0251012.MRT1 - Littelfuse Inc. - Datasheet.Directory

Speciﬁcations are subject to change without notice.

Revised: 05/31/18

Axial Lead & Cartridge Fuses

PICO® ll > Very Fast-Acting Fuse > 251/253 Series

251/253 Series, PICO® II Very Fast-Acting Fuse

Description

The PICO® II Very Fast-Acting Fuse is designed to meet an

extensive array of performance characteristics in a

space-saving subminiature package.

Agency Approvals

Features

Electrical Characteristics for Series

% of Ampere

Rating Ampere Rating Opening Time

100% 0.062A - 15A 4 Hours, Min.

200%

0.062A - 7A 1 Second, Max.

10A 3 Seconds, Max.

12 - 15A 10 Seconds, Max.

275%

0.500A, 1A, 2A,

2.5A, 3A, 4A, 5A,

7A, 10A

300 msecs., Max.

400% 0.5A, 1A, 2A, 2.5A,

3A, 4A, 5A, 7A, 10A 30 msecs., Max.

1000%

0.500A, 1A, 2A,

2.5A, 3A, 4A, 5A,

7A, 10A

4 msecs., Max.

Applications

• Flat–panel display TV

• LCD monitor

• LCD backlight inverter

• Ofﬁce machines

• Power supply

• Audio/Video system

• Lighting system

• Medical equipment

Secondary protection for space constrained applications

QPL

• Very fast-acting

• Small size

• Wide current rating range

(0.062A- 15A)

• Halogen-free available

• Wide operating

temperature range

• Low temperature re-rating

Application testing is strongly recommended.

Agency

Agency File Number

Ampere Range

253 Series 251 Series

E10480 0.062A - 15A

29862 0.062A - 15A

EPSE_NBK200416-JP1021 1A - 5A

J50158379 0.500A - 10A

FM10 N/A 0.062A - 15A

2009010207366577 0.500A, 1A, 2A,

2.5A, 3A, 4A, 5A

Note: See Electrical Speciﬁcations by Item table for speciﬁc approved ratings.

Additional Information

Datasheet Samples

Resources

Datasheet Samples

Resources

251 Series

253 Series

251 Series

253 Series

251 Series

253 Series

Speciﬁcations are subject to change without notice.

Revised: 05/31/18

Axial Lead & Cartridge Fuses

PICO® ll > Very Fast-Acting Fuse > 251/253 Series

Electrical Speciﬁcations by Item

Note: Higher ampere ratings are available. Please contact Littelfuse Technical Support or your Littelfuse products representative for assistance.

Ampere

Rating

(A)

Amp

Code

Ordering

Number

(Std.)

Ordering

Number

(Mil.)

Max

Voltage

Rating

(V)

Interrupting

Rating

Nominal

Cold

Resistance

(Ohms)

Nominal

Melting

I2t (A2 sec)

Nom

Voltage

Drop

(V)

Agency Approvals

253 Series

Only

.062 .062 251.062 253.062 125

300 A @

125VDC

50A@125VAC

7.000 0.000113 1. 4 x x x

.125 .125 251.125 253.125 125 1.700 0.00174 0.285 x x x

.200 .200 251.200 253.200 125 0.895 0.0048 0.345 x x

.250 .250 251.250 253.250 125 0.665 0.0116 0.24 x x x

.375 .375 251.375 253.375 125 0.395 0.0296 0.215 x x x

.500 .500 251.500 253.500 125 0.302 0.0598 0.2165 x x x x x

.630 .630 251.630 125 0.205 0.08 0.188 x x

.750 .750 251.750 253.750 125 0.175 0.153 0.176 x x x x

1. 0 0 0 01. 251001. 253001. 125 0.128 0.256 0.194 x x x x x x

1.25 1.25 2511.25 125 0.100 0.390 0.2 x x x

1.50 01. 5 25101.5 25301.5 125 0.0823 0.587 0.21 x x x x x

2.00 002. 251002. 253002. 125 0.0473 0.405 0.141 x x x x x x

2.50 02.5 25102.5 125 0.0360 0.721 0.132 x x x x x

3.00 003. 251003. 253003. 125 0.0295 1. 19 0.131 x x x x x x

3.50 03.5 25103.5 125 0.0240 1.58 0.1205 x x x x

4.00 004. 251004. 253004. 125 0.0204 2.45 0.114 x x x x x x

5.00 005. 251005. 253005. 125 0.0158 4.14 0.11 x x x x x x

7. 0 0 0 0 7. 251007. 253007. 125 0.0107 10.4 0.102 x x x x

10.0 010. 251010. 253010. 125 0.0072 25.5 0.1 x x x x

12.0 012. 251012. 32 0.0059 45.2 0.0878 x x

15.0 015. 251015. 253015. 32 0.00446 68.8 0.071 x x x

300A@32VDC

& 50A@32VAC

Speciﬁcations are subject to change without notice.

Revised: 05/31/18

Axial Lead & Cartridge Fuses

PICO® ll > Very Fast-Acting Fuse > 251/253 Series

Average Time Current Curves

Soldering Parameters

100

0.1

0.01

0.001

.062A

0.05 0.1 110100 1000

.125A

.250A

.375A

.500A

.750A

.630A

1.5A

2.5A

3.5A

10A

12A

15A

TIME IN SECONDS

CURRENT IN AMPERES

1.25A

Recommended Hand Soldering Parameters:

Solder Iron Temperature: 350°C +/- 5°C

Heating Time: 5 seconds max.

Note: These devices are not recommended for IR or

Convection Reﬂow process

Recommended Process Parameters:

Note:

1. Re-rating depicted in this curve is in addition to the standard derating of 25% for

continuous operation.

Temperature Re-rating Curve

Wave Parameter Lead-Free Recommendation

for 251 Series only

Preheat:

(Depends on Flux Activation Temperature) (Typical Industry Recommendation)

Temperature Minimum: 100°C

Temperature Maximum: 150°C

Preheat Time: 60-180 seconds

Solder Pot Temperature: 260°C Maximum

Solder Dwell Time: 2-5 seconds

Speciﬁcations are subject to change without notice.

Revised: 05/31/18

Axial Lead & Cartridge Fuses

PICO® ll > Very Fast-Acting Fuse > 251/253 Series

Materials

Encapsulated, Epoxy-coated Body

251 Series: Pure tin-coated copper wire leads

253 Series: Solder-coated copper wire leads

Solderability MIL-STD-202, Method 208

Lead Pull Force MIL-STD-202, Method 211, Test Condition A

(will withstand a 7lbs. axial pull test)

Fuses To MIL

SPEC

For fuses to MIL-PRF-23419, FM10 change the

series number from

251 to 253

Operating

Temperature –55ºC to +125ºC (Consider re-rating)

Product Characteristics

Vibration

MIL-STD-202, Method 201 (10–55

Hz); Method 204, Test Condition C

(55–2000 Hz at 10 G’s Peak)

Shock

MIL-STD-202, Method 213, Test

Condition I (100 G’s peak for 6

msecs.)

Insulation Resistance

(After Opening):

MIL-STD-202, Method 302,

Test Condition A (10,000 ohms

minimum at 100 volts)

Moisture Resistance MIL-STD-202, Method 106

Resistance to Soldering

Heat

Withstands 60 seconds above 200OC

and up to 260ºC, maximum

Flammability Rating UL 94V–0

Dimensions

Packaging

Part Numbering System

Packaging Option Packaging

Speciﬁcation

Quantity &

Packaging Code

*T1: 52.4mm (2.062")

Tape and Reel EIA 296 Please refer to

available quantities

above in "Part

Numbering

System”

**T3: 73mm (2.874')

Tape and Reel EIA 296

0251 xxxx N R T1

Lead Length

Type of Packaging

Quantity

Current Rating

Series

The default lead length for Ammo pack and

Loose pack is now T1 for 251 series, and

remains T3 for 253 series, therefore:

T1 = 52.4mm (2.062”), 251 series only*

Blank = 52.4mm (2.062”) for 251 series*

or 73mm (2.874”) for 253 series**

R = Reel

A = Ammo Pack

X = Loose Pack

N = 5000

P = 2000

M = 1000

H = 10 0

Refer to Amp Code column of

Electrical Speciﬁcations Table

251

= Standard type

253

= Military type

Option Codes

L = RoHS + HF

(Only applies to 251 Series)

The default lead length for both ammo pack and loose pack is T1 for 251 and is T3 for 253.

Notes: * T1 dimension is deﬁned as the length of the component between the two

tapes. The full component length is 62.7mm (2.468"). T1 length is for 251 series only.

** T3 dimension is deﬁned as the length of the component between the two

tapes. The full component length is 83.3.7mm (3.28”). T3 length is for 253 series only.

Wire Diameter:

0.64 (.025") for 0.062-10 amp,

0.81 (.032") for 15 amp

2.61 (.103")

MAX 6.35 (.25")

tape

5.0 (.197")

6.35 (.25")

tape

38.1

(1.5")

38.1

(1.5")

7.11 (.280")

83.31 (3.28")

253 Series Markings

(T3 lead length)

L1 A

73.0 (2.874")**

Wire Diameter:

0.64 (.025") for 0.062-10 amp,

0.81 (.032") for 12-15 amp

1 A

27.78

(1.094")

27.78

(1.094")

7.11 (.280")

62.7 (2.468")

52.4 (2.062")*

2.80

(.11")

MAX 6.35 (.25")

tape

5.0 (.197")

6.35 (.25")

tape

251 Series Markings

(T1 lead length)

Wire Diameter:

0.64 (.025") for 0.62-10.0 amp,

0.81 (.032") for 12-15 amp

L1 A

1 A

27.78

(1.094")

27.78

(1.094")

7.11 (.280")

62.7 (2.468")

52.4 (2.062")*

2.80

(.11")

MAX 6.35 (.25")

tape

5.0 (.197")

6.35 (.25")

tape

251 Series (Halogen-free Version) Markings

(T1 lead length)

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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: