The A16601 AC-coupled Hall-effect sensor IC is a monolithic integrated circuit that switches in response to changing differential magnetic fields created by rotating ring magnets and, when coupled with a magnet, by ferrous targets. The device is a true zero-crossing detector: the output switches precisely when the difference in magnetic field strength between the two Hall elements is zero. A unique dual-comparator scheme provides for accurate switching at the zero crossing on both the positive and negative-going regions of the differential signal while using hysteresis to prevent false switching. The zero-crossing nature of this device provides excellent repeatability and accuracy for crankshaft applications.
Changes in field strength at the device face, induced by a moving target, are sensed by the two integrated differential Hall elements. This differential design provides immunity within the operating air gap range of the A16601 by rejection of the common mode signal. Steady-state magnet and system offsets are eliminated using an on-chip differential band-pass filter. This filter also provides relative immunity to interference from external electromagnetic stray field sources. The device uses advanced temperature compensation for the high-pass filter, sensitivity, and Schmitt trigger switch points, to guarantee optimal operation to low frequencies over a wide range of air gaps and temperatures.
Each Hall-effect digital integrated circuit includes a voltage regulator, two Hall effect elements, temperature compensating circuitry, a low-level amplifier, band-pass filter, Schmitt trigger, and an output driver which utilizes an external pull-up resistor. The on-board regulator permits operation with supply voltages from 4.0 to 26.5 V. The output stage can easily switch up to 20 mA over the full frequency response range of the device, and is compatible with both TTL and CMOS logic circuits.
The device is packaged in a 3-pin plastic SIP. It is lead (Pb) free, with 100% matte-tin-plated leadframe.
