A field-programmable, unipolar Hall-effect switch from Allego designed for high-temperature applications, the A1128, uses a chopper-stabilization technique to eliminate offset inherent in single-element devices. Allegro's new device has an advanced programming algorithm to simplify the customer's end-of-line process. It also has a higher programming resolution for tighter magnetic switch points. It is targeted at the automotive and industrial markets.
The devices are externally programmable. A wide range of programmability is available on the magnetic operate point, BOP, while the hysteresis remains fixed. This advanced feature allows optimization of the sensor IC switchpoint and can drastically reduce the effects of mechanical placement tolerances found in end-use production environments. A proprietary dynamic offset cancellation technique, with an internal high-frequency clock, reduces the residual offset voltage, which is normally caused by device overmolding, temperature dependencies, and thermal stress. Having the Hall element and amplifier in a single chip minimizes many problems normally associated with low-level analog signals.
This device is offered in the UA package. The UA is a three-lead ultra-mini SIP for through-hole mounting. This package is lead (Pb) free, with 100% matte tin plated leadframes. The A1128LUA-T is priced at $0.49 in quantities of 1,000.