Programmable hall-effect linear sensor for position sensing in automotives

New programmable linear sensor A1386 from Allegro for automotive market is suitable for applications requiring absolute position sensing. It is unique in the market due to its dual operating modes of normal and low power. In normal operation mode Allegro’s A1386 operates as a accurate, user-programmable linear with ratiometric output. In low power mode, the device disables few internal components to reduce power consumption. The accuracy of the device is also compromised during low power consumption but remains serviceable as a region indicator (north or south pole of a rotating ring magnet).

These ratiometric Hall-effect sensor devices provide a voltage output that is proportional to the applied magnetic field over the entire 5.0 V supply. Both the quiescent voltage output and the magnetic sensitivity are user adjustable. The quiescent voltage output can be set to approximately 50% of the supply voltage, and the sensitivity adjusted between 1.90 mV/G and 3.50 mV/G for Vcc = 5 V. The sensitivity TC of the A1386 is programmed in the factory to 0.13%/°C to compensate for neodymium magnets. An important feature of this device is its ability to recognize when Vcc drops below a certain voltage threshold at which time the device operates at a nominal 3 V and both the quiescent voltage output and sensitivity scale ratiometrically. The device is most accurate at a nominal 5 V. These features make this device ideal for high accuracy requirements of automotive and industrial applications guaranteeing performance over an extended temperature range of 40°C to 150°C.

Each BiCMOS monolithic circuit integrates a Hall element, temperature-compensating circuitry to reduce the intrinsic sensitivity drift of the Hall element, a small-signal high-gain amplifier, a clamped low impedance output stage, and a proprietary dynamic offset cancellation technique.
Allegro’s A1386 is available in an ultra miniature (UA suffix) through-hole single-inline package. See the image below. For details visit www.allegromicro.com.