• 4222 South Staples Street • Corpus Christi Texas 78411 USA

Wire and Film Technologies Division

Telephone: 361 992 7900 • Facsimile: 361 992 3377 • Website: www.irctt.com

Sample Part No.

IRC Style

OAR

Power Rating in Watts

1 = 1W, 3 = 3W, 5 = 5W

Resistance Range

‘R’ indicates decimal point location

Tolerance

F = ±1%, G = ±2%, J = ±5%

RoHS Indicator

LF indicates RoHS compliance

Blank indicates Sn/Pb terminal

tinning; available on special request

Ordering Data

OAR

1

R100

F

LF

The typical power derating curves are based on conservative design concepts that extend from film

based products. The OAR is a solid metal alloy construction that can withstand comparably greater

operating power levels than conservative design models permit. Typically the resistive alloys can

withstand temperatures in excess of 300°C. Therefore, system thermal design considerations are a more

significant design parameter due to the heat limitations of solder joints and/or circuit board substrate

materials.

Power Derating

Pulse/Surge Chart @ 50 msec duration

0

10

20

30

40

50

60

70

80

90

100

700

600

500

400

300

200

Resistance (milli-ohms)

0

100

OAR-1(TP)

0

5

10

15

20

25

30

35

40

45

50

1400

1200

1000

800

600

400

Resistance (milli-ohms)

0

200

0

10

20

30

40

50

60

70

80

90

100

1400

1200

1000

800

600

400

Resistance (milli-ohms)

0

200

5(TP)

-

R

A

O

3(TP)

-

R

A

O

The Surge current charts are approximations of the capabilities of the OAR product and should not be

used to the exclusion of actual testing. The relative high surge currents depicted in the charts are as a

result of the robust all metal welded construction and the heat carrying capability of metal. Additionally

the OAR resistive wire provides large relative cross section for current flow as compared to other resistor

technologies, such as thin film, thick film, or metal strip.

OAR

Open Air Resistor

Metal Element Current Sense

OAR Series Issue June 2011 Sheet 3 of 3

Ordering Procedure

This product has two valid part numbers:

European (Welwyn) Part Number: OAR3-R01JI (OAR3, 10 milliohms ±5%, Pb-free)

O A R 3

-

R

0

1

J

I

1

2

3

4

5

USA (IRC) Part Number: OAR3R010JLF (OAR3, 10 milliohms ±5%, Pb-free)

O A R 3

R 0

1

0

J

L F

1

2

3

4

5

1

2

3

4

5

Type

Pitch

Value

Tolerance

Packing

OAR1 Omit for standard

3-5 characters

F = ±1%

I = Bulk

OAR3 TP = Tight Pitch See Electrical Data

G = ±2%

OAR5

R = ohms

J = ±5%

1

2

3

4

5

Type

Pitch

Value

Tolerance

Termination

OAR1 Omit for standard

4/5 characters

F = ±1%

Omit for SnPb

OAR3 TP = Tight Pitch See Electrical Data

G = ±2%

LF = Pb-free

OAR5

R = ohms

J = ±5%

Open Air Resistor

Metal Element Current Sense

OAR & OAR-TP Series

Make Possible

11.14

General Note

TT Electronics reserves the right to make changes in product specification without notice or liability.

All information is subject to TT Electronics’ own data and is considered accurate at time of going to print.

© TT Electronics plc

www.ttelectronicsresistors.com