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littelfuse.com
V
Each line of the USB-C port requires
optimized circuit protection. To
investigate, let's start at the bottom of
the table in Figure 2, at Roman numeral
five (V) and work our way up. One first
notices an ESD protector for the USB-C
port's power lines. Each V
bus
power
line could provide power at voltages
up to 20V. Typical ESD devices are
only capable of withstanding 5V, 6V, or
even 12V of sustained power. Littelfuse
SPHV24 Series is designed to handle
20V without clamping. When an ESD
event comes in, it can accurately protect
against that event.
Figure 3: Circuit protection solutions for USB 3.0 (Source: Littelfuse)
IV
IV indicates protection for the CC line and the SBU
lines. Since the data rate on these lines are fast but not
as fast as the SuperSpeed lines, the capacitance of an
ESD protector can be a little higher. For data speeding,
capacitance, and the relationship, the faster your data
speed, the lower one wants capacitance. This is because
capacitance can degrade the signal to a point where it
attenuates, and it's unreadable by the device receiving
it. So on this line, because it's lower speed, a higher
capacitance device can be used and typically is lower in
price. Littelfuse would suggest something such as the
SP1006 Series single-channel device.
III
The SuperSpeed lines carry data at extremely fast data
rates. Up to eight of these could be in action at any one
point in time. Signals with faster data speeds are more
sensitive to interference caused by the capacitance of
components connected to them. Due to the number of
data lines and very fast data speed associated with the
SuperSpeed lines, ESD protection, such as the SP3213
Series, must be very small and have extremely low
capacitance so that it fits within the allotted space and
does not interfere with the data signal.
Figure 2: Circuit protection solution for USB Type-C (Source: Littelfuse)
