Resistors perform current-sensing in high temp environments

Boone, N.C.—TT electronics IRC's open-air current sense resistor series is aimed at power electronics design engineers looking for high-current devices capable of providing current-sense and surge protection functions in high temperature environments..

The OARS-3 series surface mount metal alloy strip resistors feature a flameproof open-air design that elevates the device's "hot spot" above the PC board, where heat can be dissipated to ambient air instead of to adjacent thermally sensitive components.

Applications include computer power supplies, high-reliability server equipment, and automotive underhood applications.

The OARS-3 series resistor performs at 3 watts; however, testing conducted by IRC engineers demonstrates that the resistor is capable of handling higher power levels without forced air, depending on system thermal design. Testing at 4 watts reveals that, although the "hot spot" temperature can reach in excess of 230°C when the resistor is running at full power, the solder joint remains at 110°C or below.

The OARS-3 series resistors are nominally rated for 3W @70°C, with a resistance range from 2mΩ to 15mΩ and tolerances to ±1%. Inductance values are less than 10 nanohenries, with operating temperature ranging from -40°C to +125°C. RoHS-compliant and zero ohm jumper versions are also available. IRC will also produce devices outside these specifications to meet customer requirements.

Pricing: Approximately $0.86 each in minimum order quantities of 1900 pieces.
Availability: Lead time is from stock to 14 weeks.
Datasheet: click here.

IRC Inc., www.ttelectronics.com