Choosing Replacement Components With an Integrated Library
Much as we would like, designing a new product or system is not without its hiccups. Designs, functionality, and component changes may be made at the last minute, forcing design modification or component replacement. Replacement circuit components or replacement can require thorough knowledge of your circuit boards.
Repairing a circuit board is often more than finding a circuit breaking. Electrical equipment and service panel tinkering can go so far but spare and replacement may get your device working thoroughly again. Fortunately, there are simple strategies and software solutions that can help you choose replacement components for your PCB.
If you look through a typical component, you will see a multitude of components to choose from. Many designers have their favorite components they prefer to use, and fabricators may have component distributors they prefer to use for sourcing. Some designers have the specifications for their favorite components memorized, which helps expedite design.
There’s nothing wrong with having specifications memorized. It will probably happen naturally after you have designed enough devices. If changes are made to your device that require new components, you’ll have to look through component specifications to ensure compatibility with your updated design and functionality.
If your PCB software allows searching in your component, you can cut out the time required to manually search through component specifications. You can quickly narrow down your candidate replacement components, making it simple to analyze the tradeoffs between your replacement options.
Blue PCB with surface-mounted components
Choosing Possible Replacements
As you proceed through the design process, you may find that changes need to be made mid-design, forcing you to adapt your device to new requirements. This might require choosing replacement components for your device, and you’ll want to ensure your replacements are compatible with your device functionality.
Locating replacements for basic circuit elements like resistors and capacitors is rather simple. Some specifications for these components are really maximum tolerances, and these tolerances should not be exceeded. If you opt for a replacement component with a lower tolerance, you need to check this against your device requirements. In some cases, changes to device functionality relax these tolerance requirements, allowing you to choose from a broader range of components.
When searching replacements for other components, it might be difficult to locate a replacement component that matches every possible specification you need. Not every component has the same footprint, power consumption, input/output voltage or current, and other specifications. As you browse through available components, may only be able to constrain a few of these specifications, and you will have to accept changes in others.
Before looking for a suitable replacement component, you’ll need to decide which component specifications should not change when choosing a replacement. Other specifications are really constraints or tolerances, just as in the case of simple components. Sometimes, you cannot satisfy every constraint depending on which components can be readily sourced.
Swapping a surface-mount component for a through-hole component will require changing your land pattern, which requires a redesign. If you originally designed specific pads in your PCB to support surface-mount components, then it may be a good idea to stick with it. Only switch your land design if this is the only way to accommodate a replacement component that maintains or improves the overall functionality of your PCB.
Locating Components and Addressing Obsolescence
Every component has a finite lifecycle and eventually becomes obsolete. Sourcing starts to become very difficult, and you’ll be forced to start using new components in your device. When you are planning a manufacturing run of an old device, or when you are updating an old device, you’ll need access to supply chain information in order to identify obsolete components and find suitable replacements.
This is where a component that has real-time access to supplier information becomes invaluable. Instead of spending time browsing distributor websites, reading datasheets, and even contacting distributors by phone or email, your component can display this supplier information within your design software.
This displays your lead times, available inventory, and component specifications within a single window. If your component interface includes search functions, narrowing down available components that are compatible with your device becomes much easier. This saves you a significant amount of time as you won’t be forced to browse through your manually or search distributor websites.
Eventually, your components will be as obsolete as these old electronics.
The right design software can then integrate this sourcing information directly into your bill of materials. You won’t have to prepare this critical document by hand, ensuring that your bill of materials is accurate and complete. Providing updated sourcing information to your manufacturer/assembler also helps reduce production time and redesigns.
With so many components to choose from, you’ll need component management tools that can give all the information you need to select components and choose suitable replacements. Altium Designer® gives you access to component libraries and management tools that interface with industry-standard CAD, layout, bill of materials, and analysis tools.