![]() ![]() The simplest method uses a current mirror: two identical transistors-manufactured on the same chip so that their process, geometry, and temperatures are all identical-are connected as shown in Figure 1. It is remarkably easy to obtain a steady current output. This article summarizes some of the techniques available and suggests a number of useful circuits. This is a pity, as current outputs offer advantages in a number of situations, including analog current-loop signaling (0 mA to 20 mA and 4 mA to 20 mA) in high-noise environments, and level shifting an analog signal across a large potential difference without the use of optical or magnetic isolation techniques. Current-Output Circuit Techniques Add Versatility to Your Analog ToolboxĪlthough current mirrors and circuits such as the Howland current source are taught in analog circuit courses, a surprising number of engineers tend to think exclusively in terms of voltage when defining the output of precision analog circuitry. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |