Slow Blow Fuses
Slow Blow Fuses
Available in industry standard 1206 and 0603 chip sizes,
Raychem Slow Blow fuses help provide overcurrent
protection on systems that experience large and
frequent current surges as part of their normal
operation.
The Slow Blow 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 ideal for overcurrent protection of power
supplies, capacitor filter banks, LCD (Liquid Crystal
Display) 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
Features
• RoHS compliant
• Monolithic multilayer design
• High temperature performance
• -55°C to +125°C operating temperature range
Applications
• Small motors systems
• Portable electronics
• Input power ports
• Power over Ethernet (POE)
• Test equipment
• POL Converter Protection
• Computer drives
• Displays
• Printers
12
93
0
Table FS1 Clear Time Characteristics for Slow Blow Fuses
0603SFS Series
% of rated current
100%
200%
300%
800%(1.0A-1.5A)
800%(2.0A-5.0A)
Clear time at 25°C
4 hours (min.)
1 second (min.)
0.1 second (min.)
120 seconds (max.)
3 seconds (max.)
1206SFS Series
% of rated current
100%
200%
300%
800%
Clear time at 25°C
4 hours (min.)
1 second (min.)
0.1 second (min.)
120 seconds (max.)
3 seconds (max.)
0.0005 second (min.) 0.05 seconds (max.)
0
0.001 second (min.) 0.05 seconds (max.)
0.002 second (min.) 0.05 seconds (max.)
Table FS2
Typical Electrical Characteristics, Dimensions and Recommended Pad Layout for
Slow Blow Fuses
0603 (1608mm) Slow Blow Surface-mount Chip Fuses
Typical Electrical
Characteristics
Rated
Nominal
Nominal
Current
I
2
t
Cold DCR
2
(A sec)†
(A)
(Ω)*
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0.200
0.100
0.052
0.041
0.031
0.021
0.017
0.015
0.013
0.093
0.18
0.32
0.63
0.87
1.20
2.30
2.70
3.20
Max
Interrupt Ratings
Voltage
(V
DC
)
32
32
32
32
32
32
32
32
32
Current
(A)
40
40
40
40
40
40
40
40
40
Shape and
Dimensions
Inch (mm)
0.031±0.006
(0.80±0.15)
0.063±0.006
(1.60±0.15)
Part Number
0.031±0.006
(0.80±0.15)
0603SFS100F/32
0603SFS150F/32
0.014±0.006
(0.36±0.15)
0603SFS200F/32
0603SFS250F/32
Recommended
Pad Layout
Inch (mm)
0.110
(2.80)
0.024
(0.60)
0.039
(1.00)
0.043
(1.09)
0603SFS300F/32
0603SFS350F/32
0603SFS400F/32
0603SFS450F/32
0603SFS500F/32
1206 (3216mm) Slow Blow Surface-mount Chip Fuses
Typical Electrical
Characteristics
Nominal
Rated
Nominal
I
2
t
Current
Cold DCR
(A)
(Ω)*
(A
2
sec)†
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
0.082
0.070
0.032
0.028
0.024
0.020
0.016
0.014
0.011
0.010
0.009
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
Max
Interrupt Ratings
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
Shape and
Dimensions
Inch (mm)
0.063±0.008
(1.60±0.20)
0.126±0.008
(3.20±0.20)
Part Number
1206SFS100F/63
1206SFS125F/63
12
0.020±0.010
(0.51±0.25)
0.038±0.008
(0.97±0.20)
1206SFS150F/63
1206SFS200F/63
1206SFS250F/32
1206SFS300F/32
1206SFS350F/32
Recommended
Pad Layout
Inch (mm)
0.173
(4.40)
0.059
(1.50)
0.071
(1.80)
0.057
(1.45)
1206SFS400F/32
1206SFS450F/32
1206SFS500F/32
1206SFS550F/24
1206SFS600F/24
1206SFS700F/24
1206SFS800F/24
* Measured at 10% of rated current and 25°C ambient temperature
† Melting I
2
t at 0.001 sec clear time
94
RoHS compliant, ELV compliant
Slow Blow Fuses
Figure FS1-FS4 Family Average Clear Time
Figure FS1
0603SFS Average Clear Time
100
A
B
10
C
D
E
F
G H I
A =
B =
A
C =
D =
E =
F =
1.0A
1.5A
2.0A
2.5A
3.0A
3.5A
4.0A
4.5A
5.0A
1
G =
H =
I
=
Clear Time (Sec)
0.1
0.01
0.001
0.0001
0.00001
1
10
100
Current (A)
1
Figure FS2
A
10,000
A =
B =
C =
1000
D =
E =
F =
G =
100
H =
I
2
I
2
t (AI Sec)
0603SFS Family I
2
T vs. Clear Time
1.0A
1.5A
2.0A
2.5A
3.0A
3.5A
4.0A
4.5A
5.0A
=
12
10
G
1
I
H
F
E
D
C
0.1
B
A
0.01
0.00001
0.0001
0.001
0.01
0.1
1
10
100
Time (Sec)
Note:
Curves are typical
95
Figure FS1-FS4 Family Average Clear Time
Figure FS3
1206SFS Average Clear Time
1000
A =
1.0A
... Cont’d
B C
100
D
E
A
A
F GH I J K L
M N
B = 1.25A
A
C = 1.5A
D =
E =
F =
2.0A
2.5A
3.0A
4.0A
5.0A
6.0A
7.0A
10
G = 3.5A
H =
I
= 4.5A
Clear Time (Sec)
1
J =
L =
K = 5.5A
M=
0.1
N = 8.0A
0.01
0.001
0.0001
1
10
1
100
1000
Current (A)
Figure FS4
A
1000000
A =
C =
D =
E =
10000
F =
H =
I
1000
2
I
2
t (AI Sec)
1206SFS Family I
2
T vs. Clear Time
1.0A
1.5A
2.0A
2.5A
3.0A
4.0A
5.0A
6.0A
7.0A
B = 1.25A
100000
G = 3.5A
= 4.5A
J =
L =
12
K = 5.5A
100
M=
N = 8.0A
10
H
1
K
J
I
N
M
L
G
E
F
D
C
0.1
B
A
0.01
0.0001
0.001
0.01
0.1
1
10
100
1000
Time (Sec)
Note:
Curves are typical
96
Slow Blow Fuses
Table FS3 Environmental Specifications for Slow Blow Fuses
Operating Temperature
Mechanical Vibration
Mechanical Shock
Thermal Shock
Resistance to Soldering Heat
Solderability
Moisture Resistance
Salt Spray
-55°C to +125°C
Withstands 5-3000 Hz at 30 Gs when evaluated per Method 204 of MIL-STD-202
Withstands 1500 Gs, 0.5 millisecond half-sine pulses when evaluated per Method 213 of MIL-STD-202
Withstands 100 cycles from -65°C to +125°C when evaluated per Method 107 of MIL-STD-202
Withstands 60 seconds at +260°C when evaluated per Method 210 of MIL-STD-202
Meets 95% minimum coverage requirement when evaluated per Method 208 of MIL-STD-202
Withstands 10 cycles when evaluated per Method 106 of MIL-STD-202
Withstands 48-hour exposure when evaluated per Method 101 of MIL-STD-202
Table FS4 Material Specifications for Slow Blow Fuses
Construction Body Material
Termination Material
Fuse Element
Terminal Strength: Hanging test
Ceramic
Silver, Nickel, Tin
Silver
1.5kg, 30 seconds
Figure FS5 Thermal Derating Current for Slow Blow Fuses
Temperature Effect on Current Rating
105
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
-55
% De-rating
-35
-15
5
25
45
65
85
105
125
145
Maximum Operating Temperature (˚C)
12
Table FS5 Electrical Specifications for Slow Blow Fuses
Insulation Resistance after Opening
20,000Ω minimum @ rated voltage. Fuse clearing under low voltage conditions may result in lower
post-clearing insulation values. Under normal fault conditions values. Under normal fault conditions
Raychem fuses provide sufficient insulation resistance for circuit protection.
Withstands 100% rated current at +25°C ambient for 4 hours when evaluated per MIL-PRF-23419
Current Carrying Capacity
97
