Littelfuse 157T User Manual

Surface Mount Fuses

NANO2® > 157T Fuse and Holder Combination

157T Series – Standard Nano Fuse and Clip Assembly

Description

The 157T Series Fuse/Clip assembly is a small, square,
Time-Lag, surface mount fuse that is assembled in surface
mountable fuse clips. The unique time delay feature of this
fuse design helps solve the problem of nuisance “opening”
by accommodating inrush currents that normally cause a
fast acting fuse to open.

The fuse clip and pre-installed fuse combination can
be automatically placed in PC Board in one efficient
manufacturing operation. It permits quick and easy
replacement of fuses without performing desoldering
process, even in the field and without exposing the PC
Board to detrimental effects of rework solder heat.

Agency Approvals

AGENCY AGENCY FILE NUMBER AMPERE RANGE

E14721 0.375A ~ 5A

PS

E

NBK030205-E10480A
NBK030205-E10480B

1A

1.5A-5A

Electrical Characteristics for Series

Features

• SurfaceMountable,
Time-Lag Fuse.

• Fullycompatiblewith

RoHS/Pb-Free solder
alloys and higher
temperature profiles
associated with leadfree
assembly.

PS

E

• EasilyreplaceableonPC

Board (Field Replaceable)

• RoHSCompliantand

Halogen-free

• Availableinratingsof

0.375 ~ 5 Amperes.

% of Ampere

Rating

100% 0.375A ~ 5A 4 hours, Minimum

200% 0.375A ~ 5A

300% 0.375A ~ 5A

800% 0.375A ~ 5A

% of Ampere

Rating

Opening Time at 25ºC

1 sec. Minimum,

60 secs. Maximum

0.20 secs. Minimum,

3.00 secs. Maximum

0.02 secs. Minimum,

0.10 secs. Maximum

Applications

• Instrumentations

• BaseStations

Additional Information

Datasheet

• Telecommunications

Resources

Electrical Specifications by Item

Ampere

Rating (A)

0.375 .375 125

0.500 .500 125 0454.500 0.7047 0.240 X

0.750 .750 125 0454.750 0.3602 0.904 X

1.00 001 125 0454001. 0.2245 1.98 X X

1.50 01.5 125 045401.5 0.0934 3.65 X X

2.00 002 125 0454002. 0.0629 8.20 X X

2.50 02.5 125 045402.5 0.0452 15.0 X X

3.00 003 125 0454003. 0.0342 20.16 X X

3.50 03.5 125 045403.5 0.0226 26.53 X X

4.00 004 125 0454004. 0.0188 34.40 X X

5.00 005 125 0454005. 0.0138 53.72 X X

1. Cold resistance measured at less than 10% of rated current at 23ºC.

2

2. I

t values stated for 8ms opening time.

3. Agency Approval Table Key: X=Approved or Certified, P=Pending and Blank=Not Approved

4. Have special electrical characteristic needs? Contact Littelfuse to learn more about application specific options

Amp

Code

Max Voltage

Rating (V)

Interrupting

Rating

(A)

50A @ 125VAC/VDC

Fuse

Furnished

0454.375 1.2214 0.101 X

Nominal Cold

Resistance

(Ohms)

Nominal

Melting

2

t (A2sec)

I

Specifications are subject to change without notice.

Agency Approvals

Samples

© 2013 Littelfuse, Inc.

Revised: 12/19/13

PS

E

Surface Mount Fuses

NANO2® > 157T Fuse and Holder Combination

Temperature Rerating Curve

Note:

1. Derating depicted in this curve is in addition to the standard derating of 25% for
continuous operation.

Average Time Current Curves

.375A

.50A

.75A

1.0A

100

10

1

TIME IN SECONDS

0.1

0.01

0.001

0.1

1.5A

1

CURRENT IN AMPS

3.0A

2.5A

2.0A

3.5A4A5A

10 100

Soldering Parameters

Reflow Condition Pb – Free assembly

- Temperature Min (T

Pre Heat

- Temperature Max (T

- Time (Min to Max) (ts) 60 – 120 secs

Average ramp up rate (Liquidus Temp
(T

) to peak

L

to TL - Ramp-up Rate 5°C/second max

T

S(max)

Reflow

- Temperature (TL) (Liquidus) 217°C

- Temperature (tL) 60 – 90 seconds

Peak Temperature (TP) 250

Time within 5°C of actual peak
Temperature (t

)

p

Ramp-down Rate 5°C/second max

Time 25°C to peak Temperature (T
Do not exceed 260°C

) 150°C

s(min)

) 200°C

s(max)

5°C/second max

+0/-5

°C

20 – 40 seconds

) 8 minutes Max.

P

Temperature

T

S(max)

T

T

T

S(min)

25

P

L

time to peak temperature

(t 25ºC to peak)

Preheat

t

S

Ramp-up

t

P

Critical Zone

T

to T

L

P

t

L

Ramp-down

Time

© 2013 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 12/19/13

Product Characteristics

6.50 ± 0.20

3.90 ± 0.1
34]

[0.09]

Surface Mount Fuses

NANO2® > 157T Fuse and Holder Combination

Materials

Product
Marking

Clip Retention

Solderability

Humidity Test

Resistance to
Solvents

Dimensions

1.45

[0.057]

Body: Ceramic
Cap: For 0.375A ~ 5A – Silver plated Brass
Clip Plating: Matte Tin

Body: Brand Logo, Current Rating, “T” for

Time-Lag

Force applied at fuse center, perpendicular to
the long axis (@0.75 lbs. MIN)

MIL-STD-202, Method 208 / IPC/ EIA /
JEDEC J-STD002B, Test Condition A

MIL –STD-202, Method 103 @ 85ºC / 85%RH,
1000 hours

MIL-STD-202, Method 215 (3 solvent types)

[0.256]

6.10

[0.240]

F

L

T

3.7 ± 0.13
[0.146]

2.69

[0.106]

2.69

[0.106]

1 A

3.70

[0.146]

Operating
Temperature

Thermal Shock

Vibration

Moisture Resistance

Salt Spray/
Atmosphere

Shock

Part Numbering System

0157 005. D R T

SERIES

AMP CODE

-55ºC to 125ºC with proper derating

MIL-STD-202, Method 107,
Test Condition B
(5 cycles -65ºC to +125ºC)

MIL-STD-202, Method 201
(10-55 Hz)

MIL-STD-202, Method 106,
10 cycles

MIL-STD-202, Method 101,
Test Condition B (48 hrs.), 5% NaCl in
De-ionized Water

MIL-STD-202, Method 213,
Test Condition I (100 G’s peak for 6
milliseconds)

TIME-LAG FUSE

PACKING OPTION

R = Tape and Reel

qUANTITY CODE

D = 1500 pcs

3

[0.154]

2.50 ± 0.2
[0.098]

"A"

3.00

[0.12]

PCB Recommendation for Thermal Management

1. Minimum Copper Layer Thickness = 100um

2. Minimum Copper Trace Width = 10mm

Note:
Alternate methods of thermal management may be used. In such cases, under normal

operations, the maximum temperature of the fuse body should not exceed 80ºC in a 25ºC
ambient environment.

0.10

"B"

7.26

[0.29]

2.46

[0.10]

2.40

3.40

[0.1

Packaging

Packaging

Option

Tape and Reel Surface Mount 1500 DRT

Packaging

Specification

Quantity

Quantity &

Packaging Code

Specifications are subject to change without notice.

© 2013 Littelfuse, Inc.

Revised: 12/19/13