www.vishay.com For technical questions, contact: ww2bresistors@vishay.com Document Number: 30108
392 Revision: 10-Dec-10
WSK
Vishay Dale
Power Metal Strip® Resistors,
Low Value (down to 0.001 Ω), Surface Mount, 4-Terminal
FEATURES
• 4-Terminal design allows for 1 % tolerance
down to 0.001 Ω and 0.5 % tolerance down to
0.003 Ω
• Ideal for all types of precision current sensing,
voltage division and pulse applications
including switching and linear power supplies,
instruments, power amplifiers
• Proprietary processing technique produces
extremely low resistance values (down to
0.001 Ω)
• All welded construction
• Solderable terminations
• Solid metal nickel-chrome or manganese-copper alloy
resistive element with low TCR (< 20 ppm/°C)
• Very low inductance 0.5 nH to 5 nH
• Excellent frequency response to 50 MHz
• Compliant to RoHS Directive 2002/95/EC
Note
• Part marking: Value, tolerance; due to resistor size limitations some resistance values will be marked with only the resistance value.
STANDARD ELECTRICAL SPECIFICATIONS
GLOBAL MODEL SIZE
POWER RATING
P70 °C
W
RESISTANCE VALUE RANGE
Ω
WEIGHT
(typical)
g/1000 pieces
Tol. ± 0.5 % Tol. ± 1.0 %
WSK2512 2512 1.0 0.001 to 0.025 0.001 to 0.025 63.6
TECHNICAL SPECIFICATIONS
PARAMETER UNIT RESISTOR CHARACTERISTICS
Temperature coefficient ppm/°C
± 250 for 0.001 Ω to 0.0029 Ω,
± 75 for 0.003 Ω to 0.0049 Ω,
± 35 for 0.005 Ω to 0.025 Ω
Operating temperature range °C - 65 to + 170
Maximum working voltage V (P x R)1/2
GLOBAL PART NUMBER INFORMATION
Global Part Numbering example: WSK25125L000FTA (preferred part numbering format)
GLOBAL MODEL RESISTANCE VALUE TOLERANCE CODE PACKAGING CODE SPECIAL
WSK2512 L = mΩ*
R = Decimal
5L000 = 0.005 Ω
R0100 = 0.01 Ω
* Use “L” for resistance
values < 0.01 Ω
D = ± 0.5 %
F = ± 1.0 %
EA = Lead (Pb)-free, tape/reel
EK = Lead (Pb)-free, bulk
(Dash number)
(up to 2 digits)
From 1 to 99 as
applicable
TA = Tin/lead, tape/reel (R86)
BA = Tin/lead, bulk (B43)
Historical Part Numbering example: WSK2512 0.005 Ω 1 % R86 (will continue to be accepted)
WSK2512 0.005 Ω1 % R86
HISTORICAL MODEL RESISTANCE VALUE TOLERANCE CODE PACKAGING CODE
* Pb containing terminations are not RoHS compliant, exemptions may apply
** Please see document “Vishay Material Category Policy”: www.vishay.com/doc?99902
W S K 2 5 1 2 5 L 0 0 0 F T A
Document Number: 30108 For technical questions, contact: ww2bresistors@vishay.com www.vishay.com
Revision: 10-Dec-10 393
WSK
Power Metal Strip® Resistors,
Low Value (down to 0.001 Ω), Surface Mount, 4-Terminal
Vishay Dale
DIMENSIONS in inches (millimeters)
Note
• Embossed Carrier Tape per EIA-481.
MODEL
DIMENSIONS
RESISTANCE
RANGE
Ω
LWH T AB
WSK2512
0.001 to 0.0049 0.250 ± 0.010
(6.35 ± 0.254)
0.125 ± 0.010
(3.18 ± 0.254)
0.025 ± 0.010
(0.635 ± 0.254)
0.087 ± 0.010
(2.21 ± 0.254) 0.030 ± 0.010
(0.762 ± 0.254)
0.020 ± 0.010
(0.508 ± 0.254)
0.005 to 0.025 0.047 ± 0.010
(1.19 ± 0.254)
MODEL
SOLDER PAD DIMENSIONS
RESISTANCE
RANGE
Ω
abcde l
WSK2512 0.001 to 0.0049 0.130 (3.30) 0.130 (3.30) 0.030 (0.76) 0.020 (0.51) 0.055 (1.40) 0.065 (1.65)
0.005 to 0.025 0.090 (2.29) 0.145 (3.68)
L W
H
T
A
B
l
a
e
b d c
PERFORMANCE
TEST CONDITIONS OF TEST TEST LIMITS
Thermal shock - 55 °C to + 150 °C, 1000 cycles, 15 min at each extreme ± (0.5 % + 0.0005 Ω) ΔR
Short time overload 5 x rated power for 5 s ± (0.5 % + 0.0005 Ω) ΔR
Low temperature operation - 65 °C for 24 h ± (0.5 % + 0.0005 Ω) ΔR
High temperature exposure 1000 h at + 170 °C ± (1.0 % + 0.0005 Ω) ΔR
Bias humidity + 85 °C, 85 % RH, 10 % bias, 1000 h ± (0.5 % + 0.0005 Ω) ΔR
Mechanical shock 100 g’s for 6 ms, 5 pulses ± (0.5 % + 0.0005 Ω) ΔR
Vibration Frequency varied 10 Hz to 2000 Hz in 1 min, 3 directions, 12 h ± (0.5 % + 0.0005 Ω) ΔR
Load life 1000 h at rated power, + 70 °C, 1.5 h “ON”, 0.5 h “OFF” ± (1.0 % + 0.0005 Ω) ΔR
Resistance to solder heat + 260 °C solder, 10 s to 12 s dwell, 25 mm/s emergence ± (0.5 % + 0.0005 Ω) ΔR
Moisture resistance MIL-STD-202, method 106, 0 % power, 7a and 7b not required ± (0.5 % + 0.0005 Ω) ΔR
70
0
Derating
- 65 - 55 - 25 0 25 50 75 100 125 150 170
Ambient Temperature °C
20
40
60
80
100
120
Rated Power in %
PACKAGING
MODEL REEL
TAPE WIDTH DIAMETER PIECES/REEL CODE
WSK2512 12 mm/embossed plastic 178 mm/7" 2000 EA
Document Number: 91000 www.vishay.com
Revision: 11-Mar-11 1
Disclaimer
Legal Disclaimer Notice
Vishay
ALL PRODUCT, PRODUCT SPECIFICATIONS AND DATA ARE SUBJECT TO CHANGE WITHOUT NOTICE TO IMPROVE
RELIABILITY, FUNCTION OR DESIGN OR OTHERWISE.
Vishay Intertechnology, Inc., its affiliates, agents, and employees, and all persons acting on its or their behalf (collectively,
“Vishay”), disclaim any and all liability for any errors, inaccuracies or incompleteness contained in any datasheet or in any other
disclosure relating to any product.
Vishay makes no warranty, representation or guarantee regarding the suitability of the products for any particular purpose or
the continuing production of any product. To the maximum extent permitted by applicable law, Vishay disclaims (i) any and all
liability arising out of the application or use of any product, (ii) any and all liability, including without limitation special,
consequential or incidental damages, and (iii) any and all implied warranties, including warranties of fitness for particular
purpose, non-infringement and merchantability.
Statements regarding the suitability of products for certain types of applications are based on Vishay’s knowledge of typical
requirements that are often placed on Vishay products in generic applications. Such statements are not binding statements
about the suitability of products for a particular application. It is the customer’s responsibility to validate that a particular
product with the properties described in the product specification is suitable for use in a particular application. Parameters
provided in datasheets and/or specifications may vary in different applications and performance may vary over time. All
operating parameters, including typical parameters, must be validated for each customer application by the customer’s
technical experts. Product specifications do not expand or otherwise modify Vishay’s terms and conditions of purchase,
including but not limited to the warranty expressed therein.
Except as expressly indicated in writing, Vishay products are not designed for use in medical, life-saving, or life-sustaining
applications or for any other application in which the failure of the Vishay product could result in personal injury or death.
Customers using or selling Vishay products not expressly indicated for use in such applications do so at their own risk and agree
to fully indemnify and hold Vishay and its distributors harmless from and against any and all claims, liabilities, expenses and
damages arising or resulting in connection with such use or sale, including attorneys fees, even if such claim alleges that Vishay
or its distributor was negligent regarding the design or manufacture of the part. Please contact authorized Vishay personnel to
obtain written terms and conditions regarding products designed for such applications.
No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted by this document or by
any conduct of Vishay. Product names and markings noted herein may be trademarks of their respective owners.
