運算放大器經(jīng)典使用

As a precursor to more detailed sections following， this introductory chapter portion considers the most basic points of op amp operation. These initial discussions are oriented around the more fundamental levels of op amp applications. They include： Ideal Op Amp Attributes， Standard Op Amp Feedback Hookups， The Non-Ideal Op Amp， Op Amp Common-Mode Dynamic Range（s）， the various Functionality Differences of Single and Dual-Supply Operation， and the Device Selection process. Before op amp applications can be developed， some requirements are in order. These include an understanding of how the fundamental op amp operating modes differ， and whether dual-supply or single-supply device functionality better suits the system under consideration. Given this， then device selection can begin and an application developed. First， an operational amplifi er （hereafter simply op amp） is a differential input， single-ended output amplifi - er， as shown symbolically in Figure 1-1. This device is an amplifi er intended for use with external feedback elements， where these elements determine the resultant function， or operation. This gives rise to the name “operational amplifi er，” denoting an amplifi er that， by virtue of different feedback hookups， can perform a variety of operations.1 At this point， note that there is no need for concern with any actual technology to implement the amplifi er. Attention is focused more on the behavioral nature of this building block device.