INTRODUCTION

In Chapter 2 the basic PCB design flow was demonstrated, starting from schematic entry with Capture to board routing with PCB Editor, but no attention was given to board design issues, such as component placement and spacing rules, layer stack-up, or trace routing and spacing rules.

Design examples are used here to illustrate the various PCB design considerations described in Chapters 5 and 6 and how to use the PCB Editor tools to accomplish the design goals. The part count in each example is kept to a minimum (all designs have fewer than 10 parts and 14 pins/part) so as not to be cumbersome and not to distract the reader from understanding how to route and set up layers. In-depth discussion on PCB design for manufacturability is covered in Chapter 5 and signal integrity and routing are covered in Chapter 6.

The following examples use parts that may not be included with your version of OrCAD. You can make the parts yourself using the procedures discussed in the previous chapters, or you can copy the parts and footprints provided in the example libraries located on the Web site for the book.

The first example is a simple analog design using a single op amp. The design shows how to set up multiple plane layers for positive and negative power supplies and ground. The design also demonstrates several key concepts in Capture, such as how to connect global nets, how to assign footprints, how to perform design rule checks,...