Figure 10-1 shows a typical USB system and application of the SN75240, SN65240, and SN65220 devices. Connections to pin A from the D+ data line, pin B from the D– data line, and the device grounds from the GND line that already exists are necessary to increase the amount of ESD protection provided to the USB port.

The design of the suppressor gives it very low maximum current leakage of 1 μA, a very low typical capacitance of 35 pF, and a standoff voltage minimum of 6 V. Because of these levels, the SN75240, SN65240, and SN65220 devices will provide added protection to the USB system hardware during ESD events without introducing the high capacitance and current leakage levels typical of external transient voltage suppressors. The addition of an SN75240, SN65240, or SN65220 device is beneficial to both full-speed and low-speed USB 1.1 bandwidth standards.