Open Air Sense Resistors
Metal Alloy Strip
OARS XP
·
Zero ohm jumper available
Open Air Sense Resistors
·
Resistance values 1 mΩ to 25 mΩ
Metal Alloy Strip
·
Open air design provides cooler operation
·
Lead Free RoHS compliant construction available
Zero ohm
power surface
·
•
Extended
jumper available
mount current sense resistor
Resistance values 1 m to 25 m
·
••
Unique form factor provides
operation
TCE compliant termination
Open air design provides cooler
•
Lead Free RoHS compliant construction available
•
Extended power surface mount current sense resistor
•
Unique form factor provides TCE compliant termination
OARS XP
Electrical Data
Resistance Value
( )
0.001
0.002, 0.0025, 0.005,
0.010, 0.015, 0.020, 0.025
1
Absolute TCR
(ppm/°C)
±240
Available Tolerances
(%)
Rated Power
(W)
±1, ±5
±40
5
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 flexible for thermal expansion
Applications:
• Current sensing
• Feedback
• Power Supplies
• Motor Controllers
Electrical Data
Test Spec: AEC Q200
TCR +125 to -55°C
Thermal Shock
High Temperature Exposure 125°C
Temperature Cycling: -40 to +125°C
Operational Life
Biased Humidity
Mechanical Shock
Vibration
Moisture Resistance
Terminal Strength
Solvent Resistance
Solderability
1m
240ppm
<0.75%
<1.75%
<1.0%
<2.0%
<0.75%
<1.5%
<1.0%
<1.0
2m
- 7m
>7m
40ppm
<0.75%
<1.0%
<0.75%
<1.0%
<0.5%
<1.0%
<1.0%
<2.0
40ppm
<0.75%
<0.5%
<1.0%
<1.0%
<0.5%
<1.0%
<1.0%
<2.5%
Meets JIS-C-6429
Meets MIL-STD-202 Method 215
Meets J-STD-002 Method B
General Note
General Note
TT electronics reserves the right to make changes in product specification without notice or liability.
IRC reserves the right to make changes in product specification without notice or liability.
All
information is subject to IRC’s
to TT electronics’ own
accurate at time
considered accurate at time of going to print.
All
information is subject
own data and is considered
data and is
of going to print.
Wire
Division
• 4222 South Staples
© TT
and Film Technologies
992 3377 • Website: www.irctt.com Street • Corpus Christi Texas 78411 USA
electronics plc
Telephone: 361 992 7900 • Facsimile: 361
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
A subsidiary of
TT electronics plc
OARS-XP Issue March 2010 Sheet 1 of 3
08.12
Open Air Sense Resistors
Open Air Sense Resistors
Metal Alloy Strip
OARS XP
Metal
OARS XP
Alloy
Strip
Physical Data
L
W
H
D
T
Dimensions (Inches and (mm))
IRC
Type
OARS-XP
L (Resistance
Dependant)
0.425 - 0.470
(10.7 - 12.0)
H (Resistance
Dependant)
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
Power Derating Curve
6.0
5.0
Power Rating (watts)
4.0
3.0
Note:
2.0
0.0
25
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 significantly 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 significant
design parameter due to the heat limitations of solder joints
and/or circuit board substrate materials. Refer to additional
information below.
60
95
130
165
195
225
Ambient Temperature (°C)
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 specific
resistance values and power levels.
OARS XP R0025 Thermal Image @ 5 Watts
Ambient conditions, No forced air.
Wire and Film Technologies Division
T
:
F
:
W
:
T
O
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.
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
© TT electronics plc
08.12
Open Air Sense Resistors
Metal Alloy Strip
Open Air Sense Resistors
OARS XP
OARS XP
Metal Alloy Strip
Pulse/Surge Chart
Note:
120
Joules (watts-second)
100
80
60
40
20
0
0
5
10
15
20
25
30
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.
Resistance (milli ohms)
Recommended Pad Layout
OARS XP PAD (2 TERMINAL)
0.377
(9.58)
0.125 (3.18)
0.125 (3.18)
0.145 (3.67)
OARS XP PAD (4 TERMINAL)
0.418
(10.57)
0.020 (0.51)
0.020 (0.51)
0.145 (3.67)
0.110 (2.79)
0.280
(7.11)
0.280
(7.11)
0.060
(1.52)
0.127 (3.23)
0.110 (2.79)
0.125 (3.16)
0.020 (0.51)
0.127
(3.23)
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...
Ordering Data
Sample Part No.
IRC Type
OARS
OARS - XP
R005
J
LF
Size
Resistance Range (ohms)
Tolerance
(F = ±1%, J = ±5%)
RoHS Indicator
Wire and Film Technologies Division
• 4222 South Staples Street • Corpus Christi Texas 78411 USA
Telephone: 361 992 7900 • Facsimile: 361 992 3377 • Website: www.irctt.com
OARS-XP Issue March 2010 Sheet 3 of 3
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.
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
© TT electronics plc
08.12
