Auto-Interactive Routing with an Accurate Trace Length Calculator
If you’re a mechanical or electrical designer, you need CAD tools with accurate trace length and geometry calculations. These calculations are important for more than just placing components throughout your circuit board. Once you start working with high speed or high frequency circuits, propagation delay and skew becomes a critical point to consider, as you need to make sure that your signals are properly timed throughout your signal nets. Altium Designer is the only PCB design package that includes ultra-accurate trace length calculation tools that interface directly with your other design features using a rules-driven design engine.
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The only unified PCB design package with automated routing and trace length calculation tools.
Traces in your Printed Circuit Board are like blood vessels that breathe life into your entire circuit board. Without traces, your signals would never make it to their destination, and you would just have a mess of components on a substrate. Your CAD software requires ultra-accurate tools for placing and routing traces throughout your board. So how do you determine the right trace lengths on you board? How do you use this information to design more advanced PCBs?
If you work with the best CAD software specifically built for PCB design, your software will include utilities that automatically calculate the length of traces that appear in your board. You won’t have to count up gradations in an X-Y coordinate system, nor will you have to transfer your design into an external utility.
The best design software can do more than show you the trace length you need at the trace level or at the net level. Trace lengths are used within your interactive routing tools to ensure that your trace lengths do not exceed values specified by design rules. This becomes especially important in high speed and high frequency design. Only Altium Designer integrates an automated trace length calculator with the rest of your critical design rules, giving you full control over all aspects of your next circuit board.
Different boards have different requirements on trace lengths and on the sizes of conductive elements in general. For example, if you’re designing a printed antenna on your board, you’ll need to carefully verify the size of your antenna to ensure it will resonate at the desired frequency. If you’re working with parallel data in a signal net, you’ll need to make sure that traces are length-matched within allowed tolerances. The right PCB design software can do this for you, eliminating the need for manual measurements or an external CAD tool.
Forget About 3rd Party Calculators
In reality, there is no single formula for calculating the exact trace length you need in your Printed Circuit Board. The exact length you need to use depends on your application. In a purely DC board, you’ll need to know the resistance per unit length in order to minimize IR drop. In a high speed board, the goal is to determine the maximum propagation delay for signals that causes transmission line effects to arise.
When your PCB design software includes an automated trace length calculator, you can immediately view lengths for individual traces or for all traces in a net. You’ll be able to check your trace lengths against the propagation delay in your traces, as well as check that trace lengths are matched within allowed tolerances. The days of using an external tool or command-line based CAD tools to measure trace lengths are over.
- When your board gets packed with corners, you’ll need to route around bends and corners in your board.Learn about routing with bends and corners in your PCB design software.
- Multilayer boards can offer some convenience during the layout process. In some cases, it may be better to opt for a longer trace instead of routing through a via.Learn more about choosing between longer traces and routing through vias.
- Some devices require individual signal nets and even groups of signal nets remain length-matched in order to prevent timing skew.Learn more about incorporating length matching into your routing process.
CAD layout of a WiFi module in Altium Designer
With high speed devices, propagation delay will produce signal synchronization problems and cause transmission effects to arise. When your trace length calculator is built into your PCB design software, you can immediately check your trace lengths against the critical length that causes transmission line effects to arise. This will tell you whether you need to impedance match your traces or implement impedance controlled design. You can also check your trace lengths against signal rise times, ensuring that your signals remain synchronized within your nets.
Working With Trace Lengths in Your Design Rules
As timing skew accumulates between digital signals in a net, you’ll want to make sure your PCB design software can identify length mismatches that can create synchronization problems, leading to large BER increases. When your PCB design software includes a PCB trace length calculator, you can easily identify mismatched traces and correct them with your routing tools.
PCB design software that is built on a rules-driven design engine will check your trace lengths as you layout your board. This gives you an immediate view of problems in your board and allows you to quickly fix these problems. Many PCB design programs lack this type of real-time functionality. Those that do have this capability lack real integration between design rules and routing tools, and you won’t be able to identify problems until you’ve nearly finished your design.
- Whether you’re routing differential or single-ended signal nets, you’ll need to define net clearance rules and ensure length matching throughout your signal net.Learn more about incorporating net clearance rules in your PCB design software.
- Your design rules are a critical part of your layout process. They will prevent you from making critical routing mistakes by automatically calculating trace lengths and clearances.
- Design rules help you do more than just match trace lengths throughout your board. All aspects of your design can be checked against your design rules as part of your design workflow.
Length-matched traces in a PCB layout in Altium Designer
Most PCB design programs simply use the standard propagation delay value of 0.16 ns/inch for Printed Circuit Boards on FR4. But not all circuit boards are built on FR4, and you’ll need PCB design software that can calculate the characteristic impedance and propagation delay for your board based on its dielectric constant. You need adaptable PCB design software that allows you to design to any set of design rules and industry standards. Altium Designer integrates all of these functions and more into a single program, giving you full control over your board and access to all the best design tools in a single program.
Work With the Best High Speed Design Features in Altium Designer
When your PCB design software is built on a unified rules-driven design engine, you can rest assured that your design features will work together and are accessible within a single program. The days of sending your data between design tools are over. Altium Designer makes trace length matching and impedance controlled design easy by placing all your critical design and analysis tools in a single package.
- Fusion between autorouting and interactive routing is one of the latest advances in PCB design and layout. Integration of these features into a single tool saves you time and improves your routing accuracy.Learn more about auto-interactive routing in Altium Designer.
- Instead of waiting until your board is nearly complete, you can quickly identify and correct mismatched or incorrectly routed traces in your layout.See how you can apply immediate trace length corrections in Altium Designer.
- Differential pairs require defining accurate net clearances and trace lengths to ensure maximum crosstalk suppression.Learn more about differential pair routing Altium Designer.
Altium Designer contains all these important routing tools and design calculators in a single program. These tools also interface directly with the rest of your design features within a single program. The production planning, deliverable generation, documentation, and management features are there to help you take your design from idea to product. You can also include plenty of add-ons that will help you take your designs to the next level.
Working in an integrated design environment might seem challenging, but Altium will be there with plenty of resources to help you succeed. Between an extensive knowledge base, the AltiumLive forum, podcasts with PCB design industry experts, and detailed feature tutorials, you’ll have access to the resources you need to enter the world of modern PCB design.
Forget about using 3rd party trace length calculators, outdated command-line based CAD tools, or software packages that don’t offer real integration. Whether you’re a professional PCB designer or you’re getting started in the wide world of PCB design, Altium Designer has something for everyone. Only Altium Designer offers all the design tools you need in an integrated design environment.