The A17201 is an AC-coupled Hall-effect sensor IC which includes monolithic integrated circuits that switch in response to changing differential magnetic fields created by rotating ring magnets or, when coupled with a magnet, by ferrous targets. This device also includes an integrated tracking capacitor that provides the high accuracy of analog sensing without an external filter capacitor. This reduces cost and components, while improving the reliability of the final sensor solution.
Magnetic field changes affect the two integrated Hall transducers and then are differentially amplified on the chip. Differential design provides immunity to radial vibration, within the device operating air gap range, by rejection of this common-mode signal change. Steady-state system offsets are eliminated using an on-chip differential bandpass filter with integrated capacitor. This filter also provides relative immunity to interference from electromagnetic sources. The device uses advanced temperature compensation for the high-pass filter, sensitivity, and Schmitt trigger switchpoints to guarantee
optimal operation to low frequencies over a wide range of air gaps and temperatures.
The device includes: a voltage regulator, two Hall transducers,temperature compensating circuitry, a signal conditioning amplifier, bandpass filter, Schmitt trigger, and an output control. The on-board
regulator permits operation with supply voltages from 3.5 to 24 V. The regulated current output is configured for two-wire interface circuitry and is ideally suited for obtaining speed information in wheel speed applications. The device packages have an operating ambient temperature range of –40°C to 150°C, and are provided in a 3-pin plastic SIP (suffix UA) or a 2-pin plastic SIP (suffix UB). Both packages are lead (Pb) free, with 100% matte-tin-plated leadframes.
