Entries |
Document | Title | Date |
20080197928 | THRESHOLD VOLTAGE COMPENSATION FOR A TWO STAGE AMPLIFIER - In an example embodiment, an apparatus, such as a two stage operational amplifier, comprising a first stage amplifier having an input and an output, and a second stage amplifier having an input and an output, the input of the second stage amplifier is coupled to the output of the first stage amplifier. A first bias circuit is operable to set a common mode voltage of the first amplifier. A second bias circuit is operable to set a common mode voltage of the second amplifier. A first feedback circuit is coupled to the first bias circuit and the output of the first stage. The first feedback circuit is operable to control the common mode voltage of the first stage amplifier based on the common mode voltage set by the first bias circuit and the output of the first stage amplifier. | 08-21-2008 |
20080211580 | LOW NOISE AC DIFFERENTIAL AMPLIFIER WITH REDUCED LOW CORNER FREQUENCY AND CURRENT CONSUMPTION - An integrated amplifier may include a transconductance stage including a differential pair of input transistors of a first type of conductivity, respective resistive loads coupled to said input transistors, and a first bias circuit coupled to the input transistors. The first bias circuit may include a second differential pair of bias transistors having first conduction terminals coupled in common and second conduction terminals coupled to respective conduction terminals of the input transistors. The first bias circuit may also include respective second bias circuits coupled to the bias transistors to enable the input transistors in a conduction state with the input transistors being biased by a same respective bias current that flows through the respective input transistors. The first bias circuit may also include a capacitive network coupled to the bias transistors to define with the input transistors a feedback loop. | 09-04-2008 |
20080211581 | Amplifier circuit with internal zeros - An amplifier circuit with internal zeros provides a second pole in addition to a first pole and two zeros such that the second pole can prevent excessive gain at high frequency, so as to have high-frequency noise under control. | 09-04-2008 |
20080238548 | Differential feedback amplifier circuit with cross coupled capacitors - The present invention relates to a differential feedback amplifier circuit with cross coupled capacitors. Wherein, the first and second input terminals of a source follower are respectively coupled to the first and second output terminals of a differential amplifier, and a resistor is respectively coupled between the first output terminal of the source follower and the first input terminal of the differential amplifier and between the second output terminal of the source follower and the second input terminal of the differential amplifier in order to form a feedback loop. In addition, a capacitor is respectively coupled between the first end current source gate of the source follower and the second input terminal of the source follower and between the second end current source gate of the source follower and the first input terminal of the source follower, so as to improve the circuit gain and bandwidth. | 10-02-2008 |
20080290943 | MULTI-MODE AMPLIFIER ARRANGEMENT AND METHOD FOR CONTROLLING AN AMPLIFIER ARRANGEMENT - A multi-mode amplifier arrangement comprises an amplifier having a plurality of field effect transistors selectable in response to a control signal at a control terminal, said plurality of field effect transistors coupled to an input terminal to receive a signal to be amplified, said amplifier arranged between a supply terminal and a ground terminal. A tunable current source is coupled to the amplifier to provide in operation of the amplifier a constant drain current through the plurality of field effect transistors. | 11-27-2008 |
20090009249 | Input Stage - An input stage receives a differential input signal at first and second input nodes and provides a differential output current at first and second output nodes. The differential output current includes a component taken from the input nodes through first and second impedances, and an additional component generated in response to a sample of the voltage of the differential input signal. A transconductance cell having cross-coupled inputs may generate the additional component of the output current. | 01-08-2009 |
20090021306 | INTEGRATED CIRCUIT SYSTEM FOR LINE REGULATION OF AN AMPLIFIER - An integrated circuit system is provided including forming a differential pair; reducing a mismatch in the differential pair by: coupling an amplifier to the differential pair; and coupling a local feedback network to the amplifier in which referencing the local feedback network includes coupling a first voltage; and driving an output transistor by the amplifier. | 01-22-2009 |
20090058528 | Pre-Amplifier for a Receiver and a Method therefor - A pre-amplifier for a receiver is provided. The pre-amplifier includes a first and a second input operational amplifiers, an output module, a first and a second feedback circuits. The first and the second input operational amplifiers amplify an input differential voltage pair to output a first and a second differential voltage pairs. The output module includes a first and a second output operational amplifiers and an inverter. The first and the second output operational amplifiers amplify the first and the second differential voltage pairs to output a first and a second output amplified voltages. The inverter pulls an output voltage high or low based on the first and the second output amplified voltages. The first and second feedback circuits are respectively for pulling up the first differential voltage pair or pulling down the second differential voltage pair, such that the first and the second output operational amplifiers are not disabled. | 03-05-2009 |
20090085663 | Transconductor Having High Linearity and Programmable Gain and Mixer using the Same - A mixer having high linearity and an associated transconductor combining programmable gain amplifier and mixer functions are provided. The transconductor includes first and second resistors, a differential amplifier, first and second feedback circuits, and first and second transistors. A differential voltage signal is inputted to first and second input ends of the differential amplifier via the first and second resistors. The first and second feedback circuits are provided between a first output end and the first input end, and a second output end and the second input end of the differential amplifier, respectively. The first output end outputs a first output signal for controlling a first current passing through the first transistor. The second output end outputs a second output signal for controlling a second current passing through the second transistor. The first current and the second current determine a differential current. | 04-02-2009 |
20090096524 | Differential amplification circuit and manufacturing method thereof - A differential amplification circuit and a method corrects an offset voltage derived from a variance in resistances. With first and second input terminals brought to the same potential and set to a potential different from a reference potential, the resistance value of resistors is adjusted so that an output potential and the reference potential will be substantially equal to each other. | 04-16-2009 |
20090108937 | LOW NOISE AMPLIFIER AND DIFFERENTIAL AMPLIFIER - In a double-loop negative feedback low noise amplifier having double negative feedback paths by a feedback transformer and a feedback resistor added to a cascode amplifier comprising transistors and a resistor, a phase compensation circuit comprising a capacitor and a resistor is added between the output terminal of the double-loop negative feedback low noise amplifier and the input terminal of the cascode amplifier, i.e., the input terminal of the input transistor, and a phase compensation circuit comprising a capacitor and a resistor is added to the upper-stage transistor of the cascode amplifier, i.e., the input terminal of the upper-stage transistor. Those phase compensation circuits enable a low noise negative feedback amplifier which maintains a high feedback loop gain to a high frequency band, has a wider bandwidth than a conventional one, and has a high dynamic range. | 04-30-2009 |
20090115523 | DISCRETE TIME AMPLIFIER CIRCUIT AND ANALOG-DIGITAL CONVERTER - The present invention is intended to attain simplified circuit configuration and low current consumption in a discrete time amplifier circuit and an AD converter, to improve the convergence from the transient response state to the steady state of the amplifier circuit and to reduce noise and distortion owing to the variation in the output common-mode voltage. The discrete time amplifier circuit and the AD converter are provided with a switched-capacitor common-mode feedback (CMFB) circuit capable of detecting and feeding back the output common-mode voltage at every sampling timing in the case that the circuit operates at double sampling timing (every ½ cycle). | 05-07-2009 |
20090179699 | FULLY DIFFERENTIAL COMPARATOR AND FULLY DIFFERENTIAL AMPLIFIER - A first to a fourth sampling switch ( | 07-16-2009 |
20090179700 | AC Coupling Circuits Including Resistive Feedback and Related Methods and Devices - An integrated circuit device may include an amplifier having an amplifier input configured to receive an input signal with the amplifier being configured to provide an amplifier output signal at an amplifier output responsive to the input signal received at the amplifier input. A capacitor may be coupled to the amplifier output, and a buffer may be coupled to the capacitor so that the capacitor is coupled in series between the amplifier output and an input of the buffer with an output of the buffer being coupled to a buffered signal terminal. A variable resistive feedback circuit may be coupled between the input and output of the buffer with the variable resistive feed back circuit providing a variable resistance between the input and output of the buffer. A feedback resistance controller may be coupled to the variable resistive feedback circuit with the feedback resistance controller being configured to select a first resistance for the variable resistive feedback circuit for a first frequency of the input signal and to select a second resistance for the variable resistive feedback circuit for a second frequency of the input signal different than the first frequency with the first and second resistances being different. | 07-16-2009 |
20090195311 | INDEPENDENT DOMINANT POLE COMPENSATION OF TWO LOOPS USING ONE COMPENSATION ELEMENT - Disclosed is a differential amplifier system that maintains high speed characteristics of the differential amplifier while providing stability from a common-mode loop by using dominant pole compensation. The disclosed system includes a first and second transconductance stage, a circuit having high impedance, and a compensation circuit. | 08-06-2009 |
20090195312 | DIFFERENTIAL AMPLIFIER - A differential amplifier comprises a left amplifier having transistors, a right amplifier having transistors, a negative feedback network having a resistor, and a negative feedback network having a transformer with a center tap. Phase compensation networks comprising a capacitor and a resistor, a capacitor and a resistor, and a capacitor and a resistor are further added to the amplifier. Both ends of a secondary winding of the transformer are connected to the output terminals of the right and left amplifiers, and the center tap of the secondary winding is grounded, so that a differential amplified output signal can be fed back to a single-phase input using one transformer, thereby reducing a cost and an area. | 08-06-2009 |
20090289714 | OPERATIONAL AMPLIFIER - The present invention relates generally to an operational amplifier. In one embodiment, the present invention is an operational amplifier including a transimpedance input stage, the transimpedance input stage including a first stage connected to a first resistor and a second resistor, and an output stage connected to the transimpedance input stage. | 11-26-2009 |
20100007420 | Operational amplifier - An operational amplifier includes an input stage amplifier that receives an input signal, an output stage amplifier that amplifies a signal output from the input stage amplifier and outputs the signal, a capacitor that is connected between an input node and an output node of the output stage amplifier, and a charge and discharge control circuit that controls a charge and discharge current of the capacitor. | 01-14-2010 |
20100109775 | SEMICONDUCTOR DEVICE HAVING RESISTORS WITH A BIASED SUBSTRATE VOLTAGE - To eliminate the substrate voltage dependences of the respective resistance values of resistor elements, in the resistor elements coupled in series to each other over respective substrate regions, the ends of the resistor elements are coupled to the corresponding substrate regions by respective bias wires such that respective average potentials between the substrate regions of the resistor elements and the corresponding resistor elements have opposite polarities, and equal magnitudes. | 05-06-2010 |
20100117736 | LINE DRIVER CAPABLE OF AUTOMATIC ADJUSTMENT OF OUTPUT IMPEDANCE - A line driver includes an output terminal set for outputting an output signal, a differential amplifier for amplifying an input signal, a series resistor set coupled between the differential amplifier and the output terminal set, a negative-feedback resistor set coupled to the differential amplifier, a feedback variable resistor set coupled between the differential amplifier and the output terminal set, and an adjusting unit coupled to the feedback variable resistor set. The adjusting unit is operable to adjust resistances of the feedback variable resistor set according to the output signal. | 05-13-2010 |
20100231302 | AMPLIFICATION CIRCUIT - An amplification circuit includes a semiconductor amplification element, a current feedback circuit that is connected to a terminal close to a ground side of the semiconductor amplification element and can control gain reduction, and a voltage feedback circuit that is connected between an input terminal and an output terminal of the semiconductor amplification element and can control feedback voltage. The feedback voltage of the voltage feedback circuit may be varied according to the gain reduction controlled by the current feedback circuit. | 09-16-2010 |
20100244961 | DIFFERENTIAL AMPLIFIER - A differential amplifier unit and a feedback unit are provided The differential amplifier unit includes first and second transistors and first to fourth loads. Each of the first and second transistors is provided with a current input end, a current output end connected to a lower potential power source and a control end. The first and second loads are cascade connected between a higher potential power source and the current input end of the first transistor. The third and fourth loads are cascade connected between the higher potential power source and the current input end of the second transistor. The feedback unit generates first and second feedback currents based on first and second output voltages The feedback unit inputs the first and second feedback currents to a third node connecting the first and second loads and a fourth node connecting the third and fourth loads. | 09-30-2010 |
20100289584 | TRANSIMPEDANCE AMPLIFIER WITH DISTRIBUTED CONTROL OF FEEDBACK LINE - An apparatus includes an electronic amplifier and an electrical feedback line, a plurality of electrical sources, and an electronic controller. The electrical feedback line connects an output of the electronic amplifier to an input thereof. The electrical sources connect to nodes on the electronic feedback line. The electronic controller is configured to adjust the electrical sources in a manner responsive to a current input to the electrical feedback line. | 11-18-2010 |
20100315165 | Broadband high output current output stage - A broadband high output current output stage includes at least one first differential pair for enhancing the bandwidth. A second differential pair is further disposed in the circuit. The second differential pair is coupled to one of the first differential pair, such that a large output voltage swing is distributed to all transistors to avoid breakdowns thereof. A feedback unit is connected between each bias unit and the first differential pair. The first compensation unit compensates the electric characteristic of the high-frequency zero of the feedback unit and the bias unit, thereby broadening the linear bandwidth of the frequency response. The second compensation units are disposed between the first differential pairs. Each second compensation unit compensates the high-frequency zero of the node where each two first differential pairs are cascaded, thereby further broadening the linear bandwidth of the frequency response. | 12-16-2010 |
20110084764 | AMPLIFIER AND SIGNAL FILTER - A signal filter circuit, an amplifier circuit, combinations thereof and methods for configuring and using the same are provided. Embodiments of the amplifier circuit may provide precise reproduction and amplification of input signals. The amplifier may be built entirely with discrete components or an integrated circuit may be configured to provide some or all of the modules included in the amplifier. | 04-14-2011 |
20110109388 | DIFFERENTIAL RF AMPLIFIER - An RF amplifier including first and second branches coupled in parallel between first and second supply voltage terminals, and a differential pair including first and second transistors each having first and second main current terminals, the second main current terminal of the first transistor being coupled by a first capacitor to the first main current terminal of the second transistor, and the second main current terminal of the second transistor being coupled by a second capacitor to the first main current terminal of the first transistor, wherein the first branch includes a first resistor coupled between the first main current terminal of the first transistor and the second capacitor, and the second branch includes a second resistor; coupled between the first main current terminal of the second transistor and the first capacitor. | 05-12-2011 |
20110109389 | AMPLIFIER CIRCUIT, INTEGRATED CIRCUIT AND RADIO FREQUENCY COMMUNICATION UNIT - An amplifier circuit for amplifying a differential input signal includes a first feedback resistance, a second feedback resistance, first transconductance circuitry, and second transconductance circuitry. The first feedback resistance is connected between a first input node and a first output node of the amplifier circuit. The second feedback resistance is connected between a second input node and a second output node of the amplifier circuit. The first transconductance circuitry is arranged to inject a transconductance current at a point along the first feedback resistance, and is configurable to vary the point along the first feedback resistance where the transconductance current is injected. The second transconductance circuitry is arranged to inject another transconductance current at a point along the second feedback resistance, and is configurable to vary the point along the second feedback resistance where the another transconductance current is injected. | 05-12-2011 |
20110169568 | OPERATIONAL AMPLIFIER - The present invention relates generally to an operational amplifier. In one embodiment, the present invention is an operational amplifier including a transimpedance input stage, the transimpedance input stage including a first stage connected to a first resistor and a second resistor, and an output stage connected to the transimpedance input stage. | 07-14-2011 |
20110169569 | Device and method for eliminating feedback common mode signals - A device and a method for eliminating feedback common mode signals are provided, which belong to the electronic technology field. The device includes an operational amplifier circuit with two output ends. The two output ends are a first output end and a second output end. The device also includes a feedback unit. The feedback unit is configured to receive level signals of the first output end and the second output end of the operational amplifier circuit, and superpose feedback common mode signals to input ends of the operational amplifier circuit according to states of the level signals. The method includes: the feedback unit receives level signals of a first output end and a second output end of an operational amplifier circuit, and superposes feedback common mode signals to the input ends of the operational amplifier circuit according to the states of the level signals. Thus, the feedback common mode signals of the operational amplifier circuit are stabilized, the requirements for the operational amplifier circuit are lowered, and the performance of the operational amplifier circuit is improved. | 07-14-2011 |
20110193633 | BIOAMPLIFIER FOR NEURAL INTERFACES - A bioamplifier that includes a high pass filter, open-loop amplifier, and low pass filter in an area efficient design that can be used in implantable neural interfaces. The high pass filter can be implemented by using a switch-capacitance resistor coupled with parasitic capacitance of the electrode. The amplifier can be chopper stabilized and can include a high gain, current-ratio first stage followed by one or more dimension-ratio stages. The low pass filter utilizes the output impedance of the open-loop amplifier to form an embedded g | 08-11-2011 |
20110210794 | VOLTAGE SENSING CIRCUIT CAPABLE OF CONTROLLING A PUMP VOLTAGE STABLY GENERATED IN A LOW VOLTAGE ENVIRONMENT - Herein, a voltage sensing circuit, which is capable of controlling a pumping voltage to be stably generated in a low voltage environment, is provided. The voltage sensing circuit includes a current mirror having first and second terminals, a first switching element configured to control current on the first terminal of the current mirror by a reference voltage, a second switching element configured to control current from the second terminal of the current mirror in response to a pumping voltage, and a third switching element configured to control current sources of the first and second switching elements to receive a negative voltage. | 09-01-2011 |
20110215870 | BURST MODE AMPLIFIER - An integrator circuit cancels a DC offset component related to an average DC value of a burst mode input signal from the output of an amplifier. The integrator circuit outputs an average DC value of the input signal in a response time that is shorter than the preamble of a burst mode signal. The integrator output signal remains stable within selected amplitude limits for a length of time corresponding to the data portion of a burst mode signal. A transimpedance amplifier embodiment of the invention comprises a TIA gain stage, an integrator, and a voltage-controlled current course. Other embodiments comprise an amplifier for converting single-ended input signals to differential output signals, an amplifier for differential output offset cancellation, a monolithic semiconductor integrated circuit die, and a packaged semiconductor integrated circuit device. | 09-08-2011 |
20110227652 | Differential Amplifier and Method for the Operation of a Differential Amplifier - A differential amplifier comprises a first amplifier (A | 09-22-2011 |
20110241780 | AMPLIFIER CIRCUIT, SIGNAL PROCESSOR CIRCUIT, AND SEMICONDUCTOR INTEGRATED CIRCUIT DEVICE - An amplifier circuit is provided to be switchable between a single end output configuration and a differential output configuration without increasing a circuit area. When first and fourth switches are turned off and a second switch is turned on, a load circuit functions as an active load on a differential pair and a first output terminal is internally disconnected. The amplifier circuit is provided with a single end output configuration and differentially amplifies input voltages inputted to input terminals and outputs an imbalanced signal from a second output terminal. When the first and fourth switches are turned on and the second switch is turned off, the load circuit functions as a load on the differential pair and the first output terminal is internally connected. The amplifier circuit is provided with a differential output configuration and differentially amplifies the input voltages inputted to the input terminals and outputs balanced signals from the output terminals. | 10-06-2011 |
20110260795 | METHOD FOR REDUCING OFFSET VOLTAGE OF OPERATIONAL AMPLIFIER AND THE CIRCUIT USING THE SAME - The invention provides an operational amplifier. In one embodiment, the operational amplifier includes an input stage circuit, a feedback circuit, a fixed stage circuit, and an output stage circuit. The input stage circuit receives a positive input voltage and a negative input voltage, and amplifies the positive input voltage and the negative input voltage to output a first positive output voltage and a first negative output voltage. The feedback circuit generates a reference positive output voltage equal to the first positive output voltage according to the positive input voltage and the negative input voltage. The fixed stage circuit equally amplifies the first negative output voltage and the reference positive output voltage to generate a second positive output voltage and a second negative output voltage. The output stage circuit generates an output voltage according to a difference voltage between the second positive output voltage and a second negative voltage. | 10-27-2011 |
20110267144 | NOISE-CANCELING FOR DIFFERENTIAL AMPLIFIERS REQUIRING NO EXTERNAL MATCHING - A differential Low Noise Amplifier (LNA) includes a first stage of resistive feedback amplifiers and second stage of complementary amplifiers, where the outputs of the first stage are coupled to the inputs of the second stage in a cross-coupled fashion. An inductive load, such as a transformer, combines signals output from the complementary amplifiers of the second stage. In one example, the LNA has an input impedance of less than 75 ohms, a noise factor of less than 2 dB, and a gain of more than 20 dB. Due to the low input impedance, the LNA is usable to amplify a signal received from a source having a similar low impedance without the use of an impedance matching network between the output of the source and the input of the LNA. | 11-03-2011 |
20120019323 | CURRENT-MODE AMPLIFIER - A current-mode amplifier including an input stage, a feedback circuit and an output stage is provided. The input stage has an input terminal for receiving an input current of the current-mode amplifier. The input stage generates a corresponding inner current in accordance with the input current and a feedback current. The feedback circuit is connected to the input stage. The feedback circuit generates the corresponding feedback current in accordance with the inner current of the input stage. An input terminal of the output stage is connected to an output terminal of the input stage. An output terminal of the output stage serves as an output terminal of the current-mode amplifier. | 01-26-2012 |
20120062319 | Single-Differential Converting Circuit - There is provided a single-differential converting circuit that can reduce the variations in the input voltage of an operational amplifier sufficiently, made by changes in the voltages input from the exterior, while maintaining the function as the amplifier. The single-differential converting circuit is configured to include: an operational amplifier | 03-15-2012 |
20120068769 | HIGH-FREQUENCY DIFFERENTIAL AMPLIFIER CIRCUIT - There is provided a high-frequency differential amplifier circuit comprising: a first MOS transistor, a second MOS transistor, a first positive feedback element and a second positive feedback element. The first MOS transistor and the second MOS transistor each has a source connected to a first power source and a drain connected through loads to a second power source. The first and second MOS transistors receives at their gates, first and second input signals having phases reverse to each other. The first positive feedback element includes a first capacitor and a first variable resistance connected in series between the gate of the first MOS transistor and the drain of the second MOS transistor. The second positive feedback element includes a second capacitor and a second variable resistance connected in series between the gate of the second MOS transistor and the drain of the first MOS transistor. | 03-22-2012 |
20120068770 | ANTI-GLITCH SYSTEM FOR AUDIO AMPLIFIER - An audio amplification circuit comprises an amplifier having an input and an output, as well as an audio output to which a load can be connected. It additionally comprises a first driver stage having an input and an output which is not coupled to the audio output, and a second driver stage having an input and an output which is coupled to the audio output. The output from the amplifier is selectively coupled to the input of the first driver stage in a first phase of operation and then selectively to the input of the second driver stage in a second phase of operation following the first phase of operation. | 03-22-2012 |
20120086510 | COMMON-MODE FEEDBACK AMPLIFIER - A circuit is provided for use with a reference voltage. The circuit includes a voltage source, a common-mode feedback amplifier and a feedback impedance portion. The common-mode feedback amplifier may be connected to the voltage source and may be arranged to receive the reference voltage. The common-mode feedback amplifier may include an input stage, an output stage, a positive input, a negative input and an output. The output may be connected to the feedback impedance portion. The feedback impedance portion may additionally be connected to one of the positive input and the negative input. A feedback factor, based on the feedback impedance portion, is less than one. | 04-12-2012 |
20120133439 | Reference Voltage Buffer and Method Thereof - An apparatus comprises: an OTA (operational trans-conductance amplifier) with a positive input terminal coupled to a reference voltage, a negative input terminal coupled to a feedback node, and an output terminal shunt to a ground node via a shunt capacitor; a resistor coupling the output terminal of the OTA to the feedback node; and a load circuit coupled to the feedback node via a switch controlled by a logical signal, wherein: an impedance of the shunt capacitor is substantially smaller than an input impedance of the load circuit. In an embodiment, the load circuit is a switch capacitor circuit. A corresponding method using an OTA is also provided. | 05-31-2012 |
20120154048 | Amplifier common-mode control methods - Systems and methods for providing a fully differential amplifier performing common-mode voltage control having reduced area and power requirements are disclosed. The amplifier disclosed comprises an additional input stage at the amplifier input which senses the common mode voltage of the amplifier's inputs and applies internal feedback control to adjust the output common-mode voltage until the input common-mode voltage matches a target voltage and thereby indirectly set the output common-mode voltage. Furthermore the internal common-mode control can be implemented in such a manner as to provide a feed-forward transconductance function in addition to common-mode control if desired. Moreover it is possible to use feedback from other amplifier stages in an amplifier chain to implement common-mode feedback. | 06-21-2012 |
20120154049 | Common-Mode Feedback Circuit - A differential amplifier circuit with common-mode feedback is disclosed. The amplifier may include a first stage comprising a first differential input configured to drive a first differential pair transistor in a first differential current path, a second differential input configured to drive a second differential pair transistor in a second differential current path, a first differential output, and a second differential output, a second stage comprising a first differential input, a second differential input, a first differential output, and a second differential output, a common-mode feedback circuit, a first conducting element in a first common-mode current path parallel to the first differential current path and comprising a first conducting terminal coupled to the first differential output of the first stage, and a second conducting element in a second common-mode current path parallel to the second differential current path and comprising a first conducting terminal coupled to the second differential output of the first stage. | 06-21-2012 |
20120154050 | CIRCUIT WITH REFERENCE SOURCE TO CONTROL THE SMALL SIGNAL TRANSCONDUCTANCE OF AN AMPLIFIER TRANSISTOR - A circuit has a reference source ( | 06-21-2012 |
20120154051 | VOLTAGE REGULATOR CIRCUIT - A voltage regulator circuit includes a differential amplifier circuit that includes a first input terminal and a second input terminal, the first input terminal supplied a reference voltage, an output circuit that receives an output voltage from the differential amplifier circuit to generate a first voltage based on the output voltage, and a control circuit that compares the first voltage with a second voltage, and outputs the first voltage or a third voltage to the second input terminal based on a result of comparing, the second and third voltage being different from the first voltage. | 06-21-2012 |
20120268207 | INTEGRATED CIRCUIT - An integrated circuit includes an input unit and a voltage level detecting unit. The input unit is configured to output differential amplification signals corresponding to differential input signals in response to a voltage level detection signal. The voltage level detecting unit is configured to detect a voltage level of the differential amplification signals and output the voltage level detection signal. | 10-25-2012 |
20120268208 | SEMICONDUCTOR INTEGRATED CIRCUIT DEVICE - There is provided a semiconductor integrated circuit device including: a differential amplification circuit having a non-inverting input terminal that receives a reference voltage and an inverting input terminal connected to an output load; and an output circuit including a first MOS transistor having a gate connected to an output terminal of the differential amplification circuit, a source, and a drain connected to the inverting input terminal of the differential amplification circuit such that the first MOS transistor is ON/OFF in an operation state/a non-operation state, and a second MOS transistor connected in series between a power source and the source of the first MOS transistor, with a gate width/gate length ratio of the second MOS transistor smaller than a gate width/gate length ratio of the first MOS transistor, such that the second MOS transistor is ON in the operation state and OFF in the non-operation state. | 10-25-2012 |
20120274401 | SEMICONDUCTOR DEVICE AND METHOD FOR DRIVING THE SAME - An object is to suppress operation delay caused when a semiconductor device that amplifies and outputs an error between two potentials returns from a standby mode. Electrical connection between an output terminal of a transconductance amplifier and one electrode of a capacitor is controlled by a transistor whose channel is formed in an oxide semiconductor layer. Consequently, turning off the transistor allows the one electrode of the capacitor to hold charge for a long time even if the transconductance amplifier is in the standby mode. Moreover, when the transconductance amplifier returns from the standby mode, turning on the transistor makes it possible to settle charging and discharging of the capacitor in a short time. As a result, the operation of the semiconductor device can enter into a steady state in a short time. | 11-01-2012 |
20120280751 | Noise Rejecting High-Side Power Switch - An apparatus includes a pass element comprising an input, an output and a control input. The pass element, with a first signal on the control input, passes a voltage from the input to the output and, with a second signal on the control input, blocks the voltage on the input from passing to the output. A differential amplifier includes a non-inverting input coupled to the input, an inverting input coupled to the output, an amplifier output coupled to the control input and a bias current connection. The differential amplifier, with a bias current supplied, supplies the first signal along with a closed feedback loop from the output and supplies the second signal in absence of the bias current. A current source is coupled to the bias current connection and an enable input. The current source supplies the bias current and, in absence of an enable signal, disables the bias current. | 11-08-2012 |
20120293261 | Amplifier with Start-up Common Mode Feedback - An amplifier with a cascode device contains a common mode feedback circuit to ensure correct operating point in the amplifier. Common mode feedback is provided to the amplifier to maintain the common mode operating point during active operation. Additional common mode feedback is provided to the cascode devices to ensure correct start-up by forcing the node voltages to go to their desired voltage levels. | 11-22-2012 |
20120293262 | Amplifier - The invention relates to a configurable low noise amplifier circuit which is configurable between a first topology in which the low noise amplifier circuit includes a degeneration inductance whereby the low noise amplifier circuit operates as an inductively degenerated low noise amplifier, and a second topology in which the low noise amplifier circuit includes a feedback resistance whereby the low noise amplifier circuit operates as a resistive feedback low noise amplifier. | 11-22-2012 |
20120293263 | OPERATIONAL AMPLIFIER - An operational amplifier may include a transimpedance input stage. The operational amplifier is capable of self-biasing its input voltage(s) including a first stage, an input source connected to the first stage, an output stage connected to the first stage via feedback resistors, and feedback current sources connected to the first stage, wherein the feedback current sources are set to generate feedback currents flowing from the output stage back to the input stage via the feedback resistors, so as to self-bias the input voltage(s) at the input stage. A method for allowing for an op-amp to self-bias its input voltage(s), including generating feedback currents flowing from the output stage back to the input stage via feedback resistors, so as to self-bias the input voltage(s) at the input stage. | 11-22-2012 |
20120299654 | POWER AMPLIFIER AND METHOD FOR AMPLIFYING SIGNAL BASED ON POWER AMPLIFIER - A power amplifier for amplifying a signal includes: an operation amplifier stage, at least one buffer stage and an output stage which are consecutively connected with each other; a first feedback unit connected between an output end of the output stage and a negative input end of the operation amplifier stage; a second feedback unit connected between an input end of the output stage and the negative input end of the operation amplifier stage; a third feedback unit connected between an input end of the at least one buffer stage and the negative input end of the operation amplifier stage; and feedback signals provided by the first feedback unit, the second feedback unit and the third feedback unit being superposed at the negative input end of the operation amplifier stage. | 11-29-2012 |
20120299655 | VOLTAGE REGULATORS, AMPLIFIERS, MEMORY DEVICES AND METHODS - Circuits, devices and methods are provided, such as an amplifier (e.g., a voltage regulator) that includes a feedback circuit that supplies negative feedback through a feedback path. One such feedback path includes a capacitance coupled in series with a “one-way” isolation circuit through which a feedback signal is coupled. The “one-way” isolation circuit may allow the feedback signal to be coupled from a “downstream” node, such as an output node, to an “upstream” node, such as a node at which an error signal is generated to provide negative feedback. However, the “one-way” isolation circuit may substantially prevent variations in the voltage at the upstream node from being coupled to the capacitance in the isolation circuit. As a result, the voltage at the upstream node may quickly change since charging and discharging of the capacitance responsive to voltage variations at the upstream node may be avoided. | 11-29-2012 |
20120306574 | WIDE BANDWIDTH CLASS C AMPLIFIER WITH COMMON-MODE FEEDBACK - A method for providing common-mode feedback is provided. A common-mode current is applied to a common-gate amplifier, and the common-mode current is sensed. In response to the sensed common-mode current, a control voltage is generated. A first feedback current (which is generated in response to the control voltage) can then be applied to differential ground of the common-gate amplifier if the common-mode current is less than a predetermined threshold. Additionally, a second feedback current (which is generated in response to the control voltage) can be applied to input terminals of the common-gate amplifier if the common-mode current is greater than the predetermined threshold. | 12-06-2012 |
20120306575 | SWITCHED-CAPACITOR DC BLOCKING AMPLIFIER - A switched-capacitor DC blocking amplifier is disclosed. In an embodiment, an integrated circuit is provided that includes an amplifier having an amplifier input and an amplifier output, a capacitor connected to the amplifier input and configured to receive an input signal, and a switched capacitor circuit coupled to provide a resistance between the amplifier input and the amplifier output. In one implementation, the switched capacitor circuit is configured with a feed forward circuit to reduce aliasing. In another implementation, the switched capacitor circuit includes a switched impedance circuit to reduce noise. | 12-06-2012 |
20120313705 | Method for introducing feedback in a FET amplifier - A method of configuring a FET amplifier with two inputs demonstrating similar-phased response to similar-phased inputs. One input can be used as a feedback path in suitable amplifier circuits, improving frequency performance by decreasing feedback resistance. The second input provides the means for a high impedance connection to a drive signal. The present invention is particularly applicable to applications involving constant voltage sources and constant current active sources with or without cascoding, in both single-ended and differential configurations. | 12-13-2012 |
20120313706 | UNBALANCED/BALANCED CONVERSION DIFFERENTIAL AMPLIFIER - A differential amplifier including an input of a balanced type relative to a reference potential; a balanced output; first and second bipolar transistors mounted in common emitter configuration, emitters of the first and second transistors linked by two feedback impedances in series; and a perfect current generator, wherein an impedance Z | 12-13-2012 |
20130015919 | System and Method for Capacitive Signal Source AmplifierAANM Kropfitsch; MichaelAACI KoettmannsdorfAACO ATAAGP Kropfitsch; Michael Koettmannsdorf ATAANM Ceballos; Jose LuisAACI VillachAACO ATAAGP Ceballos; Jose Luis Villach AT - According to an embodiment, a system for amplifying a signal provided by a capacitive signal source includes a first stage and a second stage. The first stage has a voltage follower device including an input terminal configured to be coupled to a first terminal of the capacitive signal source, and a first capacitor having a first end coupled to an output terminal of the capacitive signal source. The second stage includes a differential amplifier capacitively coupled to the output terminal of the voltage follower device. | 01-17-2013 |
20130033324 | AMPLIFIER AND ASSOCIATED RECEIVER - An amplifier is arranged to receive an input signal and provide an output signal in response, and includes a main amplifier core and an auxiliary circuit. The main amplifier core includes an input node, an output node and a sum node with the input node coupled to the input signal, and is arranged to provide an interior signal to the sum node and output the output signal at the output node in response to signals provided to the sum node. The auxiliary circuit is coupled between the input node and the sum node, and is arranged to match an impedance of the input node and provide a cancelling signal to the sum node in response to the input signal. An associated receiver is also disclosed. | 02-07-2013 |
20130038395 | POWER AMPLIFYING CIRCUIT - A power amplifying circuit includes first and second operational amplifiers. The power amplifying circuit includes first to fourth feedback resistor. The power amplifying circuit includes a fully differential operational amplifier that is connected to the output terminal of the first operational amplifier at a non-inverting input terminal thereof, to the output terminal of the second operational amplifier at an inverting input terminal thereof, to a first signal output terminal at a non-inverting output terminal thereof, and to a second signal output terminal at an inverting output terminal thereof and maintains a constant differential gain. The power amplifying circuit includes a switching circuit. The power amplifying circuit includes first and second input resistors. The power amplifying circuit includes a midpoint potential controlling circuit that monitors a power supply voltage and controls the switching circuit. | 02-14-2013 |
20130057348 | Transimpedance Amplifier - A circuit includes a transimpedance amplifier portion having a first input node and a second input node, and a feedback circuit portion comprising a first transistor having a drain terminal connected to the first input node, a source terminal, and a gate terminal, a second transistor having a drain terminal connected to the second input node, a source terminal, and a gate terminal, and a third transistor having a drain terminal connected to the source terminal of the first transistor and the source terminal of the second terminal. | 03-07-2013 |
20130106516 | Fast Settling Reference Voltage Buffer and Method Thereof | 05-02-2013 |
20130120066 | REFERENCE BUFFER AMPLIFIER - A reference buffer amplifier within an integrated circuit includes a first output terminal connected to a first bond pad, the first bond pad being connected to a first external pin of the integrated circuit chip, the first external pin to allow an external capacitance to be connected to the output terminal. The reference buffer further includes a variable, settable resistance sub-circuit connected to a second bond pad, the second bond pad also being connected to the first external pin. The resistance sub-circuit is configured to be set to exhibit a resistance value to critically dampen a response of the reference buffer amplifier. | 05-16-2013 |
20130127536 | FULLY DIFFERENTIAL OPERATIONAL AMPLIFIER WITH COMMON-MODE FEEDBACK CIRCUIT - A fully differential operational amplifier includes a differential input stage, at least one output stage and a common-mode feedback circuit connected with the input stage. The differential input stage includes a differential pair of transistors and a bias circuit for the differential pair of transistors. A start-up circuit operates to detect an operating condition of the differential pair of transistors of the input stage and in response thereto turn on the bias circuit. | 05-23-2013 |
20130147560 | LOW NOISE AMPLIFIER WITH BACK-TO-BACK CONNECTED DIODES AND BACK-TO-BACK CONNECTED DIODE WITH HIGH IMPEDANCE THEREOF - A low noise amplifier with back-to-back connected diodes and a back-to-back connected diode with high impedance thereof are provided. The low noise amplifier includes a first operational amplifier (OP) and at least two first back-to-back connected diodes. The back-to-back connected diode with high impedance is formed from at least one MOS FET operated within a cut-off region. The first back-to-back connected diodes are connected electrically between the first input end and the first output end, and between the second input end and the second output end, of the first OP respectively. By the implementation of the present invention, the low noise amplifier is not only low noise, but also with low energy consumption, high stability, low circuitry complexity, and easily controlled manufacturing process. | 06-13-2013 |
20130154740 | TECHNIQUES FOR PGA LINEARITY - Techniques for designing a highly linear programmable gain amplifier (PGA). In an aspect, the PGA includes a plurality of feedback switches selectively coupling an output of an operational amplifier (op amp) to an input of the op amp via a corresponding series-coupled feedback resistance. The PGA may further include a plurality of input switches selectively coupling an input of the op amp to a PGA input voltage via a corresponding series-coupled input resistance. The switches are designed such that the ratio of on-resistances between any two switches is substantially equal to the ratio of the corresponding series-coupled resistances. In an exemplary embodiment, transistors implementing the switches may be accordingly sized to implement the desired on-resistance ratios. | 06-20-2013 |
20130154741 | APPARATUS AND CIRCUIT FOR AMPLIFYING BASEBAND SIGNAL - An operational amplifier circuit is provided. The operational amplifier circuit includes a differential amplifier of a cascade structure and a switched-capacitor type Common-Mode FeedBack (CMFB) circuit. The differential amplifier amplifies a difference between two input signals to output an anode output voltage and a negative output voltage. The switched-capacitor type CMFB circuit averages the anode output voltage and the negative output voltage of the differential amplifier, compares the average voltage with a reference voltage to generate a feedback signal based on a result of the comparison, and provides the feedback signal to the differential amplifier. Therefore, power consumption is reduced and a battery use time of a wireless terminal can be extended. Also, since an operational amplifier gain of each analog filter terminal is not negatively affected, a Direct Current (DC) offset is reduced, thereby improving signal quality. | 06-20-2013 |
20130154742 | Low Noise Amplifier for Multiple Channels - An amplifier system has an amplifier for amplifying a plurality of input signals from a plurality of different channels, and a plurality of demodulators each operatively coupled with the amplifier for receiving amplified input signals from the amplifier. Each demodulator is configured to demodulate a single amplified input channel signal from a single channel of the plurality of different channels. The system thus also has a plurality of filters, coupled with each of the demodulators, for mitigating the noise. | 06-20-2013 |
20130162353 | SIGNAL AMPLIFICATION CIRCUIT - A signal amplification circuit includes a differential amplifier configured to receive a first signal and a second signal and generate an output signal, a differential amplifier configured to receive first and second signals and generate an output signal; and a controller configured to control an amount of current flowing in the differential amplifier using the output signal. | 06-27-2013 |
20130181778 | High Fidelity Current Dumping Audio Amplifier With Combined Feedback-Clean Feedback - A high fidelity current dumping audio amplifier in which for achieving the best performance are combined the feedforward error correction and the negative feedback. | 07-18-2013 |
20130187716 | PILOT SIGNAL GENERATION CIRCUIT - In various embodiments, a pilot signal generation circuit is provided having an operational amplifier buffer connected via a first resistor to receive a source reference voltage. A differential amplifier is connected at a first input to receive the source reference voltage and at a second input to an output of the operational amplifier buffer. A first shunt transistor is connected to shunt the source reference voltage at the operational amplifier buffer in response to pulse width modulated signal. A second shunt transistor is connected to the differential operational amplifier so as to shunt the source reference voltage in response to an output of the first shunt transistor. The output of the differential amplifier provides a pulse width modulated bipolar signal at precision voltage levels in response to the pulse width modulated signal. | 07-25-2013 |
20130207722 | PEAKING AMPLIFIER WITH CAPACITIVELY-COUPLED PARALLEL INPUT STAGES - Analog peaking amplifiers with enhanced peaking capability are provided. For example, a peaking amplifier circuit includes an input node, output node, a feedback node, a first input amplifier having an input connected to the input node and an output connected to the feedback node, a second input amplifier having an input connected to the input node, a coupling capacitor connected between an output of the second input amplifier and the feedback node, a forward-path gain amplifier having an input connected to the feedback node and an output connected to the output node, and a feedback circuit having an input coupled to the output node and an output connected to the feedback node. A peaking response of the peaking amplifier circuit is realized by capacitively coupling the output of the second input amplifier to the feedback node to suppress negative feedback and increase the peaking gain at higher frequencies. | 08-15-2013 |
20130207723 | A GM-RATIOED AMPLIFIER - Embodiments provide a gm-ratioed amplifier. The gm-ratioed amplifier comprises a first input voltage terminal and a second input voltage terminal, a first output voltage terminal and a second output voltage terminal, and an amplifying unit. The amplifying unit may be coupled between the input voltage terminals and the output voltage terminals and may be adapted to supply an output voltage to the output terminals in dependence on an input voltage supplied to the input terminals. The amplifying unit may comprise a gm-load, which comprises a first load branch comprising a first field effect transistor, and a second load branch comprising a second field effect transistor. A first source/drain terminal and a gate terminal of the first field effect transistor may be coupled to the first output voltage terminal, and a first source/drain terminal and a gate terminal of the second field effect transistor may be coupled to the second output voltage terminal. A second source/drain terminal of the first field effect transistor and a second source/drain terminal of the second field effect transistor may be coupled with each other through a first transistor arrangement such that a linearity of response of the output voltage to the input voltage is improved. | 08-15-2013 |
20130214863 | Front-End System for Radio Devices - The present disclosure relates to a front-end system for a radio device, the front-end system comprising a low-noise amplifier (LNA), arranged for receiving a radio frequency input signal (RF | 08-22-2013 |
20130214864 | SIGNAL AMPLIFYING CIRCUIT OF COMMUNICATION DEVICE - A signal amplifying circuit of a communication device is disclosed including: an amplifier comprising a first input terminal, a second input terminal, and an output terminal, wherein the input terminal is coupled with a fixed voltage level; a feedback circuit coupled with the second input terminal and the output terminal of the amplifier; a digital-to-analog converter (DAC); a signal processing circuit; a switch for selectively coupling the second input terminal of the amplifier with the DAC or the signal processing circuit; and a control unit coupled with the switch for controlling the operations of the switch. | 08-22-2013 |
20130257537 | MATCHED FEEDBACK AMPLIFIER WITH IMPROVED LINEARITY - An impedance-matched amplifier utilizing a feed-forward linearization technique involving multiple negative feedbacks and distortion compensation without active tail current sources reduces noise, distortion, power consumption and heat dissipation requirements and increases linearity, dynamic range, signal-to-noise-ratio, sensitivity and quality of service. Some differential amplifier embodiments of the invention consume less than 2 mA at 5 Volts or 10 mW power consumption per 1 mW in peak and sustained output IP3 performance above 40 dBm. In contrast, for an input signal frequency of 200 MHz, a 16 dB gain state-of-the-art differential amplifier consumes 100 mA at 5 Volts with a peak output IP3 of 36 dBm while an implementation of a 16 dB gain differential amplifier embodying the invention consumes 77.7 mA at 5 Volts with a peak output IP3 of 46 dBm and sustained at or above 40 dBm over a wide frequency range. | 10-03-2013 |
20130285746 | Differential Source Follower having 6dB Gain with Applications to WiGig Baseband Filters - A differential amplifier comprising a first upper device and a first lower device series coupled between two power supplies and a second upper device and a second lower device series coupled between the two power supplies. A first DC voltage enables the first upper device and the second upper device and a second DC voltage regulates current flow in the first lower device and the second lower device. An AC signal component is coupled to the first upper device and the second lower device while the AC signal complement is coupled to the first lower device and the second upper device. Separate RC networks couple the AC signals to their respective device. A first and second output signal forms between the upper device and the lower device, respectively. All the devices are same channel type. | 10-31-2013 |
20130293304 | COMPENSATION TECHNIQUE FOR FEEDBACK AMPLIFIERS - Compensation methods and systems for voltage-feedback amplifiers provide improved dynamic performance (i.e., increased bandwidth and the elimination or alleviation of a slew limitation) at various gains by self-adaptively changing the Miller effect with respect to the gain setting. | 11-07-2013 |
20130293305 | AMPLIFIER AND FILTER HAVING CUTOFF FREQUENCY CONTROLLED ACCORDING TO DIGITAL CODE - An amplifier circuit is provided. The amplifier circuit includes an operational amplifier, a feedback resistor for changing gain and cutoff frequency characteristics of the operational amplifier, and a feedback variable capacitor for changing the cutoff frequency characteristics of the operational amplifier, wherein a capacitance of the feedback variable capacitor increases exponentially according to a digital control code, and the cutoff frequency of the operational amplifier is inversely proportional to the capacitance of the feedback variable capacitor and varies linearly on a logarithmic scale. | 11-07-2013 |
20130293306 | Comparator with Self-Limiting Positive Feedback - A method and circuit for attenuating positive feedback in a comparator in one embodiment includes an amplifier configured to compare a first input signal with a second input signal and to provide an output based upon the comparison, a non-linear function with a first input operably connected to an output of the amplifier, and a feedback loop operably connected to the output of the non-linear function and to a second input of the non-linear function, the feedback loop including a feedback limiting circuit configured to attenuate a feedback signal to the second input of the non-linear function. | 11-07-2013 |
20130314160 | LOW NOISE AMPLIFIER AND SAW-LESS RECEIVER WITH LOW-NOISE AMPLIFIER - A low noise amplifier is used to amplify a differential input pair to generate a differential output pair. The low noise amplifier includes two main paths, two assistant circuits and two adders to make noise carried on two output signals of the differential output pair be the same; therefore, the noise of the two output signals can be fully cancelled in the following operations. | 11-28-2013 |
20130335145 | HIGH-SPEED TRANSIMPEDANCE AMPLIFIER - A transimpedance amplifier includes a first inverter having a first input node and a first output node. The first input node is configured to be coupled to an input signal. A second inverter has a second input node and a second output node. The second input node is configured to receive a reference voltage terminal. The first inverter and the second inverter are configured to provide a differential output voltage signal between the first output node and the second output node. | 12-19-2013 |
20140028395 | Op-Amp Sharing by Swapping Trans-Conductance Cells - A two-stage op amp has a transconductance cell in a second stage modified to match a transconductance cell in a first stage. A transconductance swap network is inserted between transconductance cells and trans-impedance cells, such as current-steering networks, current mirrors, or drivers connected to the transconductance cells. The transconductance swap network directly connects the first transconductance cell to the first stage trans-impedance cell during a second clock phase, but crosses-over the first transconductance cell to the second-stage trans-impedance cell during a first clock phase. A first switched-capacitor network drives the gates of differential transistors in the first transconductance cell by alternately sampling an input and feedback, and equalizing to reset inputs. A second first switched-capacitor network drives differential transistors in the second transconductance cell, but during opposite clock phases. Two independent inputs are sampled by the switched-capacitor networks and alternately amplified by swapping connections within the shared op amp. | 01-30-2014 |
20140028396 | UNITY-GAIN BUFFER WITH ENHANCED SLEW RATE - A unity-gain buffer includes an operational amplifier, a control stage, and an auxiliary output stage. The operational amplifier includes a non-inverting input terminal, an output terminal, and an inverting input terminal. The control stage is connected between the non-inverting input terminal and the output terminal of the unity-gain buffer. The auxiliary output stage is connected between the control stage and the output terminal of the unity-gain buffer. According to an input voltage at the input terminal of the unity-gain buffer, the control stage generates a first driving current, the auxiliary output stage generates a second driving current, and the operational amplifier generates a third driving current, so that an overall driving current outputted from the output terminal of the unity-gain buffer is equal to the sum of the first driving current, the second driving current and the third driving current. | 01-30-2014 |
20140035672 | LEVEL SHIFTING CIRCUIT WITH ADAPTIVE FEEDBACK - An amplifier has a first pull-up path coupled between a voltage supply node and an output node, and a pull-down path coupled between the output node and a ground supply node. A second pull-up path is coupled between the voltage supply node and the output node. The second pull-up path is actuated by a feedback signal and biased by a biasing signal. An inverter circuit is operable to invert the signal at the amplifier output node to generate the feedback signal. A biasing circuit is configured to generate the biasing signal. The biasing circuit is configured to control a relative strength of the pull-down path to the second pull-up path, wherein the pull-down path is stronger than the second pull-up path in a manner that is consistently present over all PVT corners. | 02-06-2014 |
20140043099 | SEMICONDUCTOR INTEGRATED CIRCUIT AND RADIO COMMUNICATION TERMINAL INCLUDING THE SAME - A semiconductor integrated circuit includes an operational amplifier that amplifies a voltage difference between an input voltage supplied to an inverting input terminal and a reference voltage supplied to a non-inverting input terminal and outputs an amplified signal, a feedback resistor that performs negative feedback of the amplified signal to the inverting input terminal of the operational amplifier, and a variable resistor unit that sets a current path with a first resistance value in accordance with a control signal between an external input terminal and the inverting input terminal of the operational amplifier, and sets a first alternative path with a second resistance value in accordance with the control signal between a node on the current path and a reference voltage terminal to which the reference voltage is supplied. | 02-13-2014 |
20140062597 | EXTERNAL PROGRAMMABLE DFE STRENGTH - A decision feedback equalizer is disclosed. The decision feedback equalizer comprises an amplifier circuit and a latch. The amplifier circuit is configured to receive an input signal, a decision feedback signal and a control signal, and is configured to adjust its driving capability according to the decision feedback signal and the control signal to provide an amplified signal of the input signal. The latch is configured to latch the amplified signal as an output signal. | 03-06-2014 |
20140070886 | AMPLIFIER WITH VOLTAGE AND CURRENT FEEDBACK ERROR CORRECTION - Amplifiers with voltage and current feedback error correction are provided. In one embodiment, an amplifier includes a first input terminal, a second input terminal, an output terminal, a first stage, and a voltage feedback amplification circuit. The first stage can be used to generate first and second output currents, which can be used to control a voltage level of the output terminal. The first and second output currents can change in response to a current feedback signal and a differential input signal received between the first and second input terminals. The first stage can also generate a voltage feedback signal, which can be used by the voltage feedback amplification circuit to control a voltage level of the second input terminal based on a voltage level of the first input terminal. | 03-13-2014 |
20140077880 | OPERATIONAL AMPLIFIER MODULE AND METHOD FOR INCREASING SLEW RATE OF OPERATIONAL AMPLIFIER CIRCUIT - An operational amplifier module including an operational amplifier circuit, a rate-increasing circuit and an overdriving circuit is provided. The operational amplifier switches an input voltage to an output voltage and outputs the switched output voltage. The rate-increasing circuit receives the input voltage and the output voltage and increases the rate of switching the input voltage to the output voltage according to the difference between the input voltage and the output voltage. The overdriving circuit provides an overdriving voltage to the rate-increasing circuit and the operational amplifier circuit during an overdriving period according to a selection signal. The level of the overdriving voltage is higher or lower than the levels of the input voltage and the output voltage. Furthermore, a method for increasing the slew rate of the operational amplifier circuit is provided. | 03-20-2014 |
20140097899 | AMPLIFICATION CIRCUIT AND METHOD THEREFOR - In accordance with an embodiment, an audio amplification circuit includes an input stage switchably connected to a switching network through a signal generator and a signal generator stage having a first input and a first output, the first input of the signal generator stage coupled to the first output of the input stage. An output stage is connected to the signal generator stage. In accordance with another embodiment, a method for inhibiting audible transients in an audio signal comprises providing an audio amplification circuit having at least one input and at least one output and coupling a first output to a first source of operating potential in response to one of starting or turning off the audio amplification circuit. | 04-10-2014 |
20140104001 | AMPLIFIER CIRCUIT - An amplifier circuit includes a differential amplifier circuit configured to amplify a voltage between a signal input to a first input terminal and a signal input to a second input terminal, a plurality of output circuits each configured to output a signal corresponding to a signal output from the differential amplifier circuit, and a control circuit configured to set a selected one of the plurality of output circuits in an operating state to drive an output terminal of the selected output circuit, and set a remaining output circuit in a non-operating state and set an output terminal of the remaining output circuit in a high impedance state. | 04-17-2014 |
20140125413 | INSTRUMENTATION AMPLIFIER WITH RAIL-TO-RAIL INPUT RANGE - A system and method for adjusting a common mode output voltage in an instrumentation amplifier is provided. In one aspect, the common mode output voltage is increased or decreased with respect to the common mode input voltage to enable high amplification of the signal input to the instrumentation amplifier. Moreover, the common mode output voltage can be driven to (or approximately to) a target voltage value such as, but not limited to, half the supply, even if the common mode input voltage is close to supply or ground rail voltage. Thus, a high amplification of the differential input voltage can be obtained and utilized for various applications requiring rail to rail input. | 05-08-2014 |
20140132347 | LINEARIZED HIGH-OHMIC RESISTOR - Representative implementations of devices and techniques provide a linearized high-ohmic resistor. In an example, a quantity of serially connected nonlinear impedances is arranged as a resistance. In one example, the quantity of impedances is applied in an amplifier circuit, between an input of the amplifier and an output of the amplifier, and arranged to set a DC operating point for the amplifier. | 05-15-2014 |
20140159815 | High Bandwidth High Sensitivity CMOS Trans-Impedance Amplifier - A CMOS trans-impedance amplifier (TIA) in accordance with the present disclosure can achieve improved bandwidth and sensitivity by utilizing novel shunt-shunt feedback and inductor peaking. The proposed design simultaneously improves 10-Gbps TIA performance in terms of bandwidth and sensitivity, while the TIA may be fabricated through a standard 0.13 μm CMOS process. Performance of the TIA in accordance with the present disclosure is much better than that of conventional CMOS TIA in the 10-Gbps CMOS TIA design and applications. | 06-12-2014 |
20140167851 | CURRENT-MODE LINE DRIVER - Disclosed are various embodiments of a current-mode line driver that may facilitate transmitting signals to a load. The current-mode line driver may comprise a common-mode current sense element that provides a signal corresponding to the common-mode output current of the line driver. A transconductance element receives the signal from the common-mode current sense element and provides a compensating current that is based at least in part on the signal. The compensating current may reduce the common-mode output current of the line driver. | 06-19-2014 |
20140176239 | ADAPTIVE CONTROL MECHANISMS TO CONTROL INPUT AND OUTPUT COMMON-MODE VOLTAGES OF DIFFERENTIAL AMPLIFIER CIRCUITS - An amplifier circuit includes differential input nodes, a differential amplifier stage having differential input terminals and differential output terminals, and an input common-mode voltage adaptation circuit connected between the differential input nodes of the amplifier circuit and the differential input terminals of the differential amplifier stage. During an input common-mode adaptation phase, the input common-mode voltage adaptation circuit forces the differential input terminals of the differential amplifier stage to a common-mode voltage equal to an adaptive reference voltage, independent of a common-mode voltage applied to the differential input nodes of the amplifier circuit during the input common-mode adaptation phase. During a normal period of operation of the amplifier circuit, the input common-mode voltage adaptation circuit maintains the common-mode voltage at the differential input terminals of the differential amplifier stage equal to the adaptive reference voltage, independent of an input differential voltage applied during the normal period of operation. | 06-26-2014 |
20140176240 | High-frequency bandwidth amplifying circuit - A high-frequency bandwidth amplifying circuit includes a forward channel and a backward channel. An input terminal of the forward channel and an external forward input terminal are connected; an output terminal of the forward channel and a forward output port are connected. An input terminal of the backward channel and an external backward input terminal are connected; an output terminal of the backward channel and a backward output port are connected. The high-frequency bandwidth amplifying circuit further includes a feedback network. The forward channel includes a first operational amplifier and a second operational amplifier. An input terminal of the first operational amplifier is connected to the external forward input terminal; an output terminal of the first operational amplifier is connected to an input terminal of the second operational amplifier; and an output terminal of the second operational amplifier is connected to the forward output port. | 06-26-2014 |
20140184331 | Amplifier Circuits and Methods of Amplifying an Input Signal - A method of operating an amplifier circuit having a pre-charge phase and a sample/conversion phase includes, during a pre-charge phase, charging first and second capacitors to first and second bias voltages. The first capacitor is coupled to a first input of an amplifier circuit, which has a second input and an output. The second capacitor is coupled to the second input. During a sample/conversion phase, the first input of the amplifier circuit is coupled to an input signal through the first capacitor to level-shift the input signal according to the first bias voltage and the output of the amplifier is coupled to the second input through the second capacitor to level shift a feedback signal according to the second bias voltage. | 07-03-2014 |
20140184332 | AMPLIFIER CIRCUIT INCLUDING DIGITAL AMPLIFIER AND ANALOG AMPLIFIER - An amplifier circuit includes a digital amplifier configured to amplify an input signal to output a first output signal, an analog amplifier configured to amplify the input signal to output a second output signal, a check circuit configured to produce a check signal responsive to frequencies of the input signal, and a selector circuit configured to select and output one of the first output signal and the second output signal in response to the check signal. | 07-03-2014 |
20140203875 | HIGH-GAIN LOW-NOISE PREAMPLIFIER AND ASSOCIATED AMPLIFICATION AND COMMON-MODE CONTROL METHOD - A preamplifier includes a differential pair of transistors receiving a bias current having a differential input and a differential output, a first resistor coupled to a first differential output node, a first transistor having a current path coupled between the first resistor and a power supply, a second resistor coupled to the first differential output node, a second transistor having a current path coupled between the second resistor and the power supply, a third resistor coupled to a second differential output node, a third transistor having a current path coupled between the third resistor and the power supply, a fourth resistor coupled to the second differential output node, and a fourth transistor having a current path coupled between the fourth resistor and the power supply, wherein a source of the second and third transistors are coupled together. | 07-24-2014 |
20140218114 | Complementary Low Noise Transductor with Active Single Ended to Differential Signal Conversion - A method includes, in at least one aspect, receiving, at both an input node of a first input stage and in input node of a second input stage, a single-ended voltage signal; providing, by at least one of the first input stage or the second input stage, inductive degeneration to the single-ended voltage signal; converting an output from the first input stage into a first single-ended current signal; converting an output from the second input stage into a second single-ended current signal; and outputting, by an output stage, a differential output including the first single-ended current signal and the second single-ended current signal. | 08-07-2014 |
20140232465 | FREQUENCY COMPENSATION TECHNIQUES FOR LOW-POWER AND SMALL-AREA MULTISTAGE AMPLIFIERS - A three stage amplifier is provided and the three stage amplifier comprises a first gain stage, a second gain stage and a third gain stage wherein said first stage receives an amplifier input signal and said third gain stage outputs an amplifier output signal. The amplifier includes a feedback loop having a current buffer and a compensation capacitance provided from the output of said third gain stage to the output of the first gain stage. In addition, an active left half plane zero stage is embedded in said feedback loop for cancelling a parasitic pole of said feedback loop. | 08-21-2014 |
20140240044 | DUAL PATH OPERATIONAL AMPLIFIER - An operational amplifier has two paths, a high frequency path and a low frequency path. In addition, it has three main sections of stages. A stage converts input voltage to an amplified output voltage, a stage converting an input voltage in to an output current and a final stage where the outputs of the two previous sections are supplied as inputs. Among them, the final stage acts as a voltage follower to a signal applied to its plus (+) input and as a transimpedance amplifier for a signal applied to its minus input (−). In this configuration, a path for low frequencies and a path for high frequencies are created in a single operational amplifier. | 08-28-2014 |
20140253236 | Generating Negative Impedance Compensation - Apparatuses for generating negative impedance compensation are provided. Embodiments include a differential amplifier having a first output and a second output; a capacitor coupled between the first output and the second output of the differential amplifier; a first negative impedance cross-coupled circuit having a first output and a second output; and a resistance control circuit coupled in series between the first output and the second output of the differential amplifier and the first output and the second output of the first negative impedance cross-coupled circuit. | 09-11-2014 |
20140253237 | Amplifier, a Residue Amplifier, and an ADC including a Residue Amplifier - An amplifier, comprising: an input node; an output node; a gain stage having a gain stage inverting input, a gain stage non-inverting input and a gain stage output; a feedback capacitor connected in a signal path between the gain stage output and the gain stage inverting input; a sampling capacitor connected between the input node and the gain stage non-inverting input, and a controllable impedance in parallel with the feedback capacitor, wherein the controllable impedance is operable to switch between a first impedance state in which it does not affect current flow through the feedback capacitor, and a second impedance state in which it cooperates with the feedback capacitor form a bandwidth limiting circuit. | 09-11-2014 |
20140266445 | Low-Power Inverter-Based Differential Amplifier - A new inverter-based fully-differential amplifier is provided including one or more common-mode feedback transistors coupled to each inverter, which transistors operate in the liner region. Accordingly, due to the fully-differential nature of the new inverter-based fully-differential amplifier, the amplifier provides an improved Power Supply Rejection Ratio (PSRR), provides a reduced sensitivity to supply voltage and process or part variations, and does not require an auto-zeroing technique to be utilized, which ultimately saves power, all while utilizing the low-voltage and low-power advantages of an inverter-based design. | 09-18-2014 |
20140266446 | ACTIVE LUMPED ELEMENT CIRCULATOR - An integrated circuit can comprise: a first port, a second port, and a third port; and a plurality of microwave operational amplifiers coupled to each other and the first port, the second port, and the third port. The plurality of microwave operational amplifiers can be arranged to substantially pass a signal provided to the first port to the second port while substantially isolating the signal provided to the first port from the third port; the plurality of microwave operational amplifiers can be arranged to substantially pass a signal provided to the second port to the third port while substantially isolating the signal provided to the second port from the first port; and the plurality of microwave operational amplifiers can be arranged to substantially pass a signal provided to the third port to the first port while substantially isolating the signal provided to the third port from the second port. | 09-18-2014 |
20140266447 | VOLTAGE REGULATORS, AMPLIFIERS, MEMORY DEVICES AND METHODS - Circuits, devices and methods are provided, such as an amplifier (e.g., a voltage regulator) that includes a feedback circuit that supplies negative feedback through a feedback path. One such feedback path includes a capacitance coupled in series with a “one-way” isolation circuit through which a feedback signal is coupled. The “one-way” isolation circuit my allow the feedback signal to be coupled from a “downstream” node, such as an output node, to an “upstream” node, such as a node at which an error signal is generated to provide negative feedback. However, the “one-way” isolation circuit may substantially prevent variations in the voltage at the upstream node from being coupled to the capacitance in the isolation circuit. As a result, the voltage at the upstream node may quickly change since charging and discharging of the capacitance responsive to voltage variations at the upstream node may be avoided. | 09-18-2014 |
20140300415 | INPUT COMMON MODE CONTROL USING A DEDICATED COMPARATOR FOR SENSOR INTERFACES - Various embodiments of the invention allow for low-noise, high performance input common mode voltage control in capacitive sensor front end amplifiers. In certain embodiments overcome the shortcomings of the prior art by implementing a full voltage swing common mode voltage comparator in a parallel feed-forward path to compensate large common mode input signal variations. | 10-09-2014 |
20140312972 | HIGH-FREQUENCY AMPLIFIER CIRCUIT, SEMICONDUCTOR DEVICE, AND MAGNETIC RECORDING AND REPRODUCING DEVICE - A high-frequency amplifier circuit includes a balanced-unbalanced converter converting a single-ended signal into differential signals. The output of a first amplifier amplifying the single-ended signal is connected to the signal terminal on the unbalanced side of the balanced-unbalanced converter. The input of a second amplifier amplifying one of the differential signals is connected to one signal terminal on the balanced side of the balanced-unbalanced converter. The input of a third amplifier amplifying another of the differential signals is connected to another signal terminal on the balanced side of the balanced-unbalanced converter. An impedance element is inserted between an element on the balanced side of the balanced-unbalanced converter and a ground. | 10-23-2014 |
20140340150 | TRANSCONDUCTANCE CIRCUIT AND A CURRENT DIGITAL TO ANALOG CONVERTER USING SUCH TRANSCONDUCTANCE CIRCUITS - An example transconductance circuit is provided in accordance with one embodiment. The transconductance circuit can comprise: an output node; at least one transistor; a variable resistance; and a differential amplifier; wherein the at least one transistor and the variable resistance are in series connection with the output node, an output of the differential amplifier is connected to a control node of the at least one transistor, a first input of the amplifier is responsive to an input signal, and a second input of the amplifier is responsive to a voltage across the variable resistance. Such a circuit may overcome noise problems in transconductance circuits which operate over a wide range of input signals with a fixed resistor in series with the at least one transistor. | 11-20-2014 |
20140340151 | Transconductance Amplifier - A transconductance amplifier comprises a set of amplifier stages. The last stage of the amplifier is split with a certain ratio whereby one part is used to deliver output current and other part to deliver feedback current to the input. | 11-20-2014 |
20140368272 | PROGRAMMABLE HIGH-SPEED VOLTAGE-MODE DIFFERENTIAL DRIVER - A voltage-mode differential driver is disclosed. The differential driver includes two driver arms, each driver arm including a variable-impedance driver for driving a single-ended output signal. Each variable-impedance driver comprises multiple driver slices, where each driver slice includes a pre-driver circuit and a driver circuit. Advantageously, it has been determined that the disclosed voltage-mode driver design requires less power than conventional current-mode drivers. In one implementation, the disclosed voltage-mode driver design provides the capability of independently programming the delay of the two single-ended outputs so as to compensate for differential skew. Other embodiments and features are also disclosed. | 12-18-2014 |
20150008982 | ADAPTIVE HARMONIC DISTORTION SUPPRESSION IN AN AMPLIFIER UTILIZING NEGATIVE GAIN - Techniques are described herein that adaptively suppress harmonic distortion in an amplifier utilizing negative gain. The amplifier includes a first amplifier stage and a second amplifier stage, which are coupled in parallel. The first amplifier stage has a positive gain. The second amplifier stage has a negative gain to suppress total harmonic distortion of a system that includes the amplifier. The amplifier further includes shunt-peaking circuitry coupled to the first amplifier stage and the second amplifier stage to increase a maximum operating frequency at which the amplifier is capable of operating. | 01-08-2015 |
20150035598 | COMMON-MODE FEEDBACK DIFFERENTIAL AMPLIFIER - The present invention discloses a common-mode feedback differential amplifier circuit, a common-mode feedback differential amplification method, and an integrated circuit. In an example, a common-mode feedback (CMFB) loop conducts voltage division on a first common-mode signal to generate a second common-mode signal and a third common-mode signal, a differential amplifier sets a voltage of the signal with the higher voltage between the second common-mode signal and the third common-mode signal equal to a voltage of a first input terminal or a second input terminal, and the CMFB loop controls the differential amplifier to output an output signal with the minimum voltage equal to the voltage of the first common-mode signal. | 02-05-2015 |
20150048886 | TEMPERATURE DETECTING APPARATUS, SWITCH CAPACITOR APPARATUS AND VOLTAGE INTEGRATING CIRCUIT THEREOF - The invention provides a temperature detecting apparatus, a switch capacitor apparatus and a voltage integrating circuit. The voltage integrating circuit includes an operating amplifier, a capacitor and a current source. The operating amplifier has a positive input end, a negative input end and an output end. The output end of the operating amplifier generates an output voltage, and the positive input end receives a reference voltage. The capacitor is coupled between the output end and the negative input end of the operating amplifier. The current source is coupled to the output end of the operating amplifier. The current source draws a replica current from the capacitor, and a current level of the replica current is determined according to a current level of a current flowing to the negative input end of the operating amplifier. | 02-19-2015 |
20150084695 | CASCODE AMPLIFIER - In one embodiment, a cascode amplifier includes an amplifier circuit, a replica circuit, a bias circuit, and a feedback circuit. The amplifier circuit includes a first transistor and a second transistor. The second transistor is cascode-connected to the first transistor. The replica circuit includes a third transistor and a fourth transistor. The third transistor has a control terminal connected to a control terminal of the first transistor. The fourth transistor is cascode-connected to the third transistor. The bias circuit applies a bias voltage to a control terminal of the second transistor and a control terminal of the fourth transistor. The feedback circuit performs a feedback control of a voltage of the control terminal of the third transistor. The feedback circuit reduces the difference between a reference current and a current at a predetermined point of the replica circuit. | 03-26-2015 |
20150130539 | QUASI-DIFFERENTIAL RF POWER AMPLIFIER WITH HIGH LEVEL OF HARMONICS REJECTION - A quasi-differential amplifier with an input port and an output port. The amplifier has a phase shifter network with a first port connected to the input port, a second port, and a third port. A first amplifier has an input connected to the second port of the phase shifter network, and an output, and a second amplifier has an input connected to the third port of the phase shifter network, and an output. A balun circuit includes a first differential port connected to an output of the first amplifier, a second differential port connected to an output of the second amplifier, and a single-ended port. An output matching network is connected to the single-ended port of the balun circuit and to the output port. | 05-14-2015 |
20150145597 | MULTI-STAGE TRANSIMPEDANCE AMPLIFIER AND A METHOD OF USING THE SAME - A multi-stage transimpedance amplifier (TIA) which includes a common gate amplifier configured to receive a current signal, the common gate amplifier is configured to convert the current signal into an amplified voltage signal. The multi-stage TIA further includes a capacitive degeneration amplifier configured to receive the amplified voltage signal, the capacitive degeneration amplifier is configured to equalize the amplified voltage signal to form an equalized signal. The multi-stage TIA further includes an inverter configured to receive the equalized signal, the inverter is configured to increase a signal strength of the equalized signal to form an output signal. The multi-stage TIA further includes a feedback configured to receive the output signal, wherein the feedback is connected to an input and an output of the inverter. | 05-28-2015 |
20150295551 | IMPLICIT FEED-FORWARD COMPENSATED OP-AMP WITH SPLIT PAIRS - Disclosed are systems implementing an implicit Feed-Forward Compensated (FFC) op-amp, where the main FFC port is realized by the P-side of the CMOS input structure of the 2nd and 3rd stages of the op-amp, while the main signal path is through the N-side. According to some embodiments, to balance the relative strengths of the main path and feed-forward paths, the 2nd-stage NMOS input pair is split into two pairs, one is used to route the main path while the other is used for auxiliary FFC. The disclosed implicit FCC op-amp is unconditionally stable with adequate phase lead. According to some embodiments, the disclosed op-amp, which may be a wide-band op-amp, can be used in highly linear applications operative at intermediate frequency (IF), such as signal buffers for high-performance data converters or radio-frequency (RF) modulators and demodulators, continuous-time (CT) filters or sigma-delta data converters. | 10-15-2015 |
20150303880 | LOW PASS FILTER WITH COMMON-MODE NOISE REDUCTION - A low pass filter includes a first amplifier stage and a second amplifier stage. The first amplifier stage includes a differential operational amplifier, wherein the first amplifier stage is arranged to process a differential input signal to generate a differential intermediate signal, the differential input signal having a first input signal and a second input signal, and the differential intermediate signal having a first intermediate signal and a second intermediate signal. The second amplifier stage has no common-mode feedback and is arranged to process the differential intermediate signal to generate a differential output signal, wherein the differential output signal has a first output signal corresponding to the first input signal and a second output signal corresponding to the second input signal. Since the noisy common-mode feedback is removed from the second amplifier stage, the overall common-mode noise of the low pass filter can be decreased. | 10-22-2015 |
20150333705 | HIGH SPEED, RAIL-TO-RAIL CMOS DIFFERENTIAL INPUT STAGE - An apparatus is provided, comprising a single-ended input stage with signals IN_P & IN_N as input and OUT_P & OUT_N as output., wherein the differential input controlled by transistors P | 11-19-2015 |
20150349734 | DIFFERENTIAL AMPLIFIER WITH HIGH-SPEED COMMON MODE FEEDBACK - The differential signals at the outputs of a differential amplifier quickly change in response to common mode changes in the output differential signals. The amplified input signals amplified by the differential amplifier quickly change in response to common mode changes in the differential signals input into the differential amplifier. A bias voltage input to the differential amplifier is isolated to remove low-frequency components from the bias voltage. | 12-03-2015 |
20150365055 | REDUCED-POWER DISSIPATION FOR CIRCUITS HANDLING DIFFERENTIAL OR PSEUDO-DIFFERENTIAL SIGNALS - In an example, a differential amplifier is disclosed that is configured to realize low noise with decreased overall system current. The differential amplifier may include a first amplifier stage and a second amplifier stage arranged in series, wherein a pull-up current i | 12-17-2015 |
20150365058 | POWER AMPLIFIER - A power amplifier is provided. The power amplifier comprises a plurality of power amplifier units and a bias unit. The power amplifier units are connected in parallel with each other to receive a differential input signal. The power amplifier units perform a power amplifying so as to output a differential output signal. The bias unit is coupled to the power amplifier units and supplies a plurality of bias signals to the power amplifier units respectively. At least two of the power amplifier units are enable to operate in different class regions in according with the corresponding bias signals. | 12-17-2015 |
20160013765 | CURRENT SENSE CIRCUIT USING A SINGLE OPAMP HAVING DC OFFSET AUTO-ZEROING | 01-14-2016 |
20160020736 | REFERENCE AMPLIFIER COUPLED TO A VOLTAGE DIVIDER CIRCUIT TO PROVIDE FEEDBACK FOR AN AMPLIFIER - An apparatus includes a voltage divider circuit and a reference amplifier coupled to the voltage divider circuit. The reference amplifier is configured to provide a feedback voltage to input circuitry of an amplifier. | 01-21-2016 |
20160049909 | STACKED BIAS I-V REGULATION - A RF amplifier circuit including a plurality of FET devices, where a source terminal of an FET device is electrically coupled to the drain terminal of another FET device. The circuit further includes a voltage divider network and a plurality of operational amplifiers, where a separate one of the operational amplifiers is provided for each FET device. Each operational amplifier includes a positive input terminal, a negative input terminal and an output terminal, where the output terminal for a particular operational amplifier is electrically coupled to a gate terminal of a particular FET device, the negative input terminal of each operational amplifier is electrically coupled to the source terminal of the particular FET device and the positive input terminal of each operational amplifier is electrically coupled to the voltage divider network. A source resistor is electrically coupled to the source terminal of a bottom FET device in the stack. | 02-18-2016 |
20160072446 | OPERATIONAL AMPLIFYING CIRCUIT AND SEMICONDUCTOR DEVICE COMPRISING THE SAME - An operational amplifying circuit are provided. The operational amplifying circuit includes a control circuit, pull-up and pull-down transistors, first and second bias circuits, and a bias voltage generating circuit. The control circuit includes first and second input terminals, and is configured to change, when an input voltage transitions to a first level, a voltage level of a pull-up node and a pull-down node to a second level different from the first level. The pull-up transistor provides a power supply voltage to the output terminal. The pull-down transistor connects the output terminal to a ground voltage. The first bias circuit provides a first bias current to the control circuit. The bias voltage generating circuit generates a bias voltage when the voltage level of at least one of the pull-up and pull-down nodes reaches a threshold voltage level, and the second bias circuit provides a second bias current to the control circuit. | 03-10-2016 |
20160072448 | COMMON-MODE FEEDBACK CIRCUIT, CORRESPONDING SIGNAL PROCESSING CIRCUIT AND METHOD - A common-mode feedback circuit includes a transconductor input stage with differential input terminals, and a frequency-compensated gain stage coupled to the transconductor input stage with differential output terminals. The common-mode feedback circuit also includes a feedback loop having a comparator configured to produce a feedback error signal for the transconductor input stage by comparing with a reference a common-mode sensing signal indicative of a common-mode voltage level sensed at the differential output terminals. In addition, the common-mode feedback loop includes a converter for converting the common-mode voltage level sensed at said differential output terminals into a current signal coupled to the comparator. | 03-10-2016 |
20160079943 | Two Differential Amplifier Configuration - An apparatus is disclosed for providing a common mode voltage to the inputs of a first differential amplifier which outputs the difference between two signals. A second differential amplifier receives the output of the first differential amplifier, and the output of the second differential amplifier is fed back to the inputs of the first differential amplifier as a common mode voltage. Since both inputs of the first differential amplifier receive the fed hack common mode voltage, the first differential amplifier still outputs only the difference in the two signals, but the presence of the common mode voltage allows the first differential amplifier to operate with lower noise if the voltage levels of the inputs to the first differential amplifier vary. The second differential amplifier may be of significantly lower quality and cost than the first differential amplifier, without affecting the performance of the first differential amplifier. | 03-17-2016 |
20160112016 | SILICON PHOTONICS MODULATOR DRIVER - Embodiments generally relate to a conversion arrangement, a driver arrangement, and a method of producing a complementary complementary metal-oxide-semiconductor (CMOS) output signal for driving a modulator device. The conversion arrangement includes a differential amplifier configured to produce a first amplified signal based on the differential input signal, and at least two transimpedance amplifiers (TIAs) coupled with respective outputs of the differential amplifier and configured to produce a second amplified signal based on the first amplified signal. Respective bias voltages for the TIAs are based on the first amplified signal. The conversion arrangement further includes a common-mode feedback arrangement coupled with outputs of the TIAs and configured to control the first amplified signal based on the second amplified signal, thereby controlling the bias voltages, wherein the complementary CMOS output signal is based on the second amplified signal. | 04-21-2016 |
20160126909 | Programmable Hysteresis Comparator - In one embodiment, a circuit includes a differential amplifier having a differential pair with a first transistor and second transistor. Each of the first and the second transistors include a front gate contact and a back gate contact. A first digital feedback loop is coupled between an output of the differential amplifier to the back gate contact of the first transistor. A second digital feedback loop is coupled to the back gate contact of the second transistor. The first digital feedback loop is configured to be opposite in phase to the second digital feedback loop. | 05-05-2016 |
20160142016 | OPERATIONAL AMPLIFIER BASED CIRCUIT WITH COMPENSATION CIRCUIT BLOCK USED FOR STABILITY COMPENSATION - An operational amplifier based circuit has an operational amplifier, a feedback circuit, and a compensation circuit block. The feedback circuit is coupled between an output port and an input port of the operational amplifier. The compensation circuit block has circuits involved in stability compensation of the operational amplifier, wherein there is no stability compensation circuit driven at the output port of the operational amplifier. | 05-19-2016 |
20160142017 | RECONFIGURABLE OPERATIONAL AMPLIFIER - 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. | 05-19-2016 |
20160149544 | LOW VOLTAGE SUPPLY AMPLIFIER AND AMPLIFICATION METHOD - A high-gain, low power, electronic amplifier for amplification of a low magnitude voltage signal through a comparator-integrator amplification method for energy-aware applications is disclosed. The electronic amplifier comprises: a comparator arrangement with at least one comparator unit adapted to receive a first voltage signal to be amplified and a first feedback voltage signal, and to generate a first two-level voltage comparison signal; a integrator arrangement to receive the first two-level voltage comparison signal and generate a first amplifier output signal corresponding to an amplification of the voltage signal to be amplified; and a first feedback network to receive the first amplifier output signal and generate the first feedback voltage signal. | 05-26-2016 |
20160149545 | CIRCUITS AND METHODS PROVIDING ATTENUATION - An apparatus and method are disclosed for providing attenuation. An operational amplifier is in a non-inverting gain configuration with its output provided to a voltage divider having a first resistive component and a second resistive component. The first resistive component includes a plurality of resistors in series, and a feedback loop of the amplifier is defined at various points within the series of resistors and has a plurality of switches associated with each of the resistors in series. The output voltage is defined by the second resistive component. A switch of the plurality of switches may be selected to be closed to define a gain of the amplifier, thereby setting the attenuation ratio the circuit. | 05-26-2016 |
20160173033 | LINE DRIVER WITH ACTIVE TERMINATION AND ASSOCIATED METHOD | 06-16-2016 |
20160173034 | AUDIO AMPLIFYING DEVICE | 06-16-2016 |
20160173037 | TRIMMING METHOD FOR CURRENT SENSE AMPLIFIERS | 06-16-2016 |
20180026584 | NOISE CANCELLING BASEBAND AMPLIFIER | 01-25-2018 |
20180026595 | Matching network circuit and Radio-Frequency Power Amplifier with Odd Harmonic Rejection and Even Harmonic Rejection and Method of Adjusting Symmetry of Differential Signals | 01-25-2018 |
20220140795 | TRANSIMPEDANCE AMPLIFIERS WITH ADJUSTABLE INPUT RANGE - A multi-stage transimpedance amplifier (TIA) with an adjustable input linear range is disclosed. The TIA includes a first stage, configured to convert a single-ended current signal from an optical sensor of a receiver signal chain to a single-ended voltage signal, and a second stage, configured to convert the single-ended voltage signal provided by the first stage to a differential signal. In such a TIA, the input linear range may be adjusted using a clamp that is programmable with an output offset current to keep the second stage of the TIA from overloading and to maintain a linear transfer function without compression. | 05-05-2022 |