SMF05C_04 Datasheet, PDF (4/7 Pages) Semtech Corporation – TVS Diode Array For ESD and Latch-Up Protection

PROTECTION PRODUCTS
Applications Information
Device Connection for Protection of Five Data Lines
The SMF05C is designed to protect up to five unidirec-
tional data lines. The device is connected as follows:
1. Unidirectional protection of five I/O lines is
achieved by connecting pins 1, 3, 4, 5 and 6 to the
data lines. Pin 2 is connected to ground. The
ground connection should be made directly to the
ground plane for best results. The path length is
kept as short as possible to reduce the effects of
parasitic inductance in the board traces.
Circuit Board Layout Recommendations for Suppres-
sion of ESD.
Good circuit board layout is critical for the suppression
of ESD induced transients. The following guidelines are
recommended:
z Place the SMF05C near the input terminals or
connectors to restrict transient coupling.
z Minimize the path length between the SMF05C and
the protected line.
z Minimize all conductive loops including power and
ground loops.
z The ESD transient return path to ground should be
kept as short as possible.
z Never run critical signals near board edges.
z Use ground planes whenever possible.
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.
SMF05C
PRELIMINARY
SMF05C Circuit Diagram
1
3
4
5
6
2
Protection of Five Unidirectional Lines
 2004 Semtech Corp.
4
www.semtech.com