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 25 mA. 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 3 V to 24 V. The advantage of operating down to 3 V is that the device can be used in 3 V applications or with additional external resistance in series with the supply pin for greater protection against high voltage transient events.