Up to now, the op amp has been treated as an ideal device. Although these idealizations are very useful in their place, closer examination must follow. Without this knowledge, it will be impossible to accurately predict a circuit's performance for very high or low frequencies, to judge its noise characteristics, or to determine its stability with temperature or power supply variations. With this information, you will be able to optimize circuit performance for given applications. A major part of this is determining the most desirable op amp for the job. The function of this chapter, then, is to delve deeper into the specifics of individual op amps and to present methods for determining system parameters such as frequency response, noise level, offsets, and drift. The primary interest is in investigating the popular inverting and noninverting voltage amplifier topologies.