Low Resistance
Metal Alloy Resistor
LRMA Series
Low Resistance
to 100mΩ
Alloy Resistor
Metal
·
Resistance range 0.5mΩ
·
High temperature operation to 170°C
LRMA Series
·
Low thermal EMF version
·
High power version
to 100mΩ
Resistance range 1
·
Current sensing for
operation to 170°C
High temperature
power electronics
Low
compliant &
version
·
RoHS
thermal EMF
halogen free
High power version
·
AEC-Q200 qualified
Current sensing for power electronics
RoHS compliant & halogen free
Electrical Data
Power rating
@70C
Overload rating
(5s)
Resistance range
Standard values
1
Resistance tolerance
TCR
(25 to 125°C)
Ambient temperature
Insulation resistance
Element alloy
Coating
LRMA Version
Size
W
W
mΩ
mΩ
1.5
7.5
5 to 15
5, 6, 10, 15
2010
T (Standard)
%
ppm/°C
°C
MΩ
≤R01:
2, >R01: 1
3
≤R01:
10, >R01: 5
15
1 to 50
1 to 100
1, 1.5, 2, 3, 3.5, 4, 5, 6, 7, 8, 10, 11, 12, 1, 2, 3, 5, 8, 10, 11, 15, 20, 25,
15, 18, 20, 25, 30, 33, 35, 40, 50
30, 40, 50, 60, 70, 75, 80, 100
1, 5
>R01: ±75
>R001 &
≤R01:
±100,
R001: ±275
-55 to 170
>100
Cu-Ni
Cu-Ni / Mn-Cu
Black
2512
P (Power)
2512
Power rating
@70C
Overload rating
(5s)
Resistance range
Standard values
1
LRMA Version
Size
W
W
mΩ
mΩ
0.5
2.5
5 to 20
5, 9, 10, 20
±100
0805
Resistance tolerance
TCR
(25 to 125°C)
Ambient temperature
Insulation resistance
Element alloy
Coating
%
ppm/°C
MΩ
2
<R01:
2,
≥R01:
1
1
<R01:
10,
≥R01:
5
5
0.5 to 40
3 to 30
0.5, 0.75, 1, 5, 10,
3, 4, 5, 10, 15, 20, 25, 30
20, 30, 40
1, 5
>R01: ±75, >R001 &
≤R01:
±100
≤R001: ±275
±100
-55 to 170°C
>100
Mn-Cu
Cu-Ni
Black
Green
Black
2
1
5
1 to 30
1, 2, 4, 5, 6, 7, 8, 9, 10,
12, 14, 15, 20, 22, 25, 30
M (Low thermal EMF)
1206
2512
N (Inverse)
0815
Notes: 1. Non-standard values may be available for high volume requirements. 2. Requires 300mm copper pad & trace area
Physical Data
(All dimensions in mm and nominal weight in g)
Size
0805
1206
0815
2010
2512
<R001
2512
≥R001 & ≤R003
2512
>R003
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
L
W
C
t
Wt
5.5
18.3
14.1
35.6
57 to 63
2.0 ±0.1 1.25 ±0.1
3.2 ±0.2 1.6 ±0.2
2.1 ±0.25 3.75 ±0.3
5.0 ±0.2 2.5 ±0.2
6.4 ±0.2
3.2 ±0.2
0.4 ±0.2 0.6 ±0.2
0.5 ±0.3 0.6 ±0.2
0.5 ±0.2 0.7 ±0.2
0.6 ±0.3 0.6 ±0.2
2.6 ±0.2
2.0 ±0.2 0.65 ±0.25
0.9 ±0.2
© TT electronics plc
11.12
Low Resistance
Low Resistance
Metal Alloy Resistor
Metal Alloy Resistor
LRMA Series
LRMA Series
Construction
Copper electrode with
nickel then tin plating
Coating (UL94-V0)
Low TCR
resistance alloy plate
The components are marked with ohmic value, e.g. “R002” = 2mΩ, “R010” = 10 mΩ.
Marking
Solvent Resistance
The component is resistant to all normal industrial cleaning solvents suitable for printed circuits.
Performance Data
Load at rated power
(cyclic load, 1000 hours at 70C)
Short term overload
(5 x rated power for 5s)
Humidity
(1000 hours, 85°C, 85%RH)
Temperature cycle
(-40 to +125°C, 1000 cycles, 15 minute dwell)
Resistance to solder heat
(260°C ±5°C for 20s ±1s)
Solderability
(245°C ±5°C for 2s ±0.5s)
Dry heat
(1000 hours at 170C)
Low temperature storage
(1000 hours at -55°C)
Substrate bending
(board 1.6mm, fulcrum spacing 90mm, deflection 2mm)
Insulation resistance
(1 minute @ 100Vdc)
±R
±R
±R
±R
±R
±R
±R
±R
0805: 1.5 Others 1
0.5
0805: 1 Others 0.5
0805: 1 Others 0.5
0.5
>95% coverage
0805: 1.5 Others 0.5
0.5
0805: 1 Others 0.5
>100M
Maximum (%)
Typical (%)
0.3
0.15
0.15
0.15
0.3
0.3
0.15
0.3
Thermal Performance & Mounting
Temperature Derating
Temperature Rise (°C)
Typical Temperature Rise
120
100
80
60
40
20
0
0%
20%
40%
60%
80%
100%
Proportion of Pr
Proportion of Pr
100%
80%
60%
40%
20%
0%
-30
20
70
120
170
Ambient Temperature (°C)
Hot spot
Joint
Reference Pad Dimensions (mm)
Size
a
b
L
1.4
1.15
1.2
0805
1.8
1.9
1.4
1206
7.9
1.5
0.9
0815
3.4
1.5
3.5
2010
2512
≤R003
4.0
3.1
1.3
2512
>R003
4.0
2.1
4.1
L
b
a
Current
Sense
The temperature rise shown is highly
dependent on mounting conditions.
Reference conditions assume 20
copper with thermal vias to multiple
layers.
The self-heating in the current tracks
should be kept negligible, or allowed
for by temperature derating.
General Note
Welwyn Components reserves the right to make changes in product specification without notice or liability
All information is subject to Welwyn’s own data and is considered accurate at time of going to print.
08/10
Welwyn
Components Limited
Bedlington, Northumberland NE22 7AA, UK
Telephone: +44 (0) 1670 822181
Facsimile: +44 (0) 1670 829465
Email: info@welwyn-tt.com
Website: 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.
www.bitechnologies.com www.irctt.com www.welwyn-tt.com
© TT electronics plc
11.12
Low Resistance
Metal Alloy Resistor
Metal Alloy Resistor
Low Resistance
LRMA Series
LRMA Series
Packaging
Bottom Tape
Wr
ΦC
ΦB ΦA
Paper Tape
Tr
Size
0805
1206
Tape
Paper
Paper
±0.15
±0.15
1.6
A
2.0
2.6
0815
Emboss
±0.2
±0.2
±0.2
±0.2
±0.2
3.6
4.5
±0.2
2.4
B
±0.2
±0.2
±0.2
±0.05
±0.2
8.0
W
8.0
12
±0.05
±0.05
±0.1
±0.05
±0.05
3.5
F
1.75
E
3.5
5.5
1.75
1.75
1.75
1.75
±0.1
±0.1
±0.1
±0.1
±0.1
4.0
4.0
4.0
P
1
P
2
±0.1
±0.1
+-0.1
±0.1
±0.05
±0.2
±0.05
±0.05
2.0
2.0
±0.1
2.0
±0.1
4.0
P
0
ΦD
0
+0.1/-0
+0.1/-0
1.5
1.5
0.84
0.84
±0.1
±0.1
±0.1
t
ΦA
178
± 2
ΦB
ΦC
Wr
9
±1
9
±1
60
±1
13
±1
11.4
11.5
±1
±1
Tr
±0.1
4.0
4.0
178
±0.2
60
±1
13
±1
2.8
2010
Emboss
±0.2
5.3
12
5.5
4.0
2.0
2512
Emboss
±0.2
3.6
6.9
12
5.5
±0.1
4.0
2.0
±0.05
±0.05
4.0
±0.1
1.55
±0.05
1.1
4.0
+0.1/-0
+0.1/-0
1.5
1.5
0.85
±0.15
0.85
±0.15
178
±0.2
60
±1
13
±1
13
±1
15.4
±2
15.4
178
±0.2
60
±1
13
±1
13
±1 ±2
15.4
178
±0.2
60
±1
13
±1
13
±1 ±2
Storage
Processing
Conditions:
5°C to 35°C and 40% to 75%RH
Shelf life:
2 years from manufacture
LRMA series resistors are suitable for both wave and IR reflow soldering. The recommended reflow profile for Pb-
free SAC305 alloy (Sn 96.5%, Ag 3%, Cu 0.5%) soldering is as follows:
Pre-heat:
60s to 120s at 150°C to 180°C
Soldering:
20s to 40s at
≥230°C
Peak:
5s at 250°C to 255°C
Ordering Procedure
Type
Version
T
P
M
N
Example: LRMA low thermal EMF version in 2512 size and at 10 milliohms and 1% tolerance packed in tape.
LRMAM2512–R01FT4
1
Size
Value (use IEC62 code)
Tolerance (use IEC62 code)
F
J
1%
5%
Packing
T5
T4
Tape
0805, 1206
0815, 2010, 2512
5000/reel
4000/reel
Standard
Note 1: For values which require 6 characters, e.g. R00075, the hyphen is omitted.
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
11.12
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