1.5SMC6.8AT3G Series, SZ1.5SMC6.8AT3G Series 1500 Watt Peak Power Zener Transient Voltage Littelfuse.com Suppressors Unidirectional* SURFACE MOUNT The SMC series is designed to protect voltage sensitive ZENER OVERVOLTAGE components from high voltage, high energy transients. They have TRANSIENT SUPPRESSORS excellent clamping capability, high surge capability, low zener 5.8 − 78 VOLTS impedance and fast response time. The SMC series is supplied in the exclusive, cost-effective, highly reliable Littelfuse 1500 WATT PEAK POWER package and is ideally suited for use in communication systems, automotive, numerical controls, process controls, medical equipment, business machines, power supplies and many other industrial/consumer applications. SMC Specification Features CASE 403 • Working Peak Reverse Voltage Range − 5.8 to 77.8 V • Standard Zener Breakdown Voltage Range − 6.8 to 91 V • Peak Power − 1500 W @ 1.0 ms Cathode Anode • ESD Rating of Class 3 (>16 kV) per Human Body Model • Maximum Clamp Voltage @ Peak Pulse Current MARKING DIAGRAM • Low Leakage < 5.0 (cid:2)A Above 10 V • UL 497B for Isolated Loop Circuit Protection • Maximum Temperature Coefficient Specified • Response Time is Typically < 1.0 ns • xxxA = Specific Device Code SZ Prefix for Automotive and Other Applications Requiring Unique (See Table on Page 3) Site and Control Change Requirements; AEC−Q101 Qualified and A = Assembly Location PPAP Capable Y = Year • WW = Work Week These are Pb−Free Devices are Available** (cid:2) = Pb−Free Package Mechanical Characteristics (Note: Microdot may be in either location) CASE: Void-free, transfer-molded, thermosetting plastic FINISH: All external surfaces are corrosion resistant and leads are ORDERING INFORMATION readily solderable MAXIMUM CASE TEMPERATURE FOR SOLDERING PURPOSES: Device*** Package Shipping 260°C for 10 Seconds 1.5SMCxxxAT3G SMC 2,500 / LEADS: Modified L−Bend providing more contact area to bond pads (Pb−Free) Tape & Reel POLARITY: Cathode indicated by molded polarity bend SZ1.5SMCxxxAT3G SMC 2,500 / MOUNTING POSITION: Any (Pb−Free) Tape & Reel ***The “T3” suffix refers to a 13 inch reel. **Bidirectional devices will not be available in this series. Individual devices are listed on page 3 of this data sheet. Specifications subject to change without notice. © 2016 Littelfuse, Inc. 1 Publication Order Number: September 19, 2016 − Rev. 11 1.5SMC6.8AT3/D

1.5SMC6.8AT3G Series, SZ1.5SMC6.8AT3G Series MAXIMUM RATINGS Rating Symbol Value Unit Peak Power Dissipation (Note 1) @ TL = 25°C, Pulse Width = 1 ms PPK 1500 W DC Power Dissipation @ TL = 75°C PD 4.0 W Measured Zero Lead Length (Note 2) Derate Above 75°C 54.6 mW/°C Thermal Resistance, Junction−to−Lead R(cid:3)JL 18.3 °C/W DC Power Dissipation (Note 3) @ TA = 25°C PD 0.75 W Derate Above 25°C 6.1 mW/°C Thermal Resistance from Junction−to−Ambient R(cid:3)JA 165 °C/W Forward Surge Current (Note 4) @ TA = 25°C IFSM 200 A Operating and Storage Temperature Range TJ, Tstg −65 to +150 °C Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality should not be assumed, damage may occur and reliability may be affected. 1. 10 X 1000 (cid:2)s, non−repetitive 2. 1 in. square copper pad, FR−4 board 3. FR−4 board, using Littelfuse minimum recommended footprint, as shown in 403 case outline dimensions spec. 4. 1/2 sine wave (or equivalent square wave), PW = 8.3 ms, duty cycle = 4 pulses per minute maximum. ELECTRICAL CHARACTERISTICS (TA = 25°C unless I otherwise noted, VF = 3.5 V Max. @ IF (Note 5) = 100 A) IF Symbol Parameter IPP Maximum Reverse Peak Pulse Current VC Clamping Voltage @ IPP VRWM Working Peak Reverse Voltage VC VBRVRWM V IR Maximum Reverse Leakage Current @ VRWM IIRT VF VBR Breakdown Voltage @ IT IT Test Current (cid:4)VBR Maximum Temperature Coefficient of VBR IPP IF Forward Current VF Forward Voltage @ IF Uni−Directional TVS 5. 1/2 sine wave or equivalent, PW = 8.3 ms non−repetitive duty cycle Specifications subject to change without notice. © 2016 Littelfuse, Inc. 2 Publication Order Number: September 19, 2016 − Rev. 11 1.5SMC6.8AT3/D

1.5SMC6.8AT3G Series, SZ1.5SMC6.8AT3G Series ELECTRICAL CHARACTERISTICS VRWM Breakdown Voltage VC @ IPP (Note 8) Device (Note 6) IR @ VRWM VBR V (Note 7) @ IT VC IPP (cid:2)VBR Device* Marking V (cid:3)A Min Nom Max mA V A %/(cid:2)C 1.5SMC6.8AT3G 6V8A 5.8 1000 6.45 6.8 7.14 10 10.5 143 0.057 1.5SMC7.5AT3G 7V5A 6.4 500 7.13 7.5 7.88 10 11.3 132 0.061 1.5SMC8.2AT3G 8V2A 7.02 200 7.79 8.2 8.61 10 12.1 124 0.065 1.5SMC10AT3G 10A 8.55 10 9.5 10 10.5 1 14.5 103 0.073 1.5SMC12AT3G 12A 10.2 5 11.4 12 12.6 1 16.7 90 0.078 1.5SMC13AT3G 13A 11.1 5 12.4 13 13.7 1 18.2 82 0.081 1.5SMC15AT3G 15A 12.8 5 14.3 15 15.8 1 21.2 71 0.084 1.5SMC16AT3G 16A 13.6 5 15.2 16 16.8 1 22.5 67 0.086 1.5SMC18AT3G 18A 15.3 5 17.1 18 18.9 1 25.2 59.5 0.088 1.5SMC20AT3G 20A 17.1 5 19 20 21 1 27.7 54 0.09 1.5SMC22AT3G 22A 18.8 5 20.9 22 23.1 1 30.6 49 0.092 1.5SMC24AT3G 24A 20.5 5 22.8 24 25.2 1 33.2 45 0.094 1.5SMC27AT3G 27A 23.1 5 25.7 27 28.4 1 37.5 40 0.096 1.5SMC30AT3G 30A 25.6 5 28.5 30 31.5 1 41.4 36 0.097 1.5SMC33AT3G 33A 28.2 5 31.4 33 34.7 1 45.7 33 0.098 1.5SMC36AT3G 36A 30.8 5 34.2 36 37.8 1 49.9 30 0.099 1.5SMC39AT3G 39A 33.3 5 37.1 39 41 1 53.9 28 0.1 1.5SMC43AT3G 43A 36.8 5 40.9 43 45.2 1 59.3 25.3 0.101 1.5SMC47AT3G 47A 40.2 5 44.7 47 49.4 1 64.8 23.2 0.101 1.5SMC51AT3G 51A 43.6 5 48.5 51 53.6 1 70.1 21.4 0.102 1.5SMC56AT3G 56A 47.8 5 53.2 56 58.8 1 77 19.5 0.103 1.5SMC62AT3G 62A 53 5 58.9 62 65.1 1 85 17.7 0.104 1.5SMC68AT3G 68A 58.1 5 64.6 68 71.4 1 92 16.3 0.104 1.5SMC75AT3G 75A 64.1 5 71.3 75 78.8 1 103 14.6 0.105 1.5SMC82AT3G 82A 70.1 5 77.9 82 86.1 1 113 13.3 0.105 1.5SMC91AT3G 91A 77.8 5 86.5 91 95.5 1 125 12 0.106 Product parametric performance is indicated in the Electrical Characteristics for the listed test conditions, unless otherwise noted. Product performance may not be indicated by the Electrical Characteristics if operated under different conditions. 6. A transient suppressor is normally selected according to the working peak reverse voltage (VRWM), which should be equal to or greater than the DC or continuous peak operating voltage level. 7. VBR measured at pulse test current IT at an ambient temperature of 25°C. 8. Surge current waveform per Figure 2 and derate per Figure 3 of the General Data − 1500 Watt at the beginning of this group. *Include SZ-prefix devices where applicable. Specifications subject to change without notice. © 2016 Littelfuse, Inc. 3 Publication Order Number: September 19, 2016 − Rev. 11 1.5SMC6.8AT3/D

1.5SMC6.8AT3G Series, SZ1.5SMC6.8AT3G Series 100 PULSE WIDTH (tP) IS DEFINED NPUOLNSREE WPEATVIETFIVOERM tr(cid:2)≤ 10 (cid:2)s ACSU RTRHEANT TP ODEINCTA WYSH ETORE 5 0T%HE PEAK kW) SHOWN IN FIGURE 2 100 OF IPP. R ( 10 PEAK VALUE - IPP WE %) O E ( AK P VALU HALF VALUE - IP2P E 1 50 P , k p P tP 0.1 0 0.1 (cid:2)s 1 (cid:2)s 10 (cid:2)s 100 (cid:2)s 1 ms 10 ms 0 1 2 3 4 tP, PULSE WIDTH t, TIME (ms) Figure 1. Pulse Rating Curve Figure 2. Pulse Waveform 160 C 1000 LSE DERATING IN % OF°R OR CURRENT @ T= 25A 1118602400000 CURRENT (AMPS)5215200000000 tTPL(cid:2)(cid:2)==(cid:2)(cid:2)1205(cid:2)°(cid:2)Cs VBR(cid:2)(N2O02(cid:2)MV4)(cid:2)V(cid:2)=(cid:2)6.8(cid:2)TO43(cid:2)1(cid:2)V37(cid:2)1V518(cid:2)20V0(cid:2)V(cid:2)V PEAK PUAK POWE 4200 , TEST T 150 E I 2 P 0 1 0 25 50 75 100 125 150 0.3 0.5 0.7 1 2 3 5 7 10 20 30 TA, AMBIENT TEMPERATURE (°C) (cid:5)VBR, INSTANTANEOUS INCREASE IN VBR ABOVE VBR (NOM) (VOLTS) Figure 3. Pulse Derating Curve Figure 4. Dynamic Impedance UL RECOGNITION The entire series has Underwriters Laboratory including Strike Voltage Breakdown test, Endurance Recognition for the classification of protectors (QVGQ2) Conditioning, Temperature test, Dielectric Voltage-Withstand under the UL standard for safety 497B and File #E128662. test, Discharge test and several more. Many competitors only have one or two devices recognized Whereas, some competitors have only passed a or have recognition in a non-protective category. Some flammability test for the package material, we have been competitors have no recognition at all. With the UL497B recognized for much more to be included in their Protector recognition, our parts successfully passed several tests category. Specifications subject to change without notice. © 2016 Littelfuse, Inc. 4 Publication Order Number: September 19, 2016 − Rev. 11 1.5SMC6.8AT3/D

1.5SMC6.8AT3G Series, SZ1.5SMC6.8AT3G Series APPLICATION NOTES Response Time minimum lead lengths and placing the suppressor device as In most applications, the transient suppressor device is close as possible to the equipment or components to be placed in parallel with the equipment or component to be protected will minimize this overshoot. protected. In this situation, there is a time delay associated Some input impedance represented by Z is essential to in with the capacitance of the device and an overshoot prevent overstress of the protection device. This impedance condition associated with the inductance of the device and should be as high as possible, without restricting the circuit the inductance of the connection method. The capacitive operation. effect is of minor importance in the parallel protection scheme because it only produces a time delay in the Duty Cycle Derating transition from the operating voltage to the clamp voltage as The data of Figure 1 applies for non-repetitive conditions shown in Figure 5. and at a lead temperature of 25°C. If the duty cycle increases, The inductive effects in the device are due to actual the peak power must be reduced as indicated by the curves turn-on time (time required for the device to go from zero of Figure 7. Average power must be derated as the lead or current to full current) and lead inductance. This inductive ambient temperature rises above 25°C. The average power effect produces an overshoot in the voltage across the derating curve normally given on data sheets may be equipment or component being protected as shown in normalized and used for this purpose. Figure 6. Minimizing this overshoot is very important in the At first glance the derating curves of Figure 7 appear to be application, since the main purpose for adding a transient in error as the 10 ms pulse has a higher derating factor than suppressor is to clamp voltage spikes. The SMC series have the 10 (cid:2)s pulse. However, when the derating factor for a a very good response time, typically < 1.0 ns and negligible given pulse of Figure 7 is multiplied by the peak power value inductance. However, external inductive effects could of Figure 1 for the same pulse, the results follow the produce unacceptable overshoot. Proper circuit layout, expected trend. Specifications subject to change without notice. © 2016 Littelfuse, Inc. 5 Publication Order Number: September 19, 2016 − Rev. 11 1.5SMC6.8AT3/D

1.5SMC6.8AT3G Series, SZ1.5SMC6.8AT3G Series TYPICAL PROTECTION CIRCUIT Zin Vin LOAD VL Vin (TRANSIENT) OVERSHOOT DUE TO V Vin (TRANSIENT) V INDUCTIVE EFFECTS VL VL Vin td tD = TIME DELAY DUE TO CAPACITIVE EFFECT t t Figure 5. Figure 6. 1 0.7 0.5 R 0.3 O CT 0.2 A PULSE WIDTH F G 0.1 10 ms N TI 0.07 A R 0.05 E 1 ms D 0.03 0.02 100 (cid:2)s 10 (cid:2)s 0.01 0.1 0.2 0.5 1 2 5 10 20 50 100 D, DUTY CYCLE (%) Figure 7. Typical Derating Factor for Duty Cycle Specifications subject to change without notice. © 2016 Littelfuse, Inc. 6 Publication Order Number: September 19, 2016 − Rev. 11 1.5SMC6.8AT3/D

1.5SMC6.8AT3G Series, SZ1.5SMC6.8AT3G Series PACKAGE DIMENSIONS SMC CASE 403−03 ISSUE E NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. HE 2. CONTROLLING DIMENSION: INCH. 3. D DIMENSION SHALL BE MEASURED WITHIN DIMENSION P. E 4. 403-01 THRU -02 OBSOLETE, NEW STANDARD 403-03. MILLIMETERS INCHES DIM MIN NOM MAX MIN NOM MAX A 1.90 2.13 2.41 0.075 0.084 0.095 A1 0.05 0.10 0.15 0.002 0.004 0.006 b D b 2.92 3.00 3.07 0.115 0.118 0.121 c 0.15 0.23 0.30 0.006 0.009 0.012 D 5.59 5.84 6.10 0.220 0.230 0.240 E 6.60 6.86 7.11 0.260 0.270 0.280 HE 7.75 7.94 8.13 0.305 0.313 0.320 L 0.76 1.02 1.27 0.030 0.040 0.050 L1 0.51 REF 0.020 REF A c A1 L L1 SOLDERING FOOTPRINT 4.343 0.171 3.810 0.150 2.794 0.110 (cid:2) (cid:3) mm SCALE 4:1 inches Information furnished is believed to be accurate and reliable. However, users should independently evaluate the suitability of and test each product selected for their own applications.  Littelfuse products are not designed for, and shall not be used for, any purpose (including, without limitation, military, aerospace, medical, life-saving, life-sustaining or nuclear facility applications, devices intended for surgical implant into the body, or any other application in which the failure or lack of desired operation of the product may result in personal injury, death, or property damage) other than those expressly set forth in applicable Littelfuse product documentation.  Warranties granted by Littelfuse shall be deemed void for products used for any purpose not expressly set forth in applicable Littelfuse documentation.  Littelfuse shall not be liable for any claims or damages arising out of products used in applications not expressly intended by Littelfuse as set forth in applicable Littelfuse documentation.  The sale and use of Littelfuse products is subject to Littelfuse Terms and Conditions of Sale, unless otherwise agreed by Littelfuse. Littelfuse.com Specifications subject to change without notice. © 2016 Littelfuse, Inc. 7 Publication Order Number: September 19, 2016 − Rev. 11 1.5SMC6.8AT3/D