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PROTECTION PRODUCTS
RClamp0503F
Applications Information
Device Connection Options for Protection of Three
High-Speed Data Lines
This device is designed to protect three data lines from
transient over-voltages by clamping them to a fixed
reference. When the voltage on the protected line
exceeds the reference voltage (plus diode V
F
) the
steering diodes are forward biased, conducting the
transient current away from the sensitive circuitry.
Data lines are connected at pins 1, 3, and 4. The
negative reference is connected at pin 2. This pin
should be connected directly to a ground plane on the
board for best results. The path length is kept as short
as possible to minimize parasitic inductance.
Connect pin 5 directly to the positive supply rail (V
CC
).
In this configuration the data lines are referenced to
the supply voltage. The internal TVS diode prevents
over-voltage on the supply rail.
Matte Tin Lead Finish
Matte tin has become the industry standard lead-free
replacement for SnPb lead finishes. A matte tin finish
is composed of 100% tin solder with large grains.
Since the solder volume on the leads is small com-
pared to the solder paste volume that is placed on the
land pattern of the PCB, the reflow profile will be
determined by the requirements of the solder paste.
Therefore, these devices are compatible with both
lead-free and SnPb assembly techniques. In addition,
unlike other lead-free compositions, matte tin does not
have any added alloys that can cause degradation of
the solder joint.
Data Line and Power Supply Protection Using Vcc as
reference
