The new WSH2818 5-watt Power Metal Strip® resistor is the industry's first such device to offer 5 watt capability in the small 2818 package size. The new surface mount Power Metal Strip resistor, in a package measuring 0.280 in. by 0.180 in. by 0.032 in. [7.1 mm by 4.6 mm by 0.813 mm], also features very low resistance. Designed for use in current sensing, voltage division, and pulse applications, the Vishay Dale WSH2818 resistor features a proprietary construction with improved thermal management to enable a 5 watt power rating in a small package size that maintains the superior electrical performance of the Power Metal Strip construction. As a result, designers are able to incorporate the WSH2818 resistor in place of larger surface-mount components to realize significant board space savings and enable manufacture of smaller, lighter end products. Alternatively, the designer can use one WSH2818 resistor as a space and cost conserving replacement for multiple discrete resistors featuring lower power ratings.
The device's surface-mount construction enhances flexibility in the design of smaller and more robust electronics. For example, the WSH2818 resistor can be used as a 5-watt alternative to a though hole current sensing resistor, reducing manufacturing and placement costs by allowing for total solder reflow board assembly and eliminating the need for secondary lead forming and trimming operations. The Vishay Dale WSH2818 offers low inductance values (<5 nH), excellent frequency response, and low thermal EMF.
Rated for an operating temperature range of –65 °C to +170 °C, the WSH2818 is capable of higher temperature performance than devices built with thin film or thick film resistor technologies, featuring terminals with a 100% matte tin (Sn) finish over a nickel (Ni) barrier. The WSH2818's all welded metal construction includes a low TCR (<20ppm/°C) Nickel-Chrome or Manganese-Copper alloy resistive element.