CSM3637P Ultra High Precision, Surface Mount 4-Terminal Precision Resistor with Increased Power to 5W (40A max), Resistance Values from 3 m to 100 m, and TCR to 15 ppm/C FEATURES Resistance range: 3 m to 100 m Temperature coefficient of resistance (TCR): 3 mto 100m : 15 ppm/C maximum Load life stability: 0.2 % (70 C, 2000 h at rated power) INTRODUCTION Power rating: to 5 W (see Table 1) The CSM3637P is a low value current sense resistor, Resistance tolerance: to 0.1 % providing power and precision in a four terminal, surface mount configuration. Its all welded construction is made up Vishay Foil Resistors (VFR) are not restricted to standard of a Bulk Metal resistive element with plated copper values specific as required values can be supplied at no terminations. extra cost or delivery (e.g. 10.2345 m vs. 10 m) There are many current sense resistors on the market. Until Short time overload: 0.2 % typical now the combination of very stable and precise resistors Proprietary processing technique produces extremely low with low TCR of 15 ppm/C maximum, tight tolerance of resistance values with improved stability 0.1 % and load life stability of 0.2 % (2000 h, + 70 C at All welded construction rated power) was not easily available. Solderable terminations The key performance of the new CSM3637P is its high rated power up to 5W. This option became available due to a Very low inductance 0.5 nH special design which consists of a heat sink on the top of the Excellent frequency response to 50 MHz resistive element, thus allowing a better heat dissipation. Low thermal EMF < 3 V/C (DC offset error, significant for These specifications are based on tests performed in low values) accordance with methods prescribed by appropriate Maximum current: up to 40 A MIL-PRF standards (MIL-PRF-55342 and MIL-PRF-49465). Four terminal (Kelvin) design: allows for precise and The four terminal device separates the current leads from accurate measurements the voltage sensing leads. This configuration eliminates the effect of the lead wire resistance from points A to B and Terminal finishes available: lead (Pb)-free, tin/lead alloy C to D. Prototype quantities available in just 5 working days In addition, a key feature of the CSM3637P is its low thermal or sooner. For more information, please contact EMF design (very important for low ohmic value DC foil vpgsensors.com applications). The welded terminals make intimate contact For better performances, please contact us with the chip thereby minimizing temperature differentials. Our application engineering department is available to FIGURE 1 - POWER DERATING CURVE advise and make recommendations. For non-standard technical requirements and special + 70 C 100 applications, please contact: foil vpgsensors.com 80 BC 60 40 R 20 I I 0 - 65 - 50 - 25 0 25 50 75 100 125 150 170 Ambient Temperature (C) A D V ~ Zin = * 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: 63210 For any questions, contact www.vishayfoilresistors.com Revision: 13-Oct-15 foil vpgsensors.com 1 Rated Power (%)CSM3637P ABOUT CSM3637P This new high-precision Bulk Metal surface-mount Power conversion is protected from such interference in DC Metal Strip resistor features an improved load-life stability applications. of 0.2 % at + 70 C for 2000 h at rated power, an absolute The stability problems associated with analog circuits are TCR of 15 ppm/C maximum from - 55 C to + 125 C, very pervasive, but knowledgeable selection of a few + 25 C ref., and a tolerance of 0.1 %. high-quality resistors, networks, or trimming potentiometers Typical current sensing resistors exhibit 2000 hour load-life in critical locations can greatly improve circuit performance, changes more than 5 times greater than the CSM3637P. The long-term application-related performance, as well as the improved resistance stability of the CSM Series makes it designers peace-of-mind. ideal for tightened-stability voltage division and precision Additionally, the overall system cost is often reduced when a current sensing applications in switching linear power knowledgeable designer concentrates costs in a few supplies, power amplifiers, measurement instrumentation, exceptionally stable components whose proven minimal- bridge networks, and medical and test equipment. deviation load and environmental stability can often eliminate Traditional Passive current sensors and shunts generate the necessity of additional compensating circuitry or heat under power, which changes their resistance, and thus temperature-controlling systems. The higher reliability and their voltage output. The CSMs low absolute TCR of better overall system performances also achieve excellent 15 ppm/C reduces errors due to temperature changes, product results in the field, enhancing market acceptance thus reducing a major source of uncertainty in current and product reputation. measurement. The CSM can withstand unconventional Designers often unnecessarily pay for tighter tolerances than environmental conditions, including the extremely high required simply to accommodate the resistance stability temperatures and radiation-rich environments of down-hole shifts they know to be imminent in an application due to the oil exploration and well logging, or the deep-sea underwater large application-related changes in the components they repeaters in cross-ocean communications. selected. Selection of a high-stability component like the The stability of the CSM3637P can be further enhanced by CSM in these applications eliminates the need for shift post-manufacturing operations (PMO), such as temperature allowance due to planned instability and allows the use of cycling, short-time overload, and accelerated load life which looser initial tolerances than would be necessary with are uniquely applicable to Bulk Metal Foil Technology. current-sensing resistors based on other technologies. The device features a low thermal electromotive force (EMF) The Key Applications that is critical in many precision DC applications. The CSMs Applications requiring accuracy and repeatability under all-welded construction is composed of a Bulk Metal stress conditions such as the following: resistive element with welded copper terminations, plated for Switching and linear power supplies soldering. The terminations make true ohmic contact with the resistive layer along the entire side of the resistive element, Precision current-sensing thereby minimizing temperature variations. Also, the resistor Power management systems element is designed to uniformly dissipate power without Feedback circuits creating hot spots, and the welded terminations material is compatible with the element material. Power amplifiers Measurement instrumentation These design factors result in a very low thermal-EMF (3 V/C) resistor because, in addition to the low thermal Precision instrumentation amplifiers EMF compatibility of the metals, the uniformity and thermal Medical and automatic test equipment efficiency of the design minimizes the temperature Satellites and aerospace systems differential across the resistor, thereby assuring low thermal Commercial and Military avionics EMF generation at the leads. This further reduces the battery effect exhibited by most current-sensing or Test and measurement equipment voltage-reference resistors. Thus, the parasitic voltage Electronic scales generated at the junction of two dissimilar metals, which is especially important in low-value DC current-sensing resistors, is minimized, while the pure current-to-voltage www.vishayfoilresistors.com For any questions, contact Document Number: 63210 2 foil vpgsensors.com Revision: 13-Oct-15