3240 ALLEGRO

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Technical content

The A3240-- Hall-effect switch is an extremely temperature-stable and stress-resistant sensor 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, tempera- ture dependencies, and thermal stress. The 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-collector output to sink up to 25 mA. A south pole of sufficient strength will turn the output on. An on-board regulator permits operation with supply voltages of 4.2 to 24 volts. The first character of the part number suffix determines the device operating temperature range; suffix ‘E–’ is for -40°C to +85°C and ‘L–’ is -40°C to +150°C. Three package styles provide a magnetically optimized package for most applications. Suffix ‘–LH’ is a modified SOT23W surface-mount package, ‘–LT’ is a miniature SOT89/TO- 243AA transistor package for surface-mount applications; while suffix ‘–UA’ is a three-lead ultra-mini-SIP for through-hole mounting. Data Sheet27621.20b

FEATURES

I Resistant to Physical Stress I Superior Temperature Stability I Output Short-Circuit Protection I Operation From Unregulated Supply I Reverse Battery Protection I Solid-State Reliability I Small Size Suffix ‘–LT’ & ‘–UA’ Pinning (SOT89/TO-243AA & ultra-min SIP) Pinning is shown viewed from branded side. CHOPPER-STABILIZED, PRECISION HALL-EFFECT SWITCH 3240 Continuous Output Current, Package Power Dissipation, PD . See Graph Operating Temperature Range, TA Storage Temperature Range, *Internal current limiting is intended to protect the device from output short circuits. ABSOLUTE MAXIMUM RATINGS at TA = +25°C Always order by complete part number: the prefix ‘A’ + the basic four- digit part number + a suffix to indicate operating temperature range + a suffix to indicate package style, e.g., A3240ELH . Dwg. PH-003-2 1SUPPLY V CC GROUND OUTPUT X PTCT

CHOPPER-STABILIZED, PRECISION HALL-EFFECT SWITCH

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 (508) 853-50002 FUNCTIONAL BLOCK DIAGRAM Copyright © 2000, 2003, 2004 Allegro MicroSystems, Inc. Suffix ‘–LH’ Pinning (SOT23W) Dwg. FH-020-1 GROUND OUTPUT <1Ω X DYNAMIC OFFSET CANCELLATION SUPPLY CONTROL CURRENT LIMIT REG. SAMPLE & HOLD LOW-PASS FILTER TO ALL SUBCIRCUITS 600 400 200 20 60 100 140 AMBIENT TEMPERATURE in °°°°C ALLOWABLE PACKAGE POWER DISSIPATION in MILLIWATTS Dwg. GH-046-2D Suffix "–UA" R θJA = 165°C/W 40 80 120 180 700 500 300 100 160 Suffix "–LT" R θJA = 180°C/W 800 Suffix "E–" Suffix "L–" Suffix "–LH" R θJA = 228°C/W Dwg. PH-003-4 SUPPLY GROUND OUTPUT V CC X PTCT

CHOPPER-STABILIZED, PRECISION HALL-EFFECT SWITCH www.allegromicro.com 3 Limits Characteristic Symbol Test Conditions Min. Typ. Max. Units Supply Voltage Range V CC Operating, TJ < 165°C1 4.2–24V Output Leakage Current I OFF VOUT = 24 V, B < BRP ––1 0 µA Output Saturation Voltage V OUT(SAT) IOUT = 20 mA, B > BOP – 185 500 mV Output Current Limit I OM B > BOP 30 – 60 mA Power-On Time t po VCC > 4.2 V– – 50 µs Chopping Frequency f C – 340 – kHz Output Rise Time t r RL = 820 Ω , CL = 20 pF – 0.2 2.0 µs Output Fall Time t f RL = 820 Ω , CL = 20 pF – 0.1 2.0 µs Supply Current I CC B < BRP, VCC = 12 V– 3.0 6.0 mA B > BOP, VCC = 12 V– 4.0 6.0 mA Reverse Battery Current I CC VRCC = -30 V– – -5.0 mA Zener Voltage V Z + VD ICC = 15 mA, TA = 25°C 2 83 23 7V Zener Impedance z z + zD ICC = 15 mA, TA = 25°C– 5 0 – Ω NOTES:1. Maximum voltage must be adjusted for power dissipation and junction temperature. 2. BOP = operate point (output turns on); BRP = release point (output turns off). 3. Typical Data is at TA = +25°C and VCC = 12 V and is for design information only. ELECTRICAL CHARACTERISTICS over operating temperature range. Limits Characteristic Symbol Test Conditions Min. Typ. Max. Units Operate Point B OP –3 55 0G Release Point B RP 5.0 25 – G Hysteresis B hys BOP - BRP –1 0–G NOTES: 1. Typical Data is at TA = +25°C and VCC = 12 V and is for design information only. 2. 1 gauss (G) is exactly equal to 0.1 millitesla (mT). MAGNETIC CHARACTERISTICS over operating supply voltage and temperature ranges.

CHOPPER-STABILIZED, PRECISION HALL-EFFECT SWITCH Worcester, Massachusetts 01615-0036 (508) 853-50004 TYPICAL OPERATING CHARACTERISTICS as a function of temperature SUPPLY CURRENTOUTPUT SATURATION VOLTAGE SWITCH POINTS 0 50 100 AMBIENT TEMPERATURE IN °°°°C -50 Dwg. GH-026-5 SWITCH POINTS IN GAUSS OPERATE POINT 150-25 25 75 125 VCC = 4.5 V VCC = 24 V RELEASE POINT 0 25 50 75 100 300 AMBIENT TEMPERATURE IN °°°°C 200 100 -50 Dwg. GH-029-4 SATURATION VOLTAGE IN mV 150-25 125 IOUT = 20 mA VCC = 12 V 6.0 SUPPLY CURRENT IN mA 5.0 4.0 3.0 2.0 0 25 50 75 100 AMBIENT TEMPERATURE IN °°°°C -50 Dwg. GH-028-5 125-25 150 OUTPUT ON, B > BOP OUTPUT OFF, B < BRP VCC = 12 V

CHOPPER-STABILIZED, PRECISION HALL-EFFECT SWITCH www.allegromicro.com 5 SUPPLY CURRENTOUTPUT SATURATION VOLTAGE TYPICAL OPERATING CHARACTERISTICS as a function of supply voltage SWITCH POINTS 4.0 4.5 5.0 SUPPLY VOLTAGE IN VOLTS 3.0 Dw g. GH-021-2 3.5 RELEASE POINT SWITCH POINT IN GAUSS OPERATE POINT TA = 150°C TA = -40°C 4.0 4.5 5.0 SUPPLY VOLTAGE IN VOLTS 3.0 Dw g. GH-055-1 3.5 24 TA = 150°C TA = +25°C TA = -40°C IOUT = 20 mA 250 150 SATURATION VOLTAGE IN mV 200 225 175 4.0 6.0 9.0 SUPPLY VOLTAGE IN VOLTS 3.0 Dw g. GH-058-4 5.0 12 TA = 150°C TA = +25°C TA = -40°C 7.0 5.0 3.0 1.0 SUPPLY CURRENT IN mA 6.0 4.0 2.0 8.0 OUTPUT ON 10 118.07.0

CHOPPER-STABILIZED, PRECISION HALL-EFFECT SWITCH Worcester, Massachusetts 01615-0036 (508) 853-50006 SENSOR LOCATIONS Package Designator ‘LH’ Package Designator ‘UA’ Package Designator ‘LT’ 0.038" 0.96 mm 1 2 Dw g. MH-025 0.011" 0.28 mm NOM ACTIVE AREA DEPTH 0.059" 1.49 mm A 0.045" 1.14 mm 1 32 Dw g. MH-008-8A 0.0305" 0.775 mm NOM ACTIVE AREA DEPTH 0.088" 2.24 mm A 1 32 Dwg. MH-011-9B 0.0195" 0.50 mm NOM BRANDED SURFACE ACTIVE AREA DEPTH 0.080" 2.04 mm 0.056" 1.44 mm A Allegro The products described herein are manufactured under one or more of the following U.S. patents: 5,045,920; 5,264,783; 5,442,283; 5,686,894; 5,694,038; 5,729,130; 5,917,320; and other patents pending. Allegro MicroSystems, Inc. reserves the right to make, from time to time, such departures from the detail specifications as may be required to permit improvements in the performance, reliability, or manufacturability of its products. Before placing an order, the user is cautioned to verify that the information being relied upon is current. Allegro products are not authorized for use as critical components in life-support appliances, devices, or systems without express written approval. The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, Inc. assumes no responsi- bility for its use; nor for any infringements of patents or other rights of third parties that may result from its use.

CHOPPER-STABILIZED, PRECISION HALL-EFFECT SWITCH www.allegromicro.com 7 FUNCTIONAL DESCRIPTION Chopper-Stabilized Technique. The Hall element can be considered as a resistor array similar to a Wheatstone bridge. A large portion of the offset is a result of the mismatching of these resistors. These devices use a proprietary dynamic offset cancellation technique, with an internal high-frequency clock to reduce the residual offset voltage of the Hall element that is normally caused by device overmolding, temperature dependen- cies, and thermal stress. The chopper-stabilizing technique cancels the mismatching of the resistor circuit by changing the direction of the current flowing through the Hall plate using CMOS switches and Hall voltage measurement taps, while maintaing the Hall-voltage signal that is induced by the external magnetic flux. The signal is then captured by a sample-and- hold circuit and further processed using low-offset bipolar circuitry. This technique produces devices that have an extremely stable quiescent Hall output voltage, are immune to thermal stress, and have precise recoverability after temperature cycling. This technique will also slightly degrade the device output repeatability. A relatively high sampling frequency is used in order that faster signals can be processed. More detailed descriptions of the circuit operation can be found in: Technical Paper STP 97-10, Monolithic Magnetic Hall Sensor Using Dynamic Quadrature Offset Cancellation and Technical Paper STP 99-1, Chopper-Stabilized Amplifiers With A Track-and-Hold Signal Demodulator. Operation. The output of these devices switches low (turns on) when a magnetic field (south pole) perpendicular to the Hall sensor exceeds the operate point threshold (B OP ). After turn-on, the output is capable of sinking 25 mA and the output voltage is V OUT(SAT) . When the magnetic field is reduced below the release point (BRP ), the device output goes high (turns off). The difference in the magnetic operate and release points is the hysteresis (Bhys) of the device. This built-in hysteresis allows clean switching of the output even in the presence of external mechanical vibration and electrical noise. Applications. It is strongly recommended that an external bypass capacitor be connected (in close proximity to the Hall sensor) between the supply and ground of the device to reduce both external noise and noise generated by the chopper- stabilization technique. The simplest form of magnet that will operate these devices is a ring magnet. Other methods of operation, such as linear magnets, are possible. Extensive applications information on magnets and Hall-effect sensors is also available in Application Note 27701, or at www.allegromicro.com Dwg. EH-012 REG SAMPLE & HOLD X HALL VOLTAGE B Dwg. AH-011-2 OUTPUT VOLTAGE FLUX DENSITY Dwg. GH-007-2 RPB VOUT(SAT) CCV OPB SUPPLY OUTPUT Dwg. EH-013 0.1 µF SUPPLY VCC X PTCT

CHOPPER-STABILIZED, PRECISION HALL-EFFECT SWITCH Worcester, Massachusetts 01615-0036 (508) 853-50008 PACKAGE DESIGNATOR ‘LH’ (fits SC-59A solder-pad layout) NOTES: 1. Tolerances on package height and width represent allowable mold offsets. Dimensions given are measured at the widest point (parting line). 2. Exact body and lead configuration at vendor’s option within limits shown. 3. Height does not include mold gate flash. 4. Where no tolerance is specified, dimension is nominal. 5. Add "LT" to part number for tape and reel. Dimensions in Inches (for reference only) Dimensions in Millimeters (controlling dimensions) Dwg. MA-011-3 in 0.039 0.094 0.037 0.028 Dwg. MA-011-3 mm 1.00 2.40 0.95 0.70 Dwg. MA-010-3D in 0.006 0.000 0.0079 0.0050 0.083 0.073 0.118 0.106 0.037 BSC 0.022 REF 0.020 0.012 0.045 0.032 0° TO 8° 0.010 MIN GAUGE PLANE SEATING PLANE 0.010 BSC 0.122 0.114 Dwg. MA-010-3D mm 0.15 0.00 0.20 0.127 2.10 1.85 3.00 2.70 0.95 BSC 0.55 REF 0.50 0.30 1.13 0.87 0° TO 8° 0.25 MIN GAUGE PLANE SEATING PLANE 0.25 BSC 3.10 2.90

CHOPPER-STABILIZED, PRECISION HALL-EFFECT SWITCH www.allegromicro.com 9 PACKAGE DESIGNATOR ‘LT’ (SOT89/TO-243AA) Dimensions in Inches (for reference only) Dimensions in Millimeters (controlling dimensions) NOTES: 1. Exact body and lead configuration at vendor’s option within limits shown. 2. Supplied in bulk pack (500 pieces per bag) or add "TR" to part number for tape and reel. 3. Only low-temperature (≤240°C) reflow-soldering techniques are recommended for SOT89 devices. Dwg. MA-009-3A in 1 23 0.072 0.064 0.167 0.155 0.059 BSC 0.0189 0.01420.047 0.035 0.102 0.090 0.063 0.055 0.0173 0.0138 0.090 0.0840.0221 0.0173 0.118 BSC 0.181 0.173 Dwg. MA-009-3A mm 1 23 4.60 4.40 1.83 1.62 4.25 3.94 1.50 BSC 0.48 0.361.20 0.89 2.60 2.29 1.60 1.40 0.44 0.35 2.29 2.130.56 0.44 3.00 BSC B 0.098 0.031 0.102 0.047 0.181 0.079 Dwg. MA-012-3 in Pads 1, 2, 3, and A — Standard SOT89 Layout Pads 1, 2, 3, and B — Low-Stress Version Pads 1, 2, and 3 only — Lowest Stress, But Not Self Aligning 0.028 TYP 0.031 TYP A 3 13 B 2.5 0.8 2.6 1.2 4.6 2.0 Dwg. MA-012-3 mm Pads 1, 2, 3, and A — Standard SOT89 Layout Pads 1, 2, 3, and B — Low-Stress Version Pads 1, 2, and 3 only — Lowest Stress, But Not Self Aligning 0.7 TYP 0.8 TYP A

CHOPPER-STABILIZED, PRECISION HALL-EFFECT SWITCH Worcester, Massachusetts 01615-0036 (508) 853-500010 Dimensions in Inches (controlling dimensions) Dimensions in Millimeters (for reference only) PACKAGE DESIGNATOR ‘UA’ NOTES: 1. Tolerances on package height and width represent allowable mold offsets. Dimensions given are measured at the widest point (parting line). 2. Exact body and lead configuration at vendor’s option within limits shown. 3. Height does not include mold gate flash. 4. Recommended minimum PWB hole diameter to clear transition area is 0.035" (0.89 mm). 5. Where no tolerance is specified, dimension is nominal. 6. Supplied in bulk pack (500 pieces per bag). Dwg. MH-014E in 0.164 0.159 0.062 0.058 0.0173 0.0138 0.050 BSC 45° 0.640 0.600 0.0189 0.0142 0.085 MAX 45° 0.031123 0.122 0.117 SEE NOTE Dwg. MH-014E mm 4.17 4.04 1.57 1.47 0.44 0.35 1.27 BSC 45° 16.26 15.24 0.48 0.36 2.16 MAX 45° 0.79123 3.10 2.97 SEE NOTE Radial Lead Form (order A3240xUA-LC) NOTE: Lead-form dimensions are the nominals produced on the forming equipment. No dimensional tolerance is implied or guaranteed for bulk packaging (500 pieces per bag). 0.620" 0.500" (15.7 mm 12.7 mm) 0.100" (2.5 mm) Dwg. MH-026 0.108" (2.74 mm) 123