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Power Plane and Ground Plane in PCB Design: Best Practices

Key Takeaways

  • Ensure mechanical stability and minimize warpage by using a balanced layer stack-up.

  • Improve connectivity and reduce EMI by using multiple vias and implementing via stitching.

  • Utilize OrCAD X tools such as the Cross Section Editor and Shape Creation Tools for efficient power and ground plane management.

Power and ground planes will automatically adjust when routing in OrCAD X

Power and ground planes will automatically adjust when routing in OrCAD X

All printed circuit boards need a steady supply of voltage to function. In this post, we’ll discuss power and ground planes in PCBs, including best practices for incorporating them into your PCB designs and how OrCAD X can aid in designing them. 

How Do You Know When to Use a Power Plane or a Ground Plane in a PCB?

Four or more layers = Power plane

Two-layer board = Ground plan

You will generally only see power planes in boards with four or more layers. This is because the best practice for multi-layer stackups is to use an even number of layers. Odd layer stackups don’t save costs, and the resulting asymmetry can lead to warping, twisting, and other structural defects.

The popular two-layer board will generally benefit more from a ground plane than a power plane, relying on tracks to deliver power from a power source.

Best Practices for Power Planes and Ground Planes in PCBs 

Best Practice


Layer Stack-Up

  • Use a balanced layer stack-up to ensure mechanical stability and minimize warpage. 

  • Power and ground planes should be adjacent to each other to reduce EMI.

  • For boards with four or more layers, use power planes because even layer stackups are best practice.

Ground Planes for Two-Layer Boards

  • For two-layer boards, use a ground plane instead of a power plane, relying on tracks to deliver power from a power source.

Power Plane Size

  • Extend power planes to cover the entire PCB to provide a low impedance path and reduce voltage drops.

Via Placement and Stitching

  • Use multiple vias to connect power planes to pads and traces. This reduces the inductance and ensures a robust connection.

  • Implement via stitching along the edges of power planes to improve shielding and reduce EMI.

Decoupling Capacitors

  • Place decoupling capacitors close to power pins of ICs. 

  • Use a mix of capacitor values to filter different frequencies effectively.

Noise Isolation

  • Separate analog and digital power planes to minimize noise coupling.

  • Use ferrite beads or inductors where necessary.

Star Point Grounding

  • Use a star point for grounding to avoid ground loops and ensure a single point of reference for ground potential.

Domain Splitting

  • Split power planes into multiple domains to accommodate components with different voltage requirements. 

  • Follow EMI/EMC best practices to mitigate noise and crosstalk.

  • Consider using separate power rails for each circuit instead of a common power plane for high efficiency and minimal EMI/EMC issues.

Optimal Layout Tools

  • Use layout tools like OrCAD X to support cross-team collaboration, analysis, and simulation of designs to ensure proper power plane management. 

Power Plane Domain Splitting

Having a single well of power for all the components on a signal layer to draw from makes a lot of sense if they all have the same voltage requirements. Increasingly, however, more complex high-density PCB designs have made the practice of splitting a power plane into multiple domains more popular.

If your MCU requires one voltage while your I/O ports need another, you may need to split the reference plane to accommodate both voltages. This saves space but does put you at risk of higher noise, crosstalk, and other EMI/EMC problems. It’s important to follow EMI/EMC best practices such as separating your analog, digital, and high-power circuits.

That said, the most efficient routing would be to accurately account for all EMI/EMC considerations and have separate power rails for each circuit on your board, forgoing the power plane altogether in favor of efficient routing. In such situations, you will usually still have a ground plane to allow for shorter return paths and noise absorption.

Power Plane and Ground Plane Creation With OrCAD X 

Best Practice

OrCAD X Feature

Layer Stack-Up

Cross Section Editor: Manage and visualize layer stack-ups to ensure even layers and stability. Allows designers to create and manage different stack-ups within a design, ensuring layers are correctly aligned and balanced. Useful for defining dielectric and conductive layers for mechanical and electrical performance.

Ground and Power Shapes

Shape Creation Tools: Create and manage ground planes easily using various shape tools in OrCAD X. Simplifies the creation of power and ground planes using tools like rectangular and polygonal shape creators. Enables precise placement and adjustment of these planes.

Shape Management: Automatically adjust and manage shapes as needed. Dynamically adjusts shapes as components and traces are added or modified, maintaining design integrity without the need for manual repouring. Useful for creating larger power planes and ensuring proper connectivity and thermal management.

Via Placement and Stitching

Via Arrays: Create and place via arrays in various patterns to enhance connectivity and reduce EMI. Facilitates the creation of via arrays in different configurations, such as staggered or centered, to improve electrical performance and EMI shielding. Provides robust connections between layers and components.

Component Placement

Constraint-Driven Placement: Uses constraint management to define rules for components such as decoupling capacitors, ensuring they are positioned close to power pins to filter noise effectively. 

Collaboration and Teamwork

OrCAD X supports real-time collaboration, allowing multiple team members to work on the same project simultaneously. 

Features like version control, shared workspaces, and centralized libraries ensure all team members are on the same page, reducing errors and improving project management. It also includes tools for commenting and reviewing.

Whether you’re working through aircraft voltage regulators and needing a highly specific and sensitive power plane design in place, or working through more grounded high-power designs, using power plane and ground plane in PCBs will make your boards more reliable. Furthermore, having layout software that can have cross-team collaboration as well as encourage easier analysis and simulation of your designs will ensure proper power plane management. 

OrCAD X offers advanced features like the Cross Section Editor, Shape Creation Tools, and real-time collaboration capabilities to enhance your workflow. Ready to elevate your PCB design game? Explore our PCB Design and Analysis Software and discover the power of OrCAD X today!

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