Varistor Metal Oxide Varistor Products Page 79 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 Varistors > SM20 Series Repetitive Surge Capability V175SM20 - V320SM20 10,000 2,000 200 100 50 20 10 5 2 500 20 100 1,000 10,000 IMPULSE DURATION ( s) SURGE CURRENT (A) 1 2 10 4 10 5 10 6 MODEL SIZE 20mm V175SM20 - V320SM20 10 3 INDEFINITE 1,000 10 2 10 5,000 1 For applications exceeding 85C ambient temperature, the peak surge current and energy ratings must be reduced as shown below Peak Pulse Current Test Waveform for Clamping Voltage Peak Current, Energy and Power Derating Curve 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 PERCENT OF PEAK VALUE Test 0 50 100 TIM E t 1 t O 1 100 90 80 70 60 50 40 30 20 10 0 -55 50 60 70 80 90 100 110 120 130 140 150 AMBIENT TEMPERATURE ( o C) PERCENT OF RATED VALUE SM20 Series Ratings & Specifications Maximum Rating (85C) Specifications (25C) Continuous Transient Varistor Voltage at 1mA DC Test Current Maximum Clamping Voltage 8 x 20 s Typical Capacitance f = 1MHz V RMS V DC Energy 10 x 1000 s Peak Current 8 x 20 s Part Number Branding V M(AC) V M(DC) W TM 1x pulse I TM 1x pulse V NOM Min V NOM Max V C I PK C (V) (J) (A) (V) (V) (A) (pF) V26SM20 26SM20 20 26 20 160 (note 1) 2000 32 (10mA) 40 (10mA) 63 20 12000 V175SM20 175SM20 175 225 90 6500 247 303 455 100 1400 V230SM20 230SM20 230 300 122 6500 324 396 595 100 1100 V250SM20 250SM20 250 330 130 6500 354 429 650 100 1000 V275SM20 275SM20 275 369 140 6500 389 473 710 100 900 V300SM20 300SM20 300 405 165 6500 420 517 775 100 800 V320SM20 320SM20 320 420 150 6500 462 540 810 100 750 1. Energy rating for impulse duration of 30ms minimum to one half of peak current (automotive load dump).

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