Vishay Intertechnology has extended its family of thick-film power resistors with the introduction of 30-W, 50-W and 100-W devices in industry-standard TO220 and TO247 packages. The resistors use a ceramic package design (with no metal tab) for direct mounting on heatsinks, and feature an exceptionally low inductance of less than 0.1 µH, making them suitable for use in power conversion and control applications.
The Vishay Sfernice devices are available in a wide range of resistance values, from 0.010 Ω to 550 kΩ for the LTO 30 and LTO 50 families, and from 0.015 Ω to 1 MΩ for the LTO 100. All devices have a temperature coefficient of 150 ppm/°C for values above 0.5 Ω. Their compact, low-profile, direct-mounting package design improves heat dissipation and reduces space on printed circuit boards.
The LTO resistors are designed for use in pulse-loading applications, as snubber or bleeder resistors, and in a variety of other high-power equipment such as uninterruptible power supplies, power conversion for traction and industrial drives, and in medical, automotive and industrial control environments. The resistors use an optimized process of printed thick-film technology on an alumina substrate to achieve tolerances as low as ±1%, and up to ±10%.
All of the resistors are compatible with tin/lead (Sn/Pb) and lead (Pb)-free soldering processes, allowing use by all assemblers transitioning to lead (Pb)-free processes to meet incoming legislation and voluntary environmental manufacturing codes. In addition, all devices comply with EU directives on vehicle end of life, including 2000/53/EC End of Vehicle Life Directive (ELV) and 2000/53/EC Annex II to End of Vehicle Life Directive (ELV II). The devices also meet 2002/95/EC Restriction of the use of Hazardous Substances Directive (RoHS) and 2002/96/EC Waste Electrical and Electronic Equipment Directive (WEEE). Available now, the resistors are priced starting at $1.50 per piece in quantities of 5000.