Electronics Weekly
The ATS651LSH from Allegro MicroSystems Europe is a Hall-effect sensor module is designed for speed and direction sensing in automotive transmission applications. It uses patented algorithms which are designed to minimise the effects of vibration.
It is an integrated Hall-sensor/magnet assembly containing a samarium-cobalt magnet and a Hall-effect IC optimised to the magnetic circuit. The solid thermoset moulded plastic package has been designed specifically for high reliability in the harsh automotive environment.
The two-wire device communicates the speed and direction of a ferrous target – typically a rotating gear – via a pulse-width-modulation (PWM) output protocol. The patented algorithms are designed to meet the special operational requirements of transmission applications, and the device is particularly adept at handling vibration without sacrificing maximum air-gap capability or creating an erroneous ‘direction’ pulse.
Patented running-mode algorithms also protect against air-gap changes, whether or not the target is in motion. Direction information is always available on the first magnetic edge after a direction change.
Other features include an internal current regulator for 2-wire operation, automatic gain control and reference adjustment circuitry, true zero-speed operation, and a defined power-on state. The device will operate over a wide voltage range, and 3-bit factory trimming provides tight pulse-width accuracy. Under-voltage lockout circuitry and ESD and reverse polarity protection are included.
www.allegromicro.com
