What is Schematic Capture?


Orcad Schematic CaptureSo what is schematic capture you ask? Simply defined the process by which a circuit design is captured electronically is considered schematic capture. The main purpose of a schematic, related to pcb design, is the creation of a netlist. This netlist is a text file which tells the pcb layout software how all the components are connected and is the back bone of the printed circuit board design process.

Schematic capture software is everywhere and the process is easier than ever. Schematic capture software is available in full-featured expensive packages (industry standard OrCAD Capture), to very capable mid-range package (Protel), to open source software. The new craze, offered by the larger pcb fab houses, is to offer full featured software packages that allow you to complete you schematic capture and pcb layout. The reason they are willing to give away their software is so you’ll purchase your next pcb from them.

Another big advantage to capturing a schematic is the option to simulate the circuit design. Popular tools, such as OrCAD Pspice will give you piece of mind that the copper you etch will work the first time around. Just remember there is no substitute for good circuit design. You should never design a circuit using PSpice it should be for simulation purposes only. This is a topic an entirely different website, however it is worth a brief mention in this article.

So now that you have a good idea what schematic capture is and why its needed, let’s talk about what a good schematic capture design looks like.