rev.03/2006A

UT Series

Resistances from 0.005 to 260kOhms

Power Rating 0.1 to 13Watts

Resistance Tolerances to ± 0.01%

Low TCR: ± 20ppm/K Standard

MIL-R-26 / MIL-R-39007 Power Ratings

Temperature Range: -55°C to +350°C ( “V” Rating )

Non-Inductive Windings Available

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SPECIFICATIONS

Specification

Value

Tolerances

±0.01%to±10%(1%Standard)

Temperature Coefficient

>10W:±20ppm/K

1Wto10W:±50ppm/K

<1W:CallFactory

TemperatureRange

-55°Cto+250°C:CharacteristicU

-55°Cto+350°C:CharacteristicV

DielectricStrength

500VAC:UT-1/UT-1/2A/UT-1/2/UT-1A

1000VAC:AllOthers

Constuction

Centerlessgroundceramiccore

Tinnedcopperorcopperweldleads

Hightemperature/trivalent/inorganicSiliconecoating

Allweldedterminations

EnvironmentalPerformance

(MIL-STD202)

D

R

CharacteristicU

CharacteristicV

Dielectric

±0.2%+0.05W

±0.2%+0.05W

LoadLife

±1%+0.05W

±3%+0.05W

Storage

±0.2%+0.05W

±2%+0.05W

MoistureResistance

±0.2%+0.05W

±2%+0.05W

ThermalShock

±0.2%+0.05W

±2%+0.05W

5XOverload(5s)

±0.2%+0.05W

±2%+0.05W

Shock

±0.1%+0.05W

±0.2%+0.05W

Vibration

±0.1%+0.05W

±0.2%+0.05W

ForNon-InductiveWindings/inserttheletter“N”(i.e.UTN-5)

PartNumber-Resistance-Tolerance-TCR(Ifnotstandard)

Example:UT-525kOhms0.1%

0

50

100

150

200

250

300

350

400

0

20

40

60

80

100

120

AmbientTemperature(°C)

CHAR

U

CHAR

V

PowerDeratingCurve

SiliconeCoatedPowerResistors

Ordering Information

Willow Technologies Ltd. Shawlands Court, Newchapel Road, Lingfield, Surrey, RH7 6BL, United Kingdom.

+ 44 (0) 1342 835234

+ 44 (0) 1342 834306

info@willow.co.uk

http://www.willow.co.uk