Resistors
Open Air Resistor
Metal Element Current Sense
OAR
Open Air Resistor
OAR & OAR-TP Series
•
•
•
Metal Element Current Sense
Power ratings of 1, 3, & 5W @ 85°C
Superior surge performance
TCR’s to ±20ppm/°C
Hot spot isolated from PCB material
Power ratings of 1, 3, & 5W @ 85°C
Resistance wire TCR ±20ppm/°C
Resistance range from 2.5mΩ to 100mΩ
Tolerances to 1%
•
Open air design maximizes thermal performance
•
Welded copper leads minimize effects from solder wicking and provide
All Pb-free parts comply with EU Directive 2011/65/EU (RoHS2)
true 1% performance
Electrical Data
Part
Number
OAR-1 (TP)
OAR-3 (TP)
OAR-5 (TP)
Power Rating
@ 85°C
(watts)
1.0
3.0
5.0
Resistance
Range (mΩ)
3, 5, 6, 8, 10, 12, 15, 20, 25, 30, 35,
40, 50, 60, 70, 80, 100
2, 2.5, 3, 4, 5, 6, 7, 10, 15, 20, 25,
30, 40, 45, 50, 60, 70, 100
3, 4, 5, 6, 6.2, 10, 12, 15,
20, 25, 30, 40, 50
Tolerance
(±%)
Wire TCR
(±ppm/°C)
Inductance
(nH)
1, 2¹, 5
20
<10
Notes:
¹ ±2% tolerance available <5m
Ω
Please contact factory for resistance values not listed
Environmental Data
Load Life (1000 hours @ 25°C)
Moisture (no load for 1000 hours)
Temperature Cycling (-40°C to +125°C for 1000 cycles)
Operating Temperature
∆R/R
<1%
∆R/R
<1%
∆R/R
<1%
-40°C to +125°C
General Note
General Note
TT Electronics reserves the right to make changes in
without notice or liability.
without notice or liability.
IRC reserves the right to make changes in product specification
product specification
All
information is subject to TT
data and is considered accurate at time of going
accurate
All
information is subject to IRC’s own
Electronics’ own data and is considered
to print.
at time of going to print.
BI Technologies IRC Welwyn
http://www.ttelectronics.com/resistors
TT electronics plc
OAR Series Issue June 2011 Sheet 1 of 3
A subsidiary of
© TT Electronics plc
Telephone: 361 992 7900 • Facsimile: 361 992 3377 • Website: www.irctt.com
Wire and Film Technologies Division
• 4222 South Staples Street • Corpus Christi Texas 78411 USA
06.17
Open Air Resistor
Open Air Resistor
Metal Element Current Sense
OAR
Metal Element
OAR & OAR-TP Series
Current Sense
Open Air
Data
Physical Data
Physical
Resistor
OAR
Metal Element Current Sense
B
On lower ranges stand-off may be
eliminated
NOTE:
Contact factory for:
1. Variations of “A” dimension.
2. Different lead diameter.
E
F
A
Physical Data
C
On lower ranges stand-off may be
eliminated
Test Point (Kelvin connection)
NOTE:
Contact factory for:
F
1. Variations of “A” dimension.
2. Different lead diameter.
B
Type
IRC Type
OAR1
OAR-1
OAR1TP
A
0.45
+0.04/-0.02
A
(11.43
+1.02/-0.51
)
C
B max
C
Dimensions (Inches and (mm))
C
0.125 ±0.030
(3.18 ±0.762)
A
E
E
E
B
0.32 (8.12)
F
Test Point (Kelvin connection)
0.197
+0.04/-0.03
(11.43
(5.0
+1.0/-0.8
)
+1.020/-0.508)
0.600
0.60
+0.04/-0.02
+0.040/-0.020
0.450 +0.040/-0.020
0.45 (11.4)
0.32 (8.12) max
0.27 Typ
F
0.065 +0.010/-0.005
0.040 ±0.002
0.040 ±0.002
(1.65 +0.254/-0.127)
(1.02 ±0.051)
OAR3
OAR-3
IRC Type
OAR-1
OAR-3
OAR3TP
OAR-5
<R005
OAR3TP
≥R005
0.65 Typ
0.125
and (mm))
0.065 +0.010/-0.005
Dimensions (Inches
±0.030
0.92 (23.4)
(15.24
+1.02/-0.51
(15.24 +1.020/0.508)
)
0.92 (23.4) max
(3.18 ±0.762)
(1.65 +0.254/-0.127)
0.065
+0.01/-0.005
A
B
C
0.125
±0.03
E
0.275
+0.04/-0.03
0.800 +0.040/-0.020
0.65 Typ
0.125 ±0.030
0.065 +0.010/-0.005
)
(3.18
±0.76
)
(1.65
+0.25/-0.13
0.450 +0.040/-0.020
)
0.27 Typ
0.125 ±0.030
0.065 +0.010/-0.005
(7.0
+1.0/-0.8
(20.32 +1.020/-0.508) 0.88 (22.4) max
(1.65 +0.254/-0.127)
1.12 (28.5)
(3.18 ±0.762)
(11.43 +1.020/-0.508) 0.32 (8.12) max
(3.18 ±0.762)
(1.65 +0.254/-0.127)
0.197
+0.04/-0.03
(1.02 ±0.051)
0.04
±0.002
F
0.040 ±0.002
)
(1.02
±0.05
0.040 ±0.002
(1.02 ±0.051)
(1.02 ±0.051)
0.040 ±0.002
(1.02 ±0.051)
0.040 ±0.002
(1.02 ±0.051)
0.80
+0.04/-0.02
(15.24 +1.020/0.508)
Thermal Image Data
0.92 (23.4) max (3.18 ±0.762)
0.88 (22.4)
OAR5
(20.32
+1.02/-0.51
)
OAR-5
(5.0
+1.0/-0.8
0.600 +0.040/-0.020
)
0.800 +0.040/-0.020
0.65 Typ
0.65 Typ
0.125 ±0.030
0.125 ±0.030
0.065 +0.010/-0.005
(1.65 +0.254/-0.127)
0.065 +0.010/-0.005
(1.65 +0.254/-0.127)
OAR5TP
0.275
+0.04/-0.03
(20.32 +1.020/-0.508) 0.88 (22.4)
1.14 (29)
(3.18 ±0.762)
max
(7.0
+1.0/-0.8
)
Thermal Image Data
OAR-1 5 mΩ @ 1 Watt
Hot Spot:
87°C
Solder Joint: 45°C
OAR-3 5 mΩ @ 3 Watt
Hot Spot:
160°C
Solder Joint: 70°C
OAR-5 5 mΩ @ 5 Watt
Hot Spot:
230°C
Solder Joint: 96°C
The thermal images (not simulations) above are of the OAR products at their respective power rating. Notice the
solder joint temperature is much lower than the hotspot. The unique construction of the OAR isolates the tempera-
OAR-1 5
hotspot
Watt
OAR-3
preventing damage to the circuit
OAR-5 5 mΩ @ 5 Watt
thermal
ture of the
mΩ @ 1
from the circuit board material
5 mΩ @ 3 Watt
board. Additionally, the
energy is dissipated to the air instead of being conducted into the circuit board potentially causing a nearby power
Hot Spot:
87°C
Hot Spot:
160°C
Hot Spot:
230°C
component to exceed its rating.
Solder Joint: 45°C
Solder Joint: 70°C
Solder Joint: 96°C
The thermal images circuit board consists of a four layer FR4products at theirounce (70µm) outer layersNotice the
The standard test (not simulations) above are of the OAR material with 2 respective power rating. and 1 ounce
solder joint temperature is much lower of many industry designs. Theconstruction of the OARambient temperature
(35µm) inner layers, which is typical than the hotspot. The unique test conditions were in isolates the tempera-
ture of the hotspot from the circuit with no forced air. Contactdamage to the circuit board. Additionally, the thermal
conditions, approximately 22 °C board material preventing TT electronics for more details or for other thermal image
energy is dissipated to resistance values being conducted into the circuit board potentially causing a nearby power
test data for specific the air instead of and power levels.
component to exceed its rating.
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
The standard test circuit board consists of a four layer FR4 material with 2 ounce (70µm) outer layers and 1 ounce
(35µm) inner layers, which is typical of many industry designs. The test conditions were in ambient temperature
conditions, approximately 22 °C with no forced air. Contact TT electronics for more details or for other thermal image
test data for specific resistance values and power levels.
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
General Note
OAR
Series Issue
June
2011 Sheet 2 of 3
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.
OAR
Series
BI Technologies
Issue
June
2011
Welwyn
IRC
Sheet 2 of 3
http://www.ttelectronics.com/resistors
© TT Electronics plc
06.17
Open Air Resistor
Open Air Resistor
Metal Element Current Sense
OAR & OAR-TP Series
OAR
Metal Element Current Sense
Power Derating
The typical power derating curves are based on conservative design concepts that extend from
fi
lm
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.
Pulse/Surge Chart @ 50 msec duration
700
600
1400
1200
1400
1200
Surge Current (Amps)
Surge Current (Amps)
500
400
300
200
100
0
0
10
20
30
40
50
60
70
80
90
100
1000
800
600
400
200
0
0
10
20
30
40
50
60
70
80
90
100
Surge Current (Amps)
1000
800
600
400
200
0
0
5
10
15
20
25
30
35
40
45
50
Resistance (milli-ohms)
Resistance (milli-ohms)
Resistance (milli-ohms)
OAR-1(TP)
OAR-3(TP)
OAR-5(TP)
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
fl
ow as compared to other resistor
technologies, such as thin
fi
lm, thick
fi
lm, or metal strip.
Ordering Data
Sample Part No.
IRC Style
OAR
OAR
1
R100
F
LF
Power Rating in Watts
1 = 1W, 3 = 3W, 5 = 5W
Resistance Range
Tolerance
‘R’ indicates decimal point location
F = ±1%, G = ±2%, J = ±5%
RoHS Indicator
LF indicates RoHS compliance
Blank indicates Sn/Pb terminal
tinning; available on special request
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
OAR
Series Issue
June
2011 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.
BI Technologies IRC Welwyn
http://www.ttelectronics.com/resistors
© TT Electronics plc
06.17
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
Open
of the
Resistor
metal welded construction and the heat carrying capability of metal. Additionally
result
Air
robust all
the OAR resistive
Current Sense
Metal Element
wire provides large relative cross section for current
fl
ow as compared to other resistor
technologies, such as thin
fi
lm, thick
fi
lm, or metal strip.
OAR & OAR-TP Series
Ordering Data
Ordering Procedure
Sample Part No.
IRC Style
OAR
OAR
1
R100
F
LF
This product has two valid part numbers:
European
in Watts
(Welwyn) Part Number: OAR3-R01JI
(OAR3, 10 milliohms ±5%, Pb-free)
Power Rating
1 = 1W, 3 = 3W, 5 = 5W
O
Resistance Range
Tolerance
‘R’ indicates decimal point location
A
R
3
2
2
Pitch
-
R
0
3
3
1
J
4
I
5
4
Tolerance
F = ±1%
G = ±2%
J = ±5%
5
Packing
I = Bulk
1
F = ±1%, G = ±2%, J = ±5%
RoHS Indicator
LF indicates RoHS
1
compliance
Blank indicates Sn/Pb terminal
tinning; available
Type
on special request
Value
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
OAR1 Omit for standard
3-5 characters
OAR3 TP = Tight Pitch See Electrical Data
OAR5
R = ohms
OAR
Series Issue
June
2011 Sheet 3 of 3
USA (IRC) Part Number: OAR3R010JLF
(OAR3, 10 milliohms ±5%, Pb-free)
O
A
1
1
Type
2
Pitch
R
3
2
R
0
3
3
Value
1
0
J
4
L
5
4
Tolerance
F = ±1%
G = ±2%
J = ±5%
5
Termination
Omit for SnPb
LF = Pb-free
F
OAR1 Omit for standard
4/5 characters
OAR3 TP = Tight Pitch See Electrical Data
OAR5
R = ohms
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.
BI Technologies IRC Welwyn
http://www.ttelectronics.com/resistors
© TT Electronics plc
06.17
