WK / WR
Vishay Draloric
Metal Oxide Resistors, High Power
FEATURES
• Rugged metal oxide film
• High power dissipation in small size
• High temperature coating, non-inflammable
STANDARD ELECTRICAL SPECIFICATIONS
MODEL
SIZE
POWER RATING
P
70˚C
W
1.0
1.0
1.0
2.0
3.0
4.0
LIMITING ELEMENT
VOLTAGE MAX.
V
500
500
500
500
750
750
TEMPERATURE
COEFFICIENT
ppm/K
50
100
200
200
200
200
TOL.
%
1
2
5
5
2
5
2
5
2
5
RESISTANCE
RANGE
E-SERIES
Ω
4R7 - 1M0
1R0 - 1M0
R18 - 10M
0R18 - 10M
1R0 - 1M0
R18 - 10M
1R0 - 100K
R22 - 560K
1R0 - 68K
R22 - 100K
96
48
24
24
48
24
48
24
48
24
WK2
WK2
WK2
WR4
WR5
WK8
0207
0207
0207
0414
0617
0922
• Coating: green
• Marking: WR4 has colour code marking and does not have a T.C.band. WR5 and WK8 are print marked. For further information see
appropriate catalog or web page.
TECHNICAL SPECIFICATIONS
PARAMETER
Rated Dissipation at 70˚C
Limiting Element Voltage
1)
Insulation Voltage (1 min)
Thermal Resistance (max)
Insulation Resistance
Voltage Coefficient
Thermal Time Constant
Category Temperature Range
2)
Terminal Strength, axial
Failure Rate
Weight
1)
2)
UNIT
W
V
V
eff
K/W
Ω
1/V
s
˚C
N
10
-8
/h
g
WK2
1.0
500
> 500
≤
140
WR4
2.0
500
> 500
≤
100
> 10
9
< 10
-7
WR5
3.0
750
> 500
≤
70
WK8
4.0
750
> 500
≤
60
14
20
- 55 / + 200
35
70
> 60
> 80
<1
> 80
> 80
0.2
0.7
1.5
3.5
Rated Voltage P x R
For values < 10R the upper limiting temperature is 155˚C. The power rating is correspondingly lower and can be calculated by R
th
ORDERING INFORMATION
WK2
MODEL
100
TC
ppm/K
1K0
RESISTANCE
VALUE
Ω
5%
TOLERANCE
±
%
A5
PACKAGING
A2 Ammopack -2000 pcs
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Document Number 20128
Revision 05-Aug-02
WK / WR
Metal Oxide Resistors, High Power
DIMENSIONS
6 mm*
Vishay Draloric
MODEL
L
1
L
D
d
DIMENSIONS
[in millimeters]
D
L
6.3
-0.5
12.0
-1.5
16.5
-1.5
20.0
-1.5
L
1max
8.0
16.0
20.0
24.0
B
53
±1
73
±1
77
±1
77
±1
d
0.6
0.8
0.8
0.8
e
7.5
15.0
17.5
22.5
WK2
WR4
e
B
2.5
-0.5
4.1
-0.5
6.0
-0.5
9.0
-0.5
WR5
· Taping in acc. with IEC60286-1
· D and L measured in acc. with IEC60294
· d according to IEC60301
* 9mm for WR5/WK8
WK8
RATED POWER IN %
TEMPERATURE RISE IN ˚C
300
250
200
150
100
50
0
WK2
WR4
WR5
WK8
120
100
80
60
40
20
WK2
WR4
WR5
WK8
0
1.0
2.0
3.0
4.0
5.0
0 -55
0
40
80
70
120
160
200
240
280
320 360
TEMPERATURE RISE
POWER IN W
DERATING
AMBIENT TEMPERATURE IN ˚C
PACKAGING
MODEL
REEL
MIN. ORDER QTY
PIECES / REEL
WK2
5000
CODE
R5
PACKAGING UNITS
1
PIECES / BOX
5000
2000
WR4
WR5
WK8
2500
1500
1000
RE
RP
R1
2
2
2
1000
1000
500
CODE
A5
A2
A1
A1
AC
BOX
MIN. ORDER QTY
PACKAGING UNITS
1
1
2
2
2
Document Number 20128
Revision 05-Aug-02
For Technical Questions, contact ff1aresistors@vishay.com
www.vishay.com
77
WK / WR
Vishay Draloric
POWER RATING P [W]
1000
WK 8
WR 5
100
WR 4
Metal Oxide Resistors, High Power
WK 2
10
1
Secondary conditions:
–
a) P
¡
0 peak pulse, single pulse
b)
ϑu ≤
70°C
c) Û
max
see diagram below
d) ~ 10R
10
–4
10
–3
10
–2
10
–1
10
0
10
0.1
10
–5
PULSE RATING P
0
SQUARE PULSE ti [S]
POWER RATING P [W]
10
3
WK 8
WR 5
10
2
WR 4
WK 2
10
1
10
0
Secondary conditions:
a)
b)
c)
d)
P
≤
P
70
permissible constant power at
ϑu
= 70°C
ϑu ≤
70°C
Û
max
see diagram below
~ 10R
10
–4
10
–3
10
–2
10
–1
10
0
10
10
–1
10
–5
PULSE RATING P
≤
P70
SQUARE PULSE ti [S]
PULSE VOLTAGE Û MAX [V]
2000
WR 5 / WK8
WR 4
Secondary conditions:
–
a) P
max.
see Diagrams above
b) See diagrams above
c)
ϑu ≤
70°C
WK 2
1000
0
10
–5
10
–4
10
–3
10
–2
10
–1
10
0
10
MAX. PULSE VOLTAGE
SQUARE PULSE ti [S]
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For Technical Questions, contact ff1aresistors@vishay.com
Document Number 20128
Revision 05-Aug-02
WK / WR
Metal Oxide Resistors, High Power
Vishay Draloric
NON-LINEARITY A3 [dB]
120
WR5/WK8
110
WR4
CURRENT NOISE
µ
V/V
130
10
1
WR5, WK8
0.1
WR4
100
90
1K
10K
100K
1M
10M
0.01
10K
100K
1M
10M
NON-LINEARITY
RESISTANCE VALUE IN
Ω
CURRENT NOISE
RESISTANCE VALUE IN
Ω
PERFORMANCE
TEST
Rated Dissipation at 70°C
IEC 60115-1 4.25.1
Endurance at UCT
IEC 60115-1 4.25.3
Overload Test
IEC 60115-1 4.13
Thermal Shock
IEC 60115-1 4.19, IEC 60068-2-14
Climatic Sequence
IEC 60115-1 4.23
Damp Heat Steady State
IEC 60115-1 4.24, IEC 60068-2-3
Resistance to Soldering Heat
IEC 60115-1 4.18, IEC 60068-2-20
Robustness of Terminations
IEC 60115-1 4.16
Vibration
IEC 60115-1 4.22
* Limits for change of resistance at test
CONDITIONS OF TEST
1000 hours at 70˚C 1.5 hours "ON", 0.5 hours "OFF"
REQUIREMENTS*
WK2 =
±
1.5%
WK4/8 =
±
2.0%
WR4/5 =
±
5.0%
≤ ±
1%
≤ ±
0.25%
≤ ±
0.25%
≤ ±
0.5%
≤ ±
1.5%
≤ ±
0.25%
≤ ±
0.25%
≤ ±
0.25%
1000 hours at 155°C without load
Short time overload 5 seconds at 2.5 x rated voltage
or
≤ ±
twice the limiting element voltage
Rapid change between upper and lower category temperature
Dry heat, damp heat cycle, cold, low air pressure
56 days at 40°C and 93% relative humidity
10 seconds at 260°C solder bath temperature
Tensile, bending and torsion
0.75mm or 10g, 10Hz - 500Hz 6 hours
APPLICABLE SPECIFICATIONS
• CECC 40000
• EN 140000 IEC 60115 - 1
Document Number 20128
Revision 05-Aug-02
For Technical Questions, contact ff1aresistors@vishay.com
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79
