A1120, A1121, A1122, A1123, and A1125 Chopper Stabilized Precision Hall Effect Switches Features and Benefits Description Unipolar switchpoints The A1120, A1121, A1122, A1123, and A1125 Hall-effect, Resistant to physical stress unipolar switches are extremely temperature-stable and Superior temperature stability stress-resistant sensor ICs, especially suited for operation Output short-circuit protection over extended temperature ranges to 150C. Superior high- Operation from unregulated supply temperature performance is made possible through dynamic Reverse battery protection offset cancellation, which reduces the residual offset voltage Solid-state reliability normally caused by device overmolding, temperature Small package sizes 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. Packages: 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. 3-pin SOT23W For the A1120, A1121, A1122, and A1123 a south pole of (suffix LH) sufficient strength turns the output on. Removal of the magnetic field turns the output off. The A1125 is complementary, in that (A1120) (A1121, A1122, for these devices, a south pole turns the A1125 output off, and A1123, and A1125) removal of the magnetic field turns the output on. 3-pin SIP (suffix UA) Not to scale 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. Functional Block Diagram VCC Regulator To All Subcircuits VOUT Low-Pass Filter Amp Control Current Limit GND A1120-DS, Rev. 15 Dynamic Offset Cancellation Sample and HoldA1120, A1121, A1122, Chopper Stabilized Precision Hall Effect Switches A1123, and A1125 Selection Guide Switchpoints Output In South (Positive) 1 (Typ.) Part Number Packing Mounting Ambient, T A Magnetic Field B B OP RP A1120ELHLX-T 13-in. reel, 10000 pieces/reel 3-pin SOT23W surface mount 2 A1120ELHLT-T 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount 40C to 85C A1120EUA-T Bulk, 500 pieces/bag 3-pin SIP through hole 35 25 A1120LLHLX-T 13-in. reel, 10000 pieces/reel 3-pin SOT23W surface mount 2 A1120LLHLT-T 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount 40C to 150C A1120LUA-T Bulk, 500 pieces/bag 3-pin SIP through hole A1121ELHLX-T 13-in. reel, 10000 pieces/reel 3-pin SOT23W surface mount 2 A1121ELHLT-T 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount 40C to 85C A1121EUA-T Bulk, 500 pieces/bag 3-pin SIP through hole 95 70 A1121LLHLX-T 13-in. reel, 10000 pieces/reel 3-pin SOT23W surface mount 2 A1121LLHLT-T 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount 40C to 150C On (logic low) A1121LUA-T Bulk, 500 pieces/bag 3-pin SIP through hole A1122ELHLX-T 13-in. reel, 10000 pieces/reel 3-pin SOT23W surface mount 2 A1122ELHLT-T 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount 40C to 85C A1122EUA-T Bulk, 500 pieces/bag 3-pin SIP through hole 150 125 A1122LLHLX-T 13-in. reel, 10000 pieces/reel 3-pin SOT23W surface mount 2 A1122LLHLT-T 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount 40C to 150C A1122LUA-T Bulk, 500 pieces/bag 3-pin SIP through hole A1123LLHLX-T 13-in. reel, 10000 pieces/reel 3-pin SOT23W surface mount 2 A1123LLHLT-T 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount 40C to 150C 280 225 A1123LUA-T Bulk, 500 pieces/bag 3-pin SIP through hole A1125ELHLX-T 13-in. reel, 10000 pieces/reel 3-pin SOT23W surface mount 2 A1125ELHLT-T 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount 40C to 85C A1125EUA-T Bulk, 500 pieces/bag 3-pin SIP through hole 35 25 Off (logic high) A1125LLHLX-T 13-in. reel, 10000 pieces/reel 3-pin SOT23W surface mount 2 A1125LLHLT-T 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount 40C to 150C A1125LUA-T Bulk, 500 pieces/bag 3-pin SIP through hole 1 Contact Allegro for additional packing options. 2 Available through authorized Allegro distributors only. Allegro MicroSystems, LLC 2 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000 www.allegromicro.com