电流放大器

PIC results show that the occurrence of absolute instability is determined by the operating current.

通过PIC模拟，给出了采用无损耗波导结构，且工作电流为25A和10A条件下的放大器频谱图和功率图，结果表明绝对不稳定性的出现与否主要由工作电流是否超过起振的阈值电流决定，损耗波导是抑制绝对不稳定性的有效手段。

The circuit topology is a voltage feedback amplifier with the slewing characteristics of a current feedback amplifier.

该电路拓扑结构是一个具有电流反馈放大器的电压反馈放大器的回转特性。

The purpose of the enhanced fully differential foldedcascode op-amp topology presented in the paper is to modify the standard topology, shown in Fig. 1, so that the choice of bias current for M5 , M6 , M9, M10, M13, and M14 does not affect the slew rate of the op amp.

本文介绍的性能改进的全差分折叠共源共栅运算放大器拓扑结构的目的是修改图1所示的标准拓扑结构，使得M5、M6、M9、M10、M13和M14偏置电流的选择不影响运算放大器的摆率。

According to the demand of high magnetic field power supply, reference is increased with a set ramp rate and stops at a set stable value, so reference system is composed of digital setting and digit to analog converting circuit. But the stability of reference is mostly guaranteed by the performance of D/A circuit, so D/A circuit is particularly studied in reference system. The scheme of D/A circuit, the selection of DAC and its voltage reference, hardware anti-jamming design and PCB design are discussed in detail, and software of remote control and PLC are discussed in brief. Zero-flux DC current transformer well satisfies the demands of the high stability of Load current detection unit, so the principle of zero-flux DC current transformer is analyzed; in the mean time a project which detects the long term stability is designed. During 8 hours, analog signal which is detected with high precision digit multimeter is recorded in computer at 1HZ frequency by GPIB communication. The drift error source and related parameters are explained in the compare-amplify part. Detailed subtraction circuit is designed; also amplifier chip and periphery components are selected and verified according to the theory of error analysis.

根据强磁场电源的需求，参考源应按照软件设定的斜率逐渐上升到设定稳态值，则参考源系统应由数字给定和数模转换电路两大部分组成，而参考源的稳定度主要依靠完成数模转换功能的模拟电路的性能来保证，因此本文对参考源系统的研究以数模转换电路为重点，分别从电路方案的确定、数模转换芯片及其基准电压源的选取和验证、电路板硬件抗干扰和PCB设计几方面进行了论述，然后对数字给定部分的远控组态和PLC程序设计作了简要介绍；采用零磁通原理的直流电流转换器很好地满足了对负载电流检测单元高稳定度的需求，本文详细分析了零磁通检测的原理，并在选定此种类型电流转换器的基础上设计了一套检测长期稳定度的方案，8小时内以1秒为采样周期，通过计算机Labview程序和高精度数字电压表的GPIB通讯，将被高精度数字电压表数字化后的模拟信号采样值连续记录至计算机中；比较放大环节简要阐述了漂移产生的原因和相关参数指标，确定了具体的减法电路形式，并根据误差分析理论对运算放大器和外围元器件进行了选取和验证。

The noise performance of the electrometer is analyzed in detail and conclude that the input current noise is main factor on noise of the electrometer.

对静电计放大器的噪声性能做了细致的分析，确定了输入电流噪声为放大器噪声的决定因素。

These two pairs exhibit different offsets and bias currents, so when the applied input common-mode voltage changes, the AMPLIFIER input offset voltage and input bias current does also.

由于这两个差分对有不同的失调电流和偏置电流，因此加到输入共模电压变化，放大器的输入偏置电压和输入偏压电流也跟着改变。

It is shown from the accelerated lifetime test and noise measurement for integrated operational amplifiers that if their failure is caused by the drift of input bias current or input offset current, the drift is strongly correlated with 1/f noise current in these devices, and both are proportional approximately.

摘要寿命试验和噪声测试结果表明，如果集成运算放大器的主要失效模式是输入偏置电流或失调电流随时间的漂移，则这种漂移量与运放的1/f噪声电流具有强相关性，二者近似呈正比关系。

The Electrochemical measurement system used to perform DPSV measurement is constructed with two parts, a low-current measurement system consists of low input bias current operational amplifier and a high resolution SAR ADC and a potentialstat consists of high resolution DAC and high current buffer amplifier.

对于差分脉冲伏安溶出测量，我们使用高精度连续逼近寄存器型ADC和低偏置电流运放构成微电流采样系统；使用高精度DAC和高速大电流缓冲放大器构成了恒电位计，在微控制器的控制下组成电化学测量系统。

Because the primary source of noise in an amplifying IC is its input stage, you can assume that the standard deviation of the random component of output current of the paralleled-N voltage-to-current converters is σNI=σI×, where σI is the standard deviation of the random component of output current of a voltage-to-current converter.

由于放大器噪声的主要来源为输入端，假设N个并联电压电流转换器输出电流的随机器件标准差为σNI=σI×，σI为电压电流转换器输出电流的随机器件标准差。

Operational Tran conductance lifers and Grounded actorhas become one of the most important methods to implement integrated continuous-time filters. Operational Tran conductance Amplifierscan transfer input voltage into current to output,and control or change output current within large range by an external controlling current of amplifier. Most articles consider OTA as a voltage-mode circuit component and give voltage-to-voltage transfer function of all having been implemented filter circuits,i.e. The input signal and output signal of filter circuits are voltages .

运算跨导集成运算放大器OTA ( Operational Tran conductance Amplifier 以下简称跨导运放)的功能是将输入电压转换为电流输出，并通过外加偏置电流控制运放的工作电流，从而使它的输出电流在较大范围内变化，而在大多数文献中，器件都被作为电压模式元器件使用实现的各种滤波电路都是按传送电压比给出的，即滤波电路输入信号和输出信号均为电压信号。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。