Providing design engineers with a surface mount power resistor designed to facilitate thermal management, TT electronics’ BI Technologies SMT Division has developed a moulded SOIC-style package with a metal lead frame that features an integral heatsink directly under the resistor element. Designated the SMP Series, the noninductive power resistors are rated for up to 5W and are available in a two-resistor x 2W configuration. According to Jim Rieley, Sales Director for BI Technologies’ SMT Division, the moulded package and lattice-style metal lead frame are specifically designed to minimise the 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’, explained Rieley.

In addition, a metal heatsink directly under the resistive element forms a centre solderable area on the bottom of the package that is electrically isolated from the resistor, Rieley continued.

‘Soldering this central area to the printed circuit board is the most efficient method of dissipating heat from the device’.

The SMP Series resistors are suitable for a variety of applications, including high frequency emitter resistors in switching power supplies, high precision CRT colour video amplifiers, high frequency snubber and pulse handling circuits, pulse generator load resistors and inrush current protection, as well as bleeder resistors.

The SMP Series resistors are offered in power ratings of 2, 3 and 5W, and are available in configurations of one resistor x 5W, one x 3W, one x 2W and two x 2W.

Resistance range is 0.1ohm to 10kohm with tolerances of +/-1.0 and +/-5.0%.

Typical TCR is +/-100ppm/C at 10ohm and above.

Maximum operating voltage for the SMP Series resistors is 50V DC, with dielectric withstanding voltage at 250V DC.

Operating temperature range is -55 C to +155C.

The SOIC package power resistors measure 11.30 x 11.30mm, with a board mounted profile of 2.39mm thick.

BI Technologies will also produce devices outside these specifications to meet customer requirements, with comprehensive application engineering and design support available for customers worldwide.

Typical pricing for the SMP Series resistors starts at $0.70 in quantities of 500.

Lead times are from stock to 8 weeks.

Samples are available immediately for engineering evaluation and customer prototypes.