High Precision Hall Effect AC-Coupled Differential Sensor with Integrated Filter Capacitor

The A1421, A1422 and A1423 are ac-coupled Hall-effect sensors which include 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 family of devices also includes an integrated 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.

FEATUREs and Benefits
• Integrated tracking capacitor
• Senses motion of ring magnet or ferrous targets
• Wide operating temperature range
• Operation with magnetic input signal frequency from 20 Hz to 30 kHz
• EMI/ESD-resistant
• Large effective air gaps
• 4.0 to 26.5 V supply operating range
• Output compatible with both TTL and CMOS logic families
• Reverse battery protection
• Resistant to mechanical and thermal stress
• Accurate true zero crossing switchpoint (A1421 only)
• High vibration immunity, in running mode (A1423 only)