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1717 Chicago Avenue
Riverside, California 92507-2364
Phone: (951) 788-1700
Fax: (951) 369-1151
Applications Engineering
17271 North Umpqua Hwy.
Roseburg, Oregon 97470-9422
Phone: (541) 496-0700
Fax: (541) 496-0408
© 2003-2007 Caddock Electronics, Inc.
CAD KDOC
e-mail: caddock@caddock.com • web: www.caddock.com
For Caddock Distributors listed by country see caddock.com/contact/dist.html
ELECTRONICS, INC.
28_IL126.0507
Type SR Precision Current Sense Resistors
Non-inductive Design - Compact Footprint Minimizes Circuit Board Space
Kelvin Terminals (Four Wire) - Resistance Values 0.005Ω to 1.00Ω
Type SR Current Sense Resistors utilize Caddock's Micronox® resistance
lms to achieve a low cost resistor with Non-inductive Performance. This
compact construction makes this sense resistor ideal for many current
monitoring or control applications.
The special performance features of these Type SR Current Sense
Resistors include:
• Available in Standard Resistances down to 5 milliohm.
• Non-Inductive Design.
• Terminals are constructed for Kelvin connections to the circuit board.
• Compact footprint.
0.008 Ω
0.010 Ω
0.012 Ω
0.015 Ω
0.005 Ω
0.008 Ω
0.010 Ω
0.015 Ω
0.020 Ω
0.025 Ω
0.030 Ω
0.033 Ω
0.020 Ω
0.025 Ω
0.030 Ω
0.033 Ω
0.040 Ω
0.050 Ω
0.075 Ω
0.10 Ω
0.040 Ω
0.050 Ω
0.075 Ω
0.10 Ω
Custom resistance values can be manufactured for
high quantity applications. Please contact Caddock
Applications Engineering.
Specications:
Resistance Tolerance: ±1.0%
Temperature Coefficient: TC referenced to
+25°C, ∆R taken at -15°C and +105°C.
0.081 to 1.00 ohm -50 to +100 ppm/°C
0.025 to 0.080 ohm 0 to +150 ppm/°C
0.008 to 0.024 ohm 0 to +200 ppm/°C
0.005 to 0.007 ohm 0 to +300 ppm/°C
Load Life: 1000 hours at rated power at +70°C,
∆R ±(0.2 percent + 0.00001 ohm) max.
Thermal Shock: Mil-Std-202, Method 107, Cond. A,
∆R ±(0.2 percent + 0.00001 ohm) max.
Moisture Resistance: Mil-Std-202, Method 106,
∆R ±(0.2 percent + 0.00001 ohm) max.
Encapsulation: Polymer over resistance element.
Ordering Information:
DIMENSIONS IN INCHES AND (MILLIMETERS)
Measurement note: For purposes of these specications, resistance measurement shall
be made using Kelvin connections (four wire) with appropriate current and sense con-
nections to the device terminals.
C = Current connection S = Sense connection
Circuit Board Layout: The circuit board traces connecting to the current terminals must
be sized appropriately for the current owing through the trace. For example; 0.005Ω
operated at 2.0 Watts would have 20 amps owing through the circuit board traces into
the current terminals.
SR10 - 0.050 - 1%
Model Number:
Resistor Value:
Tolerance
Scale:
actual size
Front view Side view Back view
SR10 PACKAGE DIMENSIONS
CIRCUIT BOARD LAYOUT NOTES
0.15 Ω
0.20 Ω
0.25 Ω
0.30 Ω
0.15 Ω
0.20 Ω
0.25 Ω
0.30 Ω
.365 ±.020
(9.27 ±.51)
.370 ±.015
(9.40 ±.38)
.125 ±.020
(3.18 ±.51)
.045 (1.14)
.025 (.64)
.090 (2.29)
MAX.
.032 ±.007
(.81 ±.18)
SR10
0.025Ω
1%
Voltage Rating Terminal Material
1.0 Watt Power Limited Solderable
Model No.
SR10
Power Rating at
70°C*
2.0 Watts Power Limited Solderable
SR20
Resistance
Min. Max.
0.008 Ω 1.00 Ω
0.005 Ω 1.00 Ω
* Power rating:
The power rating
should be limited as
shown by the derating
curve based upon the
maximum ambient
temperature. The derating curve is based on still
air with natural convection around the resistor.
Power Derating Curve:
25 150
0
20
40
100
RATED LOAD, %
80
60
70
TEMPERATURE, °C
100
.032 ±.007
(.81 ±.18)
.400 ±.015
(10.16 ±.38)
SR20
0.050Ω
1%
.090 MAX.
(2.29 MAX.)
.565 ±.020
(14.35 ±.51)
.125 ±.020
(3.18 ±.51)
.045 (1.14)
.025 (.64)
.200 (5.08)
Section BB
.045 (1.14)
.100 (2.54)
.200 (5.08)
.045 (1.14)
.025 (.64) .025 (.64)
B
B
CSSC
.100 (2.54)
Section AA
.045 (1.14)
.100 (2.54)
.100 (2.54)
.045 (1.14)
.025 (.64) .025 (.64)
A
A
CSSC
SR10 SR20
SR20 PACKAGE DIMENSIONS
0.40 Ω
0.50 Ω
0.75 Ω
1.00 Ω
0.40 Ω
0.50 Ω
0.75 Ω
1.00 Ω
SR10 Standard Resistance Values:
SR20 Standard Resistance Values:
