USR UNR 2-T220 / T220B / T221 USS UNS 2-T220

USR UNR 2-T220 / T220B / T221
USS UNS 2-T220
Precision Foil Resistors
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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
SPECIFICATIONS
Type
Resistance Range
Power rating
free air 70°C (R<50R0)
free air 70°C (R>50R0)
with heatsink (R<50R0)
with heatsink (R>50R0)
Thermal Resistance Rthj-c
R<50R0
R>50R0
Tolerances
from 0.5 Ohms
from 10.0 Ohms
from 25.0 Ohms
from 50.0 Ohms
USR / USS
UNR /UNS
0.5 Ohms to 150 kOhms
0.5 Ohms to 5 kOhms
1.5W
1.0W
10W
6W
1.5W
1.0W
15W
10W
10.8 K/W
18.8 K/W
6.8 K/W
10.8 K/W
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 Coefficient
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
Substrate
Housing
Connector Material
NiCr-Foil
Al2O3
AlN
Epoxy + Cu heatsink nickel plated
Cu tinned
Terminals
Soldering Temperature
2
210°C <30 seconds
other versions upon request
Max. Torque
1.0 Nm
Notes
Specially designed for applications with fast
changing electrical load
Ordering Information
Part Description: Part Type - Resistance - Contact - Tolerance - TCR
Example: UNR 2-T220B 5.7kOhms C 0.5% 3ppm
USR UNR 2-T220 / T220B / T221
USS UNS 2-T220
Precision Foil Resistors
SPECIFICATIONS (continued)
Temperature Coefficient
800
600
+5ppm/K
-5ppm/K
∆R/R (ppm)
400
200
Nominal Spread
±2.3ppm/K
0
-200
Nominal ∆R/R
-400
Nominal Spread
±2.3ppm/K
-600
-800
-50
-25
0
25
50
75
100
125
Temperature (°C)
Power (% from
nominal power)
Derating
Power Rating Notes The U-Series Resistors must be attached to a suitable heatsink.
The maximum internal resistor temperature is 155°C.
To specify an appropriate heatsink use the following formula :
120
100
80
40
RθH = TMAX - ( P x RθR ) - TA
P
20
Where:
60
0
25
50
85
100
115
130
145
155
Temperature of the backplate(°C)
RθH = Thermal Resistance of Heatsink ( K/W )
RθR = Thermal Resistance of Resistor ( K/W )
TMAX = Maximum Temperature of Resistor
TA = Ambient Temperature of Heatsink ( °C )
P = Power Through Resistor ( W )
Dimensions
USS 2-T220 / UNS 2-T220
Dimension
mm
tol.
(±mm)
inches
tol.
(±inches)
A
12.70
0.2
0.50
0.008
Dimension
mm
inches
B
10.16
0.2
0.40
0.008
A
12.10
0.476
C
0.76
0.1
0.03
0.004
B
11.16
0.439
D
5.08
0.1
0.20
0.004
C
18.33
0.722
E
4.00
0.1
0.16
0.004
D
5.08
0.200
0.004
E
1.76
0.069
F
3.20
0.126
F
1.20
0.1
0.05
G
14.60
0.2
0.57
0.008
H
15.00
0.2
0.59
0.008
I
17.33
0.2
0.68
0.008
J
0.40
0.1
0.02
0.004
K
1.85
0.1
0.07
0.004
USR UNR 2-T220 / T220B / T221
USS UNS 2-T220
Precision Foil Resistors
SPECIFICATIONS (continued)
Dimensions
Dimension
USR 2-T220B / UNR 2-T220B
USR 2-T221 / UNR 2-T221
mm
tol.
(±mm)
inches
tol.
(±inches)
A
17.30
0.2
0.68
0.008
B
10.16
0.2
0.40
0.008
C
6.00
0.1
0.24
0.004
D
Ø3.7
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
H
1.30
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
0.004
J
2.00
0.1
0.08
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)
A
18.30
0.2
0.72
0.008
B
10.16
0.2
0.40
0.008
C
3.70
0.1
0.15
0.004
D
Ø3.2
0.1
Ø0.126
0.004
E
16.40
0.2
0.65
0.008
0.004
F
5.08
0.1
0.20
G
0.76
0.1
0.03
0.004
H
1.30
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
3.90
0.1
0.15
0.004
N
0.40
0.1
0.02
0.004
O
1.85
0.1
0.07
0.004
Dimension
mm
tol.
(±mm)
inches
tol.
(±inches)
USR 2-T220 / UNR 2-T220
A
15.30
0.2
0.60
0.008
B
10.00
0.2
0.39
0.008
C
2.80
0.1
0.11
0.004
D
Ø3.7
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
J
35.30
2.0
1.39
0.079
K
Ø0.6
0.1
Ø0.02
0.004
L
2.41
0.1
0.09
0.004