Bourns® Resistive Products Selecting the Right Resistor for Your Application Introduction CR Series CRT/CRL Series CAT/CAY Series 4816P CHF9838CNF Series 1/11 • e/N1064 Science and engineering students typically experiment with axial leaded resistors, learning a color code to identify the resistor value based on the stripes around the resistor body. In practice, however, axial leaded resistors are overshadowed in board fabrication by resistors for which the construction, package styles, and materials are targeted for specific applications. Bourns offers a wide variety of resistive products that include devices that range from industry standard size chip resistors to very high frequency (RF) power resistors in order to meet today’s broad market requirements. There are many advantages to incorporating Bourns® resistors into today’s designs including custom values, miniature component size, higher power ratings, and the highest quality materials and construction. Since it is far more than just the resistor value that drives the decision of which resistor to use in a circuit design, Bourns is committed to ensuring designers’ needs are met with the company’s extensive portfolio of resistive products. In this white paper, the various types of resistors will be briefly explained, and tables are provided as a quick reference for the available range of resistive products. Bourns® Resistive Products Selecting the Right Resistor for Your Application Overview of Resistor Families CR Series Regardless of the application, a resistor is essentially a current control, voltage drop product. Additionally, Bourns® components can be designed to withstand unique application challenges like an overcurrent pulse for a short duration without significant changes of resistor characteristics. Bourns® Fixed Resistors can be defined by construction type (thick film, wirewound, etc.), the way they are processed, (through-hole, surface mount, etc.) the intended use (current sense, high frequency, etc.), accuracy, size, power or many other ways. Each resistor does two main things: control current and control a drop in voltage. CRT/CRL Series Bourns also has a very broad offering of resistor network (Model 4xxx Series), in a wide selection of industry standard models. Therefore, they can be used with an industry standard footprint for seamless placement in printed circuit board designs. CAT/CAY Series Bourns® chip resistors are available in various package sizes, standard values and technologies which are designed to meet most market requirements including those for specific application and performance characteristics. Bourns® CRL series resistors offer total resistance values less than those required by industry standards providing engineers enhanced circuit design flexibility. 4816P When more precision is desired, Bourns® CRT series provides tight tolerance and high precision over a wide range of resistance values. These resistors are typically used in current sense applications and precision circuits, with specific ordering characteristics for size and performance selection. Table 1 CHF9838CNF Series 1/11 • e/N1064 CRT Series Chip Resistors Power Max. Voltage Max. Overload CRT0402 0.063 W 25 V 50 V CRT0603 0.1 W 50 V 100 V CRT0805 0.125 W 100 V 200 V CRT1206 .25 W 150 V 300 V Model TCR Options (PPM/°C) TR Range Absolute Tolerance 10 Ω - 205 kΩ 5, 10, 15, 20, 25 10 Ω - 1 M 2Ω-2M 1Ω - 2.5 M 0.01 % - 1 % Bourns® Resistive Products Selecting the Right Resistor for Your Application Overview of Resistor Families (Continued) CR Series Bourns® resistor networks and chip resistor arrays are available to meet a variety of needs, and the figures below illustrate possible configurations inside Bourns® resistor networks. CAT/CAY resistor arrays are offered in isolated and various bussed configurations. CRT/CRL Series 1 N 1 Isolated N 1 Bussed N Dual Terminator CAT/CAY Series 4816P N N N 1 1 1 Figure 1 CHF9838CNF Series Bourns offers general purpose resistors with uniform value as well as dual termination resistors, intended for specialized applications such as gigabit communication networks. Designs that feature field programmable gate arrays (FPGAs) harness the miniaturized circuitry and superior quality of the high performance Bourns® CAT16 series for low voltage differential signal (LVDS) interfaces. Table 2 Model Chip Resistors Package Description TCR Tolerance Resistance CR 0201 - 2512 Standard Chip Resistor 200 1 %, 5 % 1 - 10 MΩ CRL 0603 - 2512 Current Sense Resistor 200 - 600 1 %, 5 % 0.01 - 9 Ω 2506 LVDS Termination (Xilinx FPGA) 200 5% Special Values (Check Website) 0804/1206/1608 Resistor Array 200 1 %, 5 % 10 - 1 MΩ 0402 - 1206 Thin Film Chip Resistor 5 - 50 0.01 % - 1 % 1 Ω - 2.5 M CAT16PC4F12, CAT16LV4F12 CAY/CAT CRT 1/11 • e/N1064 Available Fixed Resistor configurations Bourns® Resistive Products Selecting the Right Resistor for Your Application Overview of Resistor Families (Continued) CR Series CRT/CRL Series CAT/CAY Series 4816P CHF9838CNF Series 1/11 • e/N1064 Bourns® pulse resistors and current sense resistors are highly specialized for applications such as motor drives and industrial equipment. The resistor typically has a very small value and provides a measure of current in critical areas of the circuit. Bourns® pulse resistors are capable of withstanding surges without a material change in the characteristics of the resistor. Bourns offers the CRA, CRF, CRM and PWR pulse and current sense resistors in typical package styles such as through-hole, bent metal and TO-220 configurations. DPAK and D2PAK are available as well. Bourns® CHF series are high frequency RF power resistors. Specialized for RF applications and high frequency signals, they are commonly used in GSM, UMTS, and WiMax interfaces with standard circuits such as isolators, combiners, and duplexers and in television and radio applications in combiner and divider interfaces. These parts are available in the 9 GHz range with power ratings up to 1 kW. The Bourns® CHF series is set apart from other high frequency resistors by its material and construction. High quality copper and solid construction provide superior characteristics. Bourns® CHF resistors are constructed with a thick film process. Bourns has decades of successful experience with this process, and a customized resistor can be created if a specific requirement is not met by a standard part. Bourns® Resistive Products Selecting the Right Resistor for Your Application Overview of Resistor Families (Continued) CR Series CRT/CRL Series Bourns® CHF resistors are provided in a standard surface mount package. These parts can be either electrically insulated or terminated. Generally, there is one exposed lead while the other lead is tied to the ground plane or to a heat sink. The substrates used in the surface mount Bourns® CHF resistors are Aluminum Nitride and Beryllium Oxide. Higher power parts with flanged packages have substrates of Beryllium Oxide, Alumina, and Aluminum Nitride. While the substrates help to dissipate heat, operation at higher power levels may require a heat sink to handle the dissipation. In some designs, the CHF series is bolted to the heat sink, printed circuit board, or ground plane. The power ratings of Bourns® CHF resistors make it possible to absorb very high pulses in high power situations. Table 3 CAT/CAY Series 4816P CHF9838CNF Series 1/11 • e/N1064 High Frequency Resistors Power (W) Frequency (GHz) VSWR Substrate Resistor Values (Ohms) CHF2010CNP 10 2 1.2 ALN 50, 100 +/- 5 % CHF1206CNT 20 3 1.25 ALN 50 +/- 5 % CHF2525CNT 40 9 1.25 ALN 50 +/- 5 % CHF3725CNP 40 4 1.2 ALN 50 +/- 5 % CHF3523CNT 150 3 1.1 ALN 50 +/- 5 % CHF3020CBF 10 4 1.35 BEO 50, 100, 200 +/- 5 % CHF5225xxF 60/30/20 4 1.2 ALN, AL203, BEO 50, 100 +/- 5 % CHF8838CNF 150 4 1.2 ALN 50, 100 +/- 5 % CHF9838CxF 250 4 1.2 ALN, BEO 50 +/- 5 % CHF12545CBF 500 1 1.1 BEO 50, 100 +/- 5 % CHR190104CBF 800 1 1.2 BEO 12.5, 25, 50, 100 +/- 5 % CHF190104KBF 1000 1 1.2 BEO 50 +/- 5 % Model Bourns® Resistive Products Selecting the Right Resistor for Your Application Benefits of Working with Bourns CR Series CRT/CRL Series Bourns offers standard resistors for vast applications needs, and when one is not available it is likely that it can be created by customizing an existing, proven part. Bourns has lead in the development and innovation of resistive products for decades and continues to expand its product offerings based on the needs of designers and on emerging market applications. As an example, certain applications including consumer goods require a resistor that is fuseable. This fuseable resistor will become an open circuit during a surge to prevent the electronics from catching fire. This is just one example of Bourns being ready to meet evolving requirements with a high quality solution. Designers’ concerns about size, power and quality of the component have been addressed when they select a resistor from Bourns. CAT/CAY Series 4816P CHF9838CNF Series For further technical support and for more information on Bourns® Resistive Products, please visit www.bourns.com “Bourns” is a registered trademark of Bourns, Inc. in the U.S. and other countries. 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