WSLT3921, WSLT5931
www.vishay.com
Vishay Dale
Power Metal Strip® Resistors, High Temperature (275 °C),
Low Value (Down to 0.0001 Ω), Surface-Mount
FEATURES
Available
• Ideal for all types of 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
0.0001 Ω
• Specially selected and stabilized materials
allow for high temperature derating
(to +275 °C)
• Sulfur resistance by construction that is unaffected by
high sulfur environments
• All welded construction
• Solid metal iron-chrome or manganese-copper alloy
resistive element with low TCR (< 20 ppm/°C)
• Very low inductance (< 5 ηH)
• Low thermal EMF (< 3 μV/°C)
• AEC-Q200 qualified available (1)
• Material categorization: for definitions of compliance
please see www.vishay.com/doc?99912
LINKS TO ADDITIONAL RESOURCES
3D 3D
3D Models
Design Tools
Note
(1) Flame retardance test may not be applicable to some resistor
technologies
STANDARD ELECTRICAL SPECIFICATIONS
GLOBAL
MODEL
SIZE
POWER RATING
P70 °C
W
TOLERANCE
%
RESISTANCE VALUE
RANGE
Ω
RESISTANCE VALUES
CURRENTLY AVAILABLE (1)
Ω
WEIGHT
(typical)
g/1000 pieces
WSLT3921
3921
3.0
1.0, 5.0
0.2m to 4m
0.2m, 0.3m, 0.5m, 0.7m, 1m,
1.5m, 2m, 2.5m, 3m, 4m
281
WSLT5931
5931
5.0
1.0, 5.0
0.3m to 3m
0.3m, 0.5m, 1m, 2m, 3m
398
Note
(1) Other values may be available, contact factory
GLOBAL PART NUMBER INFORMATION
Global Part Numbering: WSLT39212L000FEA (WSLT3921, 0.002 Ω, ± 1 %)
(visit www.vishay.net Vishay Dale parts numbering manual for all options)
W
S
L
T
3
9
2
1
2
L
0
0
0
F
E
A
GLOBAL MODEL
(7 digits)
RESISTANCE VALUE (1)
(5 digits)
TOLERANCE CODE
(1 digit)
PACKAGING CODE (2)
(2 digits)
SPECIAL (3)
(up to 2 digits)
WSLT3921
WSLT5931
L = mΩ
2L000 = 0.002 Ω
F = ± 1.0 %
J = ± 5.0 %
EA = lead (Pb)-free, tape/reel
Reserved for
future specials
Notes
(1) WSL marking (www.vishay.com/doc?30327)
(2) 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
(3) Follow link for customization capabilities: www.vishay.com/doc?48163
Revision: 24-Aug-2021
Document Number: 30136
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
WSLT3921, WSLT5931
www.vishay.com
Vishay Dale
TECHNICAL SPECIFICATIONS
PARAMETER
RESISTOR CHARACTERISTICS
WSLT3921
WSLT5931
+150 for 0.2 mΩ
+300 for 0.1 mΩ (+25 °C to +170 °C)
+170 for 0.3 mΩ
± 225 for 0.2 mΩ
+150 for 0.5 mΩ to 1 mΩ
± 175 for 0.3 mΩ and 0.5 mΩ
+50 for 1.5 mΩ to 4 mΩ
± 75 for 1 mΩ to 4 mΩ
< 20
-65 to +275
(P x R)1/2
UNIT
Component temperature coefficient
(including terminal) (1)
TCR measured from -55 °C to 150 °C
ppm/°C
Element TCR (2)
Operating temperature range
Maximum working voltage (3)
ppm/°C
°C
V
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 WSL is not voltage sensitive, but is limited by power / energy dissipation and is also not ESD sensitive
DIMENSIONS in inches (millimeters)
CONSTRUCTION OUTLINE
Typical sensing traces
I
b
1
H
1 Resistive element: Fe-Cr
(element material used is
dependent on resistance
value)
2 Terminal: solid copper
L
W
D
d
3
3 Terminal / element weld
2
T
Notes
• 3D models available: 3921 model www.vishay.com/doc?30315; 5931 model www.vishay.com/doc?30317
• Surface-mount solder profile recommendations: www.vishay.com/doc?31052
MODEL
WSLT3921
WSLT5931
L
0.394 ± 0.010
(10.0 ± 0.254)
0.591 ± 0.010
(15.0 ± 0.254)
DIMENSIONS in inches (millimeters)
W
H (1)
0.205 ± 0.015
0.020
(5.20 ± 0.381)
(0.5)
0.305 ± 0.015
0.020
(7.75 ± 0.381)
(0.5)
T
0.080 ± 0.010
(2.00 ± 0.254)
0.157 ± 0.010
(4.00 ± 0.254)
SOLDER PAD DIMENSIONS in inches (millimeters)
d
b
l
0.106 ± 0.010
0.244 ± 0.010
0.220 ± 0.005
(2.70 ± 0.254)
(6.20 ± 0.254)
(5.60 ± 0.13)
0.205 ± 0.010
0.344 ± 0.010
0.220 ± 0.005
(5.20 ± 0.254)
(8.75 ± 0.254)
(5.60 ± 0.13)
Note
(1) H dimension is reference only. Total height is H dimension + D thickness ± 0.010" (± 0.254 mm)
GLOBAL
MODEL
WSLT3921
WSLT3921
WSLT3921
WSLT3921
WSLT3921
WSLT3921
WSLT3921
WSLT5931
WSLT5931
WSLT5931
WSLT5931
WSLT5931
WSLT5931
RESISTANCE VALUE
(mΩ)
0.2
0.5
0.7
1.0
2.0
3.0
4.0
0.1
0.3
0.5
1.0
2.0
3.0
TYPICAL THERMAL RESISTANCE
(°C/W)
2.7
5.8
6.3
10.9
12.0
20.7
22.8
1.6
3.5
5.7
7.2
13.2
19.3
“D” THICKNESS
(Inches)
0.0560
0.0300
0.0205
0.0150
0.0270
0.0170
0.0130
0.0560
0.0300
0.0180
0.0330
0.0155
0.0105
ELEMENT
MATERIAL
Mn-Cu
Mn-Cu
Mn-Cu
Mn-Cu
Fe-Cr
Fe-Cr
Fe-Cr
Mn-Cu-Sn
Mn-Cu
Mn-Cu
Fe-Cr
Fe-Cr
Fe-Cr
Note
(1) The full power rating of power metal strip resistors are dependent upon the ability of the circuit board to dissipate the heat energy created
in the resistance element. It is recommended to follow common design practices for power semiconductors that ensure the junction
temperature is maintained with in thermal limits by using large pad surfaces, thermal vias, heavier copper weights, internal layers as well as
other thermal spreading features. The thermal resistance values provided function in the same manner as junction to terminal temperature
Revision: 24-Aug-2021
Document Number: 30136
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
WSLT3921, WSLT5931
www.vishay.com
Vishay Dale
DERATING - AMBIENT
TEMPERATURE
Axis Title
PULSE CAPABILITY
10000
120
click to get started
1000
80
1st line
2nd line
2nd line
Rated Power (%)
100
60
100
40
US
ILL
20
VE
TI
A
TR
S
SE
O
RP
PU
LY
ON
10
0
-65
70
0
150
200
275
www.vishay.com/resistors/power-metal-strip-calculator
Ambient Temperature (°C)
DERATING - TERMINAL TEMPERATURE
Axis Title
Axis Title
10000
120
100
1st line
2nd line
1000
Stability < 0.5 %
60
100
40
20
1000
80
Stability < 1.0 %
1st line
2nd line
Stability < 1.0 %
80
2nd line
P/PNorm. (%)
100
2nd line
P/PNorm. (%)
10000
120
60
Stability < 0.5 %
100
40
20
0
0
50
100
150
200
10
245 275 300
0
0
50
100
150
200
10
245 275 300
TK - Terminal Temperature (°C)
TK - Terminal Temperature (°C)
Example: WSLT3921 0.0005 Ω
Example: WSLT5931 0.0005 Ω
PERFORMANCE
TEST
Thermal shock
Short time overload
Low temperature storage
High temperature exposure
Bias humidity
Mechanical shock
Vibration
Load life
Resistance to solder heat
Moisture resistance
CONDITIONS OF TEST
-55 °C to +150 °C, 1000 cycles, 15 min at each extreme
Refer to link for short time overload performance and pulse capability;
www.vishay.com/resistors/power-metal-strip-calculator/
-65 °C for 24 h
1000 h at +275 °C
+85 °C, 85 % RH, 10 % bias, 1000 h
100 g’s for 6 ms, 5 pulses
Frequency varied 10 Hz to 2000 Hz in 1 min, 3 directions, 12 h
1000 h at +70 °C, 1.5 h “ON”, 0.5 h “OFF”
3x at 250 °C ± 5 °C for 30 s ± 5 s
MIL-STD-202, method 106, 0 % power, 7a and 7b not required
TEST LIMITS
± 1.0 % + 0.0005 Ω
± 0.5 %
± 0.5 % + 0.0005 Ω
± 1.0 % + 0.0005 Ω
± 0.5 % + 0.0005 Ω
± 0.5 % + 0.0005 Ω
± 0.5 % + 0.0005 Ω
± 1.0 % + 0.0005 Ω
± 0.5 % + 0.0005 Ω
± 0.5 % + 0.0005 Ω
PACKAGING
MODEL
WSLT3921
WSLT5931
TAPE WIDTH
16 mm / embossed plastic
24 mm / embossed plastic
REEL
DIAMETER
330 mm / 13"
330 mm / 13"
PIECES/REEL
3000
1500
CODE
EA
EA
Note
• Embossed carrier tape per EIA-481
Revision: 24-Aug-2021
Document Number: 30136
3
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
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www.vishay.com
Vishay
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Revision: 09-Jul-2021
1
Document Number: 91000