Editing Schematic capture

{{Short description|Stage of electronic circuit design}}
{{Use American English|date = April 2019}}
{{one source|date=October 2014}}
'''Schematic capture''' or '''schematic entry''' is a step in the [[Decision cycle|design cycle]] of [[electronic design automation]] (EDA) at which the electronic diagram, or [[Circuit diagram|electronic schematic]] of the designed [[electronic circuit]], is created by a designer. This is done [[Human-computer interaction|interactively]] with the help of a schematic capture tool also known as [[schematic editor]].<ref>{{cite journal |last1=A.D. |first1=Hugo |title=A framework for human-computer interaction in directed graph drawing |journal=Association for Computing Machinery |date=December 2001 |volume=9 |pages=63–69 |url=https://dl.acm.org/doi/10.5555/564040.564048 |access-date=December 12, 2022}}</ref>

The [[circuit design]] is the first step of actual design of an electronic circuit. Typically sketches are drawn on paper, and then entered into a computer using a schematic editor. Therefore schematic entry is said to be a [[front and back ends|front-end]] operation of several others in the [[Design flow (EDA)|design flow]].<ref>{{cite web |title=Schematic Capture |url=https://www.ece.ufl.edu/wp-content/uploads/AltiumDocs/Module4_SchematicCapture.pdf |website=University of Florida |access-date=December 12, 2022}}</ref>

Despite the complexity of modern components – huge [[ball grid array]]s and tiny passive components – schematic capture is easier today than it has been for many years.<ref>{{cite web |title=Taking a Closer Look at Schematic Capture and PCB Layout |url=https://resources.pcb.cadence.com/blog/2019-taking-a-closer-look-at-schematic-capture-and-pcb-layout |website=Cadence |date=10 June 2019 |access-date=December 12, 2022}}</ref> [[Computer-aided design|CAD software]] is easier to use and is available in full-featured expensive packages, very capable mid-range packages that sometimes have free versions and completely free versions that are either [[Open-source software|open source]] or directly linked to a [[printed circuit board]] fabrication company.

In past years, schematic diagrams with mostly [[Discrete device|discrete components]] were fairly readable. However, with the newer high pin-count parts and with the almost universal use of standard letter- or A4-sized paper, schematics have become less so. Many times, there will be a single large part on a page with nothing but pin reference keys to connect it to other pages.

[[Readability]] levels can be enhanced by using buses and superbuses, related pins can be connected into a common bus and routed to other pages. Buses don't need to be just the traditional address or data bus directly linked pins. A bus grouping can also be used for related uses, such as all analog input or all communications related pin functions.

==Other considerations==
After the [[circuit design]] is captured in a schematic, most EDA tools allow the design to be simulated.

Schematic capture involves not only entering the circuits into the CAD system, but also generally calls for decisions that may seem more appropriate for later in the design, such as [[Chip carrier|package choice]]. Although you may be able to change the package later, many PCB CAD systems ask you to choose both the part and package when placing it into the schematic capture program.

This also brings into play such considerations as prototyping and assembly. In a high-volume assembly environment, there will be plenty of opportunities for [[Design for manufacturability|DFM]] analysis. However, in a [[rapid prototyping]] environment such as at assembly houses specializing in low-volume/high-mix and quick turnaround times, the [[Surface mount|pick and place]] machines are programmed directly from the board layout files. Careful package selection during schematic capture will save time during the assembly and [[debug]] process.

With new parts, the CAD system may not have your chosen component in its parts library, so you may need to create the parts library yourself. Again, you may at the time not be overly concerned with the package, but careful creation of the part library will save time and risk later.

== See also ==
{{wikibooks|Robotics: Design Basics: Design software}}
{{Wikibooks|Practical Electronics|PCB Layout}}
* [[Comparison of EDA software]]

== Further reading ==
* {{Cite journal |author-first1=Gary |author-last1=Pratt |author-first2=Jay |author-last2=Jarrett |title=Top-Down Design Methods Bring Back The Useful Schematic Diagram |date=2001-08-06 |journal=[[Electronic Design (magazine)|Electronic Design]] |page=69 |volume=49 |issue=16 |id=ED Online ID #3784 |url=http://electronicdesign.com/boards/top-down-design-methods-bring-back-useful-schematic-diagram |issn=0013-4872}}

==References==
{{reflist}}

[[Category:Electronic design automation]]