SMDC185F/33-2 - LITTELFUSE

PolySwitch® Resettable PPTCs

Speciﬁcations are subject to change without notice.

Revised: 06/05/19

Surface Mount > SMDC Series

SMDC Series

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

Applications

Mobile Electronics and Batteries

• Computer

• Portable electronics

• Multimedia

• Game machines

• Telephone and broadband

• Automotive

• Industrial controls

• Battery

Agency Approvals

AGENCY AGENCY FILE NUMBER

E74889

78165

72161779

Electrical Characteristics

Part

Number

IHITVMAX IMAX PD MAX Max Time-to-trip RMIN R1MAX

(A) (A) (VDC) (A) (W) (A) (s) (Ω) (Ω)

SMDC Series — Size 7555mm/2920mils

SMDC125F/33 1.25 2.50 33 40 1.50 8.00 2.00 0.040 0.250

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 20°C still air.

IT : Trip current: minimum current that will switch the device from low resistance to high resistance in 20°C 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 20°C still air.

RMIN : Minimum resistance of device as supplied at 20°C unless otherwise specified.

R1MAX : Maximum resistance measured one hour post-trip or post-reflow at 20°C.

RoHS

Additional Information

Datasheet Resources Samples

PolySwitch® Resettable PTCs

Speciﬁcations are subject to change without notice.

Revised: 06/05/19

Surface Mount > SMDC Series

Temperature Rerating

Maximum Ambient Temperature

Part Number -40°C -20°C 0°C 20°C 25°C 40°C 50°C 60°C 70°C 80°C 85°C

Hold Current (A)

SMDC Series — Size 7555mm/2920mils

SMDC125F/33 2.02 1.78 1.55 1.31 1.25 1.08 0.96 0.84 0.72 0.60 0.54

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

100

120

140

160

180

200

-40 -20 0 20 40 60 80 100 120

Ambient Temperature (°C)

% of Rated Hold and Tr ip Current

Temperature Rerating Curve

PolySwitch® Resettable PPTCs

Speciﬁcations are subject to change without notice.

Revised: 06/05/19

Surface Mount > SMDC Series

Typical Time-to-Trip Curves at 20°C

SMDCxxxF

A = SMDC125F/33

B = SMDC185F/33

C = SMDC300F/24

D = SMDC310F/18

Time-to-Trip (s)

Fault Current (A)

100

0.1

0.01

0.001 110 010

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 Conditions Resistance Change

Storage Life PS300, Section 5.3.2 60°C, 1000 hrs

85°C, 1000 hrs

±3% typ

Humidity Aging PS300, Section 5.3.1 85°C, 85% R.H., 100 hrs ±1.2% typ

Thermal Shock MIL-STD-202, Method 107G 85°C, -40°C (20 Times)

125°C, -55°C (10 Times)

-33% typ

Vibration MIL-STD-883C per MIL-STD-883C No Change

Solvent Resistance PS300, Section 5.2.2

Freon

Trichloroethane

Hydrocarbons

No Change

Moisture Resistance Level Level 2a, J-STD-020

Storage Conditions 40°C 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.

PolySwitch® Resettable PTCs

Speciﬁcations are subject to change without notice.

Revised: 06/05/19

Surface Mount > SMDC Series

Figure 1

Dimension Figures

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, TÜV

SMDC300F/24 4,000 20,000 300F 24V 5.30 (0.209) 2.00 (0.079) 4.60 (0.18) UL, CSA, TÜV

SMDC310F/18 3,000 15,000 310F 18V 5.30 (0.209) 2.00 (0.079) 4.60 (0.18) UL, CSA, TUV

Recommended Pad Layout

Dimensions

Part Number

Dimensions in Millimeters (Inches)

FigureA B C D E

Min Max Min Max Min Max Min Max Min Max

SMDC Series — Size 7555mm/2920mils

SMDC125F/33 7.30 7.70 0.45 0.71 4.90 5.30 0.25 0.95 0.20 — 1

(0.287) (0.303) (0.018) (0.028) (0.193) (0.209) (0.010) (0.040) (0.008)

SMDC185F/33 7.30 7.70 0.90 1.20 4.90 5.30 0.25 0.95 0.20 — 1

(0.287) (0.303) (0.035) (0.047) (0.193) (0.209) (0.010) (0.040) (0.008)

SMDC300F/24 7.30 7.70 0.80 1.10 4.90 5.30 0.25 0.95 0.20 — 1

(0.287) (0.303) (0.031) (0.043) (0.193) (0.209) (0.010) (0.040) (0.008)

SMDC310F/18 7.30 7.70 1.10 1.70 4.90 5.30 0.95 1.45 0.35 — 1

(0.287) (0.303) (0.043) (0.067) (0.193) (0.209) (0.037) (0.057) (0.014)

PolySwitch® Resettable PPTCs

Speciﬁcations are subject to change without notice.

Revised: 06/05/19

Surface Mount > SMDC Series

Solder Reﬂow Recommendations

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.)

Critical Zone

TL to Tp

Ramp Up

t 25˚C to Peak

Reﬂow Proﬁle Time

Ramp Down

Preheat

TsMAX

TsMIN

Temperature

Proﬁle Feature Pb-Free Assembly

Average ramp up rate (TsMAX to Tp) 3°C/s max

Preheat

• Temperature min (TsMIN) 150°C

• Temperature max (TsMAX) 200°C

• Time (tsMIN to tsMAX) 60-120 s

Time maintained above:

• Temperature (TL) 217°C

• Time (tL) 60-150 s

Peak/Classiﬁcation temperature (Tp) 260°C

Time within 5°C of actual peak temperature

Time (tp) 30 s max

Ramp down rate 3°C/s max

Time 25°C to peak temperature 8 min max

Note: All temperatures refer to topside of the package, measured on the package body

surface.

SMDC 125 F /33 -2

Packaging

2 = Tape and Reel

Alternative Voltage Rating (If Applicable)

Lead Free

Hold Current Indicator

Product Series

Part Ordering Number System

PolySwitch® Resettable PTCs

Speciﬁcations are subject to change without notice.

Revised: 06/05/19

Surface Mount > SMDC Series

Tape and Reel Speciﬁcations

Description

SMDC

EIA 481-1

SMDC125F/33

SMDC185F/33

SMDC300F/24 SMDC310F/18

W16.0 ± 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

A05.5 ± 0.1 5.35 ± 0.1 5.5 ± 0.1

B07.9 ± 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

K00.9 ± 0.1 1.45 ± 0.1 2.0 ± 0.1

A max 330 330 330

N min 50 50 50

W116.4 + 2.0/-.00 16.4 + 2.0/-.00 16.4 + 2.0/-.00

W2 max 22.4 22.4 22.4

PolySwitch® Resettable PPTCs

Speciﬁcations are subject to change without notice.

Revised: 06/05/19

Surface Mount > SMDC Series

Tape and Reel Diagrams

Cover Tape

Embossment

Center lines

of cavity

A0P1

Cover Tape

Embossed Cavity

Carrier Tape

N (Hub Dia.)

W2 (Measured at Hub)

W1 (Measured at Hub)

Figure 1

Figure 2

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.

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.