Vishay announced a 5-watt Power Metal Strip resistor in a 2818 package size. The 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], features resistance values ranging from 1 milliohm to 100 milliohms. Designed for use in current-sensing, voltage division, and pulse applications, the 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 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. Alternatively, the designer can use one WSH2818 resistor as a 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 resistor can be used as a 5-watt alternative to a though-hole current-sensing resistor. In addition to a power rating of 5 watts, the Vishay Dale WSH2818 offers low inductance values (< 5 nH). 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. The WSH2818 is available in tape-and-reel packaging.
