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Circuit Protection for High-Speed Serial Interfaces
TODD PHILLIPS | Littelfuse, Inc.
These
GENERAL PORTS
Protect Against
Electrical Stress
• Static electricity: We typically refer to it as
electrostatic discharge (ESD), which commonly
comes from human touch. Effectively, we become
the source of electrical stress that can damage
sensitive electronics.
• Short circuits: They are typically caused by things
such as a power cross. A power line faulting into a data
line or a power line faulting to ground and bypassing
the load and that short circuit creates a spike in current
that could damage a piece of electronics.
• General overvoltage events: These events occur from
everyday activities such as turning on motors or lights.
Inductive load-switching can wear out electronics over
time, cause damage, and need protection.
P
orts provide a connection to the outside world,
primarily for a device looking for data or power.
Ports create an opening that becomes an easy
entry point for electrical stress (Figure 1). Common
electrical stress points would be lightning strikes to a
power line that might be traveling down the power line
itself and into the device. It could even strike nearby and
induce a voltage spike on the power line or even the data
lines that need to be protected. Other types:
General Port Protection
Littelfuse and Mouser Electronics
