SURFACE-MOUNT FUSES
Slow-Blow Chip Fuses
Available in industry standard 1206 and 0603 chip sizes,
Littelfuse slow-blow chip fuses help provide overcurrent
protection on systems that experience large and frequent
current surges as part of their normal operation.
The slow-blow chip fuse’s monolithic, multilayer design
helps provide some of the highest current ratings
available in the 1206 and 0603 footprints and enhances
high-temperature performance in a wide range of
circuit protection designs. The devices’ small size, high
reliability and strong arc suppression characteristics
make them suitable for overcurrent protection of power
supplies, capacitor filter banks, Liquid Crystal Display
(LCD) backlight inverters, electric motors and portable
electronics.
BENEFITS
• Time-delayed design prevents nuisance openings in
pulsed and high inrush current applications
• Small size with high-current ratings
• Strong arc suppression characteristics
APPLICATIONS
• Small motors systems
• Portable electronics
• Input power ports
• Power over Ethernet (PoE)
• Test equipment
• POL converter protection
• Computer drives
• Displays
• Printers
FEATURES
• Lead-free materials and RoHS compliant
• Halogen free
(refers to: Br≥900ppm, Cl≥900ppm, Br+Cl≥1500ppm)
• Monolithic multilayer design
• High-temperature performance
• -55°C to +125°C operating temperature range
102
Specifications subject to change without notice. ©2018 Littelfuse, Inc.
HF
Halogen Free
RoHS Compliant, ELV Compliant
Shape and
Surface Mount Fuses
Dimensions
in (mm)
Slow-Blow Chip Fuses
0.063±0.008
(1.60±0.20)
0.126±0.008
(3.20±0.20)
Table FS1 — Clear Time Characteristics
0603SFS Series
% of Rated Current
100%
Recommended
300%
Pad Layout
in (mm)
0.020±0.010
4 hrs
(0.51±0.25)
0.173
(4.40)
0.038±0.008
(0.97±0.20)
1206SFS Series
% of Rated Current
—
100%
200%
300%
800% (1.0A-1.5A)
800% (2.0A-8.0A)
Clear Time at 25°C
4 hrs (min)
1 s (min)
0.1 s (min)
0.0016 s (min)
0.002 s (min)
—
120 s (max)
3 s (max)
0.05 s (max)
0.05 s (max)
Clear Time at 25°C
(min)
1 s (min)
0.1 s (min)
s (min)
(1.80)
200%
120 s (max)
3 s (max)
0.05 s (max)
0.05 s (max)
800% (1.0A-1.5A)
0.059
(1.50)
0.0005
800% (2.0A-5.0A)
0.057
(1.45)
0.001 s (min)
0.071
Table FS2 — Typical Electrical Characteristics, Dimensions and Recommended
Typical
Max
Pad Layout
Electrical Characteristics
Interrupt Ratings
0603 (1608 mm) Slow-Blow Chip Fuses
Shape and
Dimensions
in (mm)
0.031±0.006
(0.80±0.15)
0.063±0.006
(1.60±0.15)
Rated
Current
(A)
Part Number
0603SFS100F/32
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
6.0
7.0
8.0
Nominal Nominal
Cold DCR
I
2
t
(Ω)*
(A
2
sec)
†
0.200
0.100
0.052
0.041
0.031
0.021
0.017
0.015
0.013
0.010
0.008
0.006
0.093
0.18
0.32
0.63
0.87
1.20
2.30
2.70
3.20
4.00
5.00
7.00
Voltage
(V
DC
)
32
32
32
32
32
32
32
32
32
32
32
32
Current
(A)
50
50
50
50
50
50
50
50
50
80
80
80
0.031±0.006
(0.80±0.15)
0603SFS150F/32
0603SFS200F/32
0.014±0.006
(0.36±0.15)
0603SFS250F/32
0603SFS300F/32
0603SFS350F/32
0603SFS400F/32
0.039
(1.00)
Recommended
Pad Layout
in (mm)
0.110
(2.80)
0.024
(0.60)
0603SFS450F/32
0603SFS500F/32
PSR-27781
PSR-27893
0.043
(1.09)
1206 (3216 mm) Slow-Blow Chip Fuses
Shape and
Dimensions
in (mm)
0.063±0.008
(1.60±0.20)
PSR-28024
Typical
0.126±0.008
(3.20±0.20)
Max
Interrupt Ratings
Electrical Characteristics
Rated
Current
(A)
Part Number
1206SFS100F/63
1.0
1.25
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
7
.0
8.0
0.360
0.200
0.150
0.088
0.065
0.034
0.028
0.024
0.020
0.016
0.014
0.011
0.010
0.009
Nominal Nominal
Cold DCR
I
2
t
(Ω)*
(A
2
sec)
†
0.11
0.22
0.23
0.63
0.90
1.20
1.60
2.20
3.60
5.30
6.40
8.50
10.00
16.90
0.038±0.008
(0.97±0.20)
Voltage
(V
DC
)
63
63
63
63
32
32
32
32
32
32
24
24
24
24
Current
(A)
50
50
50
50
50
50
50
50
50
50
50
60
60
60
0.020±0.010
(0.51±0.25)
1206SFS125F/63
1206SFS150F/63
Recommended
Pad Layout
in (mm)
0.173
(4.40)
0.059
(1.50)
0.071
(1.80)
0.057
(1.45)
1206SFS200F/63
1206SFS250F/32
1206SFS300F/32
1206SFS350F/32
1206SFS400F/32
1206SFS450F/32
1206SFS500F/32
1206SFS550F/24
Shape and
Dimensions
in (mm)
0.031±0.006
(0.80±0.15)
1206SFS600F/24
0.063±0.006
(1.60±0.15)
1206SFS700F/24
1206SFS800F/24
0.031±0.006
(0.80±0.15)
* Measured at ≤10% of rated current and 25°C ambient temperature.
† Melting I
2
t at 0.001 sec clear time.
0.014±0.006
(0.36±0.15)
RoHS Compliant, ELV Compliant
0.110
Recommended
(2.80)
Pad Layout
0.024
in (mm)
HF
Halogen Free
Specifications subject to change without notice. ©2018 Littelfuse, Inc.
Surface Mount Fuses
Slow-Blow Chip Fuses
Figures FS1-FS6 — Family Performance Curves
Figure FS1
1.0
A
100
0603SFS Average Time Current Curves
1.5
A
2. 0
2. 5
3.0A
A
3.5
A
4.0
A
4.5
A
5.0
A
10
10
Clear Time (s)
1
0.1
0.01
0.001
1
100
A
Current (A)
Figure FS2
0603SFS Family I
2
T vs. Clear Time
0603SFS I²t vs. t Curves
10,000
5.0A
4.5A
4.0A
3.5A
3.0A
2.5A
2.0A
5.0A
4.5A
4.0A
3.5A
3.0A
2.5A
1.5A 2.0A
1.0A 1.5A
1.0A
100
100
10,000
1000
1000
I
2
t (A
2
Sec)
I
2
t (A
2
s)
10
10
1
1
0.1
0.1
0.01
0.00001
0.01
0.001
0.0001
0.01
0.001
0.01
0.1
0.1
1
1
Time (Sec)
Time (s)
10
10
100
100
Note:
Curves are nominal.
104
Specifications subject to change without notice. ©2018 Littelfuse, Inc.
HF
Halogen Free
RoHS Compliant, ELV Compliant
Surface Mount Fuses
Slow-Blow Chip Fuses
Figures FS1-FS6 — Family Performance Curves
Figure FS3
1206SFS Average Time Current Curves
1. 2
5A
1.5
A
A
3.0
3 . 5A
4.0A
4.5A
5.0 A
5 . 5A
6 .0 A
7.0 A
A
8 .0
A
1.0
A
A
2. 0
2. 5
(Cont’d)
100
10
Clear Time (s)
1
0.1
0.01
0.001
1
10
100
1000
Current (A)
Figure FS4
1206SFS I²t vs. t Curves
100000
8.0A
7.0A
6.0A
5.5A
5.0A
4.5A
4.0A
3.5A
3.0A
2.5A
2.0A
1.5A
1.25A
1.0A
10000
1000
100
I
2
t (A
2
s)
10
1
0.1
0.01
0.001
0.01
0.1
1
10
100
Time (s)
Note:
Curves are nominal.
Please go to page 108 for more information about Slow-Blow Chip Fuses.
RoHS Compliant, ELV Compliant
HF
Halogen Free
Specifications subject to change without notice. ©2018 Littelfuse, Inc.
Surface Mount Fuses
Slow-Blow Chip Fuses
Figures FS1-FS6 — Family Performance Curves
Figure FS5
0603SFS PSR part Average Time Current Curves
(Cont’d)
Clear Time (s)
Current (A)
Figure FS6
0603SFS PSR part I
2
t vs. t Curve
Note:
Curves are nominal.
Current (A)
Littelfuse products are not designed for, and shall not be used for, any purpose (including, without limitation, automotive, 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.
Notice:
106
Specifications subject to change without notice. ©2018 Littelfuse, Inc.
Clear Time (s)
HF
Halogen Free
RoHS Compliant, ELV Compliant