UM5304 Datasheet, PDF (4/8 Pages) Union Semiconductor, Inc. – Quad Channel Low Capacitance ESD Protection Array

UM5304EEXF
Applications Information
Device Connection Options for Protection of Four High-Speed Data Lines
This device is designed to protect data lines by clamping them to a fixed reference. When the voltage on the
protected line exceeds the reference voltage the steering diodes are forward biased, conducting the transient
current away from the sensitive circuitry. Data lines are connected at pins 1, 3, 4 and 6. Pin 2 should be
connected directly to a ground plane. The path length is kept as short as possible to minimize parasitic
inductance. The positive reference is connected at pin 5. The options for connecting the positive reference are as
follows:
To protect data lines and the power line, connect pin 5 directly to the positive supply rail (VCC). In this
configuration the data lines are referenced to the supply voltage.
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 compared 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.
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http://www.union-ic.com Rev.03 May.2008
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