IRC Wire and Film Technologies Division
General Note
A subsidiary of
TT electronics plc
W20 Series Issue November 2006
IRC reserves the right to make changes in product specifi cation without notice or liability.
All information is subject to IRC’s own data and is considered accurate at time of printing.
© IRC Wire and Film Technologies Division
Telephone: 828 264 8861 • Facsimile: 828 264 8866 • Website: www.irctt.com
• 736 Greenway Road Boone, North Carolina 28607-1860
Vitreous Enamelled Wirewound Resistors
Specifi cations
W20 Series
• Rugged all-welded construction
• High purity ceramic substrate
• Impervious lead-free vitreous enamel coating
• High stability and high reliability
• Suitable for harsh environments
• Overload charcteristics ideal for protection circuits
• Lead-free, RoHS-compliant construction
Notes
1 See temperature rise graph
Part
Number
Power rating
@25°C
(Watts)
Resistance
Range
(Ohms)
Tolerance
(±%)
TCR
(±ppm/°C)
Limiting Element
Voltage
(Volts)
Thermal
Impedance1
(°C/watt)
W21 3.0 1 - 10K 1 Typical: <+75
Maximum: +200
100 88
0.5 - 10K 2
0.1 - 10K 5
W215 5.0 1 - 15K 1 Typical: <+75
Maximum: +200
160 58
0.5 - 15K 2
0.1 - 15K 5
W22 7.0 1 - 22K 1 Typical: <+75
Maximum: +200
200 44
0.5 - 22K 2
0.1 - 22K 5
W23 10.0 1 - 60K 1 Typical: <+75
Maximum: +200
500 29
1 - 60K 2
0.15 - 60K 5
W24 14.0 1 - 100K 1 Typical: <+75
Maximum: +200
750 22
1 - 100K 2
0.15 - 100K 5
Application Notes
The terminations should not be bent closer than 1.6mm from the body of the resistor, and the recommended
bend radius is 1.2mm. Terminations are solderable to within 4mm from the resistor body.
When cold, vitreous enamel has excellent insulation resistance. In common with all insulation materials, the
specifi c resistance of the enamel decreases with increased temperatures. Therefore, resistors operated at
near-maximum temperature cannot be considered as insulated and should not be used in contact with any
conductive material.
Care must be taken when determining clearance distance between the resistor body and printed circuit board
or other components to ensure these are not overheated. Resistance is measured 6mm from the resistor body.
bn802 W20 Series Datasheet_2.ind1 1bn802 W20 Series Datasheet_2.ind1 1 11/17/06 4:40:29 PM11/17/06 4:40:29 PM
IRC Wire and Film Technologies Division
General Note
A subsidiary of
TT electronics plc
W20 Series Issue November 2006
IRC reserves the right to make changes in product specifi cation without notice or liability.
All information is subject to IRC’s own data and is considered accurate at time of printing.
© IRC Wire and Film Technologies Division
Telephone: 828 264 8861 • Facsimile: 828 264 8866 • Website: www.irctt.com
• 736 Greenway Road Boone, North Carolina 28607-1860
Environmental Performance
Test Maximum Typical
Load at commercial rating: 1000 Hours at room temperature ∆R% 54
Dry heat: 1000 hours at 200°C ∆R% 2 1
Shelf life: 12 months at room temperature ∆R% 0.03 0.02
Short term overload ∆R% 1.0 0.2
Climatic ∆R% 0.5 0.2
Long term damp heat ∆R% 0.05 0.02
Temperature rapid change ∆R% 0.5 0.2
Resistance to solder heat ∆R% 0.25 0.03
Vibration and bump ∆R% 0.25 0.05
Noise (in a decade of frequency) µV/V zero zero
Insulation resistance Ω>0.1GΩ>0.1GΩ
Dielectric withstanding voltage V 500 min. 500 min.
Operating temperature range °C -55 to +200
Construction
A high purity ceramic substrate is assembled with
interference-fi t end caps, to which are welded the
termination wires. The resistive element is wound
on the substrate and welded to the caps, and the
vitreous enamel protective coating is then applied.
Terminations
Copper-clad steel wire, nickel-plated and
solder-coated.
Marking
The resistors are legend-marked with type
reference, resistance value and tolerance.
Solvent resistance
The body protection and marking are resistant to
all normal industrial cleaning solvents suitable for
printed circuits.
Dissipation (watts)
0 5 10 15 20
p
Temperature Rise (ºC)
400
300
200
100
W21 W215 W22 W23 W24
Temperature Rise Curve
bn802 W20 Series Datasheet_2.ind2 2bn802 W20 Series Datasheet_2.ind2 2 11/17/06 4:40:30 PM11/17/06 4:40:30 PM
General Note
A subsidiary of
TT electronics plc
W20 Series Issue November 2006
IRC reserves the right to make changes in product specifi cation without notice or liability.
All information is subject to IRC’s own data and is considered accurate at time of printing.
© IRC Wire and Film Technologies Division
Telephone: 828 264 8861 • Facsimile: 828 264 8866 • Website: www.irctt.com
• 736 Greenway Road Boone, North Carolina 28607-1860
IRC Wire and Film Technologies Division
Dimensions (mm)
Type L
(max.)
D
(max.)
f
(min)
ød
(nom.)
Weight
(g)
W21 12.7 5.6 22.75 0.8 1.0
W215 22.0 7.0 23.1 0.8 2.0
W22 22.2 8.0 23.1 0.8 2.0
W23 38.0 8.0 30* 0.8 3.5
W24 53.5 8.0 30* 0.8 5.0
Notes
1 * W23 and W24 Series resistors are supplied loose-packed in boxes.
Ordering Information
Specify type, resistance, tolerance and packaging.
This example is for a W21, 9000Ω, 5%, taped and
ammo-packed.
All W20 Series resistors are RoHS-compliant.
Packaging
W21 and W215 resistors are taped and packaged in
ammo packs; W22 resistors are on tape-and-reel;
W23 and W24 resistors are loose-packed in boxes.
Standard quantities per package
Type Pack-
aging
Code
W21 W215 W22 W23 W24
Ammo
pack
A 1000 750 - - -
Reel R - - 700 - -
Box B - - - 50 25
L f
D
d dia
IRC Style
W20
Resistance Value
(≥1007 - First 3 significant digits
plus 4th digit multiplier)
Example:
1007 = 1000;
10007 = 1001;
150K7 = 1503.
(>
100
7
- "R" is used to designate decimal
)
Example:
517 = 51R0,
17 = 1R00;
0.257 = R250
Sample Part No.
Tolerance
F = ±1%,
G = ±2%,
J = ±5%
Packaging
(A = ammo; R= reel; B = box)
W21 9001 J A
A6
10±0.5
f - f ≤1.4mm
12
f1f2
Type A
W21 63±2
W215 73±2
W22 73±2
bn802 W20 Series Datasheet_2.ind3 3bn802 W20 Series Datasheet_2.ind3 3 11/17/06 4:40:30 PM11/17/06 4:40:30 PM
