Class / Patent application number | Description | Number of patent applications / Date published |
330009000 | WITH PERIODIC SWITCHING INPUT-OUTPUT (E.G., FOR DRIFT CORRECTION) | 67 |
20080197920 | Arrangement For Carrying Out Current-To-Voltage Conversion - An arrangement for carrying out current-to-voltage conversion, preferably for an infrared receiver, in which the static offset, which has an interfering effect with regard to sensitivity or malfunctions, is reduced during the carrying out of current-to-voltage conversion of received input pulses. In this arrangement, outputs of a second stage are fed back to inputs of a first stage of the multistage transimpedance stage. | 08-21-2008 |
20080197921 | System and method for minimizing DC offset in outputs of audio power amplifiers - An amplifier system receives an input signal and generating therefrom an amplified output signal. The amplifier system is recited as comprising an input stage and an amplifier stage. The input stage is configured to receive the input signal and provide a level-shifted signal that has an average signal level that is shifted in regards a level shift value. The amplifier stage is configured to receive the level-shifted input signal from the input stage and generate therefrom the amplified output signal. The level shift value being selected to minimize a DC offset in the amplified output signal at least when the amplifier system is initially powered on. Since the amplified output signal has a minimal or zero DC offset, the amplifier system avoids generation of undesirable noises when it is initially powered on. | 08-21-2008 |
20080211574 | CHOPPER-STABILIZED INSTRUMENTATION AMPLIFIER - This disclosure describes a chopper stabilized instrumentation amplifier. The amplifier is configured to achieve stable measurements at low frequency with very low power consumption. The instrumentation amplifier uses a differential architecture and a mixer amplifier to substantially eliminate noise and offset from an output signal produced by the amplifier. Dynamic limitations, i.e., glitching, that result from chopper stabilization at low power are substantially eliminated through a combination of chopping at low impedance nodes within the mixer amplifier and feedback. The signal path of the amplifier operates as a continuous time system, providing minimal aliasing of noise or external signals entering the signal pathway at the chop frequency or its harmonics. The amplifier can be used in a low power system, such as an implantable medical device, to provide a stable, low-noise output signal. | 09-04-2008 |
20080224768 | Operational Amplifier Capable of Compensating Offset Voltage - An operational amplifier capable of compensating offset voltage includes an input stage circuit having a positive input end, a negative input end, a first current output end, and a second current output end, for outputting current corresponding to voltage received by the positive and negative input ends, an output stage circuit coupled to the first current output end and the second current output end of the input stage circuit, for outputting voltage according to current outputted from the first current output end and the second current output end, and an trimming device coupled between the input stage circuit and the output stage circuit, for adjusting current of the first current output end or the second current output end for compensating offset voltage. | 09-18-2008 |
20080231356 | Voltage margining with a low power, high speed, input offset cancelling equalizer - A switched-capacitor circuit that may be used for equalization, but configurable for voltage margining. The switched-capacitor circuit cancels the offset voltage inherent in an amplifier and sets the common mode of an input signal at half the rail voltage. Two capacitors level shift an input signal before being applied to the two input ports of an amplifier. When used for voltage margining, the input voltage swing is reduced at the input ports of the amplifier by connecting a digital-to-analog controlled voltage source to the two capacitors. | 09-25-2008 |
20080238539 | ARRANGEMENT FOR CANCELING OFFSET OF AN OPERATIONAL AMPLIFIER - Operational amplifier circuitry drives a device which may be run with a combination of output signals fewer in number than the output signals delivered from plural output circuits. Each output circuit adjusts the gain of an input signal supplied to its operational amplifier. An output selector selects and outputs output signals from the output circuits necessary for driving the device. A decision circuit compares an output signal not selected with a reference signal to adjust the gain of the output circuits to thereby cancel the offset of the operational amplifier. The operational amplifier has sets of feedback elements different in number between the sets formed by capacitances. Switching is made from one set to another until the decision circuit makes an acceptable decision. Offset may thus be canceled during the operational amplification even in case capacitive or resistance element is connected in circuit outside the operational amplifier. | 10-02-2008 |
20080252369 | Operational amplifier, line driver, and liquid crystal display device - An operational amplifier capable of offset cancel in a shorter period, as well as a line driver capable of shortening one horizontal period and a liquid crystal display device are provided. In the operational amplifier of the invention, a time necessary for feed back control can be shortened than usual by a constitution that an output voltage VO in one horizontal period H | 10-16-2008 |
20080252370 | Digital Audio Amplifier and Digital Audio Amplifying Method Therefor - A digital audio signal amplifier and a digital audio signal amplifying method therefor are provided. More particularly, a digital audio signal amplifier in which both safety and power efficiency are achieved by integrating a switching mode power supply and a digital audio amplifier into one, and a digital audio signal amplifying method appropriate to the amplifier are provided. The digital audio amplifier includes: a pulse modulation unit generating a pulse modulated audio signal by pulse-modulating an input audio signal; a switching unit switching a DC voltage based on the pulse modulated audio signal; an insulation transformer transforming the output of the switching unit and outputting the result of the transforming; and a low-pass filter obtaining an audio signal corresponding to the input audio signal by low-pass filtering the output of the insulation transformer, and outputting the output audio signal. By integrating a switching mode power supply and a digital audio amplifier into one, the digital audio amplifier satisfies the insulation requirement and at the same time increases power efficiency. | 10-16-2008 |
20080258809 | Amplifier Device Capable of Reducing Offset Voltage - An amplifier device capable of reducing offset voltage includes an offset-voltage cancellation device, an input stage circuit, an output stage circuit, a pseudo output stage circuit, a switch circuit, and an output end. The switch circuit is coupled to the input stage circuit, the output stage circuit, and the pseudo output stage circuit, and is utilized for transmitting an amplified signal provided by the input stage circuit to the output stage circuit and transmitting a first feedback voltage provided by the output stage circuit to the input stage circuit or transmitting the amplified signal provided by the input stage circuit to the pseudo output stage circuit and transmitting a second feedback voltage provided by the pseudo output stage circuit to the input stage circuit according to an operating mode. | 10-23-2008 |
20080284507 | Autozeroing current feedback instrumentation amplifier - An embodiment is directed to an instrumentation amplifier. The instrumentation amplifier includes an output stage for generating an output voltage, a low-frequency path coupled with the output stage, and a high-frequency path coupled with the output stage. The high-frequency path dominates the low-frequency path at frequencies above a particular frequency, and the low-frequency path dominates the high-frequency path at frequencies below the particular frequency. The low-frequency path includes an input stage for sensing a differential input and generating an intermediate current based thereon, a feedback stage coupled with the input and output stages, the feedback stage for generating a feedback current based on the output voltage, and an auto-zeroing circuit coupled with the input, feedback, and output stages, the auto-zeroing circuit for generating a nulling current. The nulling current compensates for errors in the intermediate and feedback currents resulting from input offsets in the input and feedback stages. | 11-20-2008 |
20080297243 | Linear programmable switch-capacitance gain amplifier - A linear programmable switch-capacitance gain amplifier (PGA) is described. The PGA divides the dB-gain curve into several parts by the concept of piece-wise linearity, and then simultaneously executes the dB-linear gain adjustment of MSB and the LSB at the same gain stage. Present invention achieves the PGA dB-linearity by setting up every capacitance of the sampling capacitor array and the holding capacitor array, then arranging the sampling capacitor array and the holding capacitor array by coordinating the switching of the capacitor switches. | 12-04-2008 |
20090009239 | Low glitch offset correction circuit for auto-zero sensor amplifiers and method - An instrumentation amplifier includes first ( | 01-08-2009 |
20090009240 | Amplifier Circuit - An amplifier circuit block and a compensation circuit block are provided. The amplifier circuit block includes an analog adder for subtracting an output signal of the compensation circuit block from an input signal and an amplifier circuit operating in a wide band. The compensation circuit block includes an amplifier circuit with a low offset voltage and a low noise in a low frequency region, an analog adder block for subtracting an output signal of the amplifier circuit from an output signal of the amplifier circuit and generating a differential signal thereof, and a feedback circuit block for negatively feeding back the differential signal to the analog adder. The amplifier circuit block can reduce the offset voltage and the low-band noise by the negative feedback of the differential signal, and at the same time, the operation band of the entire amplifier circuit can be decided by the characteristic of the amplifier circuit. | 01-08-2009 |
20090039956 | AMPLIFIER CIRCUITS, IMAGER, SYSTEM AND METHOD OF OPERATION - Systems, imagers, amplifiers and methods for use in operating a multi-channel amplifier. The multi-channel amplifier operates in a plurality of channels. A respective plurality of non-overlapping clock signals is generated for connecting a shared operational amplifier into respective portions of a switched-capacitor amplifier circuit. Between assertions of the non-overlapping clock signals, the shared operational amplifier is substantially electrically isolated from the switched-capacitor amplifier circuit to remove current leakage paths. Inputs and outputs of the shared operational amplifier are shorted to remove residual charge from the circuit. | 02-12-2009 |
20090108929 | Apparatuses and methods for providing offset compensation for operational amplifier - Apparatuses and methods for providing offset compensation include a primary amplifier which includes a first output, a second output, a first load input, and a second load input, a first feedback loop connected to the primary amplifier and which includes a first switch located between the first output of the primary amplifier and the first load input, and a first sampling capacitor coupled to the first switch between the first switch and the first load input and a second feedback loop connected to the primary amplifier and which includes a second switch located between the second output of the primary amplifier and the second load input, and a second sampling capacitor coupled to the second switch between the second switch and the second load input. | 04-30-2009 |
20090115507 | METHOD OF AND APPARATUS FOR REDUCING SETTLING TIME OF A SWITCHED CAPACITOR AMPLIFIER - A method and apparatus for reducing settling time of a switched capacitor amplifier. The method includes disconnecting first and second capacitors from an amplifier. When the first and second capacitors are disconnected from the amplifier, they are charged by respective first and second input signals. The apparatus includes a plurality of sampling capacitors, each configured to sample a respective one of a plurality of signals during a sampling phase, an amplifier, and a plurality of decoupling switches configured to isolate the sampling capacitors from the amplifier during the sampling phase and to connect the plurality of sampling capacitors to the amplifier during the amplifying phase. | 05-07-2009 |
20090128232 | SWITCHED-CAPACITOR AMPLIFIER WITH IMPROVED RESET PHASE - A switch-capacitor (“SC”) amplifier includes a two-stage operational amplifier (“OP-AMP”), an input SC network, and a feedback SC network. The two-stage OP-AMP includes a first OP-AMP stage having an output coupled to an input of a second OP-AMP stage. The input SC network is coupled to an input of the first OP-AMP stage. The feedback SC network is configured to selectively couple the output of the first OP-AMP stage to the input of the first OP-AMP stage during a first phase of operation of the scamplifier and to couple an output of the second OP-AMP stage to the input of the first OP-AMP stage during a second phase of operation of the SC amplifier. | 05-21-2009 |
20090140802 | SEMICONDUCTOR INTEGRATED CIRCUIT - The present invention is directed to reduce offset error voltage in a signal source impedance of analog input signal voltage supplied to an input terminal due to input offset voltage of an operational amplifier in a sampling circuit or a multiplexer coupled to an input terminal of an A/D converter. A semiconductor integrated circuit has an A/D converter and a sampling circuit. The sampling circuit samples an analog input signal in first and second sample modes. The A/D converter converts the sampled analog signal to a digital signal in a conversion mode. By switching of an internal circuit of an operational amplifier between the first and second sample modes, the functions of a non-inverting input terminal (+) and an inverting input terminal (−) realized by first and second input terminals are switched. Synchronously with the switching, supply of an analog signal to the non-inverting input terminal by input switches is also switched. | 06-04-2009 |
20090153241 | Simultaneous filtering and compensation circuitry and method in chopping amplifier - A chopper-stabilized amplifier ( | 06-18-2009 |
20090167430 | Switched-Capacitor Amplifier Arrangement and Method - A switched-capacitor amplifier arrangement and a method to amplify a signal are presented. A forward path has at least one switched capacitor ( | 07-02-2009 |
20090195305 | Analog Switch Controller - Methods and systems for implementing an analog switch controller to improve linearity of analog switches are described. | 08-06-2009 |
20090195306 | SWITCHED-CAPACITOR CIRCUIT HAVING SWITCH-LESS FEEDBACK PATH - A switched-capacitor circuit includes a plurality of cascaded differential-input, single-ended-output amplifiers. A negative feedback path, from an output terminal of a last of the cascaded amplifiers to an input terminal of a first of the cascaded amplifiers, is configured to exclude, and not be shorted out by, any switches. | 08-06-2009 |
20090212856 | ANALOG AMPLIFIER HAVING DC OFFSET CANCELLATION CIRCUIT AND METHOD OF OFFSET CANCELLATION FOR ANALOG AMPLIFIERS - An amplifier having DC offset compensation includes at least one input node and a pair of differential output nodes, a biasing circuit coupled to the input node; and a plurality of current sources. Selected ones of said current sources are coupled to the input node to adjust a DC voltage at the input node to provide DC offset compensation for the amplifier | 08-27-2009 |
20090231029 | COMBINATION OFFSET VOLTAGE AND BIAS CURRENT AUTO-ZERO CIRCUIT - A circuit with an input acquisition loop and an output acquisition loop is used to compensate for the input offset voltage and bias current errors of an operational amplifier. | 09-17-2009 |
20090267687 | CHOPPER-STABILIZED AMPLIFIER AND MAGNETIC FIELD SENSOR - A chopper-stabilized amplifier has switching networks arranged to support a high frequency clocking signal and to provide a high common mode rejection and a high rejection of an offset component of an input signal. A magnetic field sensor includes a Hall effect element coupled to a modulation circuit. The modulation circuit provides a signal to the chopper-stabilized amplifier. The chopper-stabilized amplifier provides an output signal to a low pass filter, which provides an output signal from the magnetic field sensor. | 10-29-2009 |
20090273395 | PREAMPLIFIER AND METHOD FOR CALIBRATING OFFSET VOLTAGES THEREIN - A preamplifier includes cascade-connected amplifying circuits, and at least one of the cascade-connected amplifying circuits includes a differential switch pair circuit, a comparator and current sources. The differential switch pair circuit has a pair of differential inputs and a pair of differential outputs. The comparator outputs a comparison signal by comparing the differential outputs. The current sources are respectively and selectively coupled to one of the differential outputs based on the comparison signal to adjust voltages of the differential outputs. A method for calibrating offset voltages in a preamplifier is also disclosed herein. | 11-05-2009 |
20090278597 | Slew rate and settling time improvement circuitry and method for 3-stage amplifier - An operational amplifier ( | 11-12-2009 |
20090289702 | CURRENT GENERATOR - A current generator, including a chopper stabilization operational amplifier, a transistor, and an impedance unit is provided. The chopper stabilization operational amplifier includes a first input terminal, a second input terminal, and an output terminal. The transistor includes a gate coupled to the output terminal of the chopper stabilization operational amplifier, a first source/drain coupled to the first input terminal of the chopper stabilization operational amplifier, and a second source/drain serving as a current output terminal of the current generator. The impedance unit includes a first terminal coupled to the first source/drain of the transistor, and a second terminal coupled to a first voltage. | 11-26-2009 |
20090289703 | OFFSET CANCELLATION CIRCUIT AND DISPLAY DEVICE - In an offset cancellation circuit according to the present invention, a first capacitance is connected to a gate of a first transistor of a first active load, and a second capacitance is connected to a gate of a second transistor of the first active load. A switch sets a first time period and a second time period in connection states between the first and second transistors and the first and second capacitances. The connection states between the first and second transistors and the first and second capacitances are set so that a gate voltage of the first transistor is supplied to the first capacitance, and a gate voltage of the second transistor is supplied to the second capacitance during the first time period; and so that the first and second capacitances can retain charges, and the second time period becomes an output time period of the operational amplifier during the second time period. | 11-26-2009 |
20090309653 | CHOPPER STABILIZED AMPLIFIER - A chopper stabilized amplifier has differential inputs, an output, and a low frequency path and a high frequency path from the differential inputs to the output. Chopping occurs, at a chopping frequency, of a differential signal at differential inputs and outputs of an amplifier stage of the low frequency path to thereby produce a chopped differential signal that has a DC offset of the amplifier stage frequency shifted up to the chopping frequency. A continuous time filter embedded between a pair of further amplifier stages of the low frequency path is used to attenuate chopper frequency ripple resulting from the chopping at the chopping frequency. Additionally, a buffer is used to allow feedback through a compensation capacitor for the low frequency path, yet prevent chopper frequency ripple from feeding forward through the compensation capacitor to the output of the amplifier. | 12-17-2009 |
20100001792 | Low-noise DC Offset Calibration Circuit and Related Receiver Stage - A receiver stage has an operational amplifier, a feedback resistor coupled between an output of the operational amplifier and an input of the operational amplifier, and a DC offset calibration circuit. The DC offset calibration circuit includes a plurality of resistors and a plurality of switches. Each resistor has a first end coupled to a supply voltage. First ends of each of the switches are coupled to second ends of each of the resistors, respectively, and second ends of the switches are coupled to the input of the operational amplifier. | 01-07-2010 |
20100019841 | Minimizing Changes In Common Mode Voltage At Inputs Of An Operational Amplifier Used In A Switched Capacitor Differential Amplifier - A reference generation circuit provided according to an aspect of the present invention generates a reference potential at different levels in the hold phase of different cycles in an input path of a switched capacitor differential amplifier. In an embodiment, for each hold phase, the reference generator provides the reference potential with a magnitude that tracks the magnitude of the input signal applied in a corresponding (preceding) sample phase. In case of a single-ended output, the reference potential generated for each hold phase equals the magnitude of one of the inputs on the differential input path. As a result, the common mode voltage at the input terminals of an operational amplifier contained in the switched capacitor differential amplifier is maintained at a desired level. | 01-28-2010 |
20100019842 | Low-noise, wide offset range, programmable input offset amplifier front end and method - A programmable offset amplifier includes first (M | 01-28-2010 |
20100026386 | Amplifier front-end with low-noise level shift - An amplifier front-end comprises an input node for receiving a common-mode voltage V | 02-04-2010 |
20100033240 | CHOPPER-STABILIZED INSTRUMENTATION AMPLIFIER FOR IMPEDANCE MEASUREMENT - This disclosure describes a chopper stabilized instrumentation amplifier. The amplifier is configured to achieve stable measurements at low frequency with very low power consumption. The instrumentation amplifier uses a differential architecture and a mixer amplifier to substantially eliminate noise and offset from an output signal produced by the amplifier. Dynamic limitations, i.e., glitching, that result from chopper stabilization at low power are substantially eliminated through a combination of chopping at low impedance nodes within the mixer amplifier and feedback. The signal path of the amplifier operates as a continuous time system, providing minimal aliasing of noise or external signals entering the signal pathway at the chop frequency or its harmonics. The amplifier can be used in a low power system, such as an implantable medical device, to provide a stable, low-noise output signal. | 02-11-2010 |
20100060352 | Auto-correction feedback loop for offset and ripple suppression in a chopper-stabilized amplifier - A chopper-stabilized amplifier includes a main signal path having first and second chopping circuits at the inputs and outputs of a transconductance amplifier, and an auto-correction feedback loop. The feedback loop includes a transconductance amplifier connected to amplify the chopped output from the main signal path, a third chopping circuit which chops the amplified output, a filter which filters the chopped output to substantially reduce any offset voltage-induced AC component present in the signal being filtered, and a transconductance amplifier which receives the filtered output and produces an output which is coupled back into the main signal path. When properly arranged, the auto-correction feedback loop operates to suppress transconductance amplifier-related offset voltages and offset voltage-induced ripple that might otherwise be present in the amplifier's output. | 03-11-2010 |
20100066444 | WIDE-RANGE AND HIGH-RESOLUTION PROGRAMMABLE GAIN AMPLIFIER - A first gain stage and a second gain stage having different gains are linked in cascade to construct a wide range and high resolution programmable gain amplifier. The second gain stage can be used only for low gain and low power consumption. Furthermore, two pairs of chopper circuits are used to shift flicker noise when the programmable gain amplifier is operated. | 03-18-2010 |
20100079204 | Switched-capacitor amplifier arrangement having a low input current - An SC amplifier arrangement and a method for measuring an input voltage are described. | 04-01-2010 |
20100164616 | Chopping technique for continuous time sigma-delta ADCs without Q-noise folding - A chopping transconductor includes an transconductor input stage coupled with input signals of the chopping transconductor; a chopping switch coupled with an output of the transconductor input stage, the chopping switch having a switch output; and a cascode transistor, wherein the switch output is coupled to an output of the chopping transconductor through the cascode transistor. The chopping transconductor may be used in an analog-to-digital converter to isolate chopping switches from junctions with quantization noise. | 07-01-2010 |
20100176879 | Method And Device For Performing Offset Cancellation In An Amplifier Using Floating-Gate Transistors - An operational amplifier including: a differential pair of transistors coupled to a pair of input signals; and a pair of floating-gate transistors coupled to the differential pair of transistors, wherein the pair of floating-gate transistors are operable for reducing an offset voltage of the operational amplifier. | 07-15-2010 |
20100289568 | Low-Noise, Low-Power, Low Drift Offset Correction in Operational and Instrumentation Amplifiers - Low-noise, low-power, low drift offset correction in operational and instrumentation amplifiers and amplifiers using the same are disclosed. The amplifiers disclosed use different combinations of chopping and auto-zero techniques. Also disclosed are amplifiers using on-off switches to affect the chopping and auto-zeroing, with unique circuits for driving the switches on the differential input to provide boot-strapped switch controls. Other features are disclosed. | 11-18-2010 |
20110254621 | Signal Processing Circuit - A signal processing circuit comprising a chopper amplifier in combination with a circuit or device having an acquisition period, and wherein a clock controlling the chopper amplifier is controlled such that a predetermined or known number of clock transitions occur during the acquisition period. | 10-20-2011 |
20110316621 | LOW INPUT BIAS CURRENT CHOPPING SWITCH CIRCUIT AND METHOD - A chopper-stabilized circuit ( | 12-29-2011 |
20120169416 | CIRCUIT AND METHOD FOR REDUCING INPUT LEAKAGE IN CHOPPED AMPLIFIER DURING OVERLOAD CONDITIONS - A chopper-stabilized amplifier ( | 07-05-2012 |
20120306571 | VOLTAGE OUTPUT DEVICE HAVING AN OPERATIONAL AMPLIFIER - A voltage output device capable of preventing an increase in circuit scale includes an offset compensation function and is suitably applicable to a drive circuit for display devices. The voltage output device includes an operational amplifier having an inverting input terminal and a non-inverting input terminal. Resistance values of a load resistor on the inverting input side and a load resistor on the non-inverting input side are maintained when the output voltage of the amplifier has changed while sequentially varying either one or both of the resistance values of the load resistor on the inverting input side and the load resistor on the non-inverting input side in a state that the inverting input terminal and the non-inverting input terminal are connected. The voltage output device is configured to output the output voltage of the amplifier with the inverting input terminal not connected to the non-inverting input terminal. | 12-06-2012 |
20130069717 | Display Device and Method of Canceling Offset Thereof - A method of canceling an offset of display device includes coinciding offset directions of amplifiers with one another and canceling offsets of the amplifiers through a chopping operation. | 03-21-2013 |
20130113553 | Chopper - A chopper comprises a differential difference amplifier, a first switch, and a second switch. The differential difference amplifier comprises a first input stage and a second input stage. The first input stage comprises a non-inverting input terminal and an inverting input terminal. The second input stage comprises a non-inverting input terminal and an inverting input terminal. The first switch is operable to receive a first input voltage and a second input voltage and selectively transfer the first input voltage to one of the non-inverting input terminal of the first input stage and the non-inverting input terminal of the second input stage. The second switch is operable to receive a third input voltage and a fourth input voltage and selectively transfer the third input voltage to one of the inverting input terminal of the first input stage and the inverting input terminal of the second input stage. | 05-09-2013 |
20130127526 | LOW NOISE AUTO-ZERO CIRCUITS FOR AMPLIFIERS - An amplifier may include a low noise auto-zero circuit with auto-zero capacitors and switch-controlled auxiliary capacitors that function as switched-capacitor low-pass filters. In an acquisition phase of the auto-zero operation, the inputs of an amplifier may be shorted to a common voltage, and a representation of the offset voltage may be acquired by the auto-zero capacitors. In a hold phase of the auto-zero operation, the auto-zero capacitors may be connected to the auxiliary capacitors, and the resulting voltages may be applied to the circuit such that the original offset voltage is cancelled. Moreover, the switched-capacitor filters may reduce the effective sampling noise while maintaining high acquisition bandwidth. | 05-23-2013 |
20140009222 | CHOPPER CIRCUITRY OPERABLE IN A HIGH TEMPERATURE ENVIRONMENT OF A TURBINE ENGINE - Chopper circuitry may be adapted to operate in a high-temperature environment of a turbine. A first semiconductor switch ( | 01-09-2014 |
20140077873 | CHOPPED CIRCUIT WITH AC AND DC RIPPLE ERROR FEEDBACK LOOPS - The present disclosure relate to a sensor system having a low offset error. In some embodiments, the sensor system comprises a sensor configured to generate a sensor signal, which is provided to a main signal path having a first chopping correction circuit and a second chopping correction circuit. The first and second chopping correction circuit chop the sensor signal at first and second frequencies to reduce offset errors, but in doing so generate first and second chopping ripple errors. A first digital offset feedback loop generates a first compensation signal, which is fed back into the main signal path to mitigate the first chopping ripple error. A second digital offset feedback loop generates a second compensation signal, which is fed back into the main signal path to mitigate the second chopping ripple error. | 03-20-2014 |
20140139285 | Chopper Amplifier - Various apparatuses and methods are described where a signal is amplified using a chopper amplifier arrangement, and ripples caused by said chopper amplifier arrangement are reduced. In some cases, this reduction of ripples is performed by controlling a voltage offset of an amplifier of said chopper amplifier arrangement. In other embodiments, a detection of ripples or a chopping of the chopper amplifier arrangement is at least temporarily disabled. | 05-22-2014 |
20140210547 | OPERATIONAL AMPLIFIER CIRCUIT - Provided is an operational amplifier circuit having a high tolerance for clock phase difference fluctuations. An FIR filter is used to add an input signal of the FIR filter to a signal obtained by delaying the input signal of the FIR filter. In this manner, chopper noise can be removed. Thus, the operational amplifier circuit may have a high tolerance for clock phase difference fluctuations regardless of the phase difference between clocks for controlling a chopper circuit and the FIR filter. | 07-31-2014 |
20140232456 | Fast-Settling Capacitive-Coupled Amplifiers - Fast-settling capacitive-coupled amplifiers are disclosed. The amplifiers use two Capacitive Coupled paths embedded in a Multipath Hybrid Nested Miller Compensation topology. One path is a direct high frequency path and the other path is a slower stabilization path. This combination results in a flat frequency response to and through the chopper frequency, and a fast settling response. Various exemplary embodiments are disclosed, including operational amplifier and instrumentation amplifier configurations. | 08-21-2014 |
20140312967 | CHOPPER AMPLIFIER - A chopper amplifier includes a chopper modulator to modulate a certain detection signal and a bias voltage by a certain control signal and output a chopper modulation signal, a first differential amplifier to differentially amplify the chopper modulation signal from the chopper modulator and output a differential modulation signal, a chopper demodulator to demodulate the differential modulation signal from the first differential amplifier by the control signal and output a demodulation signal, a second differential amplifier to extract a detection signal component from the demodulation signal, and a plurality of filters connected at an input terminal of the second differential amplifier and having different cutoff frequencies from each other relative to the demodulation signal. | 10-23-2014 |
20140340145 | SIGNAL PROCESSING CIRCUIT, RESOLVER DIGITAL CONVERTER, AND MULTIPATH NESTED MIRROR AMPLIFIER - A signal processing circuit includes a chopper amplifier that has a differential amplifier circuit that amplifies differential input signals Vsp(t) and Vsm(t), and an adder circuit that generates an addition signal Vfil(t) by addition of the chopper output signal Vsub(t) that the chopper amplifier generates. Differential signals inputted into the differential amplifier circuit are interchanged for every first phase period and second phase period, and the adder circuit generates the addition signal by addition of the chopper output signal in the first phase period and in the second phase period. | 11-20-2014 |
20140368267 | CHOPPED CIRCUIT WITH AC AND DC RIPPLE ERROR FEEDBACK LOOPS - The present disclosure relate to a sensor system having a low offset error. In some embodiments, the sensor system comprises a sensor configured to generate a sensor signal, which is provided to a main signal path having a first chopping correction circuit and a second chopping correction circuit. The first and second chopping correction circuit chop the sensor signal at first and second frequencies to reduce offset errors, but in doing so generate first and second chopping ripple errors. A first digital offset feedback loop generates a first compensation signal, which is fed back into the main signal path to mitigate the first chopping ripple error. A second digital offset feedback loop generates a second compensation signal, which is fed back into the main signal path to mitigate the second chopping ripple error. | 12-18-2014 |
20150054576 | APPARATUS AND METHODS FOR CHOPPER AMPLIFIERS - Apparatus and methods for chopper amplifiers are provided herein. In certain configurations, a chopper amplifier includes at least one differential transistor bank including a selection circuit and a plurality of transistors. The selection circuit can select a first portion of the transistors for operation in a first transistor group and a second portion of the transistors for operation in a second transistor group. During calibration, the chopper amplifier's input offset can be observed for different transistor configurations of the differential transistor banks. Although the transistors of a particular bank can be designed to have about the same drive-strength and/or geometry, the chopper amplifier can have a different input offset in different transistor configurations due to manufacturing mismatch between transistors, such as process variation. The chopper amplifier can be programmed to operate with the selected transistor configurations of the differential transistor banks to provide the amplifier with low input offset. | 02-26-2015 |
20150130536 | MIXER - A mixer comprising a ladder having at least two resistances arranged in series and an input configured to receive an input signal and apply it across the ladder, said ladder including an output arrangement comprising at least three branches, a first branch branching from a first end of the ladder, a second branch branching from between the at least two resistances and a third branch branching from a second end of the ladder, opposite the first end, each branch including a switch for controlling a connection between its branch and an output. | 05-14-2015 |
20150137884 | AMPLIFIER CIRCUIT - An amplifier circuit is disclosed comprising: an input terminal configured to receive a radio frequency input signal; an output terminal configured to provide a radio frequency output signal; a first transistor having a first collector, a first emitter, and a first base; a second transistor having a second collector, a second emitter, and a second base; a bypass switch; and a controller. The first base is connected to the input terminal and the second emitter. The first collector is connected to a circuit voltage supply and the output terminal The first emitter is connected to ground and to the second base. The second collector is connected to a collector voltage supply. The bypass switch is connected between the first base and the output terminal. The controller is configured to operate the amplifier circuit in a normal mode of operation or a bypass mode of operation in accordance with an amplitude level of the radio frequency input signal, wherein the controller is configured to open the bypass switch in the normal mode of operation and close the bypass switch in the bypass mode of operation to selectively bypass the first transistor. | 05-21-2015 |
20150311868 | Digitally-Programmable Gain Amplifier with Direct-Charge Transfer and Offset Cancellation - A Programmable-Gain Amplifier (PGA) has a digital value that programmably adjusts the gain of the analog amplifier. A variable capacitor has several switched sub-capacitors that are enabled by the digital value. Enabled sub-capacitors are switched between a sampled input and a virtual ground on one terminal, and connect to a summing node on the other terminal. The summing node connects to the inverting input of an op amp either through a switch or through a double-sampling capacitor that stores an offset. A feedback capacitor is in parallel with a sampling capacitor during a second clock phase when direct-charge transfer occurs, reducing power consumption of the amplifier. The feedback capacitor samples the sampled input during the first clock phase. The PGA gain is proportional to the sum of capacitances of enabled sub-capacitors. The gain can be adjusted for sensor inputs to an Analog Front-End (AFE), such as for an electro-cardiogram (ECG). | 10-29-2015 |
20150326193 | AMPLIFIER INPUT STAGE AND AMPLIFIER - An amplifier input stage comprising first and second p-type transistors, wherein sources of the first and second p-type transistors are connected to a first node, a drain of the first p-type transistor is connected to a first output of the amplifier input stage, a drain of the second p-type transistor is connected to a second output of the amplifier input stage, a gate of the first p-type transistor is configured to receive a first signal of an input stage differential input signal and a gate of the second p-type transistor is configured to receive a second signal of the input stage differential input signal; first and second n-type transistors, wherein sources of the first and second n-type transistors are connected to a second node, a drain of the first n-type transistor is connected to a third output of the amplifier input stage, a drain of the second n-type transistor is connected to a fourth output of the amplifier input stage, a gate of the first n-type transistor is configured to receive the first signal of the input stage differential input signal and a gate of the second n-type transistor is configured to receive the second signal of the input stage differential input signal; a first circuit arranged to provide a first portion of a first bias current to the first node; and a second circuit arranged to draw a second portion of the first bias current from the second node; wherein the first and second portions are determined by a first signal of an amplifier input signal. | 11-12-2015 |
20150357979 | OPERATIONAL AMPLIFIER - There is provided an operational amplifier which is operable as well when an operating voltage decreases without creating a range where a circuit would not operate or reducing circuit gain. High-pass filters | 12-10-2015 |
20150357980 | SIGNAL PROCESSING CIRCUIT, RESOLVER DIGITAL CONVERTER, AND MULTIPATH NESTED MIRROR AMPLIFIER - A signal processing circuit includes a chopper amplifier that has a differential amplifier circuit that amplifies differential input signals Vsp(t) and Vsm(t), and an adder circuit that generates an addition signal Vfil(t) by addition of the chopper output signal Vsub(t) that the chopper amplifier generates. Differential signals inputted into the differential amplifier circuit are interchanged for every first phase period and second phase period, and the adder circuit generates the addition signal by addition of the chopper output signal in the first phase period and in the second phase period. | 12-10-2015 |
20160006404 | Method and Device for Controlling a Power Amplifier Capable of Utilizing Nonlinearity Correction and a Power Amplifier System - There is disclosed a method for controlling a power amplifier capable of utilizing nonlinearity correction in a nearly steady operation status of non-linearity correction, in a periodical fast switching system in time domain. The method may comprise receiving a periodic switch signal indicating switch time of the periodical fast switching system; and providing, based on the periodic switch signal, a pre-bias signal with a pre-determined voltage amplitude to the power amplifier for a pre-determined time period before each downlink time slot to preheat a transistor of the power amplifier so as to compensate a temperature change of a die inside the transistor. | 01-07-2016 |
20160079941 | INSTRUMENTATION AMPLIFIER - An instrumentation amplifier includes: a capacitive feedback closed-loop amplifier, an input capacitor charging module, a feedback capacitor discharging module, a noise separation module and a logic controller. The capacitive feedback closed-loop amplifier includes a fully differential operational amplifier, a first input capacitor, a second input capacitor, a first feedback capacitor and a second feedback capacitor. The input capacitor charging module is configured to charge the first input capacitor and the second input capacitor periodically. The feedback capacitor discharging module is configured to discharge the first feedback capacitor and the second feedback capacitor periodically. The noise separation module is configured to separate a noise from a signal using a chopping modulation technology. The logic controller is connected to the input capacitor charging module, the feedback capacitor discharging module and the noise separation module to control the modules to operate. | 03-17-2016 |
20160173041 | HOT-SWAP CURRENT-SENSING SYSTEM | 06-16-2016 |
20160190998 | AMPLIFIER CIRCUIT - A differential signal is input to a pair of gates of a differential pair, a differential signal generated by a load circuit connected to drains of the differential pair is amplified by a differential amplifier stage, and the amplified differential signal is fed back to a pair of sources of the differential pair via a feedback circuit. It is possible to maintain a high input impedance in the pair of gates of the differential pair while not being influenced by a gain of negative feedback of an amplifier circuit, and it is possible to perform amplification in an input stage by using a pair of a first transistor and a second transistor of the differential pair. Therefore, compared with the related art, it is possible to decrease the number of transistors in the input stage and to reduce a flicker noise. | 06-30-2016 |