Nexperia

PUSB3FC4

Very low capacitance unidirectional ESD protection diode array

10. Application information

The device is designed for the protection of four unidirectional data or signal lines from surge

pulses and ESD damage.

The device uses an advanced clamping structure showing a negative dynamic resistance.

This snap-back behavior strongly reduces the clamping voltage to the system behind the ESD

protection during an ESD event. Do not connect unlimited DC current sources to the data lines to

avoid keeping the ESD protection device in snap-back state after exceeding breakdown voltage

(due to an ESD pulse for instance).

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 device as close to the input terminal or connector as possible.

2. Minimize the path length between the device 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 (PCB) 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. Use ground planes whenever possible. For multilayer PCBs, use ground vias.

PUSB3FC4

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Product data sheet

18 September 2024

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