Vishay WSH2818 Power Metal Strip® Resistor

Designed for use in current sensing, voltage division, and pulse applications, the new WSH2818 resistor is intended for use in DC-to-DC conversion and VRMs in desktop and notebook computers; electronic controls in automotive systems; base station power supplies in telecom systems; lithium-ion battery protection and battery charging systems in notebook computers and consumer electronics; and motor controls for industrial systems. The Vishay Dale WSH2818 resistor features a proprietary construction with improved thermal management to enable a 5W 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/or more robust electronics. For example, the WSH2818 resistor can be used as a 5W 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. In addition to a power rating of 5W, 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. The new device is RoHS-compliant and lead (Pb)-free, 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 >5nH), excellent frequency response, and low thermal EMF.