WW/MWW/NWW Series Stackpole Electronics, Inc. General Purpose and Precision Wirewound Resistor Features: * * * * * * * * * * Resistive Product Solutions WWS offers miniature size at higher power rating High performance for low cost High power to size ratio MWW - completely molded construction with welded terminations Complete welded terminations Tinned copper leads Available in non-inductive styles High temperature silicone coating RoHS compliant Higher operating temperatures may be available. Contact factory. Electrical Specifications Type / Code MIL-R-26 Ref. (N)WWH (N)WW1 (N)WW1A RW-70 (N)WW2 RW-69 (N)WWS2 (N)WW2A (N)WW3 RW-79 (N)WWS3 RW-69 (N)WW3A (N)WW4 (N)WWS4 RW-79 (N)WW5 RW-67, RW-74 (N)WWS5 (N)WW7 (N)WWS7 RW-67, RW-74 (N)WW7B (N)WW10 RW-78 (N)WWS10 (N)MWW1 RW-70 (N)MWW3 RW-79 (N)MWW5 RW-67, RW-74 (N)MWW10 RW-68, RW-74 (1) Lesser ofPR or maximum working voltage Dielectric Strength (V) 500V 500V 500V 1,000V 500V 1,000V 1,000V 1,000V 1,000V 1,000V 1,000V 1,000V 1,000V 1,000V 1,000V 1,000V 1,000V 1,000V 1,000V 1,000V 1,000V 1,000V Power Rating (Watts) @ 25C 0.4W 1W 1W 1.5W 2.5W 2.5W 3W 3W 3W 4W 4W 5W 5W 6.5W 6.5W 7W 10W 10W 1W 3W 5W 10W Resitance Temperature Coefficient < 1 = 90ppm/C 1 to 10 = 50ppmC >10 = 20ppm/C Ohmic Range() and Tolerance(1) 0.1%, 0.5%, 1% & 5% Standard 0.1 - 2K 0.1 - 3K 0.1 - 7K 0.1 - 10K 0.1 - 3K 0.1 - 15K 0.1 - 22K 0.1 - 10K 0.1 - 30K 0.1 - 40K 0.1 - 22K 0.1 - 50K 0.1 - 40K 0.1 - 70K 0.1 - 50K 0.1 - 100K 0.1 - 150K 0.1 - 100K 0.1 - 2K 0.1 - 20K 0.1 - 40K 0.1 - 150K Non-Inductive 0.1 - 1K 0.1 - 1.5K 0.1 - 3.5K 0.1 - 5K 0.1 - 1.5K 0.1 - 7.5K 0.1 - 11K 0.1 - 5K 0.1 - 15K 0.1 - 20K 0.1 - 11K 0.1 - 25K 0.1 - 20K 0.1 - 35K 0.1 - 25K 0.1 - 50K 0.1 - 75K 0.1 - 50K - Please refer to the High Power Resistor Application Note (page 4) for more information on designing and implementing high power resistor types. Rev Date: 08/11/2011 This specification may be changed at any time without prior notice Please confirm technical specifications before you order and/or use. 1 www.seielect.com marketing@seielect.com WW/MWW/NWW Series Stackpole Electronics, Inc. General Purpose and Precision Wirewound Resistor Resistive Product Solutions Mechanical Specifications Type / Code (N)WWH (N)WW1 / (N)WWS2 (N)WW1A (N)WW2 / (N)WWS3 (N)WW2A (N)WW3 / (N)WWS4 (N)WW3A (N)WW4 / (N)WWS5 (N)WW5 / (N)WWS7 (N)WW7 (N)WW7B / (N)WWS10 (N)WW10 (N)MWW1 (N)MWW3 (N)MWW5 (N)MWW10 A B C Unit 0.312 0.062 7.9 1.6 0.375 0.062 9.5 1.6 0.42 0.062 10.7 1.6 0.37 0.062 9.4 1.6 0.55 0.062 14 1.6 0.56 0.062 14.2 1.6 0.5 0.062 12.7 1.6 0.7 0.062 17.8 1.6 0.875 0.062 22.2 1.6 1 0.062 25.4 1.6 1.2 0.062 30.5 1.6 1.78 0.062 45.2 1.6 0.385 0.062 9.8 1.6 0.56 0.062 14.2 1.6 0.925 0.062 23.5 1.6 1.965 0.062 49.9 1.6 0.11 0.031 2.8 0.8 0.11 0.031 2.8 0.8 0.11 0.031 2.8 0.8 0.156 0.031 4 0.8 0.156 0.031 4 0.8 0.187 0.031 4.8 0.8 0.218 0.031 5.5 0.8 0.27 0.031 6.9 0.8 0.312 0.031 7.9 0.8 0.312 0.031 7.9 0.8 0.312 0.031 7.9 0.8 0.375 0.031 9.5 0.8 0.135 0.031 3.4 0.8 0.205 0.031 5.2 0.8 0.33 0.031 8.4 0.8 0.48 0.031 12.2 0.8 0.025 0.002 0.64 0.05 0.025 0.002 0.64 0.05 0.025 0.002 0.64 0.05 0.032 0.002 0.81 0.05 0.032 0.002 0.81 0.05 0.032 0.002 0.81 0.05 0.032 0.002 0.81 0.05 0.036 0.002 0.91 0.05 0.036 0.002 0.91 0.05 0.036 0.002 0.91 0.05 0.036 0.002 0.91 0.05 0.036 0.002(1) 0.91 0.05(1) 0.032 0.002 0.81 0.05 0.032 0.002 0.81 0.05 0.036 0.002 0.91 0.05 0.04 0.002 1.02 0.05 inches mm inches mm inches mm inches mm inches mm inches mm inches mm inches mm inches mm inches mm inches mm inches mm inches mm inches mm inches mm inches mm (1) Available in 0.04mm / 0.0016" Performance Characteristics Test Test Condition Result Moisture Resistance 1000 hours, 95% R.H., 40C 1000 hours, cycled power 1.5 hours ON, 0.5 hours OFF, 25C 5 cycles, -55C to 200C 5 times rated power for 5 seconds 1% max Load Life Temperature Cycling Short Time Overload Rev Date: 08/11/2011 This specification may be changed at any time without prior notice Please confirm technical specifications before you order and/or use. 2 1% 0.5% 1% www.seielect.com marketing@seielect.com WW/MWW/NWW Series Stackpole Electronics, Inc. General Purpose and Precision Wirewound Resistor Resistive Product Solutions 120 Power Derating Curve: Percent Rated Power (%) 100 80 60 40 20 25 75 125 175 225 275 325 350 Ambient Temperature (C) Operating Temperature Range: -25C to +350C How to Order Product Series Standard WW Mini WWS Molded MWW Non-Inductive NWW Mini NWWS Non-Inductive 1 2 3 4 5 6 7 8 9 W W 1 F T 1 K 0 0 Type/Code (N)WWH (N)WW1 (N)WW1A (N)WW2 (N)WWS2 (N)WW2A (N)WW3 (N)WWS3 (N)WW3A (N)WW4 (N)WWS4 (N)WW5 (N)WWS5 (N)WW7 (N)WWS7 (N)WW7B (N)WW10 (N)WWS10 (N)MWW1 (N)MWW3 (N)MWW5 (N)MWW10 Power Rating @ 25C 0.4W 1W 1W 1.5W 2.5W 2.5W 3W 3W 3W 4W 4W 5W 5W 6.5W 6.5W 7W 10W 10W 1W 3W 5W 10W Tolerance Tol Code 0.1% B 0.5% D 1% F 5% J Code Description T 11" reel tape Size (N)WWH, (N)WW1, (N)WWS2, (N)WW1A, (N)MWW1 (N)WW2, (N)WWS3, (N)WW2A, (N)WW3, (N)WWS4, (N)MWW3 (N)WW3A, (N)WW4, (N)WWS5 (N)WW5, (N)WWS7, (N)WW7, (N)WW7B, (N)WWS10, (N)MWW5 (N)WW10, (N)MWW10 Quantity Resistance Value 2,500 Four characters with the multiplier used as the decimal holder. 2,000 0.1 ohm = R100 2 Kohm = 2K00 500 250 Legacy Part Number (before January 3, 2011): SEI Type Code Nominal Resistance Tolerance Packaging WW 1 10K 1% R Type WW WWS MWW NWW NWWS Description Standard Mini Molded Non-Inductive Mini Non-Inductive Tolerance 0.1% 0.5% 1% 5% Rev Date: 08/11/2011 This specification may be changed at any time without prior notice Please confirm technical specifications before you order and/or use. Types (N)WWH, (N)WW1, (N)WWS2, (N)WW1A, (N)MWW1 (N)WW2, (N)WWS3, (N)WW2A, (N)WW3, (N)WWS4, (N)MWW3 (N)WW3A, (N)WW4, (N)WWS5, (N)WW5, (N)WWS7, (N)WW7, (N)WW7B, (N)WWS10, (N)MWW5 (N)WW10, (N)MWW10 3 Qty 2,500 Description Code 11" reel tape R 2,000 500 250 www.seielect.com marketing@seielect.com WW/MWW/NWW Series General Purpose and Precision Wirewound Resistor Stackpole Electronics, Inc. Resistive Product Solutions High Power Chip Resistors and Thermal Management Stackpole has developed several surface mount resistor series in addition to our current sense resistors, which have had higher power ratings than standard resistor chips. This has caused some uncertainty and even confusion by users as to how to reliably use these resistors at the higher power ratings in their designs. The data sheets for the RHC, RMCP, RNCP, CSR, CSRN, CSRF, CSS, and CSSH state that the rated power assumes an ambient temperature of no more than 100 degrees C for the CSS / CSSH series and 70 degrees C for all other high power resistor series. In addition, IPC and UL best practices dictate that the combined temperature on any resistor due to power dissipated and ambient air shall be no more than 105C. At first glance this wouldn't seem too difficult, however the graph below shows typical heat rise for the CSR 1/2 100 milliohm at full rated power. The heat rise for the RMCP and RNCP would be similar. The RHC with its unique materials, design, and processes would have less heat rise and therefore would be easier to implement for any given customer. The 102 degrees C heat rise shown here would indicate there will be additional thermal reduction techniques needed to keep this part under 105C total hot spot temperature if this part is to be used at 0.75 watts of power. However, this same part at the usual power rating for this size would have a heat rise of around 72 degrees C. This additional heat rise may be dealt with using wider conductor traces, larger solder pads and land patterns under the solder mask, heavier copper in the conductors, vias through PCB, air movement, and heat sinks, among many other techniques. Because of the variety of methods customers can use to lower the effective heat rise of the circuit, resistor manufacturers simply specify power ratings with the limitations on ambient air temperature and total hot spot temperatures and leave the details of how to best accomplish this to the design engineers. Design guidelines for products in various market segments can vary widely so it would be unnecessarily constraining for a resistor manufacturer to recommend the use of any of these methods over another. Note: The final resistance value can be affected by the board layout and assembly process, especially the size of the mounting pads and the amount of solder used. This is especially notable for resistance values 50 m. This should be taken into account when designing. Rev Date: 08/11/2011 This specification may be changed at any time without prior notice Please confirm technical specifications before you order and/or use. 4 www.seielect.com marketing@seielect.com