CSM Series
Bulk Metal
®
Technology High Precision, Current Sensing, Power
Surface Mount, Metal Strip Resistor with Resistance Value from 1 m
,
Rated Power up to 3 W and TCR to 0 ± 15 ppm/°C Maximum
FEATURES
Temperature coefficient of resistance:
± 15 ppm/°C max. (- 55 °C to + 125 °C, + 25 °C
ref.); ± 10 ppm/°C max. (- 55 °C to + 125 °C,
+ 25 °C ref.) is available on request (see table 1)
Power rating: 1 W to 3 W
Resistance tolerance: ± 0.1 %
Resistance range: 1 m to 200 m
Bulk Metal
®
Foil resistors are not restricted to standard
values, specific “as required” values can be supplied at no
extra cost or delivery (e.g. 2.3456 m vs. 2 m)
Load life stability to ± 0.2 % (70 °C, 2000 h at rated power)
Short time overload: ± 0.1 % typical
Thermal EMF: 3 µV/°C (DC offset error, significant for low
values)
Maximum current: up to 54 A
Proprietary processing techniques produce low TCR, tight
tolerance and improve stability
Low inductance < 5 nH
Solderable terminations
Excellent frequency response to 50 MHz
Matched sets are available on request
Screening in accordance with EEE-INST002 available
(per MIL-PRF-55342 and MIL-PRF-49465; see 303144
and 303145 datasheets)
Terminal finishes available: lead (Pb)-free, tin/lead alloy
Quick prototype quantities available, please contact
foil@vpgsensors.com
For better performance please contact Application
Engineering
Compliant to RoHS directive 2002/95/EC
No minimum order quantity and any value at any
tolerance available within resistance range.
The Vishay Foil Resistors (VFR) application engineering
department is available to advise and make
recommendations.
For non-standard technical requirements and special
applications, please contact
foil@vpgsensors.com.
B
I
A
Zin
R
C
I
D
~
=
∞
V
Four terminal (Kelvin) design: allows for precise and
accurate measurements.
FIGURE 1 - POWER DERATING CURVE
100
+ 70 °C
Rated Power (%)
80
60
40
20
0
- 65 - 50
- 25
0
25
50
75
100
125
150
170
Ambient Temperature (°C)
TABLE 1 - SPECIFICATIONS
PARAMETER
Resistance Range
Power Rating at 70 °C
Maximum Current
(2)
Tolerance
1 W
(1)
31 A
± 0.5 % (1 m to < 3 m)
± 0.1 % (3 m to 200 m)
± 50 ppm/°C (1 m to < 3 m)
± 15 ppm/°C (3 m to 200 m)
± 10 ppm/°C (3 m to 10 m) is available on request
(3)
CSM2512
1 m to 200 m
3 W ( 1 m to 10 m)
2 W (> 10 m to 200 m)
54 A
± 0.5 % (1 m to < 2 m)
± 0.1 % (2 m to 200 m)
± 25 ppm/°C (1 m to < 3 m)
± 15 ppm/°C (3 m to 200 m)
± 10 ppm/°C (1 m to 10 m) is available on request
(3)
CSM3637
Temperature Coefficient
Max. (- 55 °C to + 125 °C,
+ 25 °C Ref.)
Operating Temperature
- 65 °C to + 170 °C
Range
Maximum Working Voltage
(P x
R)
1/2
Weight (Maximum)
0.09 g
0.29 g
Notes
(1)
For values above 0.1
derate linearly to 80 % rated power at 0.5
(2)
Maximum current for a given resistance value is calculated using I
=
P
R
(3)
Please contact application engineering:
foil@vpgsensors.com
* This datasheet provides information about parts that are RoHS-compliant and/or parts that are non-RoHS-compliant. For example, parts with
lead (Pb) terminations are not RoHS compliant. Please see the information/tables in this datasheet for details.
Document Number: 63089
Revision: 17-Aug-15
For any questions, contact
foil@vpgsensors.com
www.vishayfoilresistors.com
1
CSM Series
ABOUT CSM
(Low Ohm Value 1 m to 200 m)
New high-precision Bulk Metal
®
surface-mount Power Metal
Strip
®
resistor of 1 m to 200 m that features an improved
load-life stability of ± 0.2 % at + 70 °C for 2000 h at rated
power, an absolute TCR of ± 15 ppm/°C maximum from
- 55 °C to + 125 °C, + 25 °C ref., and a tolerance of ± 0.1 %.
Typical current sensing resistors offer a load-life stability of
1 % through a 2000 h workload. The improved resistance
stability of the CSM Series makes it ideal for
tightened-stability voltage division and precision current
sensing applications in switching linear power supplies,
power amplifiers, measurement instrumentation, bridge
networks, and medical and test equipment. In addition, the
CSM Series complies with EEE-INST-002 (MIL-PRF 55342
and MIL-PRF 49465) for military and space applications.
Traditional Passive current sensors and shunts generate
heat under power, which changes their resistance, and thus
their voltage output. The CSM’s low absolute TCR reduces
errors due to temperature gradients, thus reducing a major
source of uncertainty in current measurement. The CSM
can withstand unconventional environmental conditions,
including the extremely high temperatures and radiation-rich
environments of down-hole oil exploration and well logging,
or the deep-sea underwater repeaters in cross-ocean
communications.
The stability of the CSM can be further enhanced by
post-manufacturing operations (PMO), such as temperature
cycling, short-time overload, and accelerated load life which
are uniquely applicable to Bulk Metal
®
Foil resistors.
The device features a low thermal electromotive force (EMF)
that is critical in many precision applications. The CSM’s
all-welded construction is composed of a Bulk Metal
®
resistive element with welded copper terminations, plated for
soldering. The terminations make true ohmic contact with the
resistive layer along the entire side of the resistive element,
thereby minimizing temperature variations. Also, the resistor
element is designed to uniformly dissipate power without
creating hot spots, and the welded terminations material is
compatible with the element material.
These design factors result in a very low thermal-EMF
(3 µV/°C) resistor, because in addition to the low thermal
EMF compatibility of the metals, the uniformity and thermal
efficiency of the design minimizes the temperature
differential across the resistor, thereby assuring low thermal
EMF generation at the leads. This further reduces the
“battery effect” exhibited by most current-sensing or
voltage-reference resistors. Thus, the parasitic voltage
generated at the junction of two dissimilar metals, which is
especially important in low-value current-sensing resistors, is
minimized, while the pure current-to-voltage conversion is
protected from such interference in DC applications.
The stability problems associated with analog circuits are
very pervasive, but knowledgeable selection of a few
high-quality resistors, networks, or trimming potentiometers
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2
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Document Number: 63089
Revision: 17-Aug-15
in critical locations can greatly improve circuit performance,
long-term application-related performance, as well as the
designer’s peace-of-mind.
Additionally, the overall system cost is often reduced when a
knowledgeable designer concentrates costs in a few
exceptionally stable components whose proven minimal-
deviation load and environmental stability can often eliminate
the necessity of additional compensating circuitry or
temperature-controlling systems. The higher reliability and
better overall system performances also achieve excellent
product results in the field, enhancing market acceptance
and product reputation.
Designers often unnecessarily pay for tighter tolerances than
required simply to accommodate the resistance stability
shifts they know to be imminent in an application due to the
large application-related changes in the components they
selected. Selection of a high-stability component like the
CSM in these applications eliminates the need for shift
allowance due to “planned instability” and allows the use of
looser initial tolerances than would be necessary with
current-sensing resistors based on other technologies.
The Key Applications
Applications requiring accuracy and repeatability under
stress conditions such as the following:
Switching and linear power supplies
Precision current-sensing
Power management systems
Feedback circuits
Power amplifiers
Measurement instrumentation
Precision instrumentation amplifiers
Medical and automatic test equipment
Satellites and aerospace systems
Commercial and Military avionics
Test and measurement equipment
Electronic scales
CSM Series
FIGURE 2 - DIMENSIONS AND IMPRINTING
in inches (millimeters)
CSM2512 DIMENSIONS
(1)
CSM3637 DIMENSIONS
(1)
H
H
A
B
L
T
W
B
A
L
T
W
CSM2512 LAND PATTERN
I
1
E
1
e
I
2
I
Kelvin Connection
I
1
, I
2
- Current
E
1
, E
2
- Sense
a
b
E
2
d
c
CSM3637 LAND PATTERN
E
1
I
1
E
2
c
I
2
I
a
d
b
DIMENSIONS - TOLERANCES ± 0.010 (± 0.254), * ± 0.015 (± 0.381)
MODEL
RESISTANCE RANGE (m)
1 to < 5
CSM2512
5 to < 7
7 to 200
CSM3637
1 to < 2
2 to 200
0.360 (9.144)
0.360 (9.144)
0.370 (9.398)
0.370 (9.398)
0.025 (0.635)
0.025 (0.635)
0.250 (6.350)
0.125 (3.175)
0.025 (0.635)
L
W
H
T
0.087 (2.210)
0.047 (1.194)
0.030 (0.762)
0.138 (3.505)
0.086 (2.184)
0.061 (1.55)
0.061 (1.549)
0.032 (0.813)
0.032 (0.813)
0.030 (0.762)* 0.032 (0.813)*
A
B
LAND PATTERN DIMENSIONS - TOLERANCES ± 0.003 (± 0.076)
MODEL
RANGE
0R001 to 0R0049
CSM2512
0R005 to 0R0069
0R007 to 0R2
CSM3637
Note
(1)
a
0.120 (3.05)
0.083 (2.10)
0.065 (1.65)
0.168 (4.27)
0.116 (2.95)
b
0.145 (3.68)
0.145 (3.68)
0.145 (3.68)
0.390 (9.91)
0.390 (9.91)
c
0.045 (1.14)
0.045 (1.14)
0.045 (1.14)
0.066 (1.68)
0.066 (1.68)
d
0.021 (0.53)
0.021 (0.53)
0.021 (0.53)
0.024 (0.610)
0.024 (0.610)
e
0.055 (1.39)
0.055 (1.39)
0.055 (1.39)
-
-
I
0.050 (1.27)
0.125 (3.17)
0.160 (4.06)
0.074 (1.88)
0.178 (4.52)
0R001 to 0R0019
0R002 to 0R2
White dot indicates top side of part for mounting purposes
Document Number: 63089
Revision: 17-Aug-15
For any questions, contact
foil@vpgsensors.com
www.vishayfoilresistors.com
3
CSM Series
TABLE 2 - CSM SERIES PERFORMANCE SPECIFICATIONS
TEST
Thermal Shock
Load Life Stability
Bias Humidity
Short Time Overload
High Temperature Exposure
Low Temperature Storage
Moisture Resistance
Shock
Vibration
Resistance to Soldering Heat
Solderability
CONDITIONS
- 55 °C to + 150 °C, 1000 cycles,
15 min at each extreme
2000 h, 70 °C at rated power
+ 85 °C, 85 % humidity
10 % bias, 1000 h
5 x rated power for 5 s
(See note
(3)
from table 1)
1000 h, 170 °C
- 65 °C for 24 h
MIL-STD-202, method 106,
0 power, 7a and 7b not required
100 g, 6 ms, 5 pulses
(10 Hz to 2000 Hz) 20 g
10 s to 12 s at + 260 °C
MIL-STD-202
MIL-PRF-49465B
R
LIMITS
± (0.5 % + 0.0005R)
± (1.0 % + 0.0005R)
± (0.5 % + 0.0005R)
± (0.5 % + 0.0005R)
± (1.0 % + 0.0005R)
± (0.5 % + 0.0005R)
± (0.5 % + 0.0005R)
± (0.1 % + 0.0005R)
± (0.1 % + 0.0005R)
± (0.25 % + 0.0005R)
95 % coverage
CSM2512/CSM3637
TYPICAL
R
LIMITS
0.1 %
0.2 %
0.05 %
0.1 %
0.2 %
0.05 %
0.02 %
0.02 %
0.02 %
0.05 %
-
MAXIMUM
R
LIMITS
0.3 %
1.0 %
0.2 %
0.3 %
0.3 %
0.1 %
0.05 %
0.05 %
0.05 %
0.1 %
-
FIGURE 3 - LOAD LIFE RESULTS OF CSM2512
CSM2512 0R05
Load Life 2000HRS @ 1W @ +70C (15 units)
3000
2500
2000
1500
1000
R/R (ppm)
500
0
-500 0
-1000
-1500
-2000
-2500
-3000
Time (Hours)
500
1000
1500
2000
2500
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Document Number: 63089
Revision: 17-Aug-15
CSM Series
FIGURE 4 - THERMAL SHOCK RESULTS OF CSM3637 AND CSM2512
Thermal Shock (-55°C to +150°C) x 1000 Cycles
20 Units Each Type and Value
2000
1500
1000
∆R/R (ppm)
500
0
-500
-1000
-1500
-2000
CSM3637 0R1
CSM3637 0R2
CSM2512 0R1
CSM2512 0R2
Type and Value
FIGURE 5 - BIAS HUMIDITY RESULTS OF CSM3637 AND CSM2512
Bias Humidity 1000 Hrs @ +85°C @ 85% RH
10 Units Each Type and Value
1000
800
600
400
∆R/R (ppm)
200
0
-200
-400
-600
-800
-1000
CSM3637 0R2
CSM3637 0R1
CSM2512 0R1
CSM2512 0R2
Type and Value
Document Number: 63089
Revision: 17-Aug-15
For any questions, contact
foil@vpgsensors.com
www.vishayfoilresistors.com
5
