PS/2 port

Circuit Protection of PS/2



Design Notes:

Protection Application:
The data signals used in a PS/2 port have a maximum magnitude of 5V and data rate of 10,000 bps. At this data rate, the capacitance of the suppressor does not need to be considered. The signal lines to be protected from ESD include Data and Clock. The 5VDC power should be protected against ESD and overcurrent events.
Solution Description:
As shown at the left, multilayer varistors can be used on the power bus and data lines for ESD protection. A PTC is used for resettable overcurrent protection. An alternate solution is to use a diode array for ESD protection for the data lines and power bus for part count reduction.
Companion Solutions:
Does not apply.
Regulatory Issues:
The IEC 61000-4-2 will be the most appropriate standard that applies for this port. It supplies a test method for verifying that the end product is not susceptible to ESD events.
Unique Features:
Does not apply.
Application Warnings:
Does not apply.

Solutions