Fusible, Non-Flammable Metal Film Leaded Resistors
www.vishay.com For technical questions, contact: filmresistorsleaded@vishay.com
Document Number: 28737
1 Revision: 30-Mar-10
NFR25, NFR25H
Vishay BCcomponents
DESCRIPTION
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 protection. The
encapsulant is resistant to all cleaning solvents in
accordance with IEC 60068-2-45.
FEATURES
• Technology: Metal film
• Overload protection without risk of fire
• Wide range of overload currents (refer Fusing
Characteristics graphs)
• Lead (Pb)-free solder contacts
• Pure tin plating provides compatibility with lead (Pb)-free
and lead containing soldering processes
• Compatible to RoHS directive 2002/95/EC
APPLICATIONS
•Audio
•Video
Notes
• R value is measured with probe distance of 24 mm ± 1 mm using 4-terminal method
(1)
Ohmic values (other than resistance range) are available on request
TECHNICAL SPECIFICATIONS
DESCRIPTION UNIT NFR25 NFR25H
Resistance Range
(1)
Ω 0.22 to 15k 0.22 to 15k
Resistance Tolerance % ± 5 ± 5
Resistance Series E24 E24
Rated Dissipation, P
70
W 0.33 0.5
Thermal Resistance (R
th
) K/W 240 150
Temperature Coefficient
ppm/K
0.22 Ω ≤ R ≤ 4.7 Ω≤ ± 200 ≤ ± 200
4.7 Ω < R ≤ 15 Ω≤ ± 200 ≤ ± 100
15 Ω < R ≤ 15 kΩ≤ ± 100 ≤ ± 100
Operating Voltage, U
max.
DC or RMS V 250 350
Basic Specifications IEC 60 115-1 IEC 60 115-1
Climatic Category (IEC 60068-1) 55/155/56 55/155/56
Max. Resistance Change for Resistance Range,
ΔR max., after:
Load (1000 h, P
70
): ± (1 % R + 0.05 Ω)± (1 % R + 0.05 Ω)
Long Term Damp Heat Test (56 Days): ± (1 % R + 0.05 Ω)± (1 % R + 0.05 Ω)
Soldering (260 °C, 10 s): ± (0.25 % R + 0.05 Ω) ± (0.25 % R + 0.05 Ω)
