3134

3134 BIPOLAR HALL-EFFECT SWITCH FOR HIGH-TEMPERATURE OPERATION This low-hysteresis bipolar Hall-effect switch is an extremely temperature-stable and stress-resistant sensor especially suited for operation over extended temperature ranges to +150°C. Superior high-temperature performance is made possible through a novel Schmitt trigger circuit that maintains operate and release point stability by compensating for temperature changes in the Hall element. Additionally, internal compensation provides magnetic switch points that become more sensitive with temperature, hence offsetting the usual degradation of the magnetic field with temperature. Its low hysteresis makes this device ideal for detecting small changes in magnetic field strength or for use with inexpensive magnets. The device includes on a single silicon chip a voltage regulator, quadratic Hall-voltage generator, temperature compensation circuit, signal amplifier, Schmitt trigger, and a buffered open-collector output to sink up to 25 mA. The on-board regulator permits operation with supply voltages of 4.5 volts to 24 volts. The first character of the part number suffix determines the device operating temperature range. Suffix ‘E–’ is for -40°C to +85°C, and suffix ‘L–’ is -40°C to +150°C. Two package styles provide a magnetically optimized package for most applications. Suffix ‘–LT’ is a miniature SOT89/TO-243AA transistor package for surface-mount applications while suffix ‘–UA’ is a three-lead ultra-mini-SIP. Data ...