Global Sources
EE Times-Asia
Stay in touch with EE Times Asia
EE Times-Asia > Controls/MCUs

Dual operating modes define car senor

Posted: 06 Feb 2009 ?? ?Print Version ?Bookmark and Share

Keywords:mode dual operating? sensor car Hall? position automotive?


The A1386 from Allegro MicroSystems Europe is a user-programmable linear Hall-effect sensor IC targeted at applications in the automotive market requiring flexibility and accuracy in absolute position sensing.

The new device is unique in offering dual operating modes: normal and low power. In normal mode, the A1386 operates as a highly accurate, user-programmable linear sensor with ratiometric output. In low-power mode, the device disengages some internal components to reduce power consumption. Although its accuracy is compromised during low-power operation, the sensor can still be used as a region indicatorto detect the north or south pole of a rotating ring magnet.

The A1386 is based on a BiCMOS monolithic circuit which 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 proprietary dynamic offset cancellation circuitry.

The device provides an analog voltage output that is proportional to the applied magnetic field over the entire 5V supply range. Both the quiescent voltage output and the magnetic sensitivity are user adjustable. The quiescent voltage output can be set to approximately 50 percent of the supply voltage, and the sensitivity can be adjusted between 1.90mV/G and 3.50mV/G for a forward supply voltage of 5V.

The quiescent voltage and sensitivity are extremely stable against temperature variations, minimizing the dangers of output drift and the resulting output errors. The temperature coefficient of sensitivity of the A1386 is factory-programmed to 0.13 percent/C, making the devices optimized for use with neodymium magnets with no need for user adjustment.

An important feature of the A1386 is its ability to recognize when the forward supply voltage drops below a certain voltage threshold, at which time the device operates at a nominal 3V and both the quiescent voltage output and sensitivity are scaled ratiometrically. The device is most accurate at a nominal 5V.

These features make the A1386 well-suited for high-accuracy sensing in automotive and industrial applications, with guaranteed performance over an extended temperature range of -40C to +150C.

The A1386 is available in an ultra miniature through-hole single-inline package (UA suffix) or a miniature surface mount package (LH suffix).

- Henri Arnold
EE Times Europe

Article Comments - Dual operating modes define car seno...
*? You can enter [0] more charecters.
*Verify code:


Visit Asia Webinars to learn about the latest in technology and get practical design tips.

Back to Top