The last parameter to note is capacitance, and it is probably the one most designers are familiar with. The capacitance needs to be taken into account for high speed applications so that signal degradation is minimized. The eye diagram above is shown for a USB3.0 (data rate of 5 Gbps) port being protected by Littelfuse’s SP3011 series device. It’s capacitance is only 0.4pF and optimized for protecting high speed buses. For low speed applications like audio port protection and keypads or switches the capacitance of the ESD suppressor is rarely a concern.