CSM2512S Bulk Metal Technology High Precision, Current Sensing, Power Surface Mount, Metal Strip Resistor with Improved Stability 0.05 %, Resistance Value from 10 m, Rated Power to 1 W and TCR to 0 15 ppm/C FEATURES Temperature coefficient of resistance (TCR): (- 55 C to + 125 C, + 25 C ref.) 15 ppm/C maximum 10 ppm/C maximum on special request Load life stability to 0.05 % (70 C, 2000 h at rated power) Power rating: 1 W Resistance tolerance: 0.1 % Resistance range: 10 m to 100 m Vishay Foil resistors are not restricted to standard values, we can supply specific as required values at no extra cost The CSMs series of low value current sense resistors or delivery (e.g. 10.2345 m vs. 10 m) provides power and precision in a four terminal, surface Short time overload: 0.1 % typical mount configuration. Its all welded construction is made Thermal EMF: < 3 V/C up of a Bulk Metal resistive element with plated copper Maximum current: up to 10 A terminations. Surface mount configuration Four terminal (Kelvin) design: allows for precision accurate Vishay Foil Resistors application engineering department is measurements available to advise and make recommendations. Terminal finishes available: lead (Pb)-free, tin/lead alloy Screening in accordance with EEE-INST002 available For non-standard technical requirements and special (Per MIL-PRF-55342 and MIL-PRF-49465 see applications, please contact foil vpgsensors.com. datasheets of 303144 and 303145 ) Prototype quantities available in just 5 working days or sooner. For more information, please contact foil vpgsensors.com BC For better performances please contact Application Engineering R I I FIGURE 1 - POWER DERATING CURVE + 70 C A D 100 80 V 60 ~ Zin = 40 20 0 - 65 - 50 - 25 0 25 50 75 100 125 150 170 Ambient Temperature (C) TABLE 1 - PERFORMANCE SPECIFICATIONS PARAMETER CSM2512S Resistance Range 10 m to 100 m Power Rating at 70 C 1 W Maximum Current 10 A 1/2 Maximum Working Voltage (P x R) Tightest Tolerance 0.1 % Temperature Coefficient Maximum (- 55 C to + 125 C, + 25 C ref.) 15 ppm/C, 10 ppm/C is available Operating Temperature Range - 65 C to + 170 C Weight (maximum) 0.09 g * Pb containing terminations are RoHS compliant, exemptions may apply Document Number: 63145 For any questions, contact www.vishayfoilresistors.com Revision: 4-Mar-15 foil vpgsensors.com 1 Rated Power (%)CSM2512S ABOUT CSM (Low Ohm Value 10 m to 100 m ) The CSM2512S series of low value current sense resistors element, thereby minimizing temperature variations. Also, provides power and precision in a four terminal, surface the resistor element is designed to uniformly dissipate power mount configuration. Its all welded construction is made up without creating hot spots, and the welded terminations of a Bulk Metal resistive element with plated copper material is compatible with the element material. These terminations. For low value resistors in precision applications design factors result in a very low thermal-EMF(<3 V/C) it is necessary to use four-terminal Kelvin connections to resistor, because in addition to the low thermal EMF obtain a precise voltage drop across the resistive element. compatibility of the metals, the uniformity and thermal efficiency of the design minimizes the temperature In these applications, the contact resistance and the terminal differential across the resistor, thereby assuring low thermal resistance may have the same order of magnitude or be EMF generation at the leads. This further reduces the even greater than that of the element resistance itself. Thus, battery effect exhibited by most current-sensing or significant error is introduced because the high temperature voltage-reference resistors. Thus, the parasitic voltage coefficient of resistance of the leads and the contact generated at the junction of two dissimilar metals, which is resistance are unavoidably incorporated into the especially important in low-value current-sensing resistors, is measurements when the current sense resistor has only two minimized, while the pure current-to-voltage conversion is leads. protected from such interference in DC applications. Because the ability to measure low values to tolerances of The stability problems associated with analog circuits are 0.1% or tighter is a concern to both the manufacturer and the very pervasive, but knowledgeable selection of a few user, many situations require coordination of measurement high-quality resistors, networks, or trimming potentiometers standards between both parties. Coordination is often in critical locations can greatly improve circuit performance, accomplished by exchange of serialized units with recorded long-term application-related performance, as well as the readings to align measurement practices and specific designers peace-of-mind. Additionally, the overall system reference standards. The problem is compounded when cost is often reduced when a knowledgeable designer high-precision current sensors under moderate to high concentrates costs in a few exceptionally stable components power experience self-heating (Joule effect) which causes with minimal deviation and whose load and environmental the in-service resistance value to be different from that stability can often eliminate the necessity of additional obtained using low current measurement equipment. compensating circuitry or temperature-controlling systems. Therefore, the measurement conditions must be defined and The higher reliability and better overall system performances accepted at the time of spec preparation-that is, resistance also achieve excellent product results in the field, enhancing value as determined by specified current and measured market acceptance and product reputation. Designers often IR-drop following a specified period of stabilization. unnecessarily pay for tighter tolerances than required simply Measurement equipment is available from a number of to accommodate the resistance stability shifts they know to sources with varying stated accuracies. Traditional passive be imminent in an application due to the large current sensors and shunts generate heat under power, application-related changes in the components they which changes their resistance, and thus their voltage selected. Selection of a high-stability component like the output. The CSMs low absolute TCR reduces errors due to CSM in these applications eliminates the need for shift temperature gradients, thus reducing a major source of allowance due to planned instability and allows the use of uncertainty in current measurement. The CSM can withstand looser initial tolerances than would otherwise be necessary. 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. Thermal EMF in DC applications induces a voltage offset in the resistor that is equivalent to adding a small battery into the circuit. The CSMs all-welded construction is a Bulk Metal resistive element with welded copper terminations, plated for soldering. The terminations make a true continuous contact with the resistive layer along the entire side of the resistive www.vishayfoilresistors.com For any questions, contact Document Number: 63145 2 foil vpgsensors.com Revision: 4-Mar-15