New three-wire differential speed sensor IC designed with integrated EMI protection

Allegro MicroSystems Europe has a new optimised Hall-effect three-wire differential speed sensor IC and permanent magnet pellet combination. The ATS668 has integrated EMC protection components to provide a user-friendly solution for true zero-speed digital gear tooth sensing. It is offered in a small single over-mould package that can be easily assembled and used in conjunction with a wide variety of gear tooth sensing applications. The device is designed for automotive transmission systems making it ideal for non-automotive applications such as recreational vehicles, industrial equipment, white goods and exercise equipment. 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 analogue signal provides zero-speed performance independent of air gap and dynamic adaptation of device performance to the typical operating conditions found in automotive applications (i.e. vibration and runout). 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. The fully integrated package and industry proven algorithm performance makes the device an ideal solution for a wide range of speed sensing needs. This device is available in a lead (Pb) free three-pin SIP package (SM) with matt-tin leadframe plating.