Chopper Stabilized Precision Hall Effect Switches

Transcription

1 Features and Benefits Unipolar switchpoints Resistant to physical stress Superior temperature stability Output short-circuit protection Operation from unregulated supply Reverse battery protection Solid-state reliability Small package sizes Packages: 3-pin SOT23W (suffix LH) Not to scale () 3-pin SIP (suffix UA) (,, ) Description The 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 hightemperature 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 and 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. Functional Block Diagram Regulator Dynamic Offset Cancellation Amp Sample and Hold Low-Pass Filter To All Subcircuits Control Current Limit -DS, Rev. 15

2 Selection Guide Part Number Packing 1 Mounting Ambient, T A (Typ.) Switchpoints ELHLX-T 13-in. reel, pieces/reel 3-pin SOT23W surface mount ELHLT-T 2 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount EUA-T Bulk, 500 pieces/bag 3-pin SIP through hole LLHLX-T 13-in. reel, pieces/reel 3-pin SOT23W surface mount LLHLT-T 2 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount LUA-T Bulk, 500 pieces/bag 3-pin SIP through hole ELHLX-T 13-in. reel, pieces/reel 3-pin SOT23W surface mount ELHLT-T 2 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount EUA-T Bulk, 500 pieces/bag 3-pin SIP through hole LLHLX-T 13-in. reel, pieces/reel 3-pin SOT23W surface mount LLHLT-T 2 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount LUA-T Bulk, 500 pieces/bag 3-pin SIP through hole ELHLX-T 13-in. reel, pieces/reel 3-pin SOT23W surface mount ELHLT-T 2 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount EUA-T Bulk, 500 pieces/bag 3-pin SIP through hole LLHLX-T 13-in. reel, pieces/reel 3-pin SOT23W surface mount LLHLT-T 2 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount LUA-T Bulk, 500 pieces/bag 3-pin SIP through hole LLHLX-T 13-in. reel, pieces/reel 3-pin SOT23W surface mount LLHLT-T 2 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount LUA-T Bulk, 500 pieces/bag 3-pin SIP through hole A1125ELHLX-T 13-in. reel, pieces/reel 3-pin SOT23W surface mount A1125ELHLT-T 2 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount A1125EUA-T Bulk, 500 pieces/bag 3-pin SIP through hole A1125LLHLX-T 13-in. reel, pieces/reel 3-pin SOT23W surface mount A1125LLHLT-T 2 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount A1125LUA-T Bulk, 500 pieces/bag 3-pin SIP through hole 1Contact Allegro for additional packing options. 2 Available through authorized Allegro distributors only. B OP B RP Output In South (Positive) Magnetic Field On (logic low) Off (logic high) 2

3 Absolute Maximum Ratings Characteristic Symbol Notes Rating Units Forward Supply Voltage V CC 26.5 V Reverse Supply Voltage V RCC 30 V Output Off Voltage V OUT 26 V Continuous Output Current I OUT 25 ma Reverse Output Current I ROUT 50 ma Range E 40 to 85 ºC Operating Ambient Temperature T A Range L 40 to 150 ºC Maximum Junction Temperature T J (max) 165 ºC Storage Temperature T stg 65 to 170 ºC 3 Pin-out Diagrams Package LH Package UA Terminal List Name Description Number Package LH Package UA Connects power supply to chip 1 1 Output from circuit 2 3 Ground 3 2 3

4 ELECTRICAL CHARACTERISTICS Valid over full operating voltage and ambient temperature ranges; unless otherwise noted Characteristics Symbol Test Conditions Min. Typ. 1 Max. Unit 2 Electrical Characteristics Forward Supply Voltage V CC Operating, T J < 165 C 3 24 V Output Leakage Current Output Saturation Voltage Output Current Limit I OUTOFF V OUT(SAT) I OM V OUT = 24 V, B < B RP 10 μa A1125 V OUT = 24 V, B > B OP 10 μa I OUT = 20 ma, B > B OP mv A1125 I OUT = 20 ma, B < B RP mv B > B OP ma A1125 B < B RP ma Power-On Time 3 t PO V CC > 3.0 V, B < B RP (min) 10 G, B > B OP (max) + 10 G 25 μs Chopping Frequency f C 800 khz Output Rise Time 3,4 t r R L = 820 Ω, C S = 20 pf μs Output Fall Time 3,4 t f R L = 820 Ω, C S = 20 pf μs Supply Current I CC(ON) I CC(OFF) V CC = 12 V, B > B OP 4 ma A1125 V CC = 12 V, B < B RP 4 ma V CC = 12 V, B < B RP 4 ma A1125 V CC = 12 V, B > B OP 4 ma Reverse Supply Current I RCC V RCC = 30 V 5 ma Supply Zener Clamp Voltage V Z I CC = 5 ma; T A = 25 C 28 V Zener Impedance I Z I CC = 5 ma; T A = 25 C 50 Ω Continued on the next page 4

5 ELECTRICAL CHARACTERISTICS (continued) Valid over full operating voltage and ambient temperature ranges; unless otherwise noted Characteristics Symbol Test Conditions Min. Typ. 1 Max. Unit 2 Magnetic Characteristics Operate Point Release Point B OP B RP G G G G A G 5 25 G G G G A G 10 G G Hysteresis B HYS (B OP B RP ) G G A G 1 Typical data are are at T A = 25 C and V CC = 12 V, and are for initial design estimations only. 2 1 G (gauss) = 0.1 mt (millitesla). 3 Guaranteed by device design and characterization. 4 C S = oscilloscope probe capacitance. 5