Molded Surface Mount
Wirewound Resistor
Environmental Data
Characteristics
WSM-1
WSM-2
WSM-1
Load at Rated Power: 1000 hours @ 70°C
∆R%
∆R%
∆R%
2 ± 0.001Ω
2 ± 0.001Ω
3 ± 0.001Ω
Dry Heat:
1000 hours @ 155°C
2 ± 0.001Ω
2 ± 0.001Ω
2 ± 0.001Ω
zero at 155°C
1 ± 0.001Ω
1 ± 0.001Ω
1 ± 0.001Ω
1,000
3 ± 0.001Ω
Short Term Overload
Derating from Rated Power @ 70°C
Moisture
∆R%
∆R%
∆R%
volts
1 ± 0.001Ω
1.5 ± 0.001Ω
Temperature Cycling
Resistance to Solder Heat
Isolation Voltage
Insulation Resistance
ohms
>1000M
Substrate Bend
∆R%
0.2 ± 0.001Ω
*Note: The power ratings to be applied depend upon the board used and the ambient temperature.
Ordering Data
Standard Quantities Per Package
Specify type, reference, etc. as indicated in this example of a
WSM3 6801 F resistor with tape and reel packaging.
Type
Code
WSM1
WSM2
WSM3
13" Reel
(330mm)
Sample Part No.
WSM3 6801
F
LF
TR
R
1500
800
750
IRC Type
(WSM1, WSM2, WSM3)
Packaging:
Resistance Value
WSM2 resistors are supplied on .945 (24mm) wide
carrier tape.
(100Ω and greater - First 3 significant digits plus
4th digit multiplier) Example: 100Ω = 1000, 1000Ω = 1001,
150,000Ω = 1503 (Less than 100Ω - "R" is used to designate
decimal) Example: 51Ω = 51R0, 1Ω = 1R00, 0.25Ω = R250
WSM3 resistors are supplied on 1.26 (32mm) wide
carrier tape.
Tolerance
(K = 10%, J = 5%, G = 2%, F = 1%)
Both products are reeled onto 13.00 (330mm)
diameter reels.
Lead Free, RoHS Designator
Packaging Code
(TR = 13" Reel)
*For packaging information, see Appendix "A".
Dimensions (Inches and (mm))
Ao
Bo
Ko
W
P
T
A0
P
K0
.165
(4.2)
.300
.165
.630
.315
.014
WSM1
WSM2
WSM3
(7.62) (4.20) (16.0) (8.00) (0.36)
B0
W
.266
.470
.206
.945
.473
.014
(6.75) (11.95) (5.22) (24.0) (12.0) (0.36)
.288
(7.3)
.721
(18.3)
.264
(6.7)
1.26
(32.0) (12.0)
.473
.016
(0.4)
t
Wire and Film Technologies Division • 4222 South Staples Street • Corpus Christi Texas 78411 USA
Telephone: 361 992 7900 • Facsimile: 361 992 3377 • Website: www.irctt.com
WSM Series Issue December 2008 Sheet 3 of 3
