Versatile linear Hall-effect sensors operated by permanent / electro-magnets

Now available from Farnell element14, Honeywell’s SS490 Series miniature ratiometric linear (MRL) sensors are small, versatile linear Hall effect devices operated by the magnetic field from a permanent magnet or an electro-magnet. The ratiometric output voltage is set by the supply voltage and varies in proportion to the strength of the magnetic field. Laser-trimmed thin film resistors are used in the built-in circuitry for high accuracy (null to ±3%, sensitivity up to ±3%) and temperature compensation. These linear position sensors have an operating temperature range of -40C to +150C, making them ideal for industrial and automotive environments. They respond to either positive or negative gauss, monitoring either (or both) of the magnetic poles. A quad Hall sensing element is used to minimise 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, assuring a robust design over a wide temperature range. Rail-to-rail operation over the full voltage range also ensures a more usable signal for higher accuracy, says the company. Typical applications include current sensing, motor control, position sensing, magnetic code reading, rotary encoding, ferrous metal detection, vibration sensing, liquid level sensing and weight sensing.