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 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. Max. Power Rating at 70°C Voltage Rating Terminal Material SR10 0.008 Ω 1.00 Ω 1.0 Watt Power Limited Solderable SR20 0.005 Ω 1.00 Ω 2.0 Watts Power Limited Solderable * SR10 PACKAGE DIMENSIONS Side view Front view Back view .090 (2.29) MAX. .365 ±.020 (9.27 ±.51) SR10 0.025Ω 1% .370 ±.015 (9.40 ±.38) .125 ±.020 (3.18 ±.51) .045 (1.14) .032 ±.007 (.81 ±.18) .025 (.64) SR20 PACKAGE DIMENSIONS .565 ±.020 (14.35 ±.51) SR20 0.050Ω 1% .400 ±.015 (10.16 ±.38) .125 ±.020 (3.18 ±.51) .032 ±.007 (.81 ±.18) .025 (.64) CIRCUIT BOARD LAYOUT NOTES SR10 A A Scale: actual size DIMENSIONS IN INCHES AND (MILLIMETERS) SR20 C C S S C .045 (1.14) .025 (.64) .045 (1.14) .025 (.64) Section AA B B .100 (2.54) .100 (2.54) .100 (2.54) .200 (5.08) .100 (2.54) .200 (5.08) S S C .045 (1.14) .025 (.64) .045 (1.14) Section BB .025 (.64) Measurement note: For purposes of these specifications, resistance measurement shall be made using Kelvin connections (four wire) with appropriate current and sense connections 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; 0.005Ω operated at 2.0 Watts would have 20 amps flowing through the circuit board traces into the current terminals. Applications Engineering 17271 North Umpqua Hwy. Roseburg, Oregon 97470-9422 Phone: (541) 496-0700 Fax: (541) 496-0408 © 2003-2007 Caddock Electronics, Inc. 0.008 0.010 0.012 0.015 Ω Ω Ω Ω 0.020 0.025 0.030 0.033 0.040 Ω 0.050 Ω 0.075 Ω 0.10 Ω Ω Ω Ω Ω 0.15 0.20 0.25 0.30 Ω Ω Ω Ω 0.40 0.50 0.75 1.00 Ω Ω Ω Ω SR20 Standard Resistance Values: 0.040 Ω 0.15 Ω 0.40 Ω 0.005 Ω 0.020 Ω 0.050 Ω 0.20 Ω 0.50 Ω 0.008 Ω 0.025 Ω 0.075 Ω 0.25 Ω 0.75 Ω 0.010 Ω 0.030 Ω 0.10 Ω 0.015 Ω 0.033 Ω 0.30 Ω 1.00 Ω Custom resistance values can be manufactured for high quantity applications. Please contact Caddock Applications Engineering. Specifications: .090 MAX. (2.29 MAX.) .045 (1.14) SR10 Standard Resistance Values: 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. Power Derating Curve: 100 80 * Power rating: The power rating 60 40 should be limited as 20 shown by the derating 0 curve based upon the 25 70 100 150 TEMPERATURE, °C maximum ambient temperature. The derating curve is based on still air with natural convection around the resistor. RATED LOAD, % Resistance Min. Model No. Ordering Information: Model Number: Resistor Value: ELECTRONICS, INC. e-mail: [email protected] • web: www.caddock.com For Caddock Distributors listed by country see caddock.com/contact/dist.html SR10 - 0.050 - 1% Tolerance Sales and Corporate Office 1717 Chicago Avenue Riverside, California 92507-2364 Phone: (951) 788-1700 Fax: (951) 369-1151 28_IL126.0507