Abstract: In an embodiment, a method includes receiving, between a positive input terminal and a negative input terminal, a supply voltage, receiving a data signal, generating, by a voltage generator in a branch of a plurality of branches, a branch current as a function of a respective driving signal and of a regulated voltage, each branch connected between the positive input terminal and the negative input terminal, selectively activating the voltage generator as a function of a respective enabling signal and providing, between a positive output terminal and a negative output terminal, the regulated voltage to one or more driving circuits.

Abstract: Examples are disclosed herein that relate to automatically limiting an output current of a voltage regulator circuit responsive to detecting that the voltage regulator is in a current overload mode. In one example, a voltage regulator circuit includes an amplifier stage and a current limiter stage electrically connected to an output of the amplifier stage. The amplifier stage is configured to output a DC voltage based on a reference voltage and feedback from an output voltage. The current limiter stage is configured to operate in a quiescent mode and an overload mode. In the quiescent mode, the current limiter stage is configured to operate as a buffer stage that forms a closed feedback loop to an input of the amplifier stage. In the overload mode, the current limiter stage is configured to act as a current source that clamps an output current to a designated current.

Abstract: Provided is a track-and-hold circuit capable of reducing the power consumption of a differential amplifier circuit while preserving the broadband nature (without narrowing the bandwidth). In the track-and-hold circuit 1 including a differential amplifier circuit 10, a switch circuit 20, and a hold capacitor C21, the differential amplifier circuit 10 includes a first resistor R11 having one end connected to a collector electrode of a first transistor Q11 constituting a differential pair, a second resistor R12 having one end connected to the collector electrode of a second transistor Q12 constituting the differential pair, and a third resistor R13 to which the other end of the first resistor R11 and the other end of the second resistor R12 are connected and which is connected between the other ends and a power supply VCC.

Abstract: Techniques maintaining receiver reliability, including determining a present attenuation level for an attenuator, wherein the attenuation level is set by a gain controller, determining a relative reliability threshold based on the present attenuation level, receiving a radio frequency (RF) signal, determining a voltage level of the received RF signal, comparing the voltage level of the received RF signal to the relative reliability threshold to determine that a reliability condition exists, and overriding, in response to the determination that the reliability condition exists, the present attenuation level set by the gain controller with an override attenuation level based on the present attenuation level.

Abstract: A system includes a power supply source and a power control circuit coupled to the power supply source, in which the power control circuit includes a pass field-effect transistor (FET). The system also includes a short-to-ground protection circuit coupled to an output of the pass FET. The short-to-ground protection circuit includes a sense circuit configured to detect when a magnitude and a change rate of a voltage drop at the output of the pass FET is greater than respective thresholds. The short-to-ground protection circuit also includes a control node at the output of the sense circuit. The sense circuit is configured to induce a control current at the control node in response to the magnitude and the change rate of a voltage drop at the output of the pass FET being greater than respective thresholds. The control current is used to turn off the pass FET.

Abstract: A filter can perform two filtering processes. The filter includes a switching circuit, a first filter circuit, and a second filter circuit. The first filter circuit is coupled to the switching circuit. The second filter circuit is coupled to the switching circuit. The first filter circuit performs a first filtering process on an input signal according to a state of the switching circuit. The first filter circuit and the second filter circuit work together to perform a second filtering process on the input signal according to the state of the switching circuit.

Abstract: A SerDes system is provided. The SerDes system includes channel circuits, a PLL circuit, first and second buffers, and first and second capacitors. Each channel circuit is coupled to the first and second clock lines. The PLL circuit generates a first differential signal including first and second clock signals. The first buffer buffers the first clock signal. The second buffer and buffers the second clock signal. The first capacitor receives the buffered first clock signal and outputs a third clock signal to the first clock line. The second capacitor receives a buffered second clock signal and outputs a fourth clock signal to the second clock line. A swing of a second differential signal comprising the third clock signal and the fourth clock signal is smaller than a swing of the first differential signal.

Abstract: A data transmission circuit includes: a main driver circuit suitable for driving data to an output line; an amplitude equalization window generator circuit suitable for detecting the data transitioning from a first level to a second level; an auxiliary driver circuit suitable for driving the output line with the second level in response to a detection result of the amplitude equalization window generator circuit; and a phase equalization window generator circuit suitable for detecting whether the data consecutively has the first level, wherein the main driver circuit changes a time point of driving the data in response to a detection result of the phase equalization window generator circuit.

Abstract: An impedance circuit includes a first impedance terminal, a second impedance terminal, a first transistor, a second transistor, a low frequency signal blocking element, and a current-voltage transform circuit. The first transistor is coupled to the first impedance terminal, and controlled by a first voltage. The second transistor is coupled to the first impedance terminal, and controlled by a second voltage. The low frequency signal blocking element is coupled to the first transistor and the second impedance terminal. The current-voltage transform circuit is coupled to the first impedance terminal. The current-voltage transform circuit adjusts a terminal voltage at the first terminal of the current-voltage transform circuit according to a current flowing through the current-voltage transform circuit. The impedance circuit provides impedance between the first and the second impedance terminals according to the terminal voltage and the first voltage.

Abstract: A differential comparator circuit is provided that includes a differential input pair, an active load, a pair of cross voltage generation devices and a pair of switches. The differential input pair has a pair of input terminals and a pair of first connection terminals. The active load has a pair of second connection terminals. The cross voltage generation devices are electrically coupled between the first connection terminals and the second connection terminals, wherein the cross voltage generation devices are configured to be electrically activated to establish a cross voltage therebetween in a reset phase and electrically deactivated to become a short circuit in an operation phase. The switches are configured to electrically couple the pair of input terminals respectively to the pair of first connection terminals in the reset phase and not electrically couple the pair of input terminals respectively from the pair of first connection terminals.

Abstract: In an embodiment, an amplifier includes first, second, and third stages, and a feedback network. The first stage has a first passband and is configured to generate a first output signal in response to first and second input signals, and the second stage has a second passband that is higher in frequency than the first passband and is configured to generate a second output signal in response to third and fourth input signals. The third stage has a first input node coupled to receive the first output signal, a second input node coupled to receive the second output signal, and an output node. And the feedback network is coupled between the second input node and the output node of the third stage. For example, where the first, second, and third stages are respective operational-transconductance-amplifier stages, such an amplifier may be suitable for low-power applications.

Abstract: A radio-frequency module includes a substrate, a low-noise amplifier circuit being a first amplifier circuit arranged in a first area in the substrate, a power amplifier circuit being a second amplifier circuit arranged in a second area in the substrate, and a duplexer being a component arranged between the first area and the second area in the substrate and having a heat generating property lower than that of the power amplifier circuit. The low-noise amplifier circuit includes a bias circuit configured to generate a bias current dependent on temperature characteristics of a first diode, a voltage generating circuit configured to generate a voltage dependent on temperature characteristics of a second diode as an operating voltage for the bias circuit, and an amplifier circuit configured to operate at an operating point determined by the bias current.

Abstract: According to one embodiment, the amplifier circuit includes a first and second differential amplifier. The first differential amplifier includes first and second transistors, a first current source, and a second current source that is configured to supply a current to the first and second transistors via a first switch element. The second differential amplifier includes third and fourth transistors, a third current source, and a fourth current source that is configured to supply a current to the third and fourth transistors via a second switch element. A first signal is input to the first and third transistors. The first switch elements are controlled by third and fourth signals, respectively. The third signal and the fourth signal are complementary.

Abstract: An apparatus and method are provided. The apparatus includes a multiplexer, including first, second, and third inputs, and an output; a first transistor, including a gate connected to the multiplexer, and first and second terminals; a first variable capacitor, including a first terminal connected to the first transistor, a second terminal, and an input; a first inductor, including a first terminal connected to the first transistor, and a second terminal connected to the second terminal of the first variable capacitor; a second transistor, including a gate connected to the output of the multiplexer, a first terminal, and a second terminal connected to the second terminal of the first inductor; a second inductor mutually coupled to the first inductor, including a first and second terminals; and a balun-bias switch, including first, second, and third inputs, and an output connected to the second terminal of the second inductor.

Abstract: A differential amplifier includes a pair of cascode amplifiers. A voltage clamp is coupled to the pair of cascode amplifiers.

Abstract: A power amplifier system includes a differential power amplifier and a bias circuit. The differential power amplifier is arranged for receiving a differential input pair to generate an output signal. The bias circuit is arranged for generating a bias voltage to bias the differential power amplifier, and the bias circuit comprises a source follower for receiving a reference voltage to generate the bias voltage.

Abstract: Provided herein are amplifiers, such as buffers, with increased headroom. An amplifier stage includes a follower transistor and current source configured to receive a power supply voltage comprising an alternating current component and a direct current component. The alternating current component of the power supply voltage has substantially the same frequency and magnitude as the input signal received by the follower transistor. In radio frequency (RF) and intermediate frequency (IF) buffer applications, for example, the increased headroom can allow for linear buffering of an input signals with increased amplitude so that the output power one decibel (OP1dB) compression point can be increased.

Abstract: A buffer is provided where a part of the buffer is implemented in switched capacitor or other analog discrete time processing circuitry and a dynamic response characteristic, such as an effective gain or charge transfer coefficient between the input stage and an output stage is digitally controllable. This means that the buffer can be driven as if it was a system controlled by, for example a three (3) term controller, giving rise to greater, digital flexibility in tailoring the buffer's transient response.

Abstract: One embodiment provides an enhanced slicer. The enhanced slicer includes a first clocked comparator circuitry and a current path circuitry. The first clocked comparator circuitry includes a first comparator circuitry, a first latch circuitry, a first output node (Out_P) and a second output node (Out_N). The current path circuitry is coupled to the output nodes and a reference node. The current path circuitry is to enhance current flow between at least one of the output nodes and the reference node, in response to a clock signal.

Abstract: A receiver front end capable of receiving and processing intraband non-contiguous carrier aggregate (CA) signals using multiple low noise amplifiers (LNAs) is disclosed herein. A cascode having a “common source” configured input FET and a “common gate” configured output FET can be turned on or off using the gate of the output FET. A first switch is provided that allows a connection to be either established or broken between the source terminal of the input FET of each LNA. Further switches used for switching degeneration inductors, gate capacitors and gate to ground caps for each legs can be used to further improve the matching performance of the invention.

Abstract: A switching amplifier provided, at a minimum, with: a first input transistor into which one of two input signals that operate in a complementary manner is input; a first cascode transistor cascade-connected between the first input transistor and a power supply; a second input transistor into which the other of the two input signals is input; and a second cascode transistor cascade-connected between the second input transistor and the first input transistor; the switching amplifier extracting an output signal, a connection point between the first input transistor and the second cascode transistor being used as an output terminal; wherein a first potential limiting circuit and a second potential limiting circuit for limiting the potential fluctuation range are respectively connected to the input terminal of the first cascode transistor and the input terminal of the second cascode transistor.

Abstract: An electronic circuit including a current conveyor connected to a load is provided. The load delivers at least one first voltage output and one second voltage output. Such a circuit is noteworthy in that the second voltage output has what is called a non-linear behavior relative to the magnitude of the input current of the electronic circuit in a given range.

Abstract: A charge pump comprises a charge pump circuit with bipolar switching devices with a common emitter. A collector line which comprises a first current source connects to the high potential provider. An emitter line connects the common emitter to a low potential provider and comprises a second current source. The output is provided by or connected to the collector of the second bipolar switching device and provides said output voltage. A driving stage circuit applies a charge pump circuit driving signal across the bases of the bipolar switching devices and controls the charge pump circuit driving signal in accordance with a driving stage input signal. The driving stage circuit effects a shift of a DC operating point of the charge pump circuit driving signal as an increasing function of the output voltage function of the output voltage of the charge pump circuit.

Abstract: A current source circuit flowing an output current to at least one detection element including a first terminal to which a first voltage is supplied and a second terminal being connected to the current source circuit includes a reference resistance, a current mirror circuit including at least one first transistor and at least one second transistor, and a control circuit controlling a voltage of a common wire that is connected to a terminal provided at the first transistor and a terminal provided at the second transistor such that a voltage of a terminal provided at the reference resistance comes to be equal to a reference voltage.

Abstract: Methods and systems for compensating for temperature variation in the performance of electronic circuits and systems are disclosed. In some embodiments, the systems are configured to store compensation parameters determined in calibration, where the compensation parameters are used by the systems to modify performance. In some embodiments, the systems are part of an automatic test equipment (ATE) system.

Abstract: To provide a current detection circuit capable of suppressing the occurrence of a large potential difference between input terminals of a differential amplifier circuit, and preventing degradation of input transistors. A differential amplifier circuit is equipped with a clamp circuit which limits gate-source voltages of a pair of PMOS transistors each having a bulk and a source connected to each other with the sources of the pair of PMOS transistors as input terminals.

Abstract: A differential amplifier circuit and display drive circuit having the same are disclosed herein. In one example, a differential amplifier circuit includes a differential pair transistor configure to receive a differential input signal. A current source is connected in series to the differential pair transistor and an output transistor that drives an output terminal on the basis of the differential input signal. The output transistor is configured to increase a current value of a current source on the basis of a timing at which a voltage level of the output terminal is caused to transition. The output transistor is configured to drive the output terminal only during a period in which the output terminal is caused to transition, and thus a slew rate is improved by increasing a bias current of the differential pair transistor in the period.

Abstract: Described herein is an electronic device. The electronic device includes a unity gain buffer having an input coupled to an input node to receive an input voltage and an output coupled to an output node. A current sink circuit operates in a sleep mode in an absence of a sink current flowing into the output node, and operates in a sinking mode to sink the sink current from the output node to a reference supply node when the sink current flows into the output node.

Abstract: Provided is a technology capable of preventing arithmetic operation accuracy from deteriorating even when a bipolar transistor used to form a Gilbert multiplier core has poor characteristics. A correction current generating circuit (3) uses a constant current source (301) to feed a constant current I0 to an emitter of a bipolar transistor (Q7) being a first replica transistor having the same current gain ? as bipolar transistors (Q1 to Q4) that form the Gilbert multiplier core (101), to generate a current of ?·I0 on a collector side thereof. The current is output as a correction current ?·I0, and is added to each of one of input signals (±K1·Vy) of the Gilbert multiplier core (101) as a bias current, to thereby eliminate influence of the current gain ? on an output signal being a multiplication result.

Abstract: Disclosed is a compensation circuit for a common voltage according to a gate voltage, which compensates the common voltage in accordance with variation in gate high voltage, to obtain an optimal common voltage. The compensation circuit includes a divider to divide a gate high voltage, an adder to add a fed-back common voltage to a voltage output from the divider, and a differential amplifier to differentially amplify a voltage output from the adder, and to output the amplified voltage as a compensated common voltage.

Abstract: A high slew rate operational amplifier including an input terminal, an output terminal, and at least one slew-rate enhancing circuit is disclosed. Each slew-rate enhancing circuit includes a first stage enhancing unit and a second stage enhancing unit. The first stage enhancing unit is coupled between the input terminal and the output terminal. The first stage enhancing unit and the second stage enhancing unit are coupled. The slew-rate enhancing circuit has a threshold voltage and the threshold voltage is related to the size of the first stage enhancing unit. When the threshold voltage is driven, the slew-rate enhancing circuit will rapidly start the second stage enhancing unit to perform a slew rate compensation on the high slew rate operational amplifier.

Abstract: A pixel compensation circuit includes a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a switch unit and a light emitting diode. The first transistor, the third transistor, the fourth transistor, the fifth transistor, and the switch unit are used to receive a respective switch signal. The pixel compensation circuit can compensate a threshold voltage of transistor automatically; and consequentially a driving current of light emitting diode is prevented from being affected by the change of the threshold voltage or the voltage drop of the light emitting diode.

Abstract: A differential amplifier with cascade transistors connected in series to switching transistors is disclosed. The base bias of the cascade transistors is set higher than the output LOW level of the cascade transistors by a preset amount of 0.1 to 0.2V, or lower than the input HIGH level of the switching transistors by the preset amount adding to a forward voltage of a junction diode, to provide a discharge current of the base-emitter junction Cbe from the bias control, or from the upstream stage to drive the differential circuit.

Abstract: A monitoring system for detecting stress degradation of a semiconductor integrated circuit has an amplifier circuit and degradation test transistors. Multiplexers are provided that have an output coupled to a respective electrode of the degradation test transistor. Each of the multiplexers has an input coupled to one of the monitor nodes and a respective node of the amplifier circuit. In operation, the multiplexers selectively insert the degradation test transistor into either the integrated circuit or the amplifier circuit so that when inserted into the integrated circuit the degradation test transistor is subjected to stress degradation voltages in the integrated circuit. When the degradation test transistor is inserted into the amplifier circuit, an output signal is generated that is indicative of stress degradation of the integrated circuit.

Abstract: A voltage measurement apparatus is provided that includes: a potential attenuator configured to be electrically connected between first and second conductors, which are electrically coupled to a source, wherein the potential attenuator includes a first impedance and a reference impedance arrangement in series with each other, wherein the reference impedance arrangement has an electrical characteristic that can be changed in a known fashion; and further including a processing arrangement configured to acquire at least one signal from the reference impedance arrangement, the at least one signal reflecting change of the electrical characteristic in the known fashion; and to determine a voltage between the first and second conductors in dependence on the fashion in which the electrical characteristic is changed being known and the at least one signal.

Abstract: An operational amplifier circuit includes: a first differential amplifier section containing a P-type differential pair of P-type transistors; a second differential amplifier section containing an N-type differential pair of N-type transistors; an intermediate stage connected with outputs of the first and second differential amplifier sections and containing a first current mirror circuit of P-type transistors, and a second current mirror circuit of N-type transistors; and an output stage configured to amplify an output of the intermediate stage in power. The first differential amplifier section includes a first current source and a first capacitance between sources of the P-type transistors of the P-type differential pair and a positive side power supply voltage. The second differential amplifier section includes a second current source and a second capacitance between sources of the N-type transistors of the N-type differential pair and a negative side power supply voltage.

Abstract: A method for reducing the non-linearity effect of a digital-analog converter on an electronic interface circuit of a capacitive sensor. The electronic circuit includes an amplifier connected to the common electrode by a switching unit, a logic unit connected to the amplifier for supplying first and second digital measuring signals, and a digital-analog converter for supplying a measuring voltage to the electrodes. The method includes firstly biasing the capacitor electrodes by the measuring voltage, then biasing the fixed electrode of the first capacitor at a regulated voltage and the fixed electrode of the second capacitor at a low voltage, then biasing the capacitor electrodes by the measuring voltage, and finally biasing the fixed electrode of the first capacitor at a low voltage and the fixed electrode of the second capacitor at a regulated voltage.

Abstract: Differential power amplifier circuitry includes a differential transistor pair, an input transformer, and biasing circuitry. The base contact of each transistor in the differential transistor pair may be coupled to the input transformer through a coupling capacitor. The coupling capacitors may be designed to resonate with the input transformer about a desired frequency range, thereby passing desirable signals to the differential transistor pair while blocking undesirable signals. The biasing circuitry may include a pair of emitter follower transistors, each coupled at the emitter to the base contact of each one of the transistors in the differential transistor pair and adapted to bias the differential transistor pair to maximize efficiency and stability.

Abstract: Differential amplifier circuits for LDMOS-based amplifiers are disclosed. The differential amplifier circuits comprise a high resistivity substrate and separate DC and AC ground connections. Such amplifier circuits may not require thru-substrate vias for ground connection.

Abstract: A clamping circuit for a class AB amplifier includes a reference voltage circuit, four NPN Darlington transistors having inputs coupled to the reference voltage circuit, and outputs for providing four clamped voltages and a split NPN Darlington transistor having an input coupled to the reference voltage circuit, and four separate outputs for providing four AC ground voltages.

Abstract: An amplifier includes a first transformer configured to output first differential signals, a first differential amplifier coupled to the first transformer, a second transformer coupled to the first differential amplifier, a second differential amplifier coupled to the second transformer, a third transformer configured to transform second differential signals output from the second differential amplifier to a single-ended output signal, and a first bias circuit configured to supply a first bias voltage to a first secondary coil of the first transformer, wherein the first bias circuit sets the first bias voltage to a voltage greater than or equal to a first voltage based on the input signal in a first operating area where power of the output signal is greater than or equal to a first power so that power-gain characteristics of the output signal become closer to characteristics where gain of the output signal becomes constant.

Abstract: An amplifier circuit includes an input terminal and an output terminal. A current sinking transistor includes a first conduction terminal coupled to the output terminal and a second conduction terminal coupled to a reference supply node. A voltage sensing circuit has a first input coupled to the input terminal and a second input coupled to the output terminal. An output of the voltage sensing circuit is coupled to the control terminal of the current sinking transistor. The voltage sensing circuit functions to sense a rise in the voltage at the output terminal which exceeds the voltage at the input terminal, and respond thereto by activating the current sinking transistor.

Abstract: Provided is a power amplifier which includes: a first transistor and a second transistor each having a first end connected to a first power source supplying a first voltage and to which signals having a same size but opposite polarities are input; a third transistor and a fourth transistor having first ends respectively connected to the first ends of the first transistor and the second transistor; and a fifth transistor having a first end connected to second ends of the third and fourth transistors and controlling oscillation of the third or fourth transistor.

Abstract: A differential amplifier is described that provides a high common mode rejection ration (CMRR) without requiring the use of precisely matched components. One variation employs a method of noise reduction to increase the SNR of the device. The differential amplifier may be used in an apparatus for measuring biopotentials of a patient, such as an electrode for measuring brain activity. The electrodes can communicate the measured biopotentials with a remote system for further processing, while providing electrical isolation to the patient.

Abstract: An operational transconductance amplifier for connection with multiple input voltage sources includes a resistance simulation unit, two current cancellation units, a first differential output unit, two current division units, and a second differential output unit. The resistance simulation unit is to simulate resistance. The two current cancellation units are to receive and convert the voltage of the input voltage sources into two first currents. The two first currents flow to two first output ends of the first differential output unit, respectively. The two current division units are to receive and convert the voltage of the input voltage sources into two second currents. The two second currents flow to two second output ends of the two second differential output units, respectively, and include the same potential as the two first currents.

Abstract: Embodiments and methods herein operate as two-stage voltage controlled current sources (i.e., dynamic current sources) operating in class AB mode. Phase-delayed current injection circuits are associated with first-stage bias, second-stage bias, or both. The current injection circuits operate to quickly re-charge inter-stage parasitic capacitance associated with the active side of the class AB dynamic current source shortly after that side becomes inactive. Doing so quickly dissipates an otherwise slowly-decaying residual drive signal to prevent the output stage from continuing to conduct after the associated side of the current source becomes inactive. Excessive current consumption and possible destructive operation of the output stage are mitigated as a result.

Abstract: A bias generation method or apparatus defined by any one or any practical combination of numerous features that contribute to low noise and/or high efficiency biasing, including: having a charge pump control clock output with a waveform having limited harmonic content or distortion compared to a sine wave; having a ring oscillator to generating a charge pump clock that includes inverters current limited by cascode devices and achieves substantially rail-to-rail output amplitude; having a differential ring oscillator with optional startup and/or phase locking features to produce two phase outputs suitably matched and in adequate phase opposition; having a ring oscillator of less than five stages generating a charge pump clock; capacitively coupling the clock output(s) to some or all of the charge transfer capacitor switches; biasing an FET, which is capacitively coupled to a drive signal, to a bias voltage via an “active bias resistor” circuit that conducts between output terminals only during portions of a wa

Abstract: A differential circuit topology that produces a tunable floating negative inductance, negative capacitance, negative resistance/conductance, or a combination of the three. These circuits are commonly referred to as “non-Foster circuits.” The disclosed embodiments of the circuits comprises two differential pairs of transistors that are cross-coupled, a load immittance, multiple current sources, two Common-Mode FeedBack (CMFB) networks, at least one tunable (variable) resistance, and two terminals across which the desired immittance is present. The disclosed embodiments of the circuits may be configured as either a Negative Impedance Inverter (NII) or a Negative Impedance Converter (NIC) and as either Open-Circuit-Stable (OCS) and Short-Circuit-Stable (SCS).

Abstract: Embodiments of the invention are generally directed to improving the slew rate of an amplifier as the amplifier charges or discharges a capacitive load. In one embodiment, the amplifier is coupled to a slew-enhancing circuit which uses a control signal from the amplifier to aid the amplifier when charging or discharging the load. For example, the control signal may be an internal voltage used by the amplifier to control circuit elements within the amplifier. By routing the control signal to the slew-enhancing circuit, the control signal biases the circuit elements within the slew-enhancing circuit to source a boost current when charging the capacitive load or sink the boost current when discharging the capacitive load.

Abstract: A device includes an amplifier and a first switched current sampler. The first switched current sampler includes a first transistor, a first capacitor, and first, second, and third switches. The first capacitor has a first terminal electrically connected to a gate electrode of the first transistor, and a second terminal electrically connected to a source electrode of the first transistor. The first switch has a first terminal electrically connected to a first current source, and a second terminal electrically connected to the gate electrode of the first transistor. The second switch has a first terminal electrically connected to the first current source, and a second terminal electrically connected to a drain electrode of the first transistor. The third switch has a first terminal electrically connected to the drain electrode of the first transistor, and a second terminal electrically connected to a first input terminal of the amplifier.