Infineon's New Fast-Acting Diode Protects High-Speed USB 3.0 Ports



With today's portable storage media, anyone can take their own media library with them wherever they go - everything from the latest album release by their favorite band to last summer's vacation photos and even HD-quality movies that can be played back in an instant on end-user equipment like televisions and laptop computers. The better the picture and audio quality, though, the greater the quantity of data to be transferred between the devices and the faster the device interfaces need to be. The Universal Serial Bus (USB), with its plug-and-play ease of use, has asserted its primacy in portable storage. Supporting transfer rates of up to 5Gbit per second, USB 3.0 is around ten times faster than the second-generation interfaces it succeeds and only consumes around a third of the power. However, the new USB port design is especially sensitive to electrostatic discharge (ESD). A mere touch of the hand can be sufficient to induce an electric current, and the energy generated by the discharge can damage the equipment or even render it completely unserviceable. This is not just annoying for equipment users, it can also become a costly problem for manufacturers in case of product recalls and subsequent image problems. The ESD3v3u4ulc damping diode from Infineon absorbs energy released through electrostatic discharge on a USB port to protect equipment from damage. With the lowest clamping voltage and the lowest dynamic resistance (0.23?) of any product on the market today, the diode response is extremely effective in the event of an electrostatic discharge. At 20kV, its ability to absorb energy significantly exceeds the 8kV called for in the highest industry standard IEC 61000-4-2. Even with the exceptional level of protection it affords, the ESD3v3u4ulc has minimal impact on the signal quality of the high-speed connection. With traditional solutions, effective protection comes at the expense of signal integrity, which leads to poor quality of the high-speed signal. Infineon has also married the ESD3v3u4ulc with its most recent package technology: The TSLP-9-1 enables optimum PCB layouts, with a single diode protecting up to four traces simultaneously. Particularly with high-speed interfaces, the right component package helps to ensure that signals are transmitted fast, without a loss of quality. Availability and pricing The ESD3v3u4ulc will be available in volume from January 2011. Unit prices start at US Dollar 0.60 for 10,000-unit quantities. For further information on TVS (Transient Voltage Suppressor) diodes from Infineon, please visit