Open Air Sense Resistors
Metal Alloy Strip
OARS XP
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
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
08.12
· Zero ohm jumper available
· Resistance values 1 mΩ to 25 mΩ
· Open air design provides cooler operation
· Lead Free RoHS compliant construction available
· Extended power surface mount current sense resistor
· Unique form factor provides TCE compliant termination
General Note
IRC reserves the right to make changes in product specifi cation without notice or liability.
All information is subject to IRC’s own data and is considered accurate at time of going to print. A subsidiary of
TT electronics plc
• 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
OARS XP
Open Air Sense Resistors
Metal Alloy Strip
• Zero ohm jumper available
• Resistance values 1 m: to 25 m:
• Open air design provides cooler operation
• Lead Free RoHS compliant construction available
• Extended power surface mount current sense resistor
• Unique form factor provides TCE compliant termination
Electrical Data
Resistance Value
(:)
Absolute TCR
(ppm/°C)
Available Tolerances
(%)
Rated Power
(W)
0.001 ±240
±1, ±5 5
0.002, 0.0025, 0.005,
0.010, 0.015, 0.020, 0.025 ±40
1 Non-Standard resistance values can be made available, subject to engineering charges and/or minimum order requirements.
Features:
• Superior thermal expansion cycling
• Inductance less than 10 nanohenries
• Flameproof
• Lead fl exible for thermal expansion
Applications:
• Current sensing
• Feedback
• Power Supplies
• Motor Controllers
Test Spec: AEC Q200 1m:2m: - 7m:>7m:
TCR +125 to -55°C 240ppm 40ppm 40ppm
Thermal Shock <0.75% <0.75% <0.75%
High Temperature Exposure 125°C <1.75% <0.5% <1.0%
Temperature Cycling: -40 to +125°C <1.0% <1.0% <0.75%
Operational Life <2.0% <1.0% <1.0%
Biased Humidity <0.75% <0.5% <0.5%
Mechanical Shock <1.5% <1.0% <1.0%
Vibration <1.0% <1.0% <1.0%
Moisture Resistance <1.0 <2.5% <2.0
Terminal Strength Meets JIS-C-6429
Solvent Resistance Meets MIL-STD-202 Method 215
Solderability Meets J-STD-002 Method B
Electrical Data
OARS-XP Issue March 2010 Sheet 1 of 3
Open Air Sense Resistors
Metal Alloy Strip
OARS XP
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
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
08.12
s3OUTH3TAPLES3TREETs#ORPUS#HRISTITEXAS53!
Wire and Film Technologies Division
TELEPHONE:sFACSIMILE:sWEBSITE:WWWIRCTTCOM
Physical Data
Dimensions (Inches and (mm))
IRC
Type
L (Resistance
Dependant)
H (Resistance
Dependant)
OARS-XP 0.425 - 0.470
(10.7 - 12.0)
0.090 - 0.180
(2.28 - 4.57)
0.093 ± 0.010
(2.36 ± 0.25)
0.190 ± 0.030
(4.83 ± 0.76)
0.250 ± 0.015
(6.35 ± 0.38)
*
* 0.250+0.045/-0.015(6.35+1.14/-0.38) for R001
L
H
W
D
T
OARS XP
Open Air Sense Resistors
Metal Alloy Strip
25 60 95 130 165 195 225
6.0
5.0
4.0
3.0
2.0
0.0
Ambient Temperature (°C)
Power Rating (watts)
Power Derating Curve
Note:
The power derating curve is a guidance based on a conser-
vative design model. The OARS XP is a solid metal alloy
construction that can withstand signifi cantly greater operating
temperatures than conservative design models permit. The
resistive alloys can withstand temperatures in exess of 350°C.
Therefore, the system thermal design is a more signifi cant
design parameter due to the heat limitations of solder joints
and/or circuit board substrate materials. Refer to additional
information below.
The thermal image (not a simulation) to the left is of an OARS
XP 2.5 m running at 5 Watts. Notice the hotpsot is nearly
205°C, but the solder joint is approximately 115°C (FR4 is
rated for 130°C). The unique construction of the OARS XP
isolates the hotspot from the circuit board material preventing
damage. Additionally, the thermal energy is dissipated to the
air instead of being conducted into the circuit board potentially
causing a nearby power component to exceed its rating.
The standard test circuit board consists of a four layer FR4
material with 2 ounce outer layers and 1 ounce inner layers,
which is typical of many industry designs. Contact IRC for
more details or for other thermal image test data for specifi c
resistance values and power levels.
OARS XP R0025 Thermal Image @ 5 Watts
Ambient conditions, No forced air.
O!2380)SSUE-ARCH3HEETOF
Open Air Sense Resistors
Metal Alloy Strip
OARS XP
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
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
08.12
• 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 Type
OARS
Size
Resistance Range (ohms)
Tolerance
(F = ±1%, J = ±5%)
RoHS Indicator
Ordering Data
OARS - XP R005 J LF
OARS XP
Open Air Sense Resistors
Metal Alloy Strip
Recommended Pad Layout
0 5 10 15 20 25 30
120
100
80
60
40
Resistance (milli ohms)
Joules (watts-second)
Pulse/Surge Chart
0
20
Note:
The high pulse surge capability of the OARS parts is
attributed to the solid metal alloy construction. In many
applications the cross-section of the OARS is greater
than the cross-section of the board traces connecting
the parts to the circuit board.
Cross-Sectional area ranges from approximately 1375
mils to 7250 mils.
0.377
(9.58)
0.125 (3.18)0.125 (3.18)
0.127 (3.23)
0.280
(7.11)
0.418
(10.57)
0.145 (3.67)0.145 (3.67)
0.127
(3.23)
0.280
(7.11)
0.110 (2.79)
0.060
(1.52)
0.125 (3.16)
0.020 (0.51)
0.110 (2.79)
0.020 (0.51)
0.020 (0.51)
OARS XP PAD (2 TERMINAL) OARS XP PAD (4 TERMINAL)
Note:
Recommended voltage sense
pads for Kelvin connection
Note: Recommended pad layout is based on the dimensional requirements to electrically attach to the component. Further minimum pad
requirements should account for the total thermal performance characteristics of the system; such as operating currents, thermal dissipation
capabilities of the circuit board, environmental considerations, nearby heat generating components...
OARS-XP Issue March 2010 Sheet 3 of 3
