Automotive-grade current sense resistors eliminate parallel elements
Automotive-grade Power Metal Plate current sense resistors from Vishay Intertechnology feature 2.0W and 3.0W power ratings in 2010- and 2512-sized packages.
The WFM resistors are aimed at current sensing and pulse applications in power supplies, instruments, power amplifiers, shunts, power inverters, and battery management circuitry. They allow designers to use a single high power resistor instead of running multiple resistors in parallel, which can cause current measurement errors. The resulting improvement in power density can save space on the circuit board that will in turn enable smaller and lighter products for the end consumer.
The WFM devices feature a construction that incorporates an improved thermal management design using a copper heat spreader, for resistors in the 2010 and 2512 package sizes that maintain the superior electrical characteristics of the Power Metal Plate construction, explains Vishay. A proprietary processing technique enables a wide range of low resistance values from five to 500 mOhm, with tolerances down to ± 1.0 per cent.
The devices can be used for all types of current sensing and pulse applications in automotive electronic controls, brushless DC motor controls, and battery management for electric and hybrid vehicles, high power inverter / converter controls and large motor drives for industrial applications, power supplies for downhole instrumentation, inverter control for consumer appliances and HVAC systems and power management, conversion, and safety in servers and other computing applications.
The resistors have a solid metal manganese-copper or nickel-chromium alloy resistive element with low TCR ( less than 20 ppm/ degrees C), low inductance values of 0.5 to 5 nH, low thermal EMF to less than three microV/ degrees C and an operating temperature range of -65 to +170 degrees C. The devices are RoHS-compliant and halogen-free.
Samples and production quantities of the WFM resistors are available now, with lead times of six to eight weeks for larger orders.