Surface-Mount Resistor from Vishay in Compact 4527 Package
Vishay has announced that it is expanding its WSR series of Power Metal Strip resistors with the industry's first such device to offer a 5-W power rating in the 4527 package size. Surface-Mount Resistor from Vishay in Compact 4527 PackageLike the WSR2 (2-W) and WSR3 (3-W), the new WSR5 measures just 0.455 in. by 0.275 in. [11.56 mm by 6.98 mm] with a height profile of 0.095 in. [2.41 mm], making it a compact 5-W solution for electronic controls in automotive systems, power supplies in communications base stations, and dc-to-dc converters and VRMs in high-end workstations and servers. A proprietary processing technique allows the WSR5 to offer extremely low resistance values ranging from 1 mΩ to 300 mΩ in a standard resistance tolerance of ± 1 %. A tolerance of ± 0.5 % is available for the resistance range of 10 mΩ to 300 mΩ. The WSR5's very low inductance values range from 0.5 nH to 5 nH, and the device's temperature coefficients are ± 110 ppm/°C for the 7.5–mΩ to 9.9–mΩ range and ± 75 ppm/°C for the 10–mΩ to 300–mΩ range. The WSR5 resistor's proprietary construction features a molded, high-temperature encapsulation with an integrated heat sink for improved thermal management. As a result, the new device maintains the superior electrical characteristics of the Power Metal Strip construction during operation in a variety of high-current applications. Low thermal EMF, a broad operating temperature range of – 65 °C to + 275 °C, and resistance to moisture, vibration, thermal and mechanical shock ensure reliable operation. The WSR5's proprietary Power Metal Strip design features all-welded construction, solderable terminations, and a solid metal alloy resistive element. The WSR5's high-power capability in a compact package enables designers to shift away from leaded resistors to a surface-mount solution, and thus to create smaller, lower-cost, and/or higher-performing end products. When used to replace through-hole current-sensing resistors, the WSR5 reduces manufacturing placement costs while allowing for total solder reflow assembly. Per-device costs also are further reduced by the elimination of secondary operations such as lead forming and trimming.