cancellation circuit to cancel the DC offset when the equalizer is in a first state, and then sets the time constant to a second value when the equalizer is set to a second state to permit the cancellation circuit to cancel the DC offset when the equalizer is in the second state.

Abstract: A preamplifier circuit comprises a first pair of transistors and a second pair of transistors having current flow paths therethrough coupled at first and second output nodes and providing first and second current flow lines intermediate a supply node and ground. The two pairs of transistors comprise: first and second input transistors located intermediate the outputs nodes and one of the supply node and ground providing respective input nodes, first and second load transistors intermediate the output nodes and the other of the supply node and ground. The load transistors have control terminals capacitively coupled to the other of the supply node and ground and a reset switch arrangement is provided periodically activatable to short the first output node, the second output node as well as the control terminals of the first load transistor and the second load transistor.

Abstract: A common-source differential power amplifier comprises a compensation circuit, which comprises a first and a second compensation transistors and two signal terminals, a source and a drain of the first compensation transistor are short-circuited and connected to a gate of the second compensation transistor and one signal terminal of the compensation circuit, the source and the drain of the second compensation transistor are short-circuited and connected to the gate of the first compensation transistor and the other signal terminal of the compensation circuit, the two signal terminals of the compensation circuit are further respectively connected to two differential signal input terminals of the common-source differential power amplifier directly or via a capacitor, where the first and second compensation transistors in the same compensation circuit are both NMOS transistors or both PMOS transistors. An electronic device including the power amplifier is also disclosed.

Abstract: A display apparatus includes a pixel portion in which a plurality of pixels are arranged, the plurality of pixels being connected to scan lines and data lines; a data driver configured to transmit a data signal to a source output line; a data distributer configured to selectively connect the source output line to the data lines; and a latch portion arranged between the data distributer and the pixel portion, wherein the latch portion includes a plurality of latches connected to at least one of data lines excluding a data line, from among the data lines, connected to the source output line by the data distributer at a timing at which a scan signal is transmitted to the scan lines.

Abstract: A circuit is provided. In some examples, the circuit includes a first transistor having a gate and a drain coupled together and a current source coupled to the drain of the first transistor. A second transistor has a drain coupled to a source of the first transistor. A third transistor has a gate coupled to the gate of the first transistor. A fourth transistor has a drain coupled to a source of the third transistor and a gate of the fourth transistor is coupled to a gate of the second transistor. In some examples, the third transistor is configured to limit a first current between the third transistor and the fourth transistor based on an output voltage.

Abstract: A front-end module comprises a bias network including a current mirror, a junction temperature sensor, an n-bit analog-to-digital converter, an n-bit current source bank configured to automatically set reference current levels for one or more operating temperature regions, and a power amplifier. The bias network, junction temperature sensor, n-bit analog-to-digital converter, n-bit current source bank, and power amplifier are integrated on a first semiconductor die.

Abstract: A front-end module comprises a low-dropout (LDO) voltage regulator, a reference current generator, and a power amplifier. The LDO voltage regulator, reference current generator, and power amplifier are integrated on a first semiconductor die.

Abstract: The present disclosure relates to an electronic device comprising a pair of first transistors, each first transistor being coupled to a first node by a conduction terminal, a pair of second transistors, each second transistor being coupled to a second node by a conduction terminal, and a third transistor coupling the first and second nodes, the control terminal of the third transistor being coupled to the output of an operational amplifier, the operational amplifier being coupled, at its input, to the first node and to a node of application of a reference voltage.

Abstract: A multi-stage continuous time linear equalizer (CTLE) with a reconfigurable inductor scheme is disclosed. The multi-stage CTLE comprises a first stage transformer-based inductive peaking and a second stage resistive load. The first stage transformer-based inductive peaking is configured to control high frequency peaking and set a peak frequency value to a desired value by using a coarse equalization mechanism. The stage resistive load configured to provide tuneable equalization and low frequency fine equalization by using a fine equalization mechanism.

Abstract: A high-frequency high-linear input buffer includes a first MOS transistor, a second MOS transistor, a third MOS transistor, and a signal panning unit. A gate terminal of the first MOS transistor is used as an input terminal of the buffer. A current input terminal of the first MOS transistor is connected to a current output terminal of the second MOS transistor. A current output terminal of the first MOS transistor is connected to a current input terminal of the third MOS transistor. A current input terminal of the second MOS transistor is connected to a gate terminal of the third MOS transistor. An input terminal of the signal panning unit is connected to an input terminal of the buffer. An output terminal of the signal panning unit is connected to a gate terminal of the second MOS transistor. An output terminal of the third MOS transistor is connected to ground.

Abstract: An apparatus is disclosed for bidirectional amplification with phase-shifting. In example implementations, an apparatus includes a phase shifter with a bidirectional amplifier. The bidirectional amplifier includes a first transistor coupled between a first plus node and a second minus node, a second transistor coupled between a first minus node and a second plus node, a third transistor coupled between the first plus node and the second minus node, and a fourth transistor coupled between the first minus node and the second plus node. The bidirectional amplifier also includes a fifth transistor coupled between the first plus node and the second plus node, a sixth transistor coupled between the first minus node and the second minus node, a seventh transistor coupled between the first plus node and the second plus node, and an eighth transistor coupled between the first minus node and the second minus node.

Abstract: A fully-differential two-stage operational amplifier circuit is provided, and it includes a first-stage amplification circuit, a second-stage amplification circuit, a common-mode signal acquisition circuit, a common-mode feedback circuit and a bias circuit. The first-stage amplification circuit has a telescopic structure and receives differential input signals INP and INN. The second-stage amplification circuit has a common-source structure and outputs differential output signals OUTP and OUTN. The common-mode signal acquisition circuit receives differential output signals, and outputs an operational amplifier output common-mode signal VCMO. The common-mode feedback circuit outputs common-mode feedback signals VB1 and VB2 to the first-stage amplifier circuit and the second-stage amplifier circuit respectively; The bias circuit outputs a bias voltage VB3 to the first-stage amplifier circuit, and outputs bias voltages VB4 and VB5 to the first-stage amplifier circuit respectively.

Abstract: Methods and devices used in mobile receiver front end to support multiple paths and multiple frequency bands are described. The presented devices and methods provide benefits of scalability, frequency band agility, as well as size reduction by using one low noise amplifier per simultaneous outputs. Based on the disclosed teachings, variable gain amplification of multiband signals is also presented.

Abstract: An input stage configured to differentially amplify an input signal and an output signal, a first current mirror and a second current mirror configured to receive a differential current from the input stage, an output stage including first and second output transistors, respectively including a gate connected to the first and second current mirrors, and a slew rate compensation circuit configured to (i) mirror a comparison current generated by comparing a voltage of a first input signal with a voltage of a second input signal, and (ii) provide the mirrored comparison current to the gate of the first or second output transistor.