PolySwitch(R) Resettable PPTCs Surface Mount > SMDC Series SMDC Series RoHS Description The SMDC series provides surface mount overcurrent protection for applications where space is at a premium and resettable protection is desired. Features * Broadest range of resettable devices available in industry * Low resistance * Small 2920 footprint * Fast time-to-trip * RoHS complaint, lead-free and halogen-free Agency Approvals AGENCY Applications AGENCY FILE NUMBER Mobile Electronics and Batteries E74889 78165 72161779 * Computer * Telephone and broadband * Portable electronics * Automotive * Multimedia * Industrial controls * Game machines * Battery Additional Information Datasheet Samples Resources Electrical Characteristics Part Number IH IT (A) (A) VMAX IMAX PD MAX (VDC) (A) (W) Max Time-to-trip RMIN R1MAX (A) (s) () () 2.00 0.040 0.250 SMDC Series -- Size 7555mm/2920mils SMDC125F/33 1.25 2.50 33 40 1.50 8.00 SMDC185F/33 1.85 3.70 33 40 1.70 8.00 2.50 0.050 0.150 SMDC300F/24 3.00 6.00 24 40 1.70 8.00 5.00 0.015 0.072 SMDC310F/18 3.10 6.00 18 50 1.50 8.00 25.00 0.013 0.036 Notes: IH :Hold current: maximum current device will pass without interruption in 20C still air. IT :Trip current: minimum current that will switch the device from low resistance to high resistance in 20C still air. VMAX :Maximum continuous voltage device can withstand without damage at rated current. IMAX :Maximum fault current device can withstand without damage at rated voltage. PD :Power dissipated from device when in the tripped state in 20C still air. RMIN :Minimum resistance of device as supplied at 20C unless otherwise specified. R1MAX :Maximum resistance measured one hour post-trip or post-reflow at 20C. (c) 2019 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 06/05/19 PolySwitch(R) Resettable PTCs Surface Mount > SMDC Series Temperature Rerating Maximum Ambient Temperature Part Number -40C -20C 0C 20C 25C 40C 50C 60C 70C 80C 85C 0.84 0.72 0.60 0.54 Hold Current (A) SMDC Series -- Size 7555mm/2920mils SMDC125F/33 2.02 1.78 1.55 1.31 1.25 1.08 0.96 SMDC185F/33 2.83 2.50 2.20 1.85 1.74 1.53 1.37 1.22 1.04 0.88 0.80 SMDC300F/24 4.70 4.19 3.70 3.17 3.00 2.66 2.41 2.20 1.90 1.65 1.50 SMDC310F/18 4.50 4.06 3.78 3.19 3.10 2.75 2.54 2.32 2.10 1.88 1.76 Temperature Rerating Curve 200 % of Rated Hold and Trip Current 180 160 140 120 100 80 60 40 20 0 -40 -20 0 20 40 60 Ambient Temperature (C) (c) 2019 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 06/05/19 80 100 120 PolySwitch(R) Resettable PPTCs Surface Mount > SMDC Series Typical Time-to-Trip Curves at 20C SMDCxxxF A = SMDC125F/33 B = SMDC185F/33 C = SMDC300F/24 D = SMDC310F/18 100 D A Time-to-Trip (s) 10 B C 1 0.1 D C 0.01 B A 0.001 1 10 100 Fault Current (A) Physical Specifications Terminal Pad Material 100% Matte Tin with Nickel Underplate Soldering Characteristics ANSI/J-STD-002 Category 3 Solder Heat Withstand per IEC-STD 68-2-20, Test Tb, Section 5, Method 1a Flammability Resistance per IEC 695-2-2 Needle Flame Test for 20 seconds Environmental Specifications Test Test Method Storage Life PS300, Section 5.3.2 Humidity Aging PS300, Section 5.3.1 Thermal Shock MIL-STD-202, Method 107G Vibration MIL-STD-883C Solvent Resistance PS300, Section 5.2.2 Conditions Resistance Change 60C, 1000 hrs 3% typ 85C, 1000 hrs 3% typ 85C, 85% R.H., 100 hrs 1.2% typ 85C, -40C (20 Times) -33% typ 125C, -55C (10 Times) -33% typ per MIL-STD-883C No Change Freon No Change Trichloroethane No Change Hydrocarbons No Change Moisture Resistance Level Level 2a, J-STD-020 Storage Conditions 40C max, 70% RH max; devices should remain in original sealed bags prior to use. Devices may not meet specified values if these storage conditions are exceeded. (c) 2019 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 06/05/19 PolySwitch(R) Resettable PTCs Surface Mount > SMDC Series Dimension Figures A B C C B F D D E A E Figure 1 Dimensions Dimensions in Millimeters (Inches) Part Number A B C Min Max Min Max Min SMDC125F/33 7.30 (0.287) 7.70 (0.303) 0.45 (0.018) 0.71 (0.028) 4.90 (0.193) SMDC185F/33 7.30 (0.287) 7.70 (0.303) 0.90 (0.035) 1.20 (0.047) SMDC300F/24 7.30 (0.287) 7.70 (0.303) 0.80 (0.031) SMDC310F/18 7.30 (0.287) 7.70 (0.303) 1.10 (0.043) D Max E Figure Min Max Min Max 5.30 (0.209) 0.25 (0.010) 0.95 (0.040) 0.20 (0.008) -- 1 4.90 (0.193) 5.30 (0.209) 0.25 (0.010) 0.95 (0.040) 0.20 (0.008) -- 1 1.10 (0.043) 4.90 (0.193) 5.30 (0.209) 0.25 (0.010) 0.95 (0.040) 0.20 (0.008) -- 1 1.70 (0.067) 4.90 (0.193) 5.30 (0.209) 0.95 (0.037) 1.45 (0.057) 0.35 (0.014) -- 1 SMDC Series -- Size 7555mm/2920mils Recommended Pad Layout A B C B Packaging and Marking Information Recommended Pad Layout Figures [mm (in)] Part Number Tape and Reel Quantity Standard Package Part Marking Dimension A (Nom) Dimension B (Nom) Dimension C (Nom) Agency Recognition SMDC Series -- Size 7555mm/2920mils SMDC125F/33 4,000 20,000 125F 5.30 (0.209) 2.00 (0.079) 4.60 (0.18) UL SMDC185F/33 4,000 20,000 185F 33V 5.30 (0.209) 2.00 (0.079) 4.60 (0.18) UL, CSA, TUV SMDC300F/24 4,000 20,000 300F 24V 5.30 (0.209) 2.00 (0.079) 4.60 (0.18) UL, CSA, TUV SMDC310F/18 3,000 15,000 310F 18V 5.30 (0.209) 2.00 (0.079) 4.60 (0.18) UL, CSA, TUV (c) 2019 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 06/05/19 PolySwitch(R) Resettable PPTCs Surface Mount > SMDC Series Solder Reflow Recommendations Profile Feature Pb-Free Assembly Average ramp up rate (TsMAX to Tp) 3C/s max Preheat 150C * Temperature max (TsMAX) 200C * Time (tsMIN to tsMAX) 60-120 s Time maintained above: * Temperature (TL) 217C * Time (tL) 60-150 s Peak/Classification temperature (Tp) 260C TL Temperature * Temperature min (TsMIN) tp Tp Critical Zone TL to Tp Ramp Up tL TsMAX TsMIN ts Preheat 25 Reflow Profile Ramp Down t 25C to Peak Time Time within 5C of actual peak temperature Time (tp) 30 s max Ramp down rate 3C/s max Time 25C to peak temperature 8 min max Note: All temperatures refer to topside of the package, measured on the package body surface. Solder Reflow * Recommended reflow method: IR, hot air, nitrogen. * Recommended maximum paste thickness: 0.25mm (0.010in) * Devices can be cleaned using standard methods and aqueous solvents. * Experience has shown the optimum conditions for forming acceptable solder fillets occur when a reasonable amount of solder paste is placed underneath each device's termination. As such, we request that customers comply with our recommended solder pad layouts. * Customer should validate that the solder paste amount and reflow recommendations meet its application. * We request that customer board layouts refrain from placing raised features (e.g. vias, nomenclature, traces, etc.) underneath PolySwitch devices. It is possible that raised features could negatively impact solderability performance of our devices. Rework * Standard industry practices. (Please also avoid direct contact to the device.) Part Ordering Number System SMDC 125 F /33 -2 Packaging 2 = Tape and Reel Alternative Voltage Rating (If Applicable) Lead Free Hold Current Indicator Product Series (c) 2019 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 06/05/19 PolySwitch(R) Resettable PTCs Surface Mount > SMDC Series Tape and Reel Specifications SMDC EIA 481-1 Description SMDC125F/33 SMDC185F/33 SMDC300F/24 SMDC310F/18 W 16.0 0.30 16.0 0.30 16.0 0.30 P0 4.0 0.10 4.0 0.10 4.0 0.10 P1 8.0 0.10 8.0 0.10 8.0 0.10 P2 2.0 0.10 2.0 0.10 2.0 0.10 A0 5.5 0.1 5.35 0.1 5.5 0.1 B0 7.9 0.1 7.85 0.1 8.0 0.1 B1 max 12.1 12.1 12.1 D0 1.5 + 0.10/ -.00 1.5 + 0.10/ -.00 1.5 + 0.10/ -.00 F 7.50 0.10 7.50 0.10 7.50 0.10 E1 1.75 0.10 1.75 0.10 1.75 0.10 E2 min 14.25 14.25 14.25 T max 0.35 0.35 0.35 T1 max 0.1 0.1 0.1 K0 0.9 0.1 1.45 0.1 2.0 0.1 A max 330 330 330 N min 50 50 50 W1 16.4 + 2.0/-.00 16.4 + 2.0/-.00 16.4 + 2.0/-.00 W2 max 22.4 22.4 22.4 (c) 2019 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 06/05/19 PolySwitch(R) Resettable PPTCs Surface Mount > SMDC Series Tape and Reel Diagrams T P0 Cover Tape D0 P2 E1 F B1 K0 W E2 B0 T1 A0 Embossment P1 Center lines of cavity Figure 1 W2 (Measured at Hub) Cover Tape A N (Hub Dia.) W1 (Measured at Hub) Carrier Tape Embossed Cavity Figure 2 WARNING * Users should independently evaluate the suitability of and test each product selected for their own application. * Operation beyond the maximum ratings or improper use may result in device damage and possible electrical arcing and flame. * These devices are intended for protection against damage caused by occasional overcurrent or overtemperature fault conditions and should not be used when repeated fault conditions or prolonged trip events are anticipated. * Contamination of the PPTC material with certain silicone-based oils or some aggressive solvents can adversely impact the performance of the devices. * Device performance can be impacted negatively if devices are handled in a manner inconsistent with recommended electronic, thermal, and mechanical procedures for electronic components. * PPTC devices are not recommended for installation in applications where the device is constrained such that its PTC properties are inhibited, for example in rigid potting materials or in rigid housings, which lack adequate clearance to accommodate device expansion. * Operation in circuits with a large inductance can generate a circuit voltage (Ldi/dt) above the rated voltage of the device. Disclaimer Notice - 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 may not be used in, all applications. Read complete Disclaimer Notice at www.littelfuse.com/disclaimer-electronics. (c) 2019 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 06/05/19