333
3
WSHM2818
www.vishay.com
Vishay Dale
Power Metal Strip Resistors, High Power (7 W),
Low Value (Down to 0.001 ), Surface Mount
FEATURES
Improved thermal management incorporated
into design
All welded construction of the Power Metal Strip
resistors are ideal for all types of current
sensing, voltage division, and pulse applications
Proprietary processing technique produces
extremely low resistance values
Sulfur resistance by construction that is
unaffected by high sulfur environments
Very low inductance (< 5 nH)
Solid metal nickel-chrome or manganese-
copper alloy resistive element with low TCR
LINKS TO ADDITIONAL RESOURCES
(< 20 ppm/C)
Low thermal EMF (< 3 V/C)
(1)
AEC-Q200 qualified
3D Models Design Tools Videos
PATENT(S): www.vishay.com/patents
Material categorization: for definitions of compliance
please see www.vishay.com/doc?99912
Notes
Follow link to Overview of Automotive Grade Products for more details: www.vishay.com/doc?49924
(1)
Flame retardance test may not be applicable to some resistor technologies
STANDARD ELECTRICAL SPECIFICATIONS
RESISTANCE VALUE RANGE
POWER RATING WEIGHT
GLOBAL MODEL SIZE P (typical)
70 C
W g/1000 pieces
TOL. 0.5 % TOL 1.0 %
(1)
WSHM2818 2818 7 0.010 to 0.1 0.001 to 0.1 167.8
WSHM2818 2818 6 0.101 to 0.2 0.101 to 0.2 167.8
Note
(1)
The WSHM2818 is rated at 7 W with maximum surface temperature of 180 C
GLOBAL PART NUMBER INFORMATION
Global Part Numbering: WSHM2818R1000FEA (visit www.vishay.net Vishay Dale parts numbering manual for all options)
W S H M 2 8 1 8 R 1 0 0 0 F E A
RESISTANCE
(1)
GLOBAL MODEL TOLERANCE CODE PACKAGING CODE SPECIAL
VALUE
WSHM2818 L = m * D = 0.5 % EA = lead (Pb)-free, tape / reel (dash number)
R = decimal F = 1.0 % EK = lead (Pb)-free, bulk (up to 2 digits)
4L000 = 0.004 from 1 to 99 as
R0100 = 0.01 applicable
* Use L for resistance
values < 0.01
Notes
SMD Power Metal Strip Marking (www.vishay.com/doc?30327)
(1)
Packaging code: EB (lead (Pb)-free) and TB (tin / lead) are non-standard packaging codes designating 1000 piece reels. These non-standard
packaging codes are identical to our standard EA (lead (Pb)-free) and TA (tin / lead), except that they have a package quantity of 1000 pieces
PATENT(S): www.vishay.com/patents
This Vishay product is protected by one or more United States and international patents.
Revision: 17-Mar-2020 Document Number: 30188
1
For technical questions, contact: ww2bresistors@vishay.com
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
DDD
D
WSHM2818
www.vishay.com
Vishay Dale
TECHNICAL SPECIFICATIONS
PARAMETER UNIT RESISTOR CHARACTERISTICS
200 for 1 m to 5.99 m
(1)
Component temperature coefficient (including terminal) ppm/C
75 for 6 m to 200 m
(2)
Element TCR ppm/C < 20
Inductance nH < 5
Operating temperature range C -65 to +170
(3) 1/2
Maximum working voltage V(P x R)
Notes
(1)
Component TCR - total TCR that includes the TCR effects of the resistor element and the copper terminal
(2)
Element TCR - only applies to the alloy used for the resistor element; refer to item 1 in the construction illustration on the following page
(3)
Maximum working voltage - the WSHM is not voltage sensitive, but is limited by power / energy dissipation and is also not ESD sensitive
DIMENSIONS in inches (millimeters)
L
H
a
T
b
l
W
a
Notes
3D models available: www.vishay.com/doc?30324
Surface mount solder profile recommendations: www.vishay.com/doc?31052
RESISTANCE DIMENSIONS SOLDER PAD DIMENSIONS
MODEL RANGE
LW H T a b l
0.280 0.010 0.180 0.010 0.059 0.010 0.125 0.010 0.138 0.200 0.024
WSHM2818 0.001 to 0.2
(7.1 0.25) (4.6 0.25) (1.50 0.25) (3.18 0.25) (3.5) (5.1) (0.61)
TYPICAL SENSING LAYOUT SENSING WITH VIA LAYOUT (best performance)
a
f
a e
a
a
c
b
b
l
l
d
c
ab c l ab de f l
0.138 0.210 0.020 0.024 0.143 0.210 0.026 0.105 0.020 0.024
(3.51) (5.33) (0.51) (0.61) (3.63) (5.33) (0.66) (2.67) (0.50) (0.61)
Note
Sensing locations are based on the construction of the part; terminals are wrapped from the outside to underneath. These options place the
sensing location nearest the temperature stable resistance element, which minimizes contact resistance and optimizes TCR
Revision: 17-Mar-2020 Document Number: 30188
2
For technical questions, contact: ww2bresistors@vishay.com
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000