Molded Surface Mount Wirewound Resistor
WSM Series
• • • • • Flexible Terminations All welded construction Ideal for automatic pick and place Lead free, RoHS compliant construction available Contact factory for ohmic values above published ranges
Electrical Data
IRC Type WSM-1 WSM-2 WSM-3 Power Rating Resistance Maximum Working Range @ 70°C Voltage (watts) (ohms) (volts) 1W 2W 3W 0.01 to 1K 0.01 to 2K 0.01 to 3K TCR (ppm/°C) Resistance Standard Tolerance Values (%) Ambient Temperature (°C)
√P x R
0.1Ω - 1000M 0.2 ± 0.001Ω 1.5 ± 0.001Ω WSM-1 3 ± 0.001Ω 3 ± 0.001Ω
*Note: The power ratings to be applied depend upon the board used and the ambient temperature.
Ordering Data
Specify type, reference, etc. as indicated in this example of a WSM3 6801 F resistor with tape and reel packaging.
Standard Quantities Per Package
Type
F LF TR
Code R
WSM1 1500
WSM2 800
WSM3 750
Sample Part No. IRC Type
WSM3
6801
13" Reel (330mm)
(WSM1, WSM2, WSM3) (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
Packaging: WSM2 resistors are supplied on .945 (24mm) wide carrier tape. WSM3 resistors are supplied on 1.26 (32mm) wide carrier tape. Both products are reeled onto 13.00 (330mm) diameter reels. *For packaging information, see Appendix "A".
Dimensions (Inches and (mm))
Resistance Value
Tolerance
(K = 10%, J = 5%, G = 2%, F = 1%)
Lead Free, RoHS Designator Packaging Code
(TR = 13" Reel)
Ao .165 (4.2) .266 (6.75) .288 (7.3)
Bo .300 (7.62) .470 (11.95) .721 (18.3)
Ko .165 (4.20) .206 (5.22) .264 (6.7)
W .630 (16.0) .945 (24.0) 1.26 (32.0)
P .315 (8.00) .473 (12.0) .473 (12.0)
T .014 (0.36) .014 (0.36) .016 (0.4)
B0
A0
P
K0
WSM1
WSM2
W
WSM3
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
