2004 Feb 18

10

Philips Semiconductors

Product specification

Double ESD protection diodes

in SOT23 package

PESDxS2UAT series

APPLICATION INFORMATION

The PESDxS2UAT series can protect up to two lines against damage caused by unidirectional ElectroStatic Discharge

(ESD) and surge pulses. The PESDxS2UAT series can protect lines whose signal polarities are below ground.

PESDxS2UAT series provide a surge capability of up to 330 Watts peak pulse power per line for a 8/20

µs 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:

1. Place the PESDxS2UAT as close as possible to the input terminal or connector.

2. Minimize the path length between the PESDxS2UAT and the protected line.

3. Keep parallel signal paths to a minimum.

4. Avoid running protected conductors in parallel with unprotected conductors.

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

6. Minimize the length of transient return paths to ground.

7. Avoid using shared transient return paths to a common ground point.

8. Ground planes should be used whenever possible.

9. Use vias for multi-layer printed-circuit boards.

001aaa179

PESDxS2UAT

line 1 to be protected

unidirectional protection

of two lines

bidirectional protection

of one line

line 2 to be protected

ground

PESDxS2UAT

line 1 to be protected

ground

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