INTERVIEW our connectors in many different configurations. What are some tips for finding the best connectors for a particular application? I’d say the biggest constraints are how much board space you have to work with, and how many signals you have to run. That drives everything. Once you have the general size nailed down and the configuration of the connector (whether it’s top entry, right angle, etc.), then you can start looking at which electrical parameter is most important in your particular application. In some cases, impedance performance might be important and in other cases, impedance might not matter much. The engineer needs to focus on which performance aspects are most critical in their application. Of course, if there is a spec in place, then it can be relatively easy to flip through a test report to see if the connector hits the specs. We also do quite a few system simulations on the front end, and publish those results in what we call an Application Note. For example, let’s take PCI express. A customer might have certain space requirement or a form factor in mind where a standard PCI express connector just won’t work, so they want to use one of our generic high speed connectors. What we do is take a system from the transceiver on one end to the transceiver on the other end, and then we add a certain amount of PCB trace in between. Then we add a connector pair in the middle and simulate that, and see if it meets the PCI spec requirements. We examine the eye patterns, and things like crosstalk and insertion loss. We might conclude something like, “With this pin out on this connector, you can operate PCI express at 4 Gb/sec with up to 12 inches of trace on each side”. We’ll typically publish multiple
scenarios like this in an App Note, and many customers have come to rely on this type of information. If they have a situation that’s just a bit different than a case covered in an App Note, we’ll often perform a simulation for them based on their particular requirements. Probably 20% of our current SI engineering effort at Samtec is spent doing system-type simulations like this. What are some of Samtec’s new products? One of our newest products is a combination of fiber optic and copper cables, called “FireFly.” A few years ago, Samtec acquired an optical engine design and fabrication company. We’ve been working on merging the two media and developing a system that allows customers to use fiber or copper, depending on their current and future performance requirements. Typically this is inside the box, so it’s somewhat like a high speed back plane replacement. The module mounts on the motherboard and operates with a copper cable assembly for short distances and lower speeds. If the speed, distance, or possibly EMI requirements, go up in the future, the copper can be replaced with a plug-in fiber optic assembly. What other services does Samtec provide? We provide what we call a “Final Inch,” where we step outside the connector and look at the PCB area around the connector. We develop an optimized
a PCB design for the breakout region in the area underneath the connector, including trace and via design and placement. We provide these designs in Gerber format along with SPICE models of the breakout region and traces. It makes sense for connector companies to do this because it’s basically the same for many applications. It doesn’t make sense to have to reinvent the wheel every time someone uses a connector. Similarly, we provide what we call intelligent PCB design libraries, which are libraries that a PCB designer can pull into his tool, which brings information on the footprint, pin numbering, schematic symbols, and sometimes information such as such as height and weight. We’re also seeing some system design tools evolving to where one bill of materials contains models that are used for several different design tools. The BOM is basically a collection or database of models. There will be footprint info and symbols for use in layout; height, width, and window information for thermal/airflow simulations; SPICE or s-parameter models for SI simulations; weight and height information for pick and place optimization, etc. So this mega model is a one stop shop that contains all the information about the connector that’s needed from start to finish in the system design process. We work to stay abreast of such developments, and we often participate in industry efforts to develop standards for things like this. It’s all part of our goal of making our customer’s job easier. ■
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