USRUNR4 3425 3825 3825H

USR UNR 4-3425 4-3825 4-3825H
• High Stability
• Near Temperature
Independency
• Lowest Tolerances
• Low Capacitance and
Inductance
• Customized Resistance
Values
SPECIFICATIONS
ELECTRICAL
USR 4-3425/3825
UNR 4-3425/3825
with addional heatsink 3825H
note1)
Resistance Range
:
0R05 ... 500R
0R05 ... 500R
other resistance values upon request /
power rating depending on resistor value
Power Rating
:
3 W (70°C) without heatsink
5 W (20°C) for 3825H
30 W*
50 W*
* with heatsink
Thermal Resistance Rthj-c :
3.5 K/W
2.1 K/W
Tolerances
from 0R05
from 10R
from 50R
:
:
:
:
0.1%, 0.25%, 0.5%, 1%
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%
Temperature Coefficient :
max. ±5 ppm/K (-55...155)°C
typ. ±3 ppm/K (-55...125)°C
upon request ±1 ppm/K (0...60)°C
Voltage Proof
Max. Current
Thermal EMF
:
:
:
750 VDC
15 A
< 1 µV/K
:
-55°C...155°C
:
:
:
:
:
NiCr-Foil
Al2O3
AlN
Epoxy + heatsink aluminium
Cu, tinned, 4-pin
1.0 Nm
ENVIRONMENTAL
Operating Temperature Range
MECHANICAL Resistor Material
Substrate
Housing
Connector Material
Max. torque backplate
note1): Specially designed for applications with fast changing electrical load.
Willow Technologies Ltd. Shawlands Court, Newchapel Road, Lingfield, Surrey, RH7 6BL, UK
Tel. + 44 (0) 1342 835234, Fax. + 44 (0) 1342 834306, e-mail [email protected] web www.willow.co.uk
USR UNR
4-3425 4-3825 4-3825H
TEMPERATURE COEFFICIENT
600
+5 ppm/K
dR/R (ppm )
400-5 ppm/K
200
No minal-Spread
+/-2,3 ppm/K
0
+2,2 ppm/K
-200
-1,8 ppm/K
No minal-dR/R
-400
No minal-Spread
+/-2,3 ppm/K
-600
-50
-25
0
25
50
75
100
125
115
130
145
Tem perature (°C)
Power ( % from
nominal power)
DERATING CURVE
120
100
80
60
40
20
0
25
50
85
100
155
Temperature of the backplate (°C)
DIMENSIONS
USR/UNR 4-3425
USR/UNR 4-3825 and 4-3825H
Dimensions in mm
HOW TO ORDER
UNR 4-3425 1R0 D 0.1% TK1
USR 4-3825 10R D 0.5% TK3
Willow Technologies Ltd. Shawlands Court, Newchapel Road, Lingfield, Surrey, RH7 6BL, UK
Tel. + 44 (0) 1342 835234, Fax. + 44 (0) 1342 834306, e-mail [email protected] web www.willow.co.uk