WELWYN OARS

Surface Mount Sense Resistors
OARS, 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
Power rating at 25°C
Power rating at 85ºC
Resistance range
Resistance Tolerance
Standard Values
(Enquire for unlisted values)
milliohms
Inductance
Ambient temperature range
Current rating at 25°C
Current rating at 85°C
Ambient temperature range
OARS1
OARS-XP
2, 3, 4, 5, 10, 15, 20, 22, 25, 30, 40, 50
1, 2, 2.5, 5, 7.5, 10, 20, 25
watts
watts
ohms
%
2
4
1
2
R002 to R050
R001 to R025
≤ R002: 5, > R002: 1, 5
nH
°C
<10
-55 to +160
OARS-1Z
amps
amps
°C
Comments
65
46
-55 to +160
Zero-ohm jumper
Physical Data
Dimensions (mm) and recommended solder pads
Type
L
H
3.05
OARS1 >R003, OARS-1Z
±0.76
11.18
OARS1-R003
OARS1-R002
OARS-XP
* Dependent on ohmic value
T
4.83
±0.38
11.56
±0.38
10.7 to
12.0*
3.51
±0.76
D
a nom. b nom. c nom. d nom.
3.18
4.07
±0.76
±0.38
4.7
3.56
4.45
6.35
7.24
2.36
±0.25
±0.76
2.28 to
4.57*
W
4.83
±0.76
±0.38
±0.38
c
9.37
3.07
9.58
3.18
b
d
3.23
c
a
Issue F .09.07
Surface Mount Sense Resistors
OARS, OARS-XP, OARSZ Series
Performance Data (AEC-Q200)
OARS1
OARS-XP
ppm/ºC
∆R%
∆R%
∆R%
∆R%
∆R%
∆R%
∆R%
TCR (-55 to 125ºC)
Thermal Shock
High Temp. Exposure (125ºC)
Temp. Cycling (-40 to 125ºC)
Operational Life
Biased Humidity
Mechanical Shock
Vibration
Terminal Strength
Solvent Resistance
Solderability
<R004
<R002
240
0.75
1.75
1
2
0.75
1.5
1
R004 to R015
R002 to R007
40
0.75
0.5
1
1
0.5
1
1
Meets JIS-C-6429
Meets MIL-STD-002 Method 215
Meets J-STD-002 Method B
Tem perature Derating
Pulse Energy Rating
100
Energy (J)
% of Rated Power
120
80
60
40
20
120
100
80
60
40
20
0
1
10
0
0
25
50
75
100
125
150
OARS1
Note: For OARS-1Z the above derating graph may be applied to
the square of the current rating.
Joint Temperature Rise
Hot Spot Temperature Rise
7.6mm x 7.6mm pads, 2 oz copper on FR4, still air
50 / 25
30 / 15
150
10 / 5
100
5/-
50
50%
75%
Proportion of Rated Power
100%
Temperature Rise (K)
Temperature Rise (K)
Value in m illiohm s
OARS1 / OARS-XP
200
0
25%
OARS-XP
Note: This graph relates to single pulses of short duration (≤ 100ms).
Higher energy limits apply for longer pulses and overloads
7.6m m x 7.6m m pads, 2 oz copper on FR4, still air
250
100
Value (m illiohm s)
175
Am bient Tem perature (Deg C)
300
>R015
>R007
40
0.75
1
0.75
1
0.5
1
1
100
Value in milliohms
OARS1 / OARS-XP
80
5/-
60
10 / 5
30 / 15
40
50 / 25
20
0
25%
50%
75%
100%
Proportion of Rated Power
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.
Issue F .09.07
Surface Mount Sense Resistors
OARS, OARS-XP, OARSZ Series
Flammability
The resistor will not burn or emit incandescent particles under any condition of applied temperature or overload.
Marking
The parts are legend marked with ohmic value and tolerance code.
Packaging Data
Dimensions (mm)
Type
OARS1, OARS-1Z
OARS-XP-R001
OARS-XP >R001
A
4.32±0.08
7.21±0.1
B
11.7±0.08
11.94±0.1
11.56±0.1
C
D
E
24±0.3
11.5±0.1
1.75±0.1
F
8±0.1
12±0.1
G
4±0.1
Ordering Procedure
Example: OARS1 at 10 milliohms and 5% tolerance on a reel of 1900 pieces OARS1–R01JI
Type
OARS1
OARS-XP
Value (use IEC62 code)
Tolerance (use IEC62 code)
F
J
1%
5%
Packing
I
Tape
OARS1
OARS-XP
1900/reel
1200/reel
Standard
For the zero-ohm link, order OARS-1Z (Pack quantity is 1900/reel)
Issue F .09.07