NFR25/25H
Vishay BCcomponents
Fusible, Non-Flammable Resistors
FEATURES
•
•
•
•
Overload protection without risk of fire
Wide range of overload currents
Lead (Pb)-free solder contacts
Pure tin plating provides compatibility with lead (Pb)-free
and lead containing soldering processes
•
Compatible with "Restriction of the use of Hazardous
Substances" (RoHS) directive 2002/95/EC (issue 2004)
APPLICATIONS
•
Audio
•
Video
A homogeneous film of metal alloy is deposited on a
high grade ceramic body. After a helical groove has
been cut in the resistive layer, tinned connecting wires
of electrolytic copper are welded to the end-caps. The
resistors are coated with a grey, flame retardant lacquer
which provides electrical, mechanical, and climatic pro-
tection. The encapsulation is resistant to all cleaning
solvents in accordance with “MIL-STD-202E, method 215”,
and “IEC 60068-2-45”.
TECHNICAL SPECIFICATIONS
DESCRIPTION
Resistance
Resistance tolerance and series
Maximum dissipation at T
amb
= 70
°C
Thermal resistance R
th
Temperature coefficient:
0.22
Ω ≤
R
≤
4.7
Ω
4.7
Ω <
R
≤
15
Ω
15
Ω <
R
≤
15 kΩ
Maximum permissible voltage (DC or RMS)
Basic specifications
Climatic category (IEC 60068)
Stability after:
load
climatic tests
soldering
Note
1. Ohmic values (other than resistance range) are available on request.
range
1)
VALUE
NFR25
0.22
Ω
to 15 kΩ
± 5 %; E24 series
0.33 W
240 K/W
0.5 W
150 K/W
NFR25H
≤
± 200
×
10
-6
/K
≤
± 200
×
10
-6
/K
-6
/K
≤
± 200
×
10
≤
± 100
×
10
-6
/K
-6
/K
≤
± 100
×
10
≤
± 100
×
10
-6
/K
250 V
350 V
IEC 60115-1 and 60115-2
55/155/56
∆R/R
max.: ± 1 % + 0.05
Ω
∆R/R
max.: ± 1 % + 0.05
Ω
∆R/R
max.: ± 0.25 % + 0.05
Ω
12NC INFORMATION
•
The resistors have a 12-digit numeric code starting with 23
•
The subsequent 7 digits indicate the resistor type and
packing
•
The remaining 3 digits indicate the resistance values:
– The first 2 digits indicate the resistance value
– The last digit indicates the resistance decade
Last Digit of 12NC Indicating Resistance Decade
RESISTANCE DECADE
0.22 to 0.91
Ω
1 to 9.1
Ω
10 to 91
Ω
100 to 910
Ω
1 to 9.1 kΩ
10 to 15 kΩ
LAST DIGIT
7
8
9
1
2
3
12NC Example
The 12NC for a NFR25 resistor with value 750
Ω,
supplied
on a bandolier of 1000 units in ammopack is:
2322 205 13751.
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Document Number: 28737
Revision: 02-Dec-05
NFR25/25H
Fusible, Non-Flammable Resistors
Vishay
12NC
- resistor type and packing
ORDERING CODE 23.. ... .....
BANDOLIER IN AMMOPACK
TYPE
RADIAL TAPED
4000
units
NFR25
NFR25H
06 204 03...
06 207 03...
1000
units
22 205 13...
22 207 13...
STRAIGHT LEADS
5000
units
22 205 33...
22 207 33...
BANDOLIER
ON REEL
STRAIGHT LEADS
5000
units
22 205 23...
22 207 23...
PART NUMBER
PART NUMBER: NFR2500002207JA100
N
MODEL/SIZE
NFR2500
NFR25H0
F
R
2
5
0
0
0
0
2
2
0
7
J
A
1
0
0
SPECIAL
The 2 digits
are used for
all special
parts.
00
= standard
SPECIAL CHARACTER
0
= neutral
Z
= value overflow
(Special)
TC/MATERIAL
0
= standard
VALUE
3 digit value
1 digit multiplier
Multiplier:
7
= *10
-3
8
= *10
-2
9
= *10
-1
0
= *10
0
1
= *10
1
2
= *10
2
TOLERANCE
J
=±5%
PACKING
1)
N4
A5
A1
R5
PRODUCT DESCRIPTION: NFR25 5 % A1 R22
NFR25
MODEL/SIZE
NFR25
NFR25H
1)
5%
TOLERANCE
±
5
%
A1
PACKING
1)
A1
A5
R22
RESISTANCE VALUE
47K
= 47 KΩ
50R1
= 50.1
Ω
Please refer to table PACKING for details.
Note
Products can be ordered using either the 12NC or the PART NUMBER. The PART NUMBER is shown to facilitate the introduction of a unified
part numbering system. Currently, this PART NUMBER is applicable in the Americas only.
PACKING
CODE
N4
A5
A1
R5
PIECES
4 000
5 000
1 000
5 000
DESCRIPTION
Bandolier in ammopack radial taped
Bandolier in ammopack straight leads
NFR25, NFR25H
Bandolier in ammopack straight leads
Bandolier on reel straight leads
MODEL/SIZE
Document Number: 28737
Revision: 02-Dec-05
For technical questions contact: ff3dresistors@vishay.com
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117
NFR25/25H
Vishay BCcomponents
DIMENSIONS
L
1
Fusible, Non-Flammable Resistors
∅
d
∅
D
L
2
Outline
DIMENSIONS
- resistor types and relevant physical dimensions
TYPE
NFR25
NFR25H
∅
D
MAX.
2.5
L
1
MAX.
6.5
L
2
MAX.
7.5
∅
d
0.58 ± 0.05
MASS PER 100 UNITS
TYPE
NFR25
NFR25H
MASS
(g)
20.1
20.1
OUTLINES
The length of the body (L
1
) is measured by inserting the
leads into holes of two identical gauge plates and moving
these plates parallel to each other until the resistor body is
clamped without deformation (“IEC publication 60294”).
MARKING
The nominal resistance and tolerance are marked on the
resistor using four coloured bands in accordance with
IEC publication 60062 “Colour codes for fixed resistors”.
For ease of recognition a fifth ring is added, which is violet for
type NFR25 and white for type NFR25H.
FUNCTIONAL PERFORMANCE
PRODUCT CHARACTERIZATION
Standard values of nominal resistance are taken from the
E24 series for resistors with a tolerance of ± 5 %.
The values of the E24 series are in accordance with
“IEC publication 60063”.
LIMITING VALUES
TYPE
NFR25
NFR25H
Note
1. The maximum voltage that may be continuously applied to the resistor element, see “IEC publication 60115-1”.
The maximum permissible hot-spot temperature is 155 °C.
LIMITING VOLTAGE
1)
(V)
250
350
LIMITING POWER
(W)
0.33
0.5
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Document Number: 28737
Revision: 02-Dec-05
NFR25/25H
Fusible, Non-Flammable Resistors
Vishay BCcomponents
The power that the resistor can dissipate depends on the operating
temperature.
The resistors will fuse without the risk of fire and within an indicated
range of overload. Fusing means that the resistive value of the
resistor increases at least 100 times.
The fusing characteristic is measured under constant voltage.
P
max
(%P
rated
)
100
10
3
t
(s)
10
2
50
10
1
0
- 55
0
50
70
100
155
T
amb
(°C)
10
-1
0
4
8
12
16
20
24
P
overload
(W)
Maximum dissipation (P
max
) in percentage of rated power as
a function of the ambient temperature (T
amb
)
Derating
10
3
t
(s)
10
2
NFR25
This graph is based on measured data which may deviate
according to the application. Fusing Characteristics:
≤
1
Ω
10
3
t
(s)
10
2
10
10
1
1
10
-1
10
-1
0
4
8
Poverload (W)
12
0
4
8
12
Poverload (W)
NFR25
This graph is based on measured data which may deviate
according to the application. Fusing Characteristics: 1
Ω ≤
R
≤
15
Ω
NFR25
This graph is based on measured data which may deviate
according to the application. Fusing Characteristics: 15
Ω ≤
R
≤
15 kΩ
10
3
t
(s)
10
2
10
3
t
(s)
10
2
10
10
1
1
10
-1
0
4
8
12
16
24
P
overload
(W)
20
10
-1
0
4
8
12
16
20
24
P
overload
(W)
NFR25H
This graph is based on measured data which may deviate
according to the application. Fusing Characteristics:
≤
1
Ω
Fusing Characteristic
Document Number: 28737
Revision: 02-Dec-05
NFR25H
This graph is based on measured data which may deviate
according to the application. Fusing Characteristic: 1
Ω ≤
R
≤
15 kΩ
:
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NFR25/25H
Vishay BCcomponents
Fusible, Non-Flammable Resistors
10
3
P max
(W)
10
2
10
tp/ti = 1000
500
200
100
50
20
10
1
5
2
10
-1
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
ti (s)
1
NFR25
Pulse on a regular basis; maximum permissible peak pulse power
(
P
max
)
as a function
of pulse duration (t
i
), 0.22
Ω ≤
R < 15
Ω
10
3
P max
(W)
10
2
10
tp/ti = 1000
100
1
20
2
10
-1
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
ti (s)
1
NFR25
Pulse on a regular basis; maximum permissible peak pulse power
(
P
max
)
as a function
of pulse duration (t
i
), 15
Ω <
R
≤
15 kΩ
600
V max
(V)
500
400
300
200
100
0
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
t i (s)
1
NFR25
Pulse on a regular basis; maximum permissible peak pulse voltage
(
V
max
)
as
a function of pulse duration (t
i
)
Pulse Loading Capabilities
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Document Number: 28737
Revision: 02-Dec-05
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