Varistor Metal Oxide Varistor Products Page 40 Varistor Metal-Oxide Varistor Products

2017 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 09/14/17 Metal-Oxide Varistors (MOVs) Surface Mount Multilayer Varistors (MLVs) > MLA Series Peak Current and Energy Derating Curve When transients occur in rapid succession, the average power dissipation is the energy (watt-seconds) per pulse times the number of pulses per second. The power so developed must be within the specifications shown on the Device Ratings and Specifications Table for the specific device. For applications exceeding 125C ambient temperature, the peak surge current and energy ratings must be derated as shown below. 100 80 60 40 20 0 -55 50 60 70 80 90 100 110 120 130 140 150 PERCENT OF RATED VALUE AMBIENT TEMPERATURE ( o C) T 1 T 2 100 50 0 O 1 TIME PERCENT OF PEAK VALUE T Peak Pulse Current Test Waveform for Clamping Voltage Limit V-I Characteristic for V9MLA0402L Limit V-I Characteristic for V5.5MLA0402 to V18MLA0402 1 10 100 1A 10A 100A 1mA 10mA 1A 10A 100A V9MLA0402L V5.5MLA0402L Varistor Voltage (V) Current (A) 1 10 100 1A 10A 100A 1mA 10mA 1A 10A 100A Current (A) V18MLA0402 V14MLA0402 V9MLA0402 V5.5MLA0402 Varistor Voltage (V) 0 1 = Virtual Origin of Wave T = Time from 10% to 90% of Peak T 1 = Rise Time = 1.25 x T T 2 = Decay Time Example - For an 8/20 s Current Waveform: 8 s = T 1 = Rise Time 20 s = T 2 = Decay Time Figure 1 Figure 2 Figure 3 Figure 4

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