Glenrothes, Scotland, Providing design engineers with more watts in a smaller footprint, TT electronics BI Technologies SMT Division has developed a series of metal element current sense chip resistors with power ratings up to 8 watts in a 6.4 x 12.8 x 2.5-mm package.
The BCS8 series is unique because most flat current sense components are rated for a maximum of three to four watts under the best of conditions, said the company. The BCS8 devices offer an 8-watt power rating with temperature coefficient of resistance (TCR) values as low as 30 ppm/deg;C. The resistor is constructed using a low-resistance, low-inductance, high-impulse proprietary metal element that gives the device its extended power and temperature ratings, said the company.
The current detect chip resistors have a rating current of 90 A (at 1 mΩ), a maximum current of 126 A (2.5 sec, one time), and a series inductance of 5 nH. The resistance value range is 0.5 mΩ to 5 mΩ in tolerances as low as ±1.0%. Typical TCR is ±50 ppm/°C, with ±30 ppm/°C devices available. The operating temperature range is -55°C to 175°C, and the hot spot temperature of the device at 8-W applied power is 175°C.
Special considerations when mounting the BCS8 devices include a 10°C to 20°C recommended increase in reflow solder temperature. Custom specifications are available. These devices may be used for overcurrent detection in battery chargers, servo motor control circuits, and DC/DC, DC/AC and intelligent power modules.
Other applications include industrial PC modules (IPM) and precision measurement systems, as well as current detection circuits in high-speed CPU peripherals. The devices can also be manufactured to custom length/width for use as a current shunt.
Typical pricing for the BCS8 series resistors starts at $1.50 in quantities of 500. Delivery is from stock to six weeks. Samples are available immediately for engineering evaluation and customer prototypes.
TT electronics - BI Technologies SMT Division, +44-1-592-662200, www.bitechnologies.com