For technical questions, contact: powertron@vishaypg.com
USR UNR USS UNS T220 T221
Powertron
Document Number: 64222
Revision: 20-09-10
www.powertron.de
1
Type USR / USS UNR /UNS
Resistance Range 0.5 Ohms to 150 kOhms 0.5 Ohms to 5 kOhms
Power rating
free air 70°C (R<50R0)
free air 70°C (R>50R0)
with heatsink (R<50R0)
with heatsink (R>50R0)
1.5W
1.0W
10W
6W
1.5W
1.0W
15W
10W
Thermal Resistance Rthj-c
R<50R0
R>50R0
10.8 K/W
18.8 K/W
6.8 K/W
10.8 K/W
Tolerances
from 0.5 Ohms
from 10.0 Ohms
from 25.0 Ohms
from 50.0 Ohms
0.1% / 0.25% / 0.5% / 1%
0.05% / 0.1% / 0.25% / 0.5% / 1%
0.02% / 0.05% / 0.1% / 0.25% / 0.5% / 1%
0.01% / 0.02% / 0.05% / 0.1% / 0.25% / 0.5% / 1%
Stability 0.01%
Shelf Life Stability 25ppm / ∆R after 1 year
50ppm / ∆R after 3 year
Temperature Coefcient max. ±5ppm/K (-55 to 155°C)
typ. ±3ppm/K (-55 to 125°C)
Voltage Proof 1 kVDC
Thermal EMF < 0.1µV/K
Operating Temperature Range -55 to 155°C
Resistor Material NiCr-Foil
Substrate Al2O3AlN
Housing Epoxy + Cu heatsink nickel plated
Connector Material Cu tinned
Terminals 2
Max. Torque 1.0 Nm
Notes Specially designed for applications with fast
changing electrical load
SPECIFICATIONS
Part Number - Resistance - Contact - Tolerance - TCR
UNR 2-T220B 5.7kOhms C 0.5% 3ppm
Ordering Information
Resistances from 0.5Ohm to 150kOhms•
Power Rating to 10Watt•
Resistance Tolerances to ±0.01%•
TCR to ±3ppm/K•
Load Stability to 0.01%•
TO-220 Housing•
Convenient SMD D2Pak Available•
For technical questions, contact: powertron@vishaypg.com
USR UNR USS UNS T220 T221
Powertron
Document Number: 64222
Revision: 20-09-10
www.powertron.de
2
-1500
-1000
-500
0
500
1000
1500
DR/R (ppm)
Temperature (°C)
+4,4 ppm/K
-50
-25 025 50 75 100 125
+5ppm/K
-5ppm/K
Nominal Spread
±2.3ppm/K
Nominal DR/R
0
20
40
60
80
100
120
25 50 85 100 115 130 145 155
Temperature of the backplate(°C)
Power (% from
nominal power)
Power Rating Notes -
The U-Series Resistors must be attached to a suitable heat-
sink. The maximum internal resistor temperature is 155°C.
To specify an appropriate heatsink use the following formula :
RqH = TMAX - ( P x RqR ) - TA
P
Where: RqH = Thermal Resistance of Heatsink ( K/W )
R
qR = Thermal Resistance of Resistor ( K/W )
T
MAX = Maximum Temperature of Resistor
T
A = Ambient Temperature of Heatsink ( °C )
P = Power Through Resistor ( W )
Derating
Temperature Coefcient
SPECIFICATIONS (continued)
Dimensions
Dimension mm
tol.
(±mm) inches
tol.
(±inches)
A 12.70 0.2 0.50 0.008
B 10.16 0.2 0.40 0.008
C 0.76 0.1 0.03 0.004
D 5.08 0.1 0.20 0.004
E 4.00 0.1 0.16 0.004
F 1.20 0.1 0.05 0.004
G 14.60 0.2 0.57 0.008
H 15.00 0.2 0.59 0.008
I17.33 0.2 0.68 0.008
J 0.40 0.1 0.02 0.004
K 1.85 0.1 0.07 0.004
Dimension mm inches
A 12.10 0.476
B 11.16 0.439
C18.33 0.722
D 5.08 0.200
E 1.76 0.069
F3.20 0.126
USS 2-T220 / UNS 2-T220
For technical questions, contact: powertron@vishaypg.com
USR UNR USS UNS T220 T221
Powertron
Document Number: 64222
Revision: 20-09-10
www.powertron.de
3
Dimensions
SPECIFICATIONS (continued)
Dimension mm
tol.
(±mm) inches
tol.
(±inches)
A15.30 0.2 0.60 0.008
B 10.00 0.2 0.39 0.008
C 2.80 0.1 0.11 0.004
DØ3.7 0.1 Ø0.146 0.004
E 2.00 0.1 0.08 0.004
F 5.08 0.1 0.20 0.004
G 1.27 0.1 0.05 0.004
H 4.60 0.1 0.18 0.004
I 6.00 0.2 0.24 0.008
J35.30 2.0 1.39 0.079
K Ø0.6 0.1 Ø0.02 0.004
L 2.41 0.1 0.09 0.004
USR 2-T220B / UNR 2-T220B
USR 2-T220 / UNR 2-T220
USR 2-T221 / UNR 2-T221
Dimension mm
tol.
(±mm) inches
tol.
(±inches)
A17.30 0.2 0.68 0.008
B 10.16 0.2 0.40 0.008
C 6.00 0.1 0.24 0.004
DØ3.7 0.1 Ø0.146 0.004
E 16.40 0.2 0.65 0.008
F 5.08 0.1 0.20 0.004
G 0.76 0.1 0.03 0.004
H1.30 0.1 0.05 0.004
I 10.00 0.2 0.39 0.008
I (C-Contact) 13.80 0.2 0.54 0.008
J 2.00 0.1 0.08 0.004
K 1.20 0.1 0.05 0.004
L 4.00 0.1 0.16 0.004
M 2.90 0.1 0.11 0.004
N 0.40 0.1 0.02 0.004
O 1.85 0.1 0.07 0.004
Dimension mm
tol.
(±mm) inches
tol.
(±inches)
A18.30 0.2 0.72 0.008
B 10.16 0.2 0.40 0.008
C3.70 0.1 0.15 0.004
DØ3.2 0.1 Ø0.126 0.004
E 16.40 0.2 0.65 0.008
F 5.08 0.1 0.20 0.004
G 0.76 0.1 0.03 0.004
H1.30 0.1 0.05 0.004
I 10.00 0.2 0.39 0.008
I (C-Contact) 13.80 0.2 0.54 0.008
J 2.00 0.1 0.08 0.004
K 1.20 0.1 0.05 0.004
L 4.00 0.1 0.16 0.004
M3.90 0.1 0.15 0.004
N 0.40 0.1 0.02 0.004
O 1.85 0.1 0.07 0.004
Vishay Precision Group
Document No.: 63999
Revision: 27-Apr-11
www.vishaypg.com
1
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Document No.: 63999
Revision: 27-Apr-11