The SS490 Series MRL （Miniature Ratiometric Linear） sensors are small， versatile linear Hall effect devices which are operated by the magnetic field from a permanent magnet or an electromagnet. The ratiometric output voltage is set by the supply voltage and varies in proportion to the strength of the magnetic field. The integrated circuitry provides increased temperature stability and sensitivity. Laser trimmed thin film resistors provide high accuracy （null to ± 3%， sensitivity up to ±3%） and temperature compensation. These linear position sensors have an operating temperature range of -40:C to +150°C， appropriate for industrial and automotive environments. They respond to either positive or negative gauss， monitoring either or both magnetic poles. The quad Hall sensing element minimizes the effects of mechanical or thermal stress on the output. The positive temperature coefficient of the sensitivity （+0.02%/°C typical） helps compensate for the negative temperature coefficients of low cost magnets， providing a robust design over a wide temperature range. Rail-to-rail operation （over full voltage range） provides a more usable signal for higher accuracy. The recent extension to the product line， the SS490B Series， offers costeffective MRL sensing solutions with slightly wider specifications than the SS490 high-performance products. Like the SS490 Series， the SS490B has a typical sinking or sourcing output of 1.5 mA continuous， uses 7 mA of supply current at 5.0 volts and 25:C， and provides predictable performance over the full temperature range. The SS490B Series sensors have wider null and sensitivity tolerances and a wider drift over temperature. The SS490B Series sensors are a new lower cost product line extension. They complement the SS490 Series of small size， high accuracy and high performance miniature linear products.