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Schematic Capture
Schematic Components and Libraries
Efficient use and management of schematic libraries requires an understanding of the
relationship between libraries, components, and parts. Libraries are databases which
store component descriptions. Each component then consists of one or more parts, such
as a 74LS00 which contains four parts, a capacitor which has one part, or a relay which
may be made up of a coil part and a contact part.
Components are created and modified in the Schematic Library Editor, an independent
document editor that includes tools for managing and editing libraries. The Schematic
Sheet Editor and the Schematic Library Editor can have documents open
simultaneously within the Design Explorer environment, with special features to link
between sheet and library operations. For example, you can move directly from a part
symbol on the sheet, to editing its component information inside the source library.
What is a Schematic Library?
Protel 99 SE is delivered with extensive component libraries that include the industry
standard symbolic representation, as well as ANSI-IEEE and DeMorgan equivalents.
The schematic libraries consist of component descriptions, made up of the individual
parts that are placed in the schematic sheet. Components can have one or many parts
(e.g., the gates that comprise a multi-part component like a 74LS00).
The Schematic Library Editor allows you to manage library data, create new
components, and move and copy components between libraries. Refer to the Schematic
Library Editor chapter for information on the general features and use of this editor.
♦ The Altium Library Development Center is constantly developing new
libraries – check www.protel.com to download the latest libraries for all your Protel
tools.
What is a Component and what is a Part?
The best way to think of a component is to equate it to the physical device that is
placed on the actual printed circuit board; the resistor, the integrated circuit, or the
connector for example. Many electronic components also comprise of separate parts
within the one component. Examples of these would be; a 74LS00 which contains four
parts, or a dual op amp which contains 2 op amps.
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