Glenrothes, Scotland TT electronics' BI Technologies SMT Division has developed a surface-mount power resistor in a molded SOIC-style package with a metal lead frame that features an integral heat sink directly under the resistor element for efficient heat dissipation. The non-inductive power resistors are rated for up to 5 W and are available in a 2 resistor x 2 W configuration.
The SMP series resistors are offered in power ratings of 2 W, 3 W and 5 W, and are available in configurations of 1 resistor x 5 W, 1 x 3 W, 1 x 2 W and 2 x 2 W. The resistance range is 0.1 ohms to 10 Kohms with tolerances of ±1.0% and ±5.0%. Typical temperature coefficient of resistance (TCR) is ±100 ppm/°C at 10 ohms and above. The maximum operating voltage is 50 Vdc with a dielectric withstanding voltage of 250 Vdc. The operating temperature range is -55°C to 155°C.
The molded package and lattice-style metal lead frame are specifically designed to minimize thermal resistance along each axis. "This package design increases the resistor's ability to dissipate heat, as well as its ability to withstand pulses of longer duration," said Jim Rieley, sales director for BI Technologies' SMT Division, in a statement. In addition, a metal heat sink directly under the resistive element forms a center solderable area on the bottom of the package that is electrically isolated from the resistor, and is the most efficient method of dissipating heat from the device, Rieley stated.
The power resistors measure 11.30 x 11.30 mm with a board-mounted profile of 2.39-mm thick. Custom specifications are available. They may be used in a variety of applications including high-frequency emitter resistors in switching power supplies, high precision CRT color video amplifiers, high-frequency snubber and pulse handling circuits, pulse generator load resistors and in-rush current protection, as well as bleeder resistors.
Typical pricing for the SMP series resistors starts at $0.70 in quantities of 500. Lead times are from stock to eight weeks. Samples are available immediately for engineering evaluation and customer prototypes.
TT electronics BI Technologies SMT Division, +44-1-592-662200, www.bitechnologies.com