Chopper-Stabilized, Two Wire Hall-Effect Switches

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Chad Shepherd
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FEATURES AND BENEFITS High speed, 4-phase chopper stabilization Low switchpoint drift throughout temperature range Low sensitivity to thermal and mechanical stresses On-chip

0 to 24 V operation Solid-state reliability Robust EMC and ESD performance Industry leading ISO 767-2 performance through use of proprietary, 40-V clamping structures

5 mm 4 mm 4 mm (suffix UB) DESCRIPTION The A1150, A1152, A115, A1155, comprise a family of two-wire, unipolar, Hall-effect switches, which are factory-trimmed to optimize

These devices are produced on the Allegro advanced BiCMOS wafer fabrication process, which implements a patented high frequency, 4-phase, chopper-stabilization technique.

to harsh application environments. The A115x family has a number of automotive applications.

Two-wire unipolar switches are particularly advantageous in cost-sensitive applications because they require one less wire for operation versus the more traditional

Additionally, the system designer inherently gains diagnostics because there is always output current flowing, which should be in either of two narrow ranges.

1 FEATURES AND BENEFITS High speed, 4-phase chopper stabilization Low switchpoint drift throughout temperature range Low sensitivity to thermal and mechanical stresses On-chip protection Supply transient protection Reverse battery protection On-board voltage regulator.0 to 24 V operation Solid-state reliability Robust EMC and ESD performance Industry leading ISO performance through use of proprietary, 40-V clamping structures Continued on the next page Packages -pin SOT2-W 2 mm mm 1 mm (suffix LH) Approximate footprint -pin ultramini SIP 1.5 mm 4 mm mm (suffix UA) 2-pin ultramini SIP 1.5 mm 4 mm 4 mm (suffix UB) DESCRIPTION The A1150, A1152, A115, A1155, comprise a family of two-wire, unipolar, Hall-effect switches, which are factory-trimmed to optimize magnetic switchpoint accuracy. These devices are produced on the Allegro advanced BiCMOS wafer fabrication process, which implements a patented high frequency, 4-phase, chopper-stabilization technique. This technique achieves magnetic stability over the full operating temperature range, and eliminates offsets inherent in devices with a single Hall element that are exposed to harsh application environments. The A115x family has a number of automotive applications. These include sensing seat track position, seat belt buckle presence, hood/trunk latching, and shift selector position. Two-wire unipolar switches are particularly advantageous in cost-sensitive applications because they require one less wire for operation versus the more traditional open-collector output switches. Additionally, the system designer inherently gains diagnostics because there is always output current flowing, which should be in either of two narrow ranges. Any current level not within these ranges indicates a fault condition. All family members are offered in three package styles. The LH is a SOT-2W style, miniature, low profile package for surface-mount applications. The UA is a -pin, ultra-mini, single inline package (SIP) for through-hole mounting. The UB is a 2-pin, ultra-mini, single inline package (SIP) for through-hole mounting. All three packages are lead (Pb) free, with 100% matte tin leadframe plating. UB package only V+ VCC 0. 1 µf Regulator To all subcircuits LH & UA package only µf Dynamic Offset Cancellation Clock/Logic Amp Sample and Hold Low-Pass Filter Schmitt Trigger Polarity GND GND UA package only Functional Block Diagram A1152-DS, Rev. 9

2 Features and Benefits (continued) Extended Operating Ambient temperature range, 40 C to 150 C UB package with integrated 0.1 µf bypass capacitor Selection Guide Part Number Packing Package A1150LLHLX-T 1-in. reel, pieces/reel -pin SOT2W surface mount A1150LUA-T Bulk, 500 pieces/bag -pin SIP through hole A1152LLHLX-T 1-in. reel, pieces/reel -pin SOT2W surface mount A1152LUA-T Bulk, 500 pieces/bag -pin SIP through hole A1152LUBTN-T 1-in. reel, pieces/reel 2-pin SIP through hole A115LLHLX-T 1-in. reel, pieces/reel -pin SOT2W surface mount A115LUA-T Bulk, 500 pieces/bag -pin SIP through hole A115LUBTN-T 1-in. reel, pieces/reel 2-pin SIP through hole A1155LLHLX-T 1-in. reel, pieces/reel -pin SOT2W surface mount A1155LUA-T Bulk, 500 pieces/bag -pin SIP through hole A1155LUBTN-T 1-in. reel, pieces/reel 2-pin SIP through hole A1156LLHLX-T 1-in. reel, pieces/reel -pin SOT2W surface mount A1156LUA-T Bulk, 500 pieces/bag -pin SIP through hole A1156LUBTN-T 1-in. reel, pieces/reel 2-pin SIP through hole A1157LLHLX-T 1-in. reel, pieces/reel -pin SOT2W surface mount A1157LLHLT-T 7-in. reel, 000 pieces/reel -pin SOT2W surface mount A1157LUA-T Bulk, 500 pieces/bag -pin SIP through hole A1158LLHLX-T 1-in. reel, pieces/reel -pin SOT2W surface mount A1158LLHLT-T 7-in. reel, 000 pieces/reel -pin SOT2W surface mount A1158LUA-T Bulk, 500 pieces/bag -pin SIP through hole Output (I CC ) in South Polarity Field Supply Current at I CC(L) (ma) Low 2 to 5 Low 5 to 6.9 High 5 to 6.9 Low 5 to 6.9 High 5 to 6.9 Low High Magnetic Operate Point, B OP (G) 50 to to 60 2 to 5 20 to 80 2

3 SPECIFICATIONS Absolute Maximum Ratings Characteristic Symbol Notes Rating Unit Forward Supply Voltage V CC 28 V Reverse Supply Voltage V RCC 18 V Magnetic Flux Density B Unlimited G 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 Pin-out Diagrams and Terminal List Table NC 1 2 LH Package 1 2 UA Package LH and UA Terminal List Table Number LH package Name UA package Function 1 VCC VCC Input power supply 2 NC GND LH package: no connection, it is highly recommended that this pin be tied to GND UA package: ground terminal GND GND Ground terminal UB Terminal List Table Number Name Function 1 VCC Input power supply 2 GND Ground terminal 1 2 UB Package

4 ELECTRICAL CHARACTERISTICS: valid at T A = 40 C to 150 C, T J < T J (max), C BYP = 0.01 µf, through operating supply voltage range; unless otherwise noted Characteristics Symbol Test Conditions Min. Typ. Max. Unit Supply Voltage 1,2 V CC Operating, T J 165 C.0 24 V I CC(L) A1150, A1157 B > B OP ma A1158 B < B RP A1152, A1155 B > B OP ma Supply Current A115, A1156 B < B RP I CC(H) A1150, A1152, A1155, A1157 B < B RP A115, A1156, A1158 B > B OP ma Supply Zener Clamp Voltage V Z(sup) I CC(L) (max) + ma, T A = 25 C 28 V Supply Zener Clamp Current I Z(sup) V Z(sup) = 28 V I CC(L) (max) + ma ma Reverse Supply Current I RCC V RCC = 18 V 1.6 ma Output Slew Rate di/dt LH and UA No bypass capacitor, capacitance of probe C S = 20 pf 90 ma / µs Integrated bypass capacitor, UB 0.22 ma / µs capacitance of probe C S = 20 pf Chopping Frequency f c 700 khz A1150, A1152, B > B OP + 10 G A1155, A1157 Power-Up Time 4,5 t on 25 µs A115, A1156, B < B A1158 RP 10 G Power-Up State 2,4,6,7 POS t on < t on (max), V CC slew rate > 25 mv / µs I CC(H) 1 V CC represents the generated voltage between the VCC pin and the GND pin. 2 The V CC slew rate must exceed 600 mv/ms from 0 to V. A slower slew rate through this range can affect device performance. Measured without bypass capacitor between VCC and GND. Use of a bypass capacitor results in slower current change. 4 Power-Up Time is measured without and with bypass capacitor of 0.01 µf. Adding a larger bypass capacitor would cause longer Power-Up Time. 5 Guaranteed by characterization and design. 6 Power-Up State as defined is true only with a V CC slew rate of 25 mv / µs or greater. 7 For t > t on and B RP < B < B OP, Power-Up State is not defined. MAGNETIC CHARACTERISTICS 1 Valid at T A = 40 C to 150 C, T J < T J (max); unless otherwise noted Characteristics Symbol Min. Typ. Max. Unit 2 Magnetic Operating Point B OP A1155, A G A1150, A1152, A G A1157, A G Magnetic Release Point B RP A1155, A G A1150, A1152, A G A1157, A G Hysteresis B HYS 5 0 G 1 Relative values of B use the algebraic convention, where positive values indicate south magnetic polarity, and negative values indicate north magnetic polarity; therefore greater B values indicate a stronger south polarity field (or a weaker north polarity field, if present). 2 1 G (gauss) = 0.1 mt (millitesla). 4

Thermal Characteristics may require derating at maximum conditions, see application information Characteristic Symbol Test Conditions* Value Unit Package LH, on 1-layer PCB with copper limited to

2 of copper area each side 110 ºC/W Package UA, on 1-layer PCB with copper limited to solder pads 165 ºC/W Package UB, on 1-layer PCB with copper limited to solder pads 21 ºC/W *Additional thermal

5 Thermal Characteristics may require derating at maximum conditions, see application information Characteristic Symbol Test Conditions* Value Unit Package LH, on 1-layer PCB with copper limited to solder pads 228 ºC/W Package Thermal Resistance R θja Package LH, on 2-layer PCB with 0.46 in. 2 of copper area each side 110 ºC/W Package UA, on 1-layer PCB with copper limited to solder pads 165 ºC/W Package UB, on 1-layer PCB with copper limited to solder pads 21 ºC/W *Additional thermal information available on the Allegro website LH and Power UA Derating Power Derating Curve Curve UB Power Derating Curve Maximum Allowable V CC (V) layer PCB, Package LH = 110 ºC/W) 1-layer PCB, Package UA = 165 ºC/W) 1-layer PCB, Package LH = 228 ºC/W) V CC(max) V CC(min) Temperature (ºC) Power Dissipation, PD (mw) LH and UA Power Power Dissipation versus Ambient Temperature layer PCB, Package LH = 110 ºC/W) 1-layer PCB, Package UA = 165 ºC/W) 1-layer PCB, Package LH = 228 ºC/W) Temperature ( C) UB Power Dissipation versus Ambient Temperature 5

A1244 Chopper-Stabilized, Two Wire Hall-Effect Latch

A1244 Chopper-Stabilized, Two Wire Hall-Effect Latch Features and Benefits High speed, 4-phase chopper stabilization Low switchpoint drift throughout temperature range Low sensitivity to thermal and mechanical stresses On-chip protection Supply transient