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℃. 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 25 mA.
An on - board regulator permits operation with supply voltages of 3 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.
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.