Compact 5W resistor suits automotives

Vishay Intertechnology Inc. is expanding its WSR series of power metal strip resistors with the introduction of the WSR5. It is touted as the industry's first power metal strip resistor device to offer a 5W power rating in a 4527 package.

Like the WSR2 and WSR3 devices, the WSR5 measures 11.56mm x 6.98mm x 2.41mm, making it a compact 5W solution for electronic controls in automotive systems, power supplies in communications base stations, and DC/DC converters and VRMs in high-end workstations and servers.

The WSR5 offers resistance values ranging from 1mΩ to 300mΩ in a standard resistance tolerance of ±1 percent. A tolerance of ±0.5 percent is available for the resistance range of 10mΩ to 300mΩ. The WSR5's inductance values range from 0.5nH to 5nH, and the device's temperature coefficients are ±110ppm/°C for the 7.5mΩ to 9.9mΩ range and ±75ppm/°C for the 10mΩ to 300mΩ range.

The WSR5 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, an operating temperature range of -65±C to +275±C, and resistance to moisture, vibration, thermal and mechanical shock ensure reliable operation. The WSR5 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.

Samples and production quantities of the WSR5 are available now in 24mm tape-and-reel form. Give lead time of six to eight weeks for large orders.