The ATS668LSM is an optimized Hall-effect integrated circuit (IC) and permanent magnet pellet combination with integrated EMC protection components to provide a user-friendly solution for true zero-speed digital gear tooth sensing. The small package can be easily assembled and used in conjunction with a wide variety of gear tooth sensing applications.
The device incorporates a dual element Hall IC that switches in response to differential magnetic signals created by a ferromagnetic target. The IC contains a sophisticated compensating circuit designed to eliminate the detrimental effects of magnet and system offsets. Digital processing of the analog signal provides zero-speed performance independent of air gap and also dynamic adaptation of device performance to the typical operating conditions found in automotive applications (i.e. vibration immunity and runout tolerance). High-resolution peak detecting DACs are used to set the adaptive switching thresholds of the device. Hysteresis in the thresholds reduces the negative effects of any anomalies in the magnetic signal associated with system or target anomalies typically seen in many automotive applications.
This device is available in a lead (Pb) free 3-pin SIP package (SM) with matte-tin lead frame plating.
Three-wire back-biased speed sensor optimized for transmission speed-sensing applications
Integrated in-package EMC protection circuit allows compliance to most Automotive EMC environments without external circuitry
Small-signal lockout for immunity to vibration
Tight timing accuracy over full operating temperature range
True zero-speed operation
Air gap independent switchpoints
Large operating air gaps achieved through use of gain and offset adjust circuitry
Wide operating voltage range with undervoltage lockout (UVLO)
Allegro’s products are not to be used in any devices or systems, including but not limited to life support devices or systems, in which a failure of Allegro’s product can reasonably be expected to cause bodily harm.