What Makes Part Selection Difficult?


There are several competing factors that guide part choice.  In this chapter, you will learn some of the things engineers look for when choosing a part for a design.

1. How to Choose a Part

1.1. Part Availability

Digikey is a major distributor of electronic parts.  They currently stock close to 10 million different types of parts, sometimes with millions of individual parts of each type.  Their total inventory is likely measured in billions or trillions of items.  At the same time, they sell to tens or hundreds of thousands of customers.  If we aren't careful when we are selecting our parts, there's a good chance that someone will buy up something we are looking for while we finish our design.  That can delay a project for weeks or months, or result in a costly project redesign.

Fortunately, there are other distributors out there, and for large projects, engineers can contract directly with the manufacturers to obtain their parts.

Services such as Octopart collate this information and provide up-to-date, and sometimes even up-to-the-minute stock and pricing information

Octopart ExampleThis screen capture from 2/24/2020 shows the part availability and price breaks for a Green LED