NUP2115L, SZNUP2115L

www.onsemi.com

4

APPLICATIONS

TVS diodes provide a low cost solution to conducted and

radiated

Electromagnetic

Interference

(EMI)

and

Electrostatic Discharge (ESD) noise problems. The noise

immunity level and reliability of FlexRay transceivers can

be easily increased by adding external TVS diodes to

prevent transient voltage failures.

The NUP2115L provides a transient voltage suppression

solution for FlexRay data communication lines. The

NUP2115L is a dual bidirectional TVS device in a compact

SOT−23 package. This device is based on Zener technology

that optimizes the active area of a PN junction to provide

robust protection against transient EMI surge voltage and

ESD.

TVS Diode Protection Circuit

TVS diodes provide protection to a transceiver by

clamping a surge voltage to a safe level. TVS diodes have

high impedance below and low impedance above their

breakdown voltage. A TVS Zener diode has its junction

optimized to absorb the high peak energy of a transient

event, while a standard Zener diode is designed and

specified to clamp a steady state voltage.

Figure 7 provides an example of a dual bidirectional

TVS diode array that can be used for protection with the

FlexRay network. The bidirectional array is created from

four identical Zener TVS diodes. The clamping voltage of

the composite device is equal to the breakdown voltage of

the diode that is reversed biased, plus the diode drop of the

second diode that is forwarded biased.

Figure 7. FlexRay TVS Protection Circuit