专业英语演讲稿.docVIP

INTRODUCTION The operational [??p??rei??n?l] amplifier [??mpl??fa??] is an extremely efficient and versatile [?v?:s?tail] 通用device. Its applications span the broad electronic industry filling requirements for signal conditioning, special transfer functions, analog [??n??l?:g] 模拟instrumentation, analog computation, and special systems design. The analog assets [??set ] of simplicity [sim?plisiti] and precision characterize circuits [?s?:kit]utilizing [?ju:tilaiz] operational amplifiers. 运算放大器是一个非常有效和通用设备。它的应用范围广泛的电子工业，信号调理，专项转移功能，模拟仪表，模拟计算，及特殊系统设计的灌装要求。简单性和精确度是使用运算放大器的模拟电路特点 The Feedback Technique The precision and flexibility of the operational amplifier is a direct result of the use of negative feedback. Generally speaking, amplifiers employing feedback will have superior operating characteristics at a sacrifice [?s?krifais]of gain. 在运算放大器的精度和灵活性是利用负反馈的直接结果。一般来说，采用反馈的放大器有卓越的经营特点，在牺牲增益的代价下。 With enough feedback, the closed loop amplifier characteristics become a function of the feedback elements. In the typical feedback circuit, figure 1, the feedback elements are two resistors. The precision of the “closed loop” gain is set by the ratio [?rei?i?u] 比率of the two resistors and is practically independent of the “open loop” amplifier. Thus, amplification to almost any degree of precision can be achieved with ease. 有了足够的反馈，闭环放大器的特点成为一个功能的反馈元件。在典型的反馈电路中，图1中，反馈元件是两个电阻器。的精度的“闭环”的增益设置的两个电阻的比率实际上是独立的“开环”放大器。因此，放大到几乎任何的精确度，可以容易地实现。 Notation符号 ?= Symbol (a) is a buffer [?b?f?] 缓冲器 op工作 amp放大器 ?= Symbol (b) is a differential input, single ended output op amp. This symbol represents the most common types of op amps, including voltage feedback, and current feedback. It is often times pictured with the non-inverting input at the top and the inverting input at the bottom. ?= Symbol (c) is a differential input, differential output op amp. The outputs can be thought of as “inverting” [in?v?:t] 反转and “non-inverting”, and are shown across from the opposite [??p?zit]相反 polarity [p??