The SN65220 device is a dual, and the SN65240 and SN75240 devices are quadruple, unidirectional transient voltage suppressors (TVS). These devices provide electrical noise transient protection to Universal Serial Bus (USB) low and full-speed ports. The input capacitance of 35 pF makes it unsuitable for high-speed USB 2.0 applications.
Any cabled I/O can be subjected to electrical noise transients from various sources. These noise transients can cause damage to the USB transceiver and/or the USB ASIC if they are of sufficient magnitude and duration.
The ESD performance of the SN65220, SN65240, and SN75240 devices is measured at the system level, according to IEC61000-4-2. However, system design impacts the results of these tests. To accomplish a high compliance level requires careful board design and layout techniques.