DESCRIPTION
The A1469 is an optimized Hall effect sensing IC that provides a user-friendly solution for digital ring-magnet sensing, or when coupled with a magnet, ferromagnetic target sensing, in three-wire applications. The small device package can be easily assembled into applications for use in conjunction with a wide variety of target shapes and sizes.
The integrated circuit incorporates dual Hall effect elements with a 2.2 mm spacing and signal processing that switches in response to differential magnetic signals created by ringmagnet poles. The circuitry contains a sophisticated digital circuit to reduce system offsets, to calibrate the gain for airgap–independent switchpoints, and to achieve true zero-speed operation. Signal optimization occurs at power-on through the combination of offset and gain adjust, and is maintained throughout the operating time with the use of a running-mode calibration. The running-mode calibration provides immunity to environmental effects such as micro-oscillations of the target or sudden air gap changes.
The device is ideally suited to obtaining speed and duty cycle information in ring-magnet–based speed, position, and timing applications, such as in speedometers.
The A1469 is available in a 4-pin SIP (suffix K) package. The package is lead (Pb) free, with 100% matte tin leadframe plating.

FEATURES AND BENEFITS
• Unique design for robustness against high power EMC transients
• Peak detection based switching algorithm for large operating air gaps
• Minimum differential field 20 Gpk-pk
• Running mode calibration for continuous optimization
• Precise duty cycle signal throughout operating temperature range
• Automatic Gain Control (AGC) for air-gap–independent switchpoints
• Automatic Offset Adjustment (AOA) for signal processing optimization
• True zero-speed operation
• Scan and IDDQ for increased test coverage