The A1120, A1121, A1122, A1123, and A1125 Hall - effect unipolar switches are extremely temperature - stable and stress - resistant sensor ICs, especially suited for operation over extended temperature ranges 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.
Each device includes on a single silicon chip 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.
An on - board regulator permits operation with supply voltages of 3 to 24 V. 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.
For the A1120, A1121, A1122, and A1123, a south pole of sufficient strength turns the output on. Removal of the magnetic field turns the output off. The A1125 is complementary, in that for these devices, a south pole turns the A1125 output off, and removal of the magnetic field turns the output on.
Two package styles provide a magnetically optimized package for most applications. Package type LH is a modified SOT23W, surface - mount package, while UA is a three - lead ultra - mini SIP for through - hole mounting. Each package type is lead (Pb) free (suffix, - T), with a 100% matte - tin - plated leadframe.
ALLEGRO A1120LLHLT-T