Schematic Capture and PCB Layout

Key Takeaways

• Schematic capture is the process of creating circuits using simple schematic symbols.

• A basic ECAD schematic diagram is intended to represent the functionality and connectivity of each electronic part or component present in the circuit. 

• The purpose of schematic capture in PCB layout is to leverage the information embedded in the schematic drawing to complete the PCB layout design.

Schematic capture and PCB layout

In electronics circuit design, the process of transferring a paper-drawn circuit diagram into an electronic form that can be recognized by PCB layout design software is called schematic capture. From the schematic capture, the PCB layout design can be developed. Schematic capture doesn’t have to be involved in PCB layout design; however, it is best practice to ensure nothing is missed when the layout is created.

In this article, we will explore schematic capture and PCB layout. Let’s start with a few key definitions.

Schematics

Generally, schematics are developed by design engineers to communicate the circuit assembly, its parts, functionality, connectivity, etc., to the next stage of manufacturing. Usually, schematics act as the foundation for PCB layout design. For a design engineer, drawing a schematic diagram is a way to break down complex circuits into easily readable and understandable forms.

Schematic Capture

Schematic capture is the process of creating circuits using simple schematic symbols. These schematic symbols contain basic nodal contacts. The schematic symbols depict the part configurations of the components used in the circuit.

Schematic Symbols and Connectors

Most schematics are based on simple symbols that represent components or parts. The circuit connection is usually made using lines in schematic diagrams. The IEEE and ASME associations define how to reference and annotate circuits to avoid confusion among users who are trying to decipher schematic diagrams.

Common Schematic Symbols

How to Capture Schematics

Most electronic stakeholders depend on ECAD software for capturing schematics. The software used for capturing schematics generally has minimum input requirements. The capture software is developed in such a way that any layman can create the schematics.

Basically, capture software allows the user to place individual circuit components into electronic drawing sheets. While working on the drawing sheets, you can access the various schematic symbols available in the software to complete the drawing. Line connectors are used for establishing electrical connectivity. Reference designators can be used to identify each component in the circuit.

Setting Up Your Schematic

The following steps are often involved in developing a schematic.

Modern ECAD Software and Schematic Capture

The basic ECAD schematic diagram is intended to represent the functionality and connectivity of each electronic part or component present in the circuit. However, modern ECAD software is more than embedding the connectivity and pin information to the symbols. It is possible to add extra details such as package type, manufacturer part number, etc. There is cloud-based capture software that shows the availability of the part numbers present in the schematic with the distributor. Certain ECAD software allows the user to run simulations on the model to ensure the proper operation and signal integrity.

Schematic Capture and PCB Layout

Schematic capture and PCB layout rely on each other; schematic capture is the foundation on which the PCB layout is built. Schematic capture helps the electronic design engineer organize the electrical sections of the PCB board hierarchically. The purpose of schematic capture in PCB layout is to leverage the information embedded in the schematic drawing to complete the PCB layout design. Data is embedded into the schematic capture and can be imported into the layout design platform. The data imported can be utilized to create the physical aspects of the PCB design.

Cadence’s OrCAD software allows the designer to incorporate every attribute into the schematic diagram to ensure the PCB layout design is accurate. Leading electronics providers rely on Cadence products to optimize power, space, and energy needs for a wide variety of market applications. If you’re looking to learn more about our innovative solutions, talk to our team of experts or subscribe to our YouTube channel.