It is crucial for designers of electronic systems to protect every product against the destructive forces of ESD. Systems, components and interfaces are all at risk, especially as chip geometries continue to shrink and data speeds get faster. Innovative products often bring with them new demands and fresh challenges requiring new solutions. One such case is the latest USB interface standard, which brings faster data rates and the new USB Type-C connector.
New level of protection
For USB 3.1 a new level of ESD protection is necessary, mostly because of its very high 10 Gbps data rate. Table 1 provides a summary of recent USB standards and their maximum data rates. At double that of USB 3.0, the fast data rate makes it more difficult to maintain signal integrity. For example, the small inherent capacitance of ESD protection diodes becomes a contributing factor in potential signal disturbances. Also, the smaller structures of fast systems tend to be more sensitive to ESD, demanding a more robust ESD solution.
|Standard||Name||Introduction year||Max. data rate Gbps|
|USB 3.1||SuperSpeed USB 10 Gbps||2013||10|
|USB 3.0||SuperSpeed USB||2008||5|
|USB 2.0||Hi-Speed USB||2000||0.48|
Table 1. Summary of USB maximum data rates
With our new TrEOS Protection device family we have achieved a higher level of ESD protection, ideal for the USB 3.1 interface. It offers an industry-benchmark combination of low capacitance, high system-level robustness and low clamping voltage.
Meeting signal integrity requirements
Capacitances of TrEOS devices are in the 0.3 pF range for uni-directional devices, while bi-directional devices offer capacitances down to only 0.1 pF. Low capacitances alone are not sufficient to achieve a system with good signal integrity. Signal lines should be as short and symmetrical as possible, and stubs avoided. Nexperia offers package concepts, which support RF-friendly routing.
This post offers just a taste of what you can find in the more technical blog – Protect and filter data lines at wireless frequencies. It gives you an in-depth analysis, considering how the changes to this popular interface relate to the challenges of protecting USB 3.1 products from ESD strikes.
Semiconductors and ESD protection have played a major role in Stefan’s professional life for more than a decade. As product manager for Protection and Filtering devices at Nexperia, he is responsible for product definition, roadmaps and market introductions. Integrating input from customers and the sales and application teams in a highly dynamic, international market to develop future solutions fascinates Stefan. Of course with a PhD in physics it is not surprising that the development, quality and production aspects do so as well.