Description:

The SM712 transient voltage suppressor (TVS) diode isdesigned for asymmetrical (12V to -7V ) protection inmulti-point data transmission standard RS-485 applications. The SM712 may be used to protect devicesfrom transient voltages resulting from electrostaticdischarge (ESD), electrical fast transients (EFT), andlightning.The SM712 features 400 Watts (tp = 8/20µs) ofpower handling capability to accommodate the highertransient voltage levels which may be expected inextended common mode applications. This provideshigher equipment reliability and eliminates the “guesswork” required when using zener diodes that are notrated to handle such transient conditions.The SM712 replaces four discrete components byintegrating two 12V and two 7V TVS diodes in a singlepackage. The integrated design aids in reducingvoltage over-shoot associated with trace inductance.The low clamping voltage of the SM712 minimizes thestress on the protected transceiver. The SOT23package allows flexibility in the design of “crowded”circuit boards.

Features:

‹400 watts peak pulse power (tp = 8/20µs)

‹ Transient protection for asymmetrical data lines to

IEC 61000-4-2 (ESD) ±15kV (air), ±8kV (contact)

IEC 61000-4-4 (EFT) 40A (5/50ns)

IEC 61000-4-5 (Lightning) 12A (8/20µs)

‹ Protects two +12V to -7V lines

‹ Low capacitance

‹ Low clamping voltage

‹ Solid-state silicon avalanche technology

Mechanical Characteristics:

‹ JEDEC SOT23 package

‹ Molding compound flammability rating: UL 94V-0

‹ Marking : 712

‹ Packaging : Tape and Reel per EIA 481

Applications:

 Protection of RS-485 transceivers with extendedcommon-mode range

‹ Security systems

‹ Automatic Teller Machines

‹ HFC systems‹ Networks