User's Manual

Table Of Contents

Product data sheet Rev. 01 — 4 October 2004 10 of 15

Philips Semiconductors

PESDxL1BA series

Low capacitance bidirectional ESD protection diodes in SOD323

7. Application information

The PESDxL1BA series is designed for bidirectional protection of one signal line from the

damage caused by Electro Static Discharge (ESD) and surge pulses. The PESDxL1BA

series may be used on lines where the signal polarity is above and below ground. The

PESDxL1BA series provides a surge capability of up to 500 W 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 protection device as close to the input terminal or connector as possible.

2. The path length between the protection device and the protected line should be

minimized.

3. Keep parallel signal paths to a minimum.

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

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

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

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

8. Ground planes should be used whenever possible. For multilayer printed-circuit

boards, use ground vias.

Fig 9. Typical application: Bidirectional protection of one signal line.

006aaa071

ground

PESDxL1BA

line to be protected