Data Sheet 27621.20d 3240 CHOPPER-STABILIZED, PRECISION HALL-EFFECT SWITCH Suffix ‘–LT’ & ‘–UA’ Pinning (SOT89/TO-243AA & ultra-min SIP) X PTCT The device includes on a single silicon chip a voltage regulator, Hallvoltage 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. 2 3 OUTPUT 1 GROUND CC SUPPLY V 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, temperature dependencies, and thermal stress. Three package styles provide a magnetically optimized package for most applications. Package type LH is a modified SOT23W surfacemount package, LT is a miniature SOT89/TO-243AA transistor package for surface-mount applications; while UA is a three-lead ultra-mini-SIP for through-hole mounting. The LH and UA packages are also available in a lead (Pb) free version (suffix, –T) , with a 100% matte tin plated leadframe. Dwg. PH-003-2 Pinning is shown viewed from branded side. ABSOLUTE MAXIMUM RATINGS at TA = +25°C Supply Voltage, VCC .......................... 26.5 V Reverse Battery Voltage, VRCC .......... -30 V Magnetic Flux Density, B ............ Unlimited Output OFF Voltage, VOUT .................. 26 V Continuous Output Current, IOUT ......................................... 25 mA* Reverse Output Current, IOUT ......... -50 mA Package Power Dissipation, PD See Graph Junction Temperature, TJ ................ +165°C Operating Temperature Range, TA Range ‘E’ ..................... -40°C to +85°C Range ‘L’.................... -40°C to +150°C Storage Temperature Range, TS .............................. -65°C to +170°C *Internal current limiting is intended to protect the device from output short circuits. FEATURES ■ ■ ■ ■ ■ ■ ■ Resistant to Physical Stress Superior Temperature Stability Output Short-Circuit Protection Operation From Unregulated Supply Reverse Battery Protection Solid-State Reliability Small Size 3240 CHOPPER-STABILIZED, PRECISION HALL-EFFECT SWITCH Product Selection Guide Part Number Pb-free1 Packing2 Mounting A3240ELHLT-T Yes 7-in. reel, 3000 pieces/reel Surface Mount A3240EUA-T Yes Bulk, 500 pieces/bag A3240LLHLT-T Yes 7-in. reel, 3000 pieces/reel Surface Mount A3240LUA-T Yes Bulk, 500 pieces/bag SIP through hole SIP through hole Ambient, TA (ºC) BRP(MIN) (G) BOP(MAX) (G) 5.0 50 –40 to 85 –40 to 150 1Pb-based variants are being phased out of the product line. Certain variants cited in this footnote are in production but have been determined to be NOT FOR NEW DESIGN. This classification indicates that sale of this device is currently restricted to existing customer applications. The device should not be purchased for new design applications because obsolescence in the near future is probable. Samples are no longer available. Status change: May 1, 2006. These variants include: A3240ELHLT, A3240ELT, A3240ELTTR, A3240EUA, A3240LLHLT, A3240LLT, A3240LLTTR, and A3240LUA. 2Contact Allegro for additional packing options. www.allegromicro.com 2 3240 CHOPPER-STABILIZED, PRECISION HALL-EFFECT SWITCH FUNCTIONAL BLOCK DIAGRAM SUPPLY OUTPUT LOW-PASS FILTER X TO ALL SUBCIRCUITS SAMPLE & HOLD DYNAMIC OFFSET CANCELLATION REG. CONTROL CURRENT LIMIT <1Ω GROUND Dwg. FH-020-1 Suffix ‘–LH’ Pinning (SOT23W) 700 Suffix "–UA" RθJA = 165°C/W 3 X 600 500 Suffix "–LT" RθJA = 180°C/W Suffix "–LH" RθJA = 228°C/W PTCT 400 300 V CC 1 200 20 40 60 100 80 120 AMBIENT TEMPERATURE in °C 140 160 OUTPUT Suffix "L–" GROUND 100 0 180 Dwg. PH-003-4 Dwg. GH-046-2D 3 2 Suffix "E–" SUPPLY ALLOWABLE PACKAGE POWER DISSIPATION in MILLIWATTS 800 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 Copyright © 2000, 2003, 2004 Allegro MicroSystems, Inc. 3240 CHOPPER-STABILIZED, PRECISION HALL-EFFECT SWITCH ELECTRICAL CHARACTERISTICS over operating temperature range. Limits Characteristic Symbol Test Conditions Min. Typ. Max. Units 4.2 – 24 V Supply Voltage Range VCC Operating, TJ < 165°C1 Output Leakage Current IOFF VOUT = 24 V, B < BRP – – 10 µA VOUT(SAT) IOUT = 20 mA, B > BOP – 185 500 mV Output Saturation Voltage Output Current Limit IOM B > BOP 30 – 60 mA Power-On Time tpo VCC > 4.2 V – – 50 µs Chopping Frequency fC – 340 – kHz Output Rise Time tr RL = 820 Ω, CL = 20 pF – 0.2 2.0 µs Output Fall Time tf RL = 820 Ω, CL = 20 pF – 0.1 2.0 µs B < BRP, VCC = 12 V – 3.0 6.0 mA B > BOP, VCC = 12 V – 4.0 6.0 mA VRCC = -30 V – – -5.0 mA Supply Current Reverse Battery Current ICC ICC Zener Voltage VZ + VD ICC = 15 mA, TA = 25°C 28 32 37 V Zener Impedance zz + z D ICC = 15 mA, TA = 25°C – 50 – 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. MAGNETIC CHARACTERISTICS over operating supply voltage and temperature ranges. Limits Characteristic Symbol Operate Point Test Conditions Min. Typ. Max. Units BOP – 35 50 G Release Point BRP 5.0 25 – G Hysteresis Bhys – 10 – G BOP - BRP 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). www.allegromicro.com 4 3240 CHOPPER-STABILIZED, PRECISION HALL-EFFECT SWITCH TYPICAL OPERATING CHARACTERISTICS as a function of temperature SWITCH POINTS 50 SWITCH POINTS IN GAUSS 40 OPERATE POINT 30 RELEASE POINT 20 VCC = 4.5 V VCC = 24 V 10 0 -50 -25 0 25 50 75 100 125 AMBIENT TEMPERATURE IN ° C 150 Dwg. GH-026-5 OUTPUT SATURATION VOLTAGE SUPPLY CURRENT 300 6.0 IOUT = 20 mA VCC = 12 V 5.0 SUPPLY CURRENT IN mA SATURATION VOLTAGE IN mV VCC = 12 V 200 100 4.0 OUTPUT ON, B > BOP 3.0 OUTPUT OFF, B < BRP 0 -50 -25 0 25 50 75 100 125 150 AMBIENT TEMPERATURE IN ° C 2.0 -50 -25 0 25 Dwg. GH-029-4 5 50 75 100 125 150 AMBIENT TEMPERATURE IN ° C 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 Dwg. GH-028-5 3240 CHOPPER-STABILIZED, PRECISION HALL-EFFECT SWITCH TYPICAL OPERATING CHARACTERISTICS as a function of supply voltage SWITCH POINTS 40 OPERATE POINT SWITCH POINT IN GAUSS 30 RELEASE POINT TA = 150°C TA = -40°C 20 10 0 3.0 3.5 4.0 4.5 24 5.0 SUPPLY VOLTAGE IN VOLTS Dwg. GH-021-2 OUTPUT SATURATION VOLTAGE SUPPLY CURRENT 250 8.0 OUTPUT ON TA = 150°C TA = +25°C TA = -40°C 7.0 225 6.0 SUPPLY CURRENT IN mA SATURATION VOLTAGE IN mV IOUT = 20 mA TA = 150°C TA = +25°C TA = -40°C 200 175 5.0 4.0 3.0 2.0 1.0 150 3.0 3.5 4.0 4.5 5.0 24 4.0 5.0 6.0 7.0 8.0 9.0 SUPPLY VOLTAGE IN VOLTS SUPPLY VOLTAGE IN VOLTS Dwg. GH-055-1 www.allegromicro.com 0 3.0 10 11 12 Dwg. GH-058-4 6 3240 CHOPPER-STABILIZED, PRECISION HALL-EFFECT SWITCH SENSOR LOCATIONS Package Designator ‘LH’ ACTIVE AREA DEPTH 0.011" 0.28 mm NOM 0.059" 1.49 mm 3 0.038" 0.96 mm A 1 2 Dwg. MH-025 Package Designator ‘LT’ ACTIVE AREA DEPTH 0.0305" 0.775 mm NOM 0.088" 2.24 mm 0.045" 1.14 mm A 1 2 3 Dwg. MH-008-8A Package Designator ‘UA’ ACTIVE AREA DEPTH 0.0195" 0.50 mm NOM 0.080" 2.04 mm Allegro 0.056" 1.44 mm 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. A BRANDED SURFACE 1 2 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; 5,389,889; 5,581,179; 5,517,112; 5,619,137; 5,621,319; 5,650,719; 5,686,894; 5,694,038; 5,729,130; 5,917,320; and other patents pending. 3 Dwg. MH-011-9B 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 responsibility for its use; nor for any infringements of patents or other rights of third parties that may result from its use. 7 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 3240 CHOPPER-STABILIZED, PRECISION HALL-EFFECT SWITCH FUNCTIONAL DESCRIPTION SAMPLE & HOLD REG X B +V Dwg. EH-012 — HALL VOLTAGE + Dwg. AH-011-2 +V VCC OUTPUT VOLTAGE B RP B OP VOUT(SAT) 0 0 +B FLUX DENSITY Dwg. GH-007-2 3 SUPPLY OUTPUT 2 PTCT 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 dependencies, 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-andhold 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 (BOP). After turn-on, the output is capable of sinking 25 mA and the output voltage is VOUT(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 chopperstabilization 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 V 1 CC 0.1 µF SUPPLY X Dwg. EH-013 www.allegromicro.com 8 3240 CHOPPER-STABILIZED, PRECISION HALL-EFFECT SWITCH PACKAGE DESIGNATOR ‘LH’ (fits SC-59A solder-pad layout) Dimensions in Inches (for reference only) Dimensions in Millimeters (controlling dimensions) 0.122 0.114 3.10 2.90 0.020 0.012 0.083 0.073 0.50 0.30 3 1 2 0.118 0.106 2.10 1.85 0.010 BSC 3.00 2.70 3 1 2 GAUGE PLANE REF 0° TO 8° 0.037 0.006 0.000 0.045 0.032 SEATING PLANE 0.55 0.010 REF 0° TO 8° 0.95 MIN BSC BSC GAUGE PLANE SEATING PLANE 0.022 0.25 MIN BSC 0.0079 0.0050 0.15 0.00 1.13 0.87 0.20 0.127 Dwg. MA-010-3D in Dwg. MA-010-3D mm 0.028 0.70 3 3 0.039 1.00 0.094 1 2 2.40 1 2 0.037 0.95 Dwg. MA-011-3 in Dwg. MA-011-3 mm 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. 9 0.25 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 3240 CHOPPER-STABILIZED, PRECISION HALL-EFFECT SWITCH PACKAGE DESIGNATOR ‘LT’ (SOT89/TO-243AA) Dimensions in Inches (for reference only) 0.181 0.173 0.072 0.064 0.167 0.155 1 2 0.063 0.055 0.102 0.090 3 Dimensions in Millimeters (controlling dimensions) 0.0173 0.0138 0.090 0.084 4.25 3.94 0.0189 0.0142 0.0221 0.0173 0.047 0.035 0.059 4.60 4.40 1.83 1.62 3.00 BSC Dwg. MA-009-3A in Dwg. MA-009-3A mm 2.5 2.0 0.098 0.079 B B 0.031 0.102 A 0.8 2.6 A 4.6 0.181 1 2 2.29 2.13 0.56 0.44 1.50 0.118 BSC 2.60 2.29 3 0.44 0.35 0.48 0.36 1.20 0.89 BSC BSC 2 1 1.60 1.40 3 0.047 1 2 3 1.2 0.028 0.031 0.7 0.8 TYP TYP TYP TYP 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 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 Dwg. MA-012-3 in Dwg. MA-012-3 mm 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. www.allegromicro.com 10 3240 CHOPPER-STABILIZED, PRECISION HALL-EFFECT SWITCH PACKAGE DESIGNATOR ‘UA’ Dimensions in Millimeters (for reference only) Dimensions in Inches (controlling dimensions) 0.164 0.159 4.17 4.04 0.062 0.058 45° 1.57 1.47 45° 3.10 2.97 0.122 0.117 45° 45° 0.085 1 2 3 0.031 2.16 1 2 3 16.26 15.24 0.0173 0.0138 0.640 0.600 0.0189 0.0142 SEE NOTE BSC 0.44 0.35 0.48 0.36 SEE NOTE 1.27 0.050 BSC Dwg. MH-014E in Ra 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). 11 0.79 MAX MAX 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 Dwg. MH-014E mm