Allegro A1667 speed sensor in surface-mount SOIC-8 package. Source: Allegro
The sensor IC incorporates a dual-element Hall IC that switches in response to differential magnetic signals created by a ring magnet. 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 as well as dynamic adaptation of device performance to the typical operating conditions found in automotive applications (reduced vibration sensitivity).
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 the targets used in many automotive applications. The open-drain output is configured for three-wire applications.
In addition to the eight-pin SOIC surface-mount package (suffix L), the A1667 is also available in a four-pin SIP through-hole package (suffix K). Both packages are lead free with 100% matte–tin-plated lead frames.
The A1667 (eight-pin SOIC) is priced at $0.941 in quantities of 1,000.
