Sidactor Protection Thyristor Products Page 13 SIDACtor Protection Thyristor Products

SIDACtor Protection Thyristors 2017 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 02/23/17 TVS Diodes Transient Voltage Suppressor (TVS) diodes are clamping voltage suppressors that are constructed with back-to- back PN junctions. During conduction, TVS diodes create a low impedance path by varying their resistance as voltage is applied across their terminals. Once the voltage is removed, the diode will turn off and return to its high off- state impedance. Advantages Because TVS diodes are solid state devices, they do not fatigue nor do their electrical parameters change as long as they are operated within their specified limits. TVS diodes effectively clamp fast-rising transients and are well suited for low-voltage applications that do not require large amounts of energy to be shunted. Applications Due to their low power ratings, TVS diodes are not used as primary interface protectors across Tip and Ring, but they can be used as secondary protectors that are embedded within a circuit. Overshoot Levels versus dv/dt Firgure 1.4 below shows a peak voltage comparison between SIDACtor devices, Gas Discharge Tubes (GDT), Metal-Oxide Varistors (MOVs), and TVS diodes, all with a nominal stand-off voltage rating of 230 V. The X axis represents the dv/dt (rise in voltage with respect to time) applied to each protector, and the Y axis represents the maximum voltage drop across each protector. 200 300 400 500 600 700 800 1000 900 230 V Devices 0.001 0.01 0.1 1 10 100 1000 TVS Diode MOV SIDACtor dv/dt - Volts/s Breakover Voltage - Volts Typical GDT Littelfuse SL0902A Series (Fast Acting GDT) Figure 1.4 Overshoot Levels versus dv/dt Overvoltage Protection Comparison (continued)

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