Class / Patent application number | Description | Number of patent applications / Date published |
330069000 | SUM AND DIFFERENCE AMPLIFIERS | 75 |
20080204133 | Circuits and apparatus to reduce transient output noise in an audio amplifier - Circuits and apparatus to reduce transient output noise in an audio amplifier are disclosed. A disclosed example apparatus comprises an amplifier, and an amplifier controller to digitally change a common-mode voltage of the amplifier to reduce an output noise of the amplifier. | 08-28-2008 |
20090128233 | SHARED LINEARITY MAINTENANCE IN POWER AMPLIFIERS - In some embodiments, a circuit includes a power amplifier including an input terminal configured to receive an input signal and an output terminal to provide an RF voltage, the output terminal coupled to a load, a current sensor configured to sense the current drawn by the power amplifier and provide a first sensor output signal dependent upon current consumption when the current exceeds a predetermined current threshold, a voltage sensor configured to sense the output power of the power amplifier and provide a second sensor output signal when the RF voltage during up ramp falls below a predetermined threshold voltage, and a summing circuit configured to receive the first and second sensor output signals and provide a feedback signal including a combination of a power dependent contribution and either of a voltage dependent contribution or a current dependent contribution. | 05-21-2009 |
20090167432 | INSTRUMENTATION AMPLIFICATION WITH INPUT OFFSET ADJUSTMENT - In a single-ended or differential instrument amplifier, an input offset may be adjusted by driving current into the impedance of a feedback network of the amplifier. The amplifier may be provided with programmable gain capability. The impedance does not change with different gain settings, such that the input offset adjustment is equal for all gains. The amplifier may receive the output of a sensor such as, for example, a gas detector such as a thermal conductivity detector. The gas detector may be utilized to measure a gas flowing from a gas source such as, for example, a chromatographic column. | 07-02-2009 |
20090212857 | DC Self-Biased Vacuum Tube Differential Amplifier With Grid-to-Cathode Over-Voltage Protection - A single stage differential amplifier is disclosed as comprising a pair of vacuum tube triodes for amplifying two input signals and generating two output signals. The differential amplifier has DC self-biasing ability and grid-to-cathode over-voltage protection for directly coupling from the outputs of another differential amplifier. By possessing these unique features, this differential amplifier becomes an important building block in forming a balanced amplifier by cascading multi differential amplifiers in a directly coupled fashion. | 08-27-2009 |
20100073083 | NESTED TRANSIMPEDANCE AMPLIFIER - A nested transimpedance amplifier circuit includes a first-order nested transimpedance amplifier having an input and an output. The first-order nested transimpedance amplifier is configured to be powered by a first voltage. A charge pump module is configured to receive the first voltage and a second voltage. The second voltage is different from the first voltage. The charge pump module generates a third voltage based on the first voltage and the second voltage. A first operational amplifier has an input and an output. The input of the first operational amplifier communicates with the output of the zero-order transimpedance amplifier, and the first operational amplifier is configured to be powered by the third voltage. | 03-25-2010 |
20100207691 | PHASE MISMATCH COMPENSATION DEVICE - A phase mismatch compensation device comprises a first low pass filter unit, a second low pass filter unit and a phase compensation unit. The first low pass filter unit comprises a first input unit transferring the I-channel analog input signal to an input terminal of a first OP-amp, and the first self-feedback unit transferring the I-channel output signal to the input terminal of the first OP-amp. The second low pass filter unit comprises the second input unit transferring the Q-channel analog input signal to an input terminal of a second OP-amp, and a second self-feedback unit transferring the Q-channel output signal to the input terminal of the second OP-amp. The phase compensation unit comprises a first compensation unit transferring the Q-channel analog input signal to the input terminal of the first OP-amp, and a second compensation unit transferring the I-channel analog input signal to the input terminal of the second OP-amp. | 08-19-2010 |
20100231294 | APPARATUS AND METHOD FOR SIGNAL PROCESSING OF VOLTAGE SIGNALS FROM ELECTRODES OF A MAGNETO-INDUCTIVE, FLOW MEASURING DEVICE BIER3004/FJD - Signal processing circuit for voltage signals from electrodes of a magneto-inductive, flow measuring device, wherein two measuring electrodes are connected with a fully differentially working amplifier having two inputs and two outputs. | 09-16-2010 |
20100253423 | DIFFUSED INTEGRATED RESISTOR - Methods and apparatus according to various aspects of the present invention may operate in conjunction with a resistor formed of a lightly-doped P-type region formed in a portion of a lightly-doped N-type semiconductor well extending on a lightly-doped P-type semiconductor substrate, the well being laterally delimited by a P-type wall extending down to the substrate, the portion of the well being delimited, vertically, by a heavily-doped N-type area at the limit between the well and the substrate and, horizontally, by a heavily-doped N-type wall. A diode may be placed between a terminal of the resistor and the heavily-doped N-type wall, the cathode of the diode being connected to said terminal. | 10-07-2010 |
20100259323 | VARIABLE GAIN INSTRUMENTATION AMPLIFIER - Techniques for providing an instrumentation amplifier having a plurality of selectable gain settings. In an exemplary embodiment, a gain adjustment block for accepting a differential input voltage is coupled to a differential-to-single-ended conversion block for generating a single-ended output voltage. The gain adjustment block may have a plurality of gain settings selectable by one or more switches. The instrumentation amplifier advantageously offers precise gain control without the need for external calibration, while being robust and simple to design. | 10-14-2010 |
20100259324 | BROAD-BAND ACTIVE DELAY LINE - A broad-band active delay line comprises a plurality of broad-band active delay cells configured in a cascade topology. Each broad-band active delay cell comprises a feedback loop and a feedforward path to achieve a high bandwidth. | 10-14-2010 |
20100283538 | FREQUENCY OFFSET CARTESIAN FEEDBACK SYSTEM - An amplifier system providing improved Cartesian feedback is provided. A complex band pass error amplifier is provided. A quadrature up converter is connected to the complex band pass error amplifier so as to receive as input, output from the complex band pass error amplifier. An amplifier is connected to the quadrature up converter so as to receive as input, output from the quadrature up converter. A quadrature down converter is connected at or beyond the amplifier output so as to receive as input a signal proportional to that delivered by the amplifier as output to a load, wherein the complex band pass error amplifier is connected to the quadrature down converter so as to receive as a first input, output from the quadrature down converter and as a second input, a quadrature reference signal. | 11-11-2010 |
20100301932 | NON-INVERTING AMPLIFIER AND VOLTAGE SUPPLY CIRCUIT INCLUDING THE SAME - A non-inverting amplifier includes an operational amplifier, an input resistor, and a feedback resistor. The operational amplifier amplifies and outputs a difference between an input voltage and a voltage of a control node. The input resistor is connected between a reference voltage port and the control node. The feedback resistor is connected to an output port of the operational amplifier and the control node. The non-inverting amplifier supplies a control current to the control node for controlling an offset voltage of the output port. | 12-02-2010 |
20110043278 | METHOD AND APPARATUS FOR BIASING AN AMPLIFIER - An apparatus and method for biasing each amplifier of an amplification stage provides that the voltage across each current sensing element of each amplifier of the amplification stage is measured. For each pair of voltage measurements taken, a sum and difference is calculated, where the sum is processed to determine minima peaks and the difference is averaged. A portion of the sum term and the average of the difference term are summed to yield the individual bias current conducted by a first amplifier of the amplification stage. The difference between a portion of the sum term and the average of the difference term is calculated to yield the individual bias current conducted by the second amplifier of the amplification stage. The bias current conducted by the first and second amplifiers may then be individually modified manually, or conversely, may be modified automatically based upon the bias current measurements taken. | 02-24-2011 |
20110068862 | FEEDBACK AMPLIFIER AND FEEDBACK AMPLIFICATION METHOD - A feedback amplifier comprises a differential amplifier equipped with differential input terminals and differential output terminal and a first amplifier, wherein the differential output terminal is connected to input terminal of the first amplifier, wherein output terminal of the first amplifier is connected to one of the differential input terminals, and wherein the gain of the first amplifier decreases for lower frequency component of the signal which the differential amplifier outputs than a predetermined frequency when the output voltage of the differential output exceeds a predetermined value. | 03-24-2011 |
20110080214 | OUTPUT AMPLIFIER CIRCUIT AND DATA DRIVER OF DISPLAY DEVICE USING THE CIRCUIT - An output amplifier includes a differential stage having a reference voltage supplied to a first input, a first output stage that receives an output of the differential stage, a second output stage whose output is connected to a load, a capacitor element having a first end connected to a second input of the differential stage, and connection control circuits that control switching of first and second connection modes. In the first connection mode, there are provided a non-conductive state between output of the differential stage and input of the second output stage, a non-conductive state between output of the first output stage and output of the second output stage, a conductive state between output of the first output stage and the second input of the differential stage, and voltage of a second end of the capacitor element is an input voltage from the input terminal. In the second connection mode, there are provided a conductive state between output of the differential stage and input of the second output stage, a conductive state between output of the first output stage and output of the second output stage; a non-conductive state between output of the first output stage and the second input of the differential stage, a non-conductive state of the second end of the capacitor element from the input terminal, and a conductive state between the output of the first output stage and the second end of the capacitor element. | 04-07-2011 |
20110156811 | VOLTAGE DETECTION DEVICE - A voltage detection circuit includes operational amplifiers, a battery, and a voltage circuit. The voltage circuit offsets the inverting input terminals and non-inverting input terminals of the operational amplifiers to the positive side with reference to a ground GND. | 06-30-2011 |
20110169565 | Receiving circuit - A receiving circuit in accordance with an exemplary aspect of the present invention includes a first voltage-dividing circuit that outputs a first input signal obtained by voltage division of one of differential signals based on the resistance ratio between first and second resistors, a second voltage-dividing circuit that outputs a second input signal obtained by voltage division of the other of the differential signals based on the resistance ratio between third and fourth resistors, a differential amplifier that amplifies the differential component between the first and second input signals, a common-mode voltage detection circuit that detects the common-mode voltage of the differential signals, and a bias voltage switching circuit that switches the voltage value of a bias voltage based on the common-mode voltage. | 07-14-2011 |
20110204971 | DIFFERENTIAL VOLTAGE SENSING SYSTEM AND METHOD FOR USING THE SAME - A differential voltage sensing method for achieving input impedance matching comprises the steps of: providing a first bio-potential signal to a first variable resistor for generating a first signal; providing a second bio-potential signal to a second variable resistor for generating a second signal; differentially amplifying first and second signals for generating a third signal; selecting an operation band of the third signal for generating first and second logic signals; and dynamically adjusting one of the impedances of the first and second variable resistors according to the first and second logic signals, wherein each of the first and second bio-potential signals has a common signal voltage level and a differential signal voltage level. | 08-25-2011 |
20110221521 | Active Eye Opener for Current-Source Driven, High-Speed Serial Links - A current boost circuit acts as an “eye opener” for a digital bus line. A controlled current injects a fraction of the normal signaling current magnitude from a source driver onto the bus line, after a transition between the two logical states on the bus line is detected. The duration of the additional current injection is a fraction of the unit interval. In one embodiment, a linear system uses the summation of a proportional boost current and a delayed and negated proportional boost current. In another embodiment, a positive or negative edge detection circuit triggers a monostable pulse generator that controls the injection of short bursts of additional current into the bus lines. In some embodiments the boost current is suppressed when the bus line is driven from a driver other than the source driver. | 09-15-2011 |
20110241770 | AMPLIFIER FOR PROCESSING DIFFERENTIAL INPUT USING AMPLIFIER CIRCUITS WITH DIFFERENT DRIVING CAPABILITIES AND/OR DIFFERENT FREQUENCY COMPENSATION CHARACTERISTICS - An amplifier processes a differential input received at a differential input port. The amplifier includes a first amplifier circuit and a second amplifier circuit. The first amplifier circuit is disposed in a first signal path between a first input node and a first output node of the amplifier, and arranged to amplify a first input signal received at the first input node and accordingly generate a first amplified signal to the first output node. The second amplifier circuit is disposed in a second signal path between a second input node and a second output node of the amplifier, and arranged to amplify a second input signal received at the second input node and accordingly generate a second amplified signal to the second output node. A driving capability of the first amplifier circuit is different from a driving capability of the second amplifier circuit. | 10-06-2011 |
20110260788 | AMPLIFIER DEVICE AND SENSOR MODULE - A first low-pass filter circuit includes a first input terminal which receives a sensor signal, a second input terminal, and an output terminal which outputs a first output signal. A second low-pass filter circuit includes an input terminal connected to the second input terminal of the first low-pass filter circuit, and an output terminal. A third low-pass filter circuit includes an input terminal connected to the output terminal of the second low-pass filter circuit, and an output terminal which outputs a second output signal. | 10-27-2011 |
20120062316 | SIGNAL GENERATING APPARATUS AND METHOD THEREOF - A signal generating apparatus comprises an amplifier, which comprises differential input terminals for receiving a first input signal, a common mode output signal adjusting terminal for receiving a second input signal, and an output terminal. The signal generating apparatus may provide two or more differential output signals according to the first input signal, and provide two or more common mode output signals according to the second input signal. The amplifier provides an output signal comprising one of the differential output signals and one of the common mode output signals at the output terminal. | 03-15-2012 |
20120062317 | Nanothermocouple Detector Based on Thermoelectric Nanowires - A nanothermocouple detector includes a nanowire coupled across two electrodes. The two electrodes are electrically connected to an amplifier. The two electrodes generally have a separation of about five micrometers to about thirty micrometers across which the nanowire is coupled. A focusing element is disposed to admit photons that fall on the focusing element onto the nanowire to heat it. A voltage change across the nanowire caused by the heating of the nanowire by the light is detected by the amplifier. The voltage change corresponds to the energy absorbed from the light by the nanowire. The color of a single photon can be detected using such device. An array of such devices can be used for sensing light on a two-dimensional scale, thereby providing an image showing small variances in the energies of the light impinging upon the detector array. | 03-15-2012 |
20120126888 | Differential Output Inductor for Class D Amplifier - A circuit includes a first input terminal for receiving a first pulsed voltage and a second input terminal for receiving a second pulsed voltage. The circuit further includes a load and an LC filter. The LC filter includes a coupled inductor pair that includes a first winding and a second winding magnetically coupled to each other. The first winding is coupled between the first input terminal and the load, and the second winding is coupled between the second input terminal and the load. A frequency of a first current flowing through the first winding is increased by the second pulsed voltage applied to the second winding. | 05-24-2012 |
20120133430 | OFFSET CANCELLATION FOR AUDIO AMPLIFIER - An audio amplification circuit is provided having an amplifier that receives an input signal, an output, and a digital control input for receiving a control value in a number n of bits; a comparator having a first input that receives the amplifier's output signal image, a second input that receives a reference potential, and an output; and a thermometer counter having a selection input coupled to the comparator output, and an output delivering an n-bit digital value to the amplifier control input. The amplifier comprises a differential input stage having a first and a second differential branch, each traversed by a bias current, the current in the first branch being modifiable by n basic current sources which each deliver either a current identical for all current sources, or no current, as a function of one respective bit of the digital control value received at the control input. | 05-31-2012 |
20120133431 | POWER AMPLIFICATION CIRCUIT HAVING TRANSFORMER - In order to realize a wider bandwidth of a frequency characteristic of a power amplification circuit, outputs of differential push-pull amplifiers which are matched at respectively different frequencies are combined together by secondary inductors, and the combined signal is outputted. | 05-31-2012 |
20120146720 | ADAPTIVE AMPLIFICATION CIRCUIT - An adaptive amplification circuit is disclosed, which includes an operational amplifier including a variable bias current source for providing a variable bias current for the operational amplifier, a simulation unit for simulating operational characteristics of the operational amplifier and transforming a simulation input voltage to a simulation output voltage, and a bias control unit for generating a bias control signal to the variable bias current source according to the simulation output voltage so as to adjust the variable bias current. | 06-14-2012 |
20120146721 | VOLTAGE DETECTION CIRCUIT - A voltage detection circuit including a comparator circuit, a tunable gain circuit and a switch circuit is disclosed. The comparator circuit has a first input terminal and a second input terminal. The tunable gain circuit is coupled between the first input terminal and a reference signal. The tunable gain circuit has a plurality of gain configurations. The tunable gain circuit adjusts the reference signal and transmits the adjusted reference signal to the first input terminal. The switch circuit selectively transmits a signal under test or the reference signal to the second input terminal. When the voltage detection circuit is in an auto-trimming mode, the switch circuit transmits the reference signal to the second input terminal and the tunable gain circuit sequentially adopts the gain configurations until the comparator circuit detects that voltage levels of the first input terminal and the second input terminal are substantially equal. | 06-14-2012 |
20120169417 | CURRENT GENERATOR - A current generating circuit for providing one or more than one load current is provided. The current generating circuit includes: one or more than one operational amplifier, coupled to a reference voltage source, wherein each positive input end of the one or more than one operational amplifier receives the reference voltage source; | 07-05-2012 |
20120182068 | DC OFFSET TRACKING CIRCUIT - This document discusses, among other things, an amplifier circuit including first and second amplifiers configured to receive an input signal and to provide a differential output signal using a feedback loop including a transconductance amplifier. A non-inverting input of a first amplifier can be configured to receive an input signal. The feedback loop can be configured to receive the outputs from the first and second amplifiers and to provide a feedback signal to the non-inverting input of the second amplifier, for example, to reduce a DC offset error or to increase a dynamic range of the amplifier circuit. | 07-19-2012 |
20120188009 | APPARATUS AND METHOD FOR AMPLIFICATION WITH HIGH FRONT-END GAIN IN THE PRESENCE OF LARGE DC OFFSETS - Apparatus and methods reduce the likelihood of amplifier saturation due to propagated DC offsets, and reduce the recover from saturated stated when such saturation occurs. Advantageously, these attributes are beneficial for monitoring of bioelectric signals. A circuit uses an instrumentation amplifier connected as a high pass filter to attenuate large DC offsets and amplify small signals. The circuit can include an instrumentation amplifier electrically coupled with a first feedback circuit including at least one resistor and a second feedback circuit including an op-amp. The feedback circuit can also include a low-pass filter. The op-amp in the second feedback circuit can be configured as a non-inverting amplifier, an inverting amplifier, and/or an integrator circuit. Alternatively, the circuit can include an instrumentation amplifier with one feedback circuit including at least one resistor, and a coupling capacitor electrically coupled with a reference voltage. | 07-26-2012 |
20120194268 | DIFFERENTIAL VOLTAGE SENSING METHOD - A differential voltage sensing method for achieving input impedance matching comprises the steps of: providing a first bio-potential signal to a first variable resistor for generating a first signal; providing a second bio-potential signal to a second variable resistor for generating a second signal; differentially amplifying first and second signals for generating a third signal; selecting an operation band of the third signal for generating first and second logic signals; and dynamically adjusting one of the impedances of the first and second variable resistors according to the first and second logic signals, wherein each of the first and second bio-potential signals has a common signal voltage level and a differential signal voltage level. | 08-02-2012 |
20120206197 | DIFFERENTIAL AMPLIFYING APPARATUS - A differential amplifier amplifies the difference between a signal input to the non-inverting terminal via a capacitor and a signal input to the inverting terminal. A switch switches whether to input the signal to the non-inverting terminal via the capacitor. A resistance is connected between the non-inverting terminal and the inverting terminal. An offset voltage corrector corrects the offset voltage of the differential amplifier based on the output signal of the differential amplifier during a correction period in which the switch is controlled not to input the signal to the non-inverting terminal via the capacitor. | 08-16-2012 |
20120206198 | DIFFERENTIAL AMPLIFIER WITH DUTY CYCLE COMPENSATION - A differential amplifier replicates the input stage and cross-connects the inputs, so that the input-to-output delay will be balanced in an averaged sense. The outputs of each of the two input stages are then summed after an open loop delay matched inversion has taken place. The result is a reduction in the duty cycle distortion of the receiver amplifier over process voltage and temperature (PVT) variation. This is enabled by the fact that a full swing CMOS delay cell can be made to have good delay matching over PVT, whereas the input stage to a differential amplifier may, depending on architecture, have poor delay matching because of impedance mismatches within the amplifier. | 08-16-2012 |
20120212291 | High Efficiency Amplification - A radio frequency amplification stage comprising: an amplifier for receiving an input signal to be amplified and a power supply voltage; and a power supply voltage stage for supplying said power supply voltage, comprising: means for providing a reference signal representing the envelope of the input signal; means for selecting one of a plurality of supply voltage levels in dependence on the reference signal; and means for generating an adjusted selected power supply voltage, comprising an ac amplifier for amplifying a difference between the reference signal and one of the selected supply voltage level or the adjusted selected supply voltage level, and a summer for summing the amplified difference with the selected supply voltage to thereby generate the adjusted supply voltage. | 08-23-2012 |
20120223772 | MULTILEVEL CLASS-D AMPLIFIER - A multilevel class-D differential amplifier which can be operated in at least three modes includes a first power stage and a second power stage. In an idle mode, an output of the first power stage varies between a first voltage level and a second voltage level, wherein an output of the second power stage varies between the first voltage level and the second voltage level. In a PWM mode, the output of the first power stage varies between the first voltage level and the second voltage level, wherein the output of the second power stage varies between the first voltage level and the second voltage level. In a Multi-Level mode, the output of said first power stage varies between said second voltage level and a third voltage level, wherein said output of said second power stage is fixed at said first voltage level, and wherein said differential signal between said outputs of said power stages is pulse width modulated. | 09-06-2012 |
20120229204 | SWITCHED CAPACITOR CIRCUIT - According to the present invention, a switched capacitor circuit comprises: an inverting amplifier for removing the offset by using a chopper stabilization circuit; a sampling unit which is connected between an input terminal and the inverting amplifier; and a feedback unit which is connected to the inverting amplifier in parallel. | 09-13-2012 |
20120229205 | AMPLIFIER CIRCUIT - An amplifier circuit capable of reducing load of a circuit at the previous stage by providing increased input impedance producing less noises. The amplifier circuit includes a fully-differential operational amplifier composed of an inverting input terminal, a non-inverting input terminal receiving a signal different from a signal to be input to the inverting input terminal, an inverting output terminal with the same polarity of the inverting input terminal, and a non-inverting output terminal with reverse polarity; an input impedance element with one end connected to the inverting input terminal; an input impedance element with one end connected to the non-inverting input terminal; and positive feedback impedance elements, with one end of connected to the other end of the input impedance element and the other end connected to the inverting output terminal or to the non-inverting output terminal. | 09-13-2012 |
20120242404 | ADC Preamplifier and the Multistage Auto-Zero Technique - Embodiments of the present invention provide a sample and hold amplifier that provides a preamplifier with a multi-stage zeroing architecture. The multi-stage architecture reduces effects of parasitic capacitance exponentially over prior attempts, which yields increased accuracy. | 09-27-2012 |
20120256684 | Power Amplification Based on Frequency Control Signal - Methods and systems for vector combining power amplification are disclosed herein. In one embodiment, a plurality of signals is individually amplified, then summed to form a desired time-varying complex envelope signal. Phase and/or frequency characteristics of one or more of the signals are controlled to provide the desired phase, frequency, and/or amplitude characteristics of the desired time-varying complex envelope signal. In another embodiment, a time-varying complex envelope signal is decomposed into a plurality of constant envelope constituent signals. The constituent signals are amplified equally or substantially equally, and then summed to construct an amplified version of the original time-varying envelope signal. Embodiments also perform frequency up-conversion. | 10-11-2012 |
20120262231 | CONTACT AND CONTACTLESS DIFFERENTIAL I/O PADS FOR CHIP-TO-CHIP COMMUNICATION AND WIRELESS PROBING - Contactless differential coupling structures can be used to communicate signals between circuits located on separate chips or from one chip to a probing device. The contactless coupling structures avoid problems (breaks, erosion, corrosion) that can degrade the performance of ohmic-type contact pads. The contactless coupling structures comprise pairs of conductive pads placed in close proximity. Differential signals are applied across a first pair of differential pads, and the signals are coupled wirelessly to a mating pair of conductive pads. Circuitry for generating and receiving differential signals is described. | 10-18-2012 |
20120268202 | DIGITAL CHARGE AMPLIFIER AND METHOD FOR CONVERTING CHARGE SIGNALS INTO DIGITAL SIGNALS - A circuit for a charge amplifier for converting piezoelectric measurement signals continuously sets the output signal of the amplifier to a value close to zero, such that a reset switch becomes unnecessary. The amplifier includes a pulse generator that provides the output signal of the amplifier in the form of pulses, which are easy to transmit with low interference. The pulse frequency is proportional to the rate of change of charge. The pulses, which are added in a counter, represent a value proportional to the change in the charge since the last counter reset, which is proportional to the present measured value at the measurement element. | 10-25-2012 |
20120286859 | INPUT COMMON MODE VOLTAGE COMPENSATION CIRCUIT - A voltage level shifter for a direct coupling of an external voltage source to a common mode of a circuit may include an amplifier, a voltage-controlled current source, a first and second resistors. A first input of the amplifier may be connected to the common mode. A second input of the amplifier may, via the first and second resistors, receive a voltage indicative of the external voltage source. The output of the amplifier may indicate a voltage difference between the first and second inputs. The voltage-controlled current source may be controlled by the voltage difference to supply a current to a common node of the first and second resistors so that the voltage difference between the first and second inputs may be minimized. | 11-15-2012 |
20120319769 | COMBINER-LESS MULTIPLE INPUT SINGLE OUTPUT (MISO) AMPLIFICATION WITH BLENDED CONTROL - Multiple-Input-Single-Output (MISO) amplification and associated VPA control algorithms are provided herein. According to embodiments of the present invention, MISO amplifiers driven by VPA control algorithms outperform conventional outphasing amplifiers, including cascades of separate branch amplifiers using conventional power combiner technologies. MISO amplifiers can be operated at enhanced efficiencies over the entire output power dynamic range by blending the control of the power source, source impedances, bias levels, outphasing, and branch amplitudes. These blending constituents are combined to provide an optimized transfer characteristic function. | 12-20-2012 |
20120326778 | CLOSED LOOP BIAS CONTROL - This disclosure relates to radio frequency (RF) amplification devices and methods for amplifying an RF input signal. To set the quiescent operating level of the RF output signal, a bias signal to be applied to the RF input signal is received prior to amplifying the RF input signal. The bias signal is amplified to generate the RF output signal at the quiescent operating level and a feedback signal is received that is indicative of the quiescent operating level of the RF output signal. Prior to amplifying the RF input signal, the bias signal level of the bias signal is adjusted such that the quiescent operating level is set to a reference signal level based on the feedback signal level. This allows for adjustments to be made to the quiescent operating level and maintain the quiescent operating level at a desired value. | 12-27-2012 |
20130015916 | Common-Mode Amplifier Step Response - An auto-zero amplifier includes a main amplifier for amplifying an input signal; the main amplifier receives an offset-correction signal for cancelling an offset at a first common-mode level of the input signal. At the first common-mode level, the offset-correction signal is based on a first value stored using a first offset-storage element. When a change is detected in the input common-mode from the first level to a second level, the first offset-storage element is switched out and a second offset-storage element, having a second value based on the second common-mode level, is switched in. | 01-17-2013 |
20130033312 | SINGLE-ENDED TO DIFFERENTIAL AMPLIFIER - A circuit for single ended to differential conversion is disclosed. The circuit comprises a source for providing a single ended signal; and a transformer for receiving the single ended signal. The transformer includes first and second inductors. The first and second inductors are mutually coupled. When the operating frequency changes, a phase difference of currents flowing through the inductors changes, and therefore a phase difference between effective impedance of the first and second inductors changes to maintain a substantially 180 degree phase difference due to the mutual coupling. | 02-07-2013 |
20130033313 | RF Power Transmission, Modulation, and Amplification Embodiments - Methods and systems for vector combining power amplification are disclosed herein. In one embodiment, a plurality of signals are individually amplified, then summed to form a desired time-varying complex envelope signal. Phase and/or frequency characteristics of one or more of the signals are controlled to provide the desired phase, frequency, and/or amplitude characteristics of the desired time-varying complex envelope signal. In another embodiment, a time-varying complex envelope signal is decomposed into a plurality of constant envelope constituent signals. The constituent signals are amplified equally or substantially equally, and then summed to construct an amplified version of the original time-varying envelope signal. Embodiments also perform frequency up-conversion. | 02-07-2013 |
20130038388 | AUTO-ZERO AMPLIFIER AND SENSOR MODULE USING SAME - An auto-zero amplifier is disclosed, having an amplifying circuit, a switch, and a difference signal generating circuit. The amplifying circuit receives a first input signal for generating a first output signal, and receives a second input signal for generating a second output signal. The switch is coupled between the amplifying circuit and a capacitor. The switch is conducted for charging or discharging the capacitor to a voltage with the first output signal, and the switch is not conducted for keeping the capacitor at the voltage. The difference signal generating circuit is coupled with the amplifying circuit and the capacitor for generating a difference signal of the first output signal and the second output signal, a multiple of the difference signal, a part of the difference signal, and/or a digital output value for the difference signal. | 02-14-2013 |
20130043942 | SENSING DEVICES AND DISPLAY DEVICES - A sensing device is provided. The sensing device successively operates in a plurality of operation periods and includes a plurality of first electrodes, a plurality of differential amplifiers, and a plurality of sensing circuits. The first electrodes are disposed successively. The differential amplifiers at least comprise a first differential amplifier and a second differential amplifier. Each of the differential amplifiers comprises a first input terminal and a second input terminal. Each of the sensing circuits has an input terminal and an output terminal. The sensing circuits at least comprise first, second, and third sensing circuits. The input terminals of the sensing circuits are coupled to the first electrodes. The output terminals of sensing circuits are coupled to the differential amplifiers. The output terminal of at least one of the sensing circuits is coupled to both of the first differential amplifier and the second differential amplifier. | 02-21-2013 |
20130063207 | SCHEME TO ACHIEVE ROBUSTNESS TO ELECTROMAGNETIC INTERFERENCE IN INERTIAL SENSORS - A capacitive sensor system and method resistant to electromagnetic interference is disclosed. The system includes a capacitive core, differential amplifier with inverting and non-inverting inputs, capacitive paths, and chopping system. Core can include inputs and outputs coupled to variable capacitors, and common nodes coupling variable capacitors. Capacitive paths couple core outputs to amplifier inputs. When chopping system is high, one polarity voltage is applied to core inputs, a first core output is coupled to the inverting input and a second core output is coupled to the non-inverting input. When the chopping system is low, opposite polarity voltage is applied to core inputs, and core output to amplifier input couplings are flipped. Capacitive paths can include bond wires. Chopping system can be varied between high and low at frequencies that smear noise away from a frequency band of interest, or that smear noise substantially evenly across a wide frequency range. | 03-14-2013 |
20130069718 | APPARATUS AND METHODS FOR ELECTRONIC AMPLIFICATION - Apparatus and methods for electronic amplification are provided. In one embodiment, an amplifier includes a first adaptive level shifter (ALS), a second ALS, a first transconductance amplification circuit, a second transconductance amplification circuit, and a transimpedance amplification circuit. The first ALS and the second ALS are electrically coupled to the first and second transconductance amplification circuits to improve the input voltage range and common-mode rejection ratio (CMRR) of the amplifier. The transimpedance amplification block is electrically coupled to the first and second transconductance amplification blocks and generates an output voltage of the amplifier. The first ALS receives a differential input voltage, and the second ALS is configured to receive a feedback signal configured to change in relation to the output voltage signal. | 03-21-2013 |
20130082770 | ELECTRONIC CIRCUIT HAVING BAND-GAP REFERENCE CIRCUIT AND START-UP CIRCUIT, AND METHOD OF STARTING-UP BAND-GAP REFERNCE CIRCUIT - An electronic circuit includes a band-gap reference circuit and a start-up circuit. The band-gap reference circuit includes an operational amplifier which has an output and first and second inputs. The band-gap reference circuit is configured to generate a predetermined reference voltage at the output of the operational amplifier after a start-up phase of the band-gap reference circuit. The start-up circuit includes at least one switch arranged to connect at least one current source to at least one of the inputs of the operational amplifier during the start-up phase, and to disconnect the at least one current source from the at least one of the inputs of the operational amplifier after the start-up phase. | 04-04-2013 |
20130099857 | AUDIO PROGRAMMABLE GAIN AMPLIFIER WITH AUTOMATIC RECONFIGURATION - A reconfigurable amplifier comprising a first operational amplifier having two inputs and an output. A second operational amplifier having two inputs and an output. A plurality of switches coupled to the two inputs and the output of the first operational amplifier and the two inputs and the output of the second operational amplifier, wherein a first configuration of the plurality of switches causes the first operational amplifier and the second operational amplifier to operate as an inverting differential input amplifier, and wherein a second configuration of the plurality of switches causes the first operational amplifier and the second operational amplifier to operate as a non-inverting differential input instrumentation amplifier. | 04-25-2013 |
20130099858 | DUAL PRIMARY SWITCHED TRANSFORMER FOR IMPEDANCE AND POWER SCALING - This application reduces the power of series combined transformers and of parallel combined transformers while maintaining efficiency. In one embodiment, a series combined transformer is provided with a switch between a first primary inductor and a second primary inductor, in order to provide at least two modes. In a high power mode, the switch is open and the series combined transformer operates normally. In a low power mode, the switch is closed, one amplifier from a first differential amplifier pair is shut down, one amplifier from a second differential pair is shut down, and the series combined transformer operates efficiently in a low power mode. | 04-25-2013 |
20130099859 | Multilevel Class-D Amplifier - A multilevel class-D differential amplifier which can be operated in at least three modes includes a first power stage and a second power stage. In an idle mode, an output of the first power stage varies between a first voltage level and a second voltage level, wherein an output of the second power stage varies between the first voltage level and the second voltage level. In a PWM mode, the output of the first power stage varies between the first voltage level and the second voltage level, wherein the output of the second power stage varies between the first voltage level and the second voltage level. In a Multi-Level mode, the output of said first power stage varies between said second voltage level and a third voltage level, wherein said output of said second power stage is fixed at said first voltage level, and wherein said differential signal between said outputs of said power stages is pulse width modulated. | 04-25-2013 |
20130106506 | Adjustable gain audio power amplifying circuit | 05-02-2013 |
20130181771 | LIGHT RECEIVING CIRCUIT AND PHOTO-COUPLING TYPE INSULATED CIRCUIT - According to one embodiment, a light receiving circuit includes a light receiving element, an amplifier, and a first compensator. The light receiving element is configured to output an optical current by receiving an optical signal. The amplifier is configured to convert the optical current into a voltage and amplify the voltage. The first compensator is connected to the amplifier and configured to suppress a variation in an opposite direction from a voltage variation of the amplifier when the optical current increases. | 07-18-2013 |
20130181772 | PRIMARY-SIDE FEEDBACK CONTROLLED AC/DC CONVERTER WITH AN IMPROVED ERROR AMPLIFIER - An error amplifier, a controller using the error amplifier, and a primary-side feedback controlled AC/DC converter using the controller are discussed. When the output voltage of the primary-side feedback controlled AC/DC converter according to present invention changes, the alternating current path enjoys a fast response and adjusts the output voltage quickly with a lower precision, avoiding large voltage fluctuate, then the direct current path functions slowly to reduce equivalent output error. In such a way, the output voltage precision is enhanced while the stability of the primary-side feedback controlled AC/DC converter is maintained. | 07-18-2013 |
20130241637 | Auto-Zeroed Amplifier with Low Input Leakage - An amplifier having an inverting input and a non-inverting input; a capacitor coupled to inverting input of the amplifier; an input voltage conveyance control circuit, having a first switch and a second switch, the first switch coupled to the capacitor, and the second switch coupled to the non-inverting input of the amplifier; a reference voltage conveyance control circuit having a third switch and a fourth switch, a shared node coupled between third switch and fourth switch, the fourth switch coupled to the non-inverting input of the amplifier; a fifth switch coupled to an output of the amplifier; a leakage control circuit having a sixth switch and seventh switch, the sixth switch coupled between the inverting amplifier input and the fifth switch, the seventh switch coupled to the sixth switch and the capacitor; and a first resistor coupled from the output of the amplifier to the first switch. | 09-19-2013 |
20130241638 | SIGNAL AMPLIFIER CIRCUIT FOR USB PORT - A signal amplifier circuit for USB port includes a USB controller, an amplifier circuit, a USB port and a signal regulator circuit. The USB controller includes a super speed transmitter differential pair and a super speed receiver differential pair. The amplifier circuit includes two first input terminals, two second input terminals, two first output terminals, and two second output terminals. The USB port includes two first differential signal receiving terminals and two first differential signal transmitting terminals. The super speed transmitter differential pair and the super speed receiver differential pair are electrically connected to the first input terminals and the second output terminals. The first output terminals and the second input terminals are electrically connected to the first differential signal receiving terminals and the first differential signal transmitting terminals. The signal regulator circuit regulates amplitude and jitter of differential signals amplified by the amplifier circuit. | 09-19-2013 |
20130249627 | TIME DIFFERENCE AMPLIFIER AND AMPLIFICATION METHOD USING SLEW RATE CONTROL - When a time difference is amplified by a time difference amplifier, slew rates of internal output voltages are changed according to a phase combination of digital input signals so that a time gain is determined by a ratio between the slew rates and the slew rates can be controlled from an outside. After a voltage is charged to the level of a power supply voltage in first and second charging capacitors, the charged voltage of the first charging capacitor is decreased with a first slew rate when a first digital input signal transitions, and both charged voltages of the first and second charging capacitors are decreased with a second slew rate when a second digital input signal transitions so that both first and second digital input signals are changed from initial phases, while being compared with a reference voltage to generate first and second digital output signals. | 09-26-2013 |
20130278331 | Reference Potential Converter Circuit - A reference potential converter circuit comprises: a first resistor (resistance value R | 10-24-2013 |
20130293293 | 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 high gains by direct feedback of an AC signal (i.e., an intermediate voltage) to an amplifier input without being attenuated by feedback resistor network. | 11-07-2013 |
20130293294 | PROGRAMMABLE GAIN AMPLIFIER WITH AMPLIFIER COMMON MODE SAMPLING SYSTEM - A programmable gain amplifier (“PGA”) may include a differential amplifier, a pair of input capacitors, a pair of feedback capacitors provided in feedback configuration about the amplifier, a first chop circuit, provided at an input of the PGA and an output of the PGA and a second chop circuit provided at an output of the PGA. The PGA also may include circuit systems to sample voltages across the input capacitors in a sampling phase. The sampled voltages may correspond to a difference between a common mode voltage of input signals to the PGA and a common mode voltage of the differential amplifier. The sampled voltage, thus, defines a common mode voltage at the amplifier's inputs during other phases of operation, when the chop circuits are operational. | 11-07-2013 |
20130335141 | APPARATUS AND METHODS FOR ELECTRONIC AMPLIFICATION - Apparatus and methods for electronic amplification are provided. In one embodiment, a method of electronic amplification includes amplifying a differential input voltage signal to generate a feed-forward signal, chopping the feed-forward signal at a chopping frequency to generate a chopped feed-forward signal, notch filtering the chopped feed-forward signal at the chopping frequency to generate a notched signal, generating an input offset correction signal based at least partly on the notched signal, and amplifying the differential input voltage signal using a signal amplification block to generate an output signal. Amplifying the differential input voltage signal using the signal amplification block includes chopping the input signal at the chopping frequency to generate a chopped input signal and combining the chopped input signal and the offset correction signal to reduce input offset error of the signal amplification block. | 12-19-2013 |
20140009223 | Common Mode Bias Circuit - A bias voltage source for a differential circuit has low output impedance at DC, but considerably higher output impedance within the frequency band of the differential signal being processed, to provide an accurate, well-matched common-mode bias voltage to each component of a differential signal path, while providing a low noise current, minimizing the conversion between common-mode and differential modes, and preserving available headroom, and all without requiring the use of large resistors. | 01-09-2014 |
20140084999 | APPARATUS AND METHOD FOR WIDE COMMON MODE DIFFERENCE - Apparatus and methods reduce increase the common mode range of a difference amplifier. A circuit uses one or more floating powers and one or more floating grounds coupled to an input stage of an amplifier to increase the common mode range of a difference amplifier. The floating power can be configured to select from the greater of the voltage level of one of the differential signals and the system power high source. The floating ground can be configured to select from the lesser of the voltage level of one of the differential signals and the system power low source. | 03-27-2014 |
20140132341 | MULTI-MODE OPAMP-BASED CIRCUIT - A multi-mode OPAMP-based circuit is provided. An input amplifying stage amplifies a pair of input differential signals to provide a pair of intermediate differential signals. An output amplifying stage amplifies the pair of intermediate differential signals to provide a pair of output differential signals. A first capacitor is disposed in a first negative feedback loop of the output amplifying stage. A second capacitor is disposed in a second negative feedback loop of the output amplifying stage. A third capacitor is selectively disposed in a first positive feedback loop of the output amplifying stage or coupled to the first capacitor in parallel according to a control signal. A fourth capacitor is selectively disposed in a second positive feedback loop of the output amplifying stage or coupled to the second capacitor in parallel according to the control signal. | 05-15-2014 |
20140145785 | APPARATUS AND METHODS FOR EQUALIZATION - Apparatus and methods for equalization are provided. In certain implementations, an equalizer includes first and second feedback resistors, first and second equalization resistors, an equalization capacitor, and an amplification circuit that includes first to fourth input terminals and first and second output terminals. The amplification circuit can receive a differential input voltage signal between the first and third input terminals, and the first and second equalization resistors and the equalization capacitor are electrically connected in series between the second and fourth input terminals with the equalization capacitor between the first and second equalization resistors. Additionally, the first feedback resistor is electrically connected between the first output terminal and the second input terminal, and the second feedback resistor is electrically connected between the second output terminal and the fourth input terminal. | 05-29-2014 |
20140176236 | PILOT SIGNAL GENERATION CIRCUIT - In some embodiments, a pilot signal generation circuit is provided including a buffer and a differential amplifier responsive to an output of the buffer. A first transistor is connected to control a reference voltage at an input of the buffer in response to a pulse width modulated logic signal and a second transistor connected to control a reference voltage at an input of the differential amplifier based on the pulse width modulated logic signal such that the second transistor is connected so as to turn on when the first transistor is turned off and to turn off when the first transistor is turned on. The differential amplifier is configured to provide at an output a pilot signal proportional to a gain of the differential amplifier. | 06-26-2014 |
20140232457 | FAST, LOW POWER COMPARATOR WITH DYNAMIC BIAS BACKGROUND - A comparator circuit comprising an operational amplifier configured to compare a difference between a switching voltage and a reference voltage, and a dynamically adjustable bias current generator coupled to the operational amplifier. A method of conserving power in a comparator circuit includes estimating a switching regulator load current value, communicating the value to a current bias generator, enabling the bias generator with a signal from a switching regulator PFM logic circuit, and establishing a bias current at an operational amplifier of the comparator circuit on the basis of the enabling. | 08-21-2014 |
20140354354 | NANOVOLT AMPLIFIER DESIGN - A circuit can include operational amplifier having a first input, a second input, and an output, first and second resistors in series between the output of the op-amp and a ground, and multiple switches configurable to toggle the circuit between a positive phase and a negative phase. | 12-04-2014 |
20150341046 | SIGMA-DELTA ANALOG-TO-DIGITAL CONVERTER - The present invention is related to a sigma-delta analog-to-digital converter (ADC). It further relates to a method for designing and manufacturing a sigma-delta ADC, and to a digital control loop comprising the same. According to the present invention, part of the filtering function required for noise-shaping is implemented in the feedback path. By suitably distributing the poles over the forward and feedback paths, stable operation can be achieved while offering low latency. | 11-26-2015 |
20160079949 | RESISTOR ATTENUATOR WITH SWITCH DISTORTION CANCELLATION - A programmable (multistep) resistor attenuator includes distortion cancellation for harmonic distortion currents. The attenuator includes at last one attenuation stage coupled between a signal input node and a virtual ground node (such as an input to a differential amplifier). The attenuation node is: (a) coupled to the input node through a resistor R; (b) coupled to the virtual ground node through a resistor kR and a virtual ground switch Swf with an on resistance Rswf; and (c) coupled to a differential ground through a resistor mR and a differential ground switch Swp with an on resistance Rswp. Swp is sized relative to Swf such that, when both Swp and Swf are conducting, a component Ipnf of a current Ipn through Rswp and mR to the attenuation node and branching into kR and Rswf, matches, in phase and magnitude, a harmonic current Ifn from the virtual ground through Rswf and kR to the attenuation node, thereby substantially canceling the harmonic distortion appearing at the virtual ground. Distortion cancellation can be based on cancellation is based on matching switches Swf and Swp and the resistors R, mR, kR, and hence is insensitive to PVT variations, input frequency and amplitude. an optimum ratio of Rswp and Rswf is a function of only a ratio of resistors, and hence is insensitive to values of Rswp and Rswf. The attenuator architecture is extendable to multistage configurations. | 03-17-2016 |