Vishay Intertechnology recently announced the WSL3921 and WSL5931, surface-mount Power Metal Strip resistors with power ratings of 3 W and 5 W, respectively. The devices feature a solid metal nickel-chrome or manganese-copper alloy resistive element, and a proprietary processing technique produces low resistance values ranging from 0.2 mΩ to 4.0 mΩ with tight tolerances of 1% and 5%. The new resistors are ideal for current-sensing and voltage division, and feature an all-welded construction that contributes to electrical performance. They also provide very low inductance of 0.5 nH to 5 nH, excellent frequency response and low thermal EMF. Other features include good overload capability, using the printed circuit board as a cooling device, and long-term stability through a broad range of environmental conditions. These new resistors also enable designers to use a single low-value resistor in place of multiple high-value resistors running in parallel.
The new WSL3921 resistor measures 0.394 in. × 0.205 in. with a maximum height profile of 0.071 in., and the WSL5931 resistor measures 0.591 in. × 0.305 in. with a height profile of 0.068 in. They are available in tape-and-reel packaging; pricing starts at $0.36 per piece in 10,000-piece quantities.