The A110x family of unipolar Hall-effect switches from Allegro Microsystems takes the vendor¡¯s existing A312x and A314x families and adds better performance and features. The lead-free units are BiCMOS devices with fast power-on and low-noise operation. To counter the effects of package stress on device parameters, the switches are programmed after packaging to eliminate offsets. Each switch in the familywhich are the same except for magnetic switchpoints—is a monolithic device with voltage regulator, Hall-voltage generator, small-signal amplifier, Schmitt trigger, and an MOS output transistor. Operation is specified from 3.8 to 24V supply, and on-board protection circuitry allows these switches to withstand ¡¾30V maximum voltage, well-suited for auto and industrial applications. Packaging options include a three-pin single in-line package or a surface-mount package. Prices are between $0.39 and $0.61, depending on model, in 10,000 orders.
