Surface Mount Sense Resistors
OARS, OARS-XP, OARSZ Series
Flexible leads for thermal expansion
Open-airdesignreducesPCBheang
Values down to 1milliohm
Element TCR ±20ppm/°C
Zero-ohm 65A jumper version
Surface Mount Sense Resistors
AO RS, OARS-XP, OARSZ Series
Flexible leads for thermal expansion
Open-air design reduces PCB heating
Values down to 1mΩ
Element TCR ±20ppm/ºC
Zero-ohm 65A jumper version
RoHS compliant
Electrical Data
OARS1/3 OARS-XP
Power rating at 25ºC watts 2 4
Power rating at 85ºC watts 1 2
Resistance range ohms R002 to R050 R001 to R025
Resistance Tolerance % ≤R002: 5, > R002: 1, 5
Standard Values
(Enquire for unlisted values) milliohms 2, 3, 4, 5, 10, 15, 20, 22, 25, 30, 40, 50 1, 2, 2.5, 5, 7.5, 10, 20, 25
Inductance nH <10
Ambient temperature range °C -55 to +160
OARS-1Z Comments
Current rating at 25ºC amps 65
Current rating at 85ºC amps 46
Ambient temperature range °C -55 to +160
Zero-ohm jumper
Physical Data
Dimensions (mm) and recommended solder pads
Type L H T D W a nom. bnom. cnom. dnom.
OARS1/3 > R003, OARS-1Z 3.05
±0.76
OARS1/3 - R003
11.18
±0.38
4.83
±0.76
3.18
±0.38 4.07
OARS1/3 - R002 11.56
±0.38
3.51
±0.76 4.7
±0.76
3.56
±0.38 4.45
9.37 3.07
OARS-XP 10.7 to
12.0*
2.28 to
4.57*
2.36
±0.25
4.83
±0.76
6.35
±0.38 7.24 9.58 3.18
3.23
* Dependent on ohmic value
a
b
d
c
c
07.11
Electrical Data
OARS1
OARS3
OARS-XP
Power rating
at 70°C ambient, or 140°C
terminal temperature
watts 2 3 5
Resistance range
R002 to R050
R002 to R015
R001 to R025
Resistance Tolerance
≤ R002: 5, > R002: 1, 5
Standard Values
(Enquire for unlisted values) milliohms
2, 3, 4, 5, 10, 15, 20,
22, 25, 30, 40, 50
2, 3, 4, 5, 10, 15
Inductance
<10
Ambient temperature range
-55 to +160
OARS-1Z
Comments
Current rating at 25°C ambient
65
Zero-ohm jumper
Max residual resistance
0.3
Ambient temperature range
-55 to +160
Temperature Derating
OARSZ
OARS1/3/XP
Note: For OARS1/3/XP this relates to power rating, for OARSZ it relates to current rating.
1, 2, 2.5, 5, 7.5,
12.5, 10, 20, 25
Surface Mount Sense Resistors
AO RS, OARS-XP, OARSZ Series
Flexible leads for thermal expansion
Open-air design reduces PCB heating
Values down to 1mΩ
Element TCR ±20ppm/ºC
Zero-ohm 65A jumper version
RoHS compliant
Electrical Data
OARS1/3 OARS-XP
Power rating at 25ºC watts 2 4
Power rating at 85ºC watts 1 2
Resistance range ohms R002 to R050 R001 to R025
Resistance Tolerance % ≤R002: 5, > R002: 1, 5
Standard Values
(Enquire for unlisted values) milliohms 2, 3, 4, 5, 10, 15, 20, 22, 25, 30, 40, 50 1, 2, 2.5, 5, 7.5, 10, 20, 25
Inductance nH <10
Ambient temperature range °C -55 to +160
OARS-1Z Comments
Current rating at 25ºC amps 65
Current rating at 85ºC amps 46
Ambient temperature range °C -55 to +160
Zero-ohm jumper
Physical Data
Dimensions (mm) and recommended solder pads
Type L H T D W a nom. bnom. cnom. dnom.
OARS1/3 > R003, OARS-1Z 3.05
±0.76
OARS1/3 - R003
11.18
±0.38
4.83
±0.76
3.18
±0.38 4.07
OARS1/3 - R002 11.56
±0.38
3.51
±0.76 4.7
±0.76
3.56
±0.38 4.45
9.37 3.07
OARS-XP 10.7 to
12.0*
2.28 to
4.57*
2.36
±0.25
4.83
±0.76
6.35
±0.38 7.24 9.58 3.18
3.23
* Dependent on ohmic value
a
b
d
c
c
07.11
Resistors
AllpartsarePb-freeandcomplywithEUDirecve2011/65/EU(RoHS2)
11.16
General Note
TT Electronics reserves the right to make changes in product specication 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
http://www.ttelectronics.com/resistors
BI Technologies IRC Welwyn
Surface Mount
Sense Resistors
OARS, OARS-XP, OARSZ Series
Surface Mount Sense Resistors
OARS, OARS-XP, OARSZ Series
Performance Data (AEC-Q200)
OARS1/3 <R004 R004 to R015 >R015
OARS-XP <R002 R002 to R007 >R007
TCR (-55 to 125ºC) ppm/ºC 240 40 40
Thermal Shock ∆R% 0.75 0.75 0.75
High Temp. Exposure (125ºC) ∆R% 1.75 0.5 1
Temp. Cycling (-40 to 125ºC) ∆R% 1 1 0.75
Operational Life ∆R% 211
Biased Humidity ∆R% 0.75 0.5 0.5
Mechanical Shock ∆R% 1.5 1 1
Vibration ∆R% 111
Terminal Strength Meets JIS-C-6429
Solvent Resistance Meets MIL-STD-002 Method 215
Solderability Meets J-STD-002 Method B
Note: Temperature rise data are given here for typical mounting conditions. Actual figures depend on PCB copper weight, mounting pad size, track
width and substrate type. Also, the open air format responds better to forced air cooling than chip format resistors. For values below 5 milliohms
allowance should be made for heat generated in the copper tracks themselves. Application-specific guidance is available on request.
Temperature Derating
0
20
40
60
80
100
120
0 25 50 75 100 125 150 175
Am bient Tem perature (De g C)
% of Rated Power
Pulse Energy Rating
0
20
40
60
80
100
120
1 10 100
Value (m illiohm s)
Energy (J)
OARS1/3 OARS-XP
Note: For OARS-1Z the above derating graph may be applied to
the square of the current rating.
Note: This graph relates to single pulses of short duration (≤100ms).
Higher energy limits apply for longer pulses and overloads
Hot Spot Temperature Rise
7.6m m x 7.6m m pads, 2 oz copper on FR4, still air
0
50
100
150
200
250
300
25% 50% 75% 100%
Proportion of Rated Power
Temperature Rise (K)
50 / 25
30 / 15
10 / 5
5 / -
Value in m illiohm s
OARS1/3 / OARS-XP
Joint Temperature Rise
7.6mm x 7.6mm pads, 2 oz copper on FR4, still air
0
20
40
60
80
100
25% 50% 75% 100%
Proportion of Rated Power
Temperature Rise (K)
5 / -
10 / 5
30 / 15
50 / 25
Value in milliohms
OARS1/3 / OARS-XP
07.11
Electrical Data
OARS1
OARS3
OARS-XP
Power rating
at 70°C ambient, or 140°C
terminal temperature
watts 2 3 5
Resistance range
ohms
R002 to R050
R002 to R015
R001 to R025
Resistance Tolerance
%
≤ R002: 5, > R002: 1, 5
Standard Values
(Enquire for unlisted values)
milliohms
2, 3, 4, 5, 10, 15, 20,
22, 25, 30, 40, 50
2, 3, 4, 5, 10, 15
Inductance
nH
<10
Ambient temperature range
°C
-55 to +160
OARS-1Z
Comments
Current rating at 25°C ambient
amps
65
Zero-ohm jumper
Max residual resistance
milliohms
0.3
Ambient temperature range
°C
-55 to +160
Temperature Derating
OARSZ
OARS1/3/XP
Note: For OARS1/3/XP this relates to power rating, for OARSZ it relates to current rating.
1, 2, 2.5, 5, 7.5,
12.5, 10, 20, 25
11.16
General Note
TT Electronics reserves the right to make changes in product specication 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
http://www.ttelectronics.com/resistors
BI Technologies IRC Welwyn
Thermal Performance Examples
These thermal images were taken under ambient conditions of still air at 25°C with the components
mounted on horizontal standard test boards as defined below.
JEDEC standard circuit board:
2” (50.8mm) square FR4
2outer power planes, 2 ounce (70μ) Cu
1” (25.4mm) square exposed
2 inner signal planes, 1 ounce (35μ) Cu
(continuous planes)
In contrast to the flat chip format, the OARS format keeps the hot spot thermally distant from the
solder j oints and reduces undesirable heat delivery into the PCB. Further thermal images for other
ohmic values and power dissipations are available on request.
Kelvin (4 Terminal) Mounting
For high precision applications a Kelvin (4
Terminal) mounting method is
recommended. An example to illustrate the
design principle is shown. High current
connections are made to the two pairs of
larger pads, whilst the voltage sense
connections are made to the two smaller
central pads.
OARS1-R005 at 2W
OARSXP-R0025 at 5W
Surface Mount
Sense Resistors
OARS, OARS-XP, OARSZ Series
11.16
General Note
TT Electronics reserves the right to make changes in product specication 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
http://www.ttelectronics.com/resistors
BI Technologies IRC Welwyn
Surface Mount Sense Resistors
OARS, OARS-XP, OARSZ Series
Flamm
Construction
ability
The resistor will not burn or emit incandescent particles under any condition of applied temperature or overload.
Marking
The parts are legend marked with
Copper terminations are welded to resistance alloy strip which is then formed. Value adjustment is achieved
by control of width, without the need for subsequent abrasion or notch trimming.
Pb-free termination finish is 96% Sn / 4% Ag alloy.
ohmic value and tolerance code.
Packaging Data
Dimensions (mm)
Type A B C D E F G
OARS1/3, OARS-1Z 4.32±0.08 11.7±0.08 8±0.1
OARS-XP-R001 11.94±0.1
OARS-XP >R001 7.21±0.1 11.56±0.1
24±0.3 11.5±0.1 1.75±0.1 12±0.1 4±0.1
07.11
Surface Mount
Sense Resistors
OARS, OARS-XP, OARSZ Series
Standard 4-Terminal Probe Positions for Measuring Unmounted Parts
0.79
6.35
1.27
Ø 0.76
7.94
All dimensions in mm
Standard 4-Terminal Probe Positions for Measuring Unmounted Parts
0.79
6.35
1.27
Ø 0.76
7.94
All dimensions in mm
11.16
General Note
TT Electronics reserves the right to make changes in product specication 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
http://www.ttelectronics.com/resistors
BI Technologies IRC Welwyn
Ordering Procedure
Ordering Procedure
This product has two valid part numbers:
European (Welwyn) Part Numbers: OARS1-R01JI(OARS1, 10 milliohms ±5%, Pb-free)
OARS-1Z (OARS-1Z, Pb-free)
O
A
R
S
1
-
R
0
1
J
I
1
2
3
4
O
A
R
S
-
1
Z
1
USA (IRC) Part Numbers: OARS1R010JLF (OARS1, 10 milliohms ±5%, Pb-free)
OARS-1ZLF(OARS-1Z, Pb-free)
O
A
R
S
1
R
0
1
0
J
L
F
1
2
3
4
O
A
R
S
-
1
Z
L
F
1
2
1
2
3
4
Type ValueTolerance Termination & Packing
OARS1
3-5 characters
See Electrical Data
R = ohms
F = ±1%
I = Pb-free, Tape & Reel
OARS3
J = ±5%
OARS1, OARS3
1900/reel
OARS-XP
OARS-XP
1200/reel
1
Type
OARS-1Z
No value or tolerance applies. Termination is Pb-free. Packing is Tape & Reel, 1900/reel.
1
2
3
4
Type ValueTolerance Termination & Packing
OARS1
4/5 characters
See Electrical Data
R = ohms
F = ±1%
LF = Pb-free
OARS3
J = ±5%
OARS1, OARS3
1900/reel
OARS-XP
OARS-XP
1200/reel
1
2
Type Termination & Packing
OARS-1Z
No value or tolerance applies.
LF= Pb-free, Tape & Reel, 1900/reel.
Surface Mount
Sense Resistors
OARS, OARS-XP, OARSZ Series
11.16
General Note
TT Electronics reserves the right to make changes in product specication 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
http://www.ttelectronics.com/resistors
BI Technologies IRC Welwyn
Mouser Electronics
Authorized Distributor
Click to View Pricing, Inventory, Delivery & Lifecycle Information:
TT Electronics:
OARS1R030J OARS1R010FLF OARS1R015JLF OARS1R003JLF OARS1R005FLF OARS1R004FLF
OARS1R005JLF OARS1R003J OARS1R003F OARS1R003FTR-LF OARS1R005FTR-LF OARS1R005JTR-LF
OARS1R010FTR-LF OARS1R010JTR-LF OARS1R015FTR OARS1R015JTR-LF OARS1R020FTR-LF
OARS1R022FTR-LF OARS1R025FTR-LF OARS1R030FTR-LF OARS1R030JTR-LF OARS1R040FTR
OARS1R050FTR-LF OARS1R050JTR OARS1R050JTR-LF OARS1R050JLF OARS1R010JLF OARS1R030JLF
OARS1R015FLF OARS1R010J OARS1R010F OARS1R004F OARS1R003FLF OARS1R020JLF OARS1R005J
OARS1R005F OARS1R015J OARS1R020FLF OARS1R040J OARS1R020J OARS1R020F OARS1R040JLF
OARS1R015F OARS1R050J OARS1R015JTR OARS1R050FLF OARS1R040JTR-LF OARS1ZEROHMTR-LF
OARS1ZEROHMTR OARSXPR001FLF OARSXPR0025FLF OARSXPR020FLF OARSXPR002FLF
OARSXPR005FLF OARSXPR010FLF OARSXPR025FLF OARSR025FLF OARSR020FLF OARSR030FLF
OARSR005FLF OARSR010FLF OARSR015FLF OARSR003FLF OARS3R002JLF OARS3R003FLF
OARS3R004FLF OARS3R005FLF OARS3R010FLF OARS3R015FLF OARS1R002FLF OARSXPR0075FLF
OARSXPR005JLF OARS1R025FLF OARS1R002JLF OARS1R030FLF OARS1R040FLF OARSXPR002JLF
OARSXPR001JLF OARSXPR0025JLF OARSXPR0075JLF OARS3R015JLF OARS1R025JLF OARSXPR010JLF
OARSXPR020JLF OARS3R003JLF OARS3R005JLF OARS3R002FLF OARS3R004JLF OARS3R010JLF
OARSXPR025JLF OARSXPR0125JLF OARS1R004JLF OARS1R022JLF OARSXPR0125FLF OARS1R022FLF
OARS-1ZLF