A3280, A3281, and A3283 Chopper-Stabilized, Precision Hall-Effect Latches Discontinued Product This device is no longer in production. The device should not be purchased for new design applications. Samples are no longer available. Date of status change: January 31, 2011 Recommended Substitutions: For existing customer transition, and for new customers or new applications, refer to the A1220, A1221, and A1223. NOTE: For detailed information on purchasing options, contact your local Allegro field applications engineer or sales representative. Allegro MicroSystems, Inc. reserves the right to make, from time to time, revisions to the anticipated product life cycle plan for a product to accommodate changes in production capabilities, alternative product availabilities, or market demand. 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 which may result from its use. A3280, A3281, and A3283 Chopper-Stabilized, Precision Hall-Effect Latches Features and Benefits Description ▪ Symmetrical switch points ▪ Resistant to physical stress ▪ Superior temperature stability ▪ Output short-circuit protection ▪ Operation from unregulated supply ▪ Reverse battery protection ▪ Solid-state reliability ▪ Small size The A3280, A3281, and A3283 Hall-effect latches are extremely temperature-stable and stress-resistant sensor ICs 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. The three devices are identical except for magnetic switch points. Packages: 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-collector output to sink up to 25 mA. A south pole of sufficient strength will turn the output on. A north pole is necessary to turn the output off. An on-board regulator permits operation with supply voltages of 4.2 to 24 volts. Package LH Package LT Not to scale Package UA Three package styles provide a magnetically optimized package for most applications. Package type LH is a modified SOT23W surface-mount 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. Each package type is lead (Pb) free (suffix, –T), with 100% matte tin leadframe plating. Functional Block Diagram 27609.20-DS, Rev. M Chopper-Stabilized, Precision Hall-Effect Latches A3280, A3281 and A3283 Selection Guide Part Number Packing* Mounting A3283ELTTR-T 7-in. reel, 1000 pieces/reel SOT89 Surface Mount Bulk, 500 pieces/bag 3-pin SIP through hole A3283LLHLT-T 7-in. reel, 3000 pieces/reel SOT23W Surface Mount A3283LLTTR-T 7-in. reel, 1000 pieces/reel SOT89 Surface Mount Bulk, 500 pieces/bag 3-pin SIP through hole A3283EUA-T A3283LUA-T Ambient, TA (°C) BRP(MIN) (TA = 25°C) (G) BOP(MAX) (TA = 25°C) (G) –180 180 –40 to 85 –40 to 150 *Contact Allegro for additional packing options. Absolute Maximum Ratings Characteristic Symbol Notes Rating Units Supply Voltage VCC 26.5 V Reverse Battery Voltage VRCC –30 V Magnetic Flux Density B Unlimited G Output Off Voltage VOUT 26 V Continuous Output Current IOUT 25 mA Reverse Output Currrent IROUT Internal current limiting is intended to protect the device from output short circuits. –50 mA Range E –40 to 85 ºC Range L Operating Ambient Temperature TA –40 to 150 ºC Maximum Junction Temperature TJ(max) 165 ºC Tstg –65 to 170 ºC Storage Temperature Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 2 Chopper-Stabilized, Precision Hall-Effect Latches A3280, A3281 and A3283 X PTCT 2 3 OUTPUT 1 GROUND CC SUPPLY V Dwg. PH-003-2 Suffix '–LT' & '–UA' Pinning (SOT89/TO-243AA & ultra-mini SIP) Suffix ‘–LH’ Pinning (SOT23W) Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 3 Chopper-Stabilized, Precision Hall-Effect Latches A3280, A3281 and A3283 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 < 170°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 , CL = 20 pF – 0.2 2.0 μs Output Fall Time tf RL = 820 , CL = 20 pF – 0.1 2.0 μs B < BRP, VCC = 12 V – 3.0 8.0 mA B > BOP, VCC = 12 V – 4.0 8.0 mA VRCC = -30 V – – -5.0 mA Supply Current ICC Reverse Battery Current ICC Zener Voltage VZ + VD ICC = 15 mA, TA = 25°C 28 32 37 V Zener Impedance zz + zD ICC = 15 mA, TA = 25°C – 50 – 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 voltage range. Part Numbers1 A3280 Characteristic Test Conditions Operate Point, BOP A3281 A3283 Min. Typ. Max. Min. Typ. Max. Min. Typ. Max. Units at TA = +25°C and TA = max. 5.0 22 40 15 50 90 100 150 180 G at TA = -40°C 5.0 – 40 15 – 90 100 – 200 G at TA = +25°C and TA = max. -40 -23 -5.0 -90 -50 -15 -180 -150 -100 G at TA = -40°C -40 – -5.0 -90 – -15 -200 – -100 G Hysteresis, Bhys at TA = +25°C and TA = max. 10 45 80 30 100 180 – 300 360 G (BOP - BRP) at TA = -40°C – – 80 – – 180 – – 360 G Release Point, BRP NOTES: 1. Complete part number includes a suffix to identify operating temperature range (E or L) and package type (LH, LT, or UA). 2. As used here, negative flux densities are defined as less than zero (algebraic convention) and -50 G is less than +10 G. 3. Typical Data is at TA = +25°C and VCC = 12 V and is for design information only. 4. 1 gauss (G) is exactly equal to 0.1 millitesla (mT). Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 4 A3280, A3281 and A3283 Chopper-Stabilized, Precision Hall-Effect Latches TYPICAL OPERATING CHARACTERISTICS as a function of temperature Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 5 Chopper-Stabilized, Precision Hall-Effect Latches A3280, A3281 and A3283 TYPICAL OPERATING CHARACTERISTICS as a function of temperature (cont'd) OUTPUT SATURATION VOLTAGE SUPPLY CURRENT 6.0 300 IOUT = 20 mA V CC = 12 V V CC = 12 V 5.0 200 4.0 OUTPUT ON, B > B OP OP 100 3.0 0 -50 -25 0 25 50 75 100 125 150 2.0 OUTPUT OFF, B < BRP -50 -25 0 RP 25 50 75 100 125 150 AMBIENT TEMPERATURE IN °C AMBIENT TEMPERATURE IN °C Dwg. GH-028-5 Dwg. GH-029-4 TYPICAL OPERATING CHARACTERISTICS as a function of supply voltage A3281* SWITCH POINTS A3280* SWITCH POINTS 80 40 OPERATE POINT OPERATE POINT 40 20 T A = 150°C T A = -40°C 0 -20 -40 3.0 -40 RELEASE POINT 3.5 4.0 4.5 T A = 150°C T A = -40°C 0 5.0 24 -80 3.0 RELEASE POINT 3.5 4.0 4.5 24 5.0 SUPPLY VOLTAGE IN VOLTS SUPPLY VOLTAGE IN VOLTS Dwg. GH-021-3 Dwg. GH-021-1 Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 6 Chopper-Stabilized, Precision Hall-Effect Latches A3280, A3281 and A3283 TYPICAL OPERATING CHARACTERISTICS as a function of supply voltage (cont’d) OUTPUT SATURATION VOLTAGE 250 IOUT = 20 mA T A = 150°C T A = +25°C T A = -40°C 225 200 175 150 3.0 3.5 4.0 4.5 24 5.0 SUPPLY VOLTAGE IN VOLTS Dwg. GH-055-1 SUPPLY CURRENT 8.0 OUTPUT ON T A = 150°C T A = +25°C T A = -40°C 7.0 6.0 5.0 4.0 3.0 2.0 1.0 0 3.0 4.0 5.0 6.0 7.0 8.0 SUPPLY VOLTAGE IN VOLTS 9.0 10 11 12 Dwg. GH-058-4 Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 7 Chopper-Stabilized, Precision Hall-Effect Latches A3280, A3281 and A3283 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 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 Hallvoltage 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 Sensing 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 perpendicular to the Hall element exceeds the operate point threshold (BOP). After turn-on, the output is capable of sinking 25 mA and the output voltage is VOUT(SAT). Note that the device latches; that is, a south pole of sufficient strength towards the branded surface of the device will turn the device on; removal of the south pole will leave the device on. 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. Powering up in the absence of a magnetic field (less than BOP and higher than BRP) will allow an indeterminate output state. The correct state is warranted after the first excursion beyond BOP or BRP. It is strongly recommended that an external bypass capacitor Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 8 Chopper-Stabilized, Precision Hall-Effect Latches A3280, A3281 and A3283 APPLICATIONS INFORMATION be connected (in close proximity to the Hall element) 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 for Hall-effect devices is available in: • Hall-Effect IC Applications Guide, Application Note 27701; • Guidelines for Designing Subassemblies Using Hall-Effect De- vices, Application Note 27703.1 More detailed descriptions of the chopper-stabilized circuit operation can be found in: • Monolithic Magnetic Hall Sensing Using Dynamic Quadrature Offset Cancelation, Technical Paper STP 97-10; and • Chopper-Stabilized Amplifiers With A Track-and-Hold Signal Demodulator, Technical Paper STP 99-1. All are provided at www.allegromicro.com 3 SUPPLY 2 PTCT OUTPUT V 1 CC 0.1 MF SUPPLY Dwg. EH-013 Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 9 X Chopper-Stabilized, Precision Hall-Effect Latches A3280, A3281 and A3283 Package LH, 3-Pin (SOT-23W) +0.12 2.98 –0.08 1.49 D 4°±4° 3 A +0.020 0.180–0.053 0.96 D +0.10 2.90 –0.20 +0.19 1.91 –0.06 2.40 0.70 D 0.25 MIN 1.00 2 1 0.55 REF 0.25 BSC 0.95 Seating Plane Gauge Plane 8X 10° REF B PCB Layout Reference View Branded Face 1.00 ±0.13 +0.10 0.05 –0.05 0.95 BSC 0.40 ±0.10 For Reference Only; not for tooling use (reference dwg. 802840) Dimensions in millimeters Dimensions exclusive of mold flash, gate burrs, and dambar protrusions Exact case and lead configuration at supplier discretion within limits shown A Active Area Depth, 0.28 mm REF B Reference land pattern layout All pads a minimum of 0.20 mm from all adjacent pads; adjust as necessary to meet application process requirements and PCB layout tolerances C Branding scale and appearance at supplier discretion D Hall element, not to scale NNT 1 C Standard Branding Reference View N = Last two digits of device part number T = Temperature code Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 10 Chopper-Stabilized, Precision Hall-Effect Latches A3280, A3281 and A3283 Package LT, 3-Pin SOT89 4.50±0.10 +0.10 1.73 –0.11 2.50 2.00 A 2.24 0.80 1.14 +0.15 4.10 –0.16 +0.15 2.45 –0.16 +0.09 2.20 –0.07 2.60 +0.20 1.00 –0.11 1 2 3 4.60 Parting Line 1.00 +0.04 0.40 –0.05 0.70 1.50±0.10 B 1.50 PCB Layout Reference View Basic pads for low-stress, not self-aligning Additional pad for low-stress, self-aligning Additional area for IPC reference layout 0.42±0.06 0.50±0.06 2X 1.50 BSC For Reference Only; not for tooling use (reference JEDEC. TO-243AA) Dimensions in millimeters Dimensions exclusive of mold flash, gate burrs, and dambar protrusions Exact case and lead configuration at supplier discretion within limits shown A Active Area Depth, 0.78 mm REF B C Reference land pattern layout (reference IPC7351 SOT89N); All pads a minimum of 0.20 mm from all adjacent pads; adjust as necessary to meet application process requirements and PCB layout tolerances Branding scale and appearance at supplier discretion D Hall element, not to scale NNT 1 C Standard Branding Reference View = Supplier emblem N = Last two digits of device part number T = Temperature code Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 11 Chopper-Stabilized, Precision Hall-Effect Latches A3280, A3281 and A3283 Package UA, 3-Pin SIP +0.08 4.09 –0.05 45° B C E 2.06 1.52 ±0.05 1.45 E Mold Ejector Pin Indent +0.08 3.02 –0.05 E Branded Face 45° 1 2.16 MAX D Standard Branding Reference View = Supplier emblem N = Last two digits of device part number T = Temperature code 0.79 REF A 0.51 REF NNT 1 2 3 +0.03 0.41 –0.06 15.75 ±0.51 For Reference Only; not for tooling use (reference DWG-9049) Dimensions in millimeters Dimensions exclusive of mold flash, gate burrs, and dambar protrusions Exact case and lead configuration at supplier discretion within limits shown A Dambar removal protrusion (6X) B Gate burr area C Active Area Depth, 0.50 mm REF +0.05 0.43 –0.07 D Branding scale and appearance at supplier discretion E Hall element, not to scale 1.27 NOM Copyright ©2002-2010, Allegro MicroSystems, Inc. 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’s products are not to be used in life support devices or systems, if a failure of an Allegro product can reasonably be expected to cause the failure of that life support device or system, or to affect the safety or effectiveness of that device or system. The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, Inc. assumes no responsibility for its use; nor for any infringement of patents or other rights of third parties which may result from its use. For the latest version of this document, visit our website: www.allegromicro.com Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 12