The A1684LUB is an optimized Hall-effect sensing integrated
circuit that provides a user-friendly solution for true zero-speed
digital ring magnet and—when magnetically back-biased—gear tooth
sensing in two-wire applications. The Hall-effect IC has
been optimized for the automotive environment. This small
package can be used in conjunction with a wide variety of
target shapes and sizes.
The single integrated circuit incorporates a dual element Hall
effect sensor IC and signal processing circuitry that switches
in response to differential magnetic signals created by a ring
magnet, or by a rotating ferromagnetic target when used in
combination with a back-biasing magnet. The device contains
a sophisticated compensating circuit to eliminate magnetic and
system offsets. Digital tracking of the analog signal is used
to achieve true zero-speed operation. Advanced calibration
algorithms are used to adjust the device gain and offset at
power-up, resulting in air gap independent switchpoints, which
greatly improves output accuracy. In addition, advanced running
mode calibration circuits mitigate the effect of system anomalies
such as target vibration and sudden changes in air gap.
The regulated current output is configured for two-wire
operation. When configured with a back-biasing magnet, this
sensor IC is ideal for obtaining edge and duty cycle information
in gear-tooth–based applications such as transmission speed.
The A1684 is provided in a 2-pin miniature SIP package (suffix
UB) that is lead (Pb) free, with 100% matte tin leadframe plating.