ATS645LSH Datasheet | Allegro MicroSystems

Features and Benefits - - - - - - - Fully optimized differential digital gear tooth sensor Single chip IC for high reliability Internal current regulator for 2-wire operation Small mechanical size (8 mm diameter x 5.5 mm depth) Air gap independent switchpoints Digital output representing gear profile Precise duty cycle signal over operating temperature range - Large operating air gaps - Automatic Gain Control (AGC) Description The ponents in speed sensing applications continue to diminish in size to meet spatial constraints and weight reduction requirements. As the geometries of gears bee smaller, this can promise the capabilities of a gear speed sensor. The ATS645 Hall-element-to-Hall-element spacing of only 1.5 mm makes this device uniquely capable of acmodating very fine-pitch gears. In addition, the ATS645 signal peak-detecting algorithm supports consistent switching at relatively large air gaps, where the peak-to-peak amplitude is small. These features make the ATS645 the ideal solution to detect the speed of finepitch targets such as those found in ABS (antilock braking) systems. The ATS645 bines a Hall-effect sensing integrated circuit and magnet to provide a manufacturer-friendly solution for true zero-speed digital gear-tooth sensing in two-wire applications. The device consists of a single-shot molded plastic package that includes a samarium cobalt magnet, a pole piece, and a Hall-effect integrated circuit that has been optimized to the magnetic circuit. This small package can be easily assembled and used in conjunction with a wide variety of gear shapes and sizes. Continued on the next page… Packages: 4 pin SIP (suffix SH) Continued on the next page… Not to scale Functional Block Diagram Hall Amplifier Gain Automatic Offset Control AOA DAC AGC DAC Internal Regulator Tracking DAC Peak Hold Test Signals Test ATS645-DS, Rev. 3 Features and Benefits (continued) - Automatic Offset Adjustment (AOA) - True zero-speed...