Micronas > HAL 710/730: Hall-Effect Sensors with Direction Detection
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HAL 710/730: Hall-Effect Sensors with Direction DetectionHAL 710/730 DescriptionThe HAL® 710 and the HAL® 730 are monolithic integrated Hall-effect sensors manufactured in CMOS technology with two independent Hall plates S1 and S2 spaced 2.35 mm apart. The devices have two open-drain outputs: – The Count Output operates like a single latched Hall switch according to the magnetic field present at Hall plate S1.– The Direction Output indicates the direction of a linear or rotating movement of magnetic objects. In combination with an active target providing a sequence of alternating magnetic north and south poles, the sensors generate the signals required to control position, speed, and direction of the target movement. The internal circuitry evaluates the direction of the movement and updates the Direction Output at every edge of the Count Signal (rising and falling). The state of the Direction Output only changes at a rising or falling edge of the Count Output. The design ensures a setup time for the Direction Output with respect to the corresponding Count Signal edge of 1/2 clock periods (1 µs minimum). The devices include temperature compensation and active offset compensation. These features provide excellent stability and matching of the switching points in the presence of mechanical stress over the whole temperature and supply voltage range. This is required by systems determining the direction from the comparison of two signals. The sensors are designed for industrial and automotive applications and operate with supply voltages from 3.8 V to 24 V in the ambient temperature range from -40°C up to 125°C. The HAL 710 and the HAL 730 are available in the SMD-package SOT89B-2 HAL 710/730 System ArchitectureThe HAL 710 and the HAL 730 are monolithic integrated circuits with two independent subblocks each consisting of a Hall plate and the corresponding comparator. Each subblock independently switches the comparator output in response to the magnetic field at the location of the corresponding sensitive area. If a magnetic field with flux lines perpendicular to the sensitive area is present, the biased Hall plate generates a Hall voltage proportional to this field. The Hall voltage is compared with the actual threshold level in the comparator. The output of comparator 1 (connected to S1) directly controls the Count Output. The outputs of both comparators enter the Direction Detection Block controlling the state of the Direction Output. The Direction Output is updated at every edge of comparator 1 (rising and falling). The previous state of the Direction Output is maintained between two edges of the Count Output and in case the edges at comparator 1 and comparator 2 occur in the same clock period. The subblocks are designed to have closely matched switching points HAL 710/730 Block Diagram
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HAL 710/730 Features
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