2004 Apr 15

10

Philips Semiconductors

Product specification

Double ESD protection diodes

in SOT23 package

PESDxS2UT series

APPLICATION INFORMATION

The PESDxS2UT series is designed for uni-directional protection for up to two lines against damage caused by

ElectroStatic Discharge (ESD) and surge pulses. The PESDxS2UT series may be used on lines where the signal

waveform.

Circuit board layout and protection device placement

Circuit board layout is critical for the suppression of ESD, Electrical Fast Transient (EFT) and surge transients. The

following guidelines are recommended:

• Place the PESDxS2UT as close as possible to the input terminal or connector.

• The path length between the PESDxS2UT and the protected line should be minimized.

• Keep parallel signal paths to a minimum.

• Avoid running protected conductors in parallel with unprotected conductors.

• Minimize all printed-circuit board conductive loops including power and ground loops.

• Minimize the length of transient return paths to ground.

• Avoid using shared return paths to a common ground point.

• Ground planes should be used whenever possible. For multilayer printed-circuit boards use ground vias.

001aaa491

PESDxS2UT

line 1 to be protected

unidirectional protection

of two lines

bidirectional protection

of one line

line 2 to be protected

ground

PESDxS2UT

line 1 to be protected

ground

Fig.10 Typical application: ESD protection of data lines.