|Allegro's A1220, A1221, and A1222 Hall-effect sensor ICs are extremely temperature-stable and stress-resistant devices. They are especially suited for operation over extended temperature ranges up to 150°C. Superior high-temperature performance is made possible through dynamic offset cancellation, which reduces the residual offset voltage normally caused by device overmolding, temperature dependencies, and thermal stress.
On a single silicon chip, each device includes a voltage regulator, Hall-voltage generator, small-signal amplifier, chopper stabilization, Schmitt trigger, and a short-circuit protected open-drain output to sink up to 25mA. A south pole of sufficient strength turns the output on. A north pole of sufficient strength is necessary to turn the output off.
An onboard regulator permits operation with supply voltages of 3V to 24V. The advantage of operating down to 3V is that the device can be used in 3V applications or with additional external resistance in series with the supply pin for greater protection against high voltage transient events. Datasheet