UM7222 Datasheet, PDF (7/10 Pages) Union Semiconductor, Inc. – High-Speed USB2.0 (480 Mbps) DPDT Switch

Typical Performance Characteristics (continued)
UM7222/7222A
Crosstalk
0.3
1
10
100
Frequency (MHz)
1000
Applications Information
Power-Off Protection
For a VBUS short circuit, the switch is expected to withstand such a condition for at least 24
hours. The UM7222 has specially designed circuitry which prevents unintended signal bleed
through as well as guaranteed system reliability during a power-down, over-voltage condition.
The protection has been added to the common pins (D+, D-).
Power-On Protection
The USB 2.0 specification also notes that the USB device should be capable of withstanding a
VBUS short during transmission of data. This modification works by limiting current flow back
into the V+ rail during the over-voltage event so current remains within the safe operating range.
In this application, the switch passes the full 5.25V input signal through to the selected output
while maintaining specified off isolation on the un-selected pins.
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http://www.union-ic.com Rev.05 Sep.2013
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