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公开(公告)号：US20230118397A1
公开(公告)日：2023-04-20
申请号：US17501210
申请日：2021-10-14
摘要： In examples of a chopper operational amplifier, a current control circuit comprises a pair of voltage sources, each of which may be varied to generate a voltage signal of a particular value, and multiple inverters, each of which is configured to receive either a clock signal or its complement signal and one of the voltage signals. Based on these inputs, each inverter generates a control signal that is delivered to a corresponding switch in the input stage of the chopper operational amplifier to control the gate voltage of that switch. Based on the difference between the values of the voltage signals, the current control circuit operates to reduce the amplitudes of base currents induced by charge injection at the input terminals of the chopper operational amplifier.
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2.发明授权公开(公告)号：US11296666B1
公开(公告)日：2022-04-05
申请号：US16796475
申请日：2020-02-20
发明人： Christian Larsen , John L. Melanson
摘要： A high CMRR current monitoring circuit includes a first stage that receives a current sense signal, a voltage across a current sense resistor in series with an output of a class-D amplifier. First stage is powered by at least one floating supply and/or reference that tracks the amplifier output. First stage applies gain to the current sense signal to generate an intermediate signal. A second stage receives the intermediate signal and is powered by a ground-referenced supply and provides an amplified representation of the current sense signal. The floating supply is supplied by a capacitive-coupled power source driven by the ground-referenced supply. The second stage output may be a voltage relative to ground or a digital signal. The intermediate signal may be a current, digital signal, or amplified version of the current sense signal voltage. The first stage may be a transconductance amplifier and the second stage a transimpedance amplifier.
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3.发明授权公开(公告)号：US10826449B2
公开(公告)日：2020-11-03
申请号：US16249138
申请日：2019-01-16
发明人： Po-Yin Chao , Hung-Wei Chen , Shui-Chu Lee
摘要： Disclosed is a high accurate measurement circuit, and the feature is using bias switching circuit for compensating front end offset, and the back end offset of amplifier is also cancelled. In the real measurement environment, offset exists in the amplifier of the measurement circuit has, and non-ideal effects also exist in the interface between measurement terminal and the measurement circuit, such as leakage current of chip package pins or mismatch of the circuit. The above non-ideal effects belong to front end offset and cannot be compensated by the prior arts. The disclosed structure uses the bias switch circuit and uses different switching method in the two measurement timings. By subtracting the measurement results for the two measurement timings, the front end offset is compensated, and the back end offset of the amplifier is also cancelled.
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公开(公告)号：US10797659B2
公开(公告)日：2020-10-06
申请号：US16159769
申请日：2018-10-15
摘要： According to an aspect, an audio amplifier includes a first sigma-delta modulator configured to receive a digital audio signal and generate a first multi-level output signal based on the audio signal, and a second sigma-delta modulator configured to receive the first multi-level output signal from the first sigma-delta modulator and generate a second multi-level output signal. The second multi-level output signal has a number of levels less than a number of levels of the first multi-level output signal.
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公开(公告)号：US10224879B1
公开(公告)日：2019-03-05
申请号：US15854135
申请日：2017-12-26
发明人： Chua-Chin Wang , Deng-Shian Wang , Hao-Chun Huang
摘要： A peak detector utilizes two choppers to cancel offset voltage of a transconductance amplifier, so the influence of the offset voltage is preventable and the peak detection accuracy of the peak detector can be improved significantly.
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公开(公告)号：US10044327B2
公开(公告)日：2018-08-07
申请号：US15600484
申请日：2017-05-19
发明人： Hanqing Wang , Gerard Mora-Puchalt
IPC分类号： H03F3/00 , H03F1/02 , H03F1/32 , H03F1/56 , H03F3/393 , H03F3/42 , H03F3/45 , H03F1/14 , H03F3/387 , H03M3/00
摘要： A capacitive gain amplifier circuit includes two sets of Miller capacitors and two output stage differential amplifier circuits. A first set of Miller capacitors is used to compensate the first output stage differential amplifier circuit during a first phase that resets the first output stage differential amplifier circuit. The second set of Miller capacitors is used to compensate the first output stage differential amplifier circuit during a second phase that chops a signal being amplified. The second set of Miller capacitors is swapped from one polarity to an opposite polarity of the first output stage differential amplifier circuit during successive second phases. The second output stage differential amplifier circuit includes a set of inputs selectively coupled with the inputs of the first output stage differential amplifier circuit and a set of outputs selectively coupled with the outputs of the first output stage differential amplifier circuit during the second phase.
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公开(公告)号：US09912309B1
公开(公告)日：2018-03-06
申请号：US15165809
申请日：2016-05-26
发明人： Reuven Ecker , Shimon Avitan
CPC分类号： H03F3/393 , H03F3/45183 , H03F3/45475 , H03F3/45753 , H03F3/45775 , H03F3/45977 , H03F3/72 , H03F2200/271 , H03F2200/384 , H03F2203/45212 , H03F2203/45352 , H03F2203/45371 , H03F2203/45396 , H03F2203/7236
摘要： Aspects of the disclosure provide an amplifier system and a method for dynamically cancelling an offset voltage. The amplifier system includes a chopper amplifier system that includes a differential amplifier with an offset calibration circuit. The chopper amplifier system is configured to generate an output signal including voltage variations indicating an offset voltage of the differential amplifier. The amplifier system also includes a feedback circuit configured to determine a polarity of the offset voltage of the differential amplifier based on the output signal, and to transmit a control signal to the offset calibration circuit to reduce the offset voltage of the differential amplifier.
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公开(公告)号：US09614481B2
公开(公告)日：2017-04-04
申请号：US14675087
申请日：2015-03-31
申请人： Analog Devices, Inc.
发明人： Evgueni Ivanov
CPC分类号： H03F1/26 , H03F1/0205 , H03F3/393 , H03F3/45183 , H03F3/45475 , H03F3/45753 , H03F3/45977 , H03F2200/249 , H03F2200/375 , H03F2200/78 , H03F2203/45212 , H03F2203/7212
摘要： Apparatus and methods for digitally-assisted feedback offset correction are provided herein. In certain configurations, an amplifier includes amplification circuitry for providing amplification to an input signal and chopping circuitry for compensating for an input offset voltage of the amplifier. Additionally, the amplifier further includes a digitally-assisted feedback offset correction circuit, which includes a chopping ripple detection circuit, a feedback-path chopping circuit, a digital correction control circuit, and an offset correction circuit. The chopping ripple detection circuit generates a detected ripple signal based on detecting an output ripple of the amplifier. Additionally, the feedback-path chopping circuit demodulates the detected ripple signal using the amplifier's chopping clock signal. The digital correction control circuit receives the demodulated ripple signal, which the digital correction control circuit uses to control a value of a digital offset control signal that controls an amount of input offset correction provided by the offset correction circuit.
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公开(公告)号：US20160173041A1
公开(公告)日：2016-06-16
申请号：US14965588
申请日：2015-12-10
发明人： SUDHEER PRASAD
CPC分类号： H03F3/393 , H03F1/086 , H03F3/45475 , H03F3/45977 , H03F2200/252 , H03F2200/267 , H03F2200/271 , H03F2200/297 , H03F2200/471 , H03F2203/45151 , H03F2203/45212 , H03F2203/45264 , H03F2203/45288
摘要： One example includes a hot-swap control system. The system includes a sense resistor network provides a sense voltage in response to an output current. The system also includes a sense control circuit includes a chopper amplifier system arranged in a servo feedback arrangement to generate a monitoring voltage having an amplitude that is associated with the output current based on the sense voltage. A notch filter chopping stage filters out signal ripple in the chopper amplifier system across a unity-gain bandwidth of the chopper amplifier system, and a capacitive compensation network provides stability-compensation of the chopper amplifier system across the unity-gain bandwidth. A transconductance amplifier configured to compare the monitoring voltage with a predetermined reference voltage to generate a control voltage. The system further includes a power transistor configured to conduct the output current to an output based on the control voltage.
摘要翻译： 一个例子包括热插拔控制系统。 该系统包括检测电阻器网络，以响应于输出电流提供感测电压。 该系统还包括感测控制电路，其包括布置在伺服反馈装置中的斩波放大器系统，以基于感测电压产生具有与输出电流相关联的幅度的监视电压。 陷波滤波器斩波级跨越斩波放大器系统的单位增益带宽滤除斩波放大器系统中的信号纹波，并且电容补偿网络提供斩波放大器系统跨单位增益带宽的稳定补偿。 一种跨导放大器，被配置为将监视电压与预定参考电压进行比较以产生控制电压。 该系统还包括功率晶体管，其配置为基于控制电压将输出电流传导到输出。
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公开(公告)号：US5343161A
公开(公告)日：1994-08-30
申请号：US60056
申请日：1993-05-13
申请人： Akio Tokumo , Masayuki Kato
发明人： Akio Tokumo , Masayuki Kato
CPC分类号： H03F3/217
摘要： A power amplifier apparatus having an operational amplifier which works as a PWM (pulse width modulation) amplifier as well as an analog amplifier according to an input signal level to miniaturize the size of the apparatus and to maintain amplifying function thereof at the changeover of the function, which allows gain and frequency characteristic of the operational amplifier to have continuity before and after the changeover. The power amplifier apparatus according to the present invention comprising: an operational amplifier having two input terminals, an input signal being inputted to one of the input terminals; a triangular waveform generator for outputting voltage with triangular waveform; an input signal level detecting circuit for applying the voltage with triangular waveform from the triangular waveform generator to the other input terminal of the operational amplifier; a broadband power amplifier for amplifying an output of the operational amplifier; and a low-pass filter connected to an output terminal of the broadband power amplifier.
摘要翻译： 一种功率放大器装置，具有作为PWM（脉冲宽度调制）放大器的运算放大器以及根据输入信号电平的模拟放大器，以使装置的尺寸小型化并且在功能切换时保持其放大功能 ，其允许运算放大器的增益和频率特性在切换之前和之后具有连续性。 根据本发明的功率放大器装置包括：运算放大器，具有两个输入端，输入信号被输入到一个输入端; 用三角波输出电压的三角波形发生器; 输入信号电平检测电路，用于将来自三角波形发生器的三角波形的电压施加到运算放大器的另一个输入端; 宽带功率放大器，用于放大运算放大器的输出; 以及连接到宽带功率放大器的输出端子的低通滤波器。
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