Type SR Precision Current Sense Resistors
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Sales and Corporate Office 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. CADDOCK 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 0.005Ù to 1.00Ù Type SR Current Sense Resistors utilize Caddock's Micronox® resistance films 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 Ù 0.010 Ù 0.012 Ù 0.015 Ù 0.005 Ù 0.008 Ù 0.010 Ù 0.015 Ù 0.020 Ù 0.025 Ù 0.030 Ù 0.033 Ù 0.020 Ù 0.025 Ù 0.030 Ù 0.033 Ù 0.040 Ù 0.050 Ù 0.075 Ù 0.10 Ù 0.040 Ù 0.050 Ù 0.075 Ù 0.10 Ù Custom resistance values can be manufactured for high quantity applications. Please contact Caddock Applications Engineering. Specifications: Resistance Tolerance: ±1.0% Temperature Coefficient: TC referenced to +25°C, ÄR 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, ÄR ±(0.2 percent + 0.00001 ohm) max. Thermal Shock: Mil-Std-202, Method 107, Cond. A, ÄR ±(0.2 percent + 0.00001 ohm) max. Moisture Resistance: Mil-Std-202, Method 106, ÄR ±(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 specifications, resistance measurement shall be made using Kelvin connections (four wire) with appropriate current and sense con n ections 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 flowing through the trace. For example; 0.005Ù operated at 2.0 Watts would have 20 amps flowing 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 Ù 0.20 Ù 0.25 Ù 0.30 Ù 0.15 Ù 0.20 Ù 0.25 Ù 0.30 Ù .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 0.025Ù 1% Voltage Rating Terminal Material 1.0 Watt Power Limited Solderable Model No. SR10 Power Rating at 70°C* SR20 2.0 Watts Power Limited Solderable Resistance Min. Max. 0.008 Ù 1.00 Ù 0.005 Ù 1.00 Ù * Power rating: T h e p owe r r a t i n g should be limited as shown by the derating curve based upon the ma x imum amb i e n t 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 0.050Ù 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 C S S C .100 (2.54) Section AA .045 (1.14) .100 (2.54) .100 (2.54) .045 (1.14) .025 (.64) .025 (.64) A A C S S C SR10 SR20 SR20 PACKAGE DIMENSIONS 0.40 Ù 0.50 Ù 0.75 Ù 1.00 Ù 0.40 Ù 0.50 Ù 0.75 Ù 1.00 Ù SR10 Standard Resistance Values: SR20 Standard Resistance Values: