3422

3422 ALLEGRO

Document overview

• Manufacturer or author: Provided By www.digicamel.com(FREE DATASHEET DOWNLOAD SITE)
• PDF pages: 10

Technical content

X VCC 1 432 5 Dwg PH -015 LOGIC X E1 E2 SUPPLY DIRECTION GROUND E1 OUTPUT SPEED The A3422xKA Hall-effect, direction-detection sensor is a new generation of special-function integrated sensors that is capable of sens- ing the direction of rotation of a ring magnet. This transducer provides separate digital outputs that provide in for ma tion on magnet rotation speed, direction, and magnet pole count. This device elim i nates the ma- jor manufacturing hurdles encountered in fi ne-pitch direction-detection ap pli ca tions, namely maintaining accurate me chan i cal location between the two active Hall elements. Here, the two Hall elements are photo- lithographically aligned to better than 1 μm, as contrasted with 100 μm or worse mechanical location tol er ance when manufactured discretely. This highly sensitive, tem per a ture-stable, magnetic transducer is ideal for use in digital-encoder systems in the harsh environments of auto- motive or industrial ap pli ca tions. The A3422xKA is a high-sensitivity device op ti mized for use with high-density magnets. The A3422xKA monolithic integrated circuit contains two in de - pen dent Hall-effect bipolar switches whose digital outputs are in ter nal ly cou pled to CMOS logic circuitry that decodes signal speed and di rec - tion. Ex treme ly low-drift BiCMOS circuitry is used for the amplifi ers to ensure symmetry between the two switches so that signal quadrature can be maintained. An on-chip voltage regulator allows the use of this device from a 4.5 V to 18 V supply. The outputs are stan dard open-col- lector outputs. Two operating temperature ranges are provided; suffi x ‘E–’ is for the automotive and industrial temperature range of -40°C to +85°C, suf- fi x ‘L–’ is for the automotive and military temperature range of -40°C to +150°C. The 5-pin ‘KA’ SIP package provides a cost-com- pet i tive solution to magnetic sensing in harsh en vi ron ments.

FEATURES

• Internal Direction-Decoding Circuitry
• Two Matched Hall Bipolar Switches on a Single Substrate
• Superior Temperature Stability
• 4.5 V to 18 V Operation Electrically Defi ned Power-On State Undervoltage Lockout HALL-EFFECT, DIRECTION-DETECTION SENSORS Pinning is shown viewed from branded side. ABSOLUTE MAXIMUM RAT INGS Magnetic Flux Density, B . . . . Unlimited Package Power Dissipation, Operating Temperature Range, TA Storage Temperature Range, 3422 Data Sheet 27650.1B

HALL-EFFECT, DIRECTION-DETECTION SENSOR

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 (508) 853-50002 Copyright © 2001, 2003 Allegro MicroSystems, Inc. Selection Guide 1Pb-based variants are being phased out of the product line. The variants cited in this footnote are in production but have been determined to be NOT FOR NEW DESIGN. This classifi cation indicates that sale of this device is currently restricted to existing customer applications. The variants 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: A3422EKA and A3422LKA. 2Contact Allegro for additional packing options. FUNCTIONAL BLOCK DIAGRAM TIMING DIAGRAM BOP1 BRP1 Dwg. WH-012A BRP2 OUTE1 OUTE2 (INTERNAL) SPEED (OUTE1 XOR OUTE2) BOP2 DIRECTION CHANGE IN DIRECTION td SPEED DIRECTION2 E1 OUTPUT X X Dwg. FH-018 GROUND LOGIC SUPPLY POWER-ON LOGICREGUVLO Part Number Pb-Free 1 Packing2 Mounting Ambient, TA (°C) A3422EKA-T Yes Bulk, 500 pieces/bag 5-pin SIP through hole –40 to 85 A3422LKA-T Yes Bulk, 500 pieces/bag 5-pin SIP through hole –40 to 150

HALL-EFFECT, DIRECTION-DETECTION SENSOR www.allegromicro.com 3 Limits Characteristic Symbol Test Conditions Min. Typ. Max. Units Supply Voltage Range V CC Operating, TJ < 165°C1 4.5 —18 V Output Leakage Current I OFF VOUT = VCC = 18 V —<1.0 10 µA Output Saturation Voltage V OUT(SAT) IOUT = 20 mA —0.21 0.50 V Power-On State POS V CC = 0 → 5 V, OFF OFF OFF — BRP1 < B < BOP1, BRP2 < B < BOP2 Undervoltage Lockout V CC(UV) IOUT = 20 mA, VCC = 0 → 5 V —3.5 —V Undervoltage Hysteresis V CC(hys) Lockout (VCC(UV)) - Shutdown —0.5 —V Power-On Time t po VCC > 4.5 V ——50 µs Output Rise Time t r CL = 20 pF, RL = 820 Ω —200 —ns Output Fall Time t f CL = 20 pF, RL = 820 Ω —200 —ns Direction Change Delay t d CL = 20 pF, RL = 820 Ω 0.5 1.0 5.0 µs Supply Current I CC VCC = 8 V, All outputs OFF 5.0 9.0 18 mA ELECTRICAL CHARACTERISTICS over operating temperature range. NOTES:1. Maximum supply voltage must be adjusted for power dissipation and ambient temperature. 2. Typical Data is at VCC = 12 V and TA = +25°C and is for design information only. 50 75 100 125 175 0.5 0.1 ALLOWABLE PACKAGE POWER DISSIPATION IN WATTSTEMPERATURE IN °°°°C 0.4 0.3 0.2 Dwg. GH-069 R θJA = 164°C/W 0.6 150

HALL-EFFECT, DIRECTION-DETECTION SENSOR Worcester, Massachusetts 01615-0036 (508) 853-50004 Limits Characteristic Symbol Test Conditions Min. Typ. Max. Units Operate Point B OP TA = -40°C——8 5 G TA = +25°C —29 75 G TA = Maximum ——75 G Release Point3 BRP TA = -40°C -85 ——G TA = Maximum -75 ——G Hysteresis B hys TA = -40°C1 0 ——G TA = +25°C1 0 4 6 —G TA = Maximum 10 ——G Operate Differential —B OP1 - BOP2 —— ±60 G Release Differential —B RP1 - BRP2 —— ±60 G MAGNETIC CHARACTERISTICS over operating voltage range. NOTES:1. Magnetic flux density is measured at most sensitive area of device, nominally located 0.0165” (0.42 mm) below the branded face of the package. 2. Typical Data is at VCC = 12 V and TA = +25°C and is for design information only. 3. As used here, negative flux densities are defined as less than zero (algebraic convention). Typical Magnetic Characteristics 0 50 100 AMBIENT TEMPERATURE IN °°°°C -50 Dwg. GH-026-1 SWITCH POINTS IN GAUSS OPERATE POINT RELEASE POINT 150-25 25 75 125 -50 -40 -30 -20 -10 V = 8 VCC 0 25 50 75 100 AMBIENT TEMPERATURE IN °°°°C -50 Dwg. GH-051-1 125-25 HYSTERESIS IN GAUSS 150 100 V = 8 VCC

HALL-EFFECT, DIRECTION-DETECTION SENSOR www.allegromicro.com 5 0 25 50 75 100 AMBIENT TEMPERATURE IN °°°°C -50 Dwg. GH-053-1 125-25 SUPPLY CURRENT IN mA 9.0 8.0 7.0 6.0 150 V = 8 VCC ALL OUTPUTS ON ALL OUTPUTS OFF 0 25 50 75 100 300 AMBIENT TEMPERATURE IN °°°°C 200 100 -50 Dwg. GH-029-2 SATURATION VOLTAGE IN mV 150-25 125 I = 20 mAOUT250 150 SUPPLY VOLTAGE IN VOLTS 8.0 6.0 Dwg. GH-058-3 SUPPLY CURRENT IN mA 9.0 7.0 5.0 ALL OUTPUTS ON ALL OUTPUTS OFF 2.0 6.0 10 14 18 T = 25°CA Typical Electrical Characteristics

HALL-EFFECT, DIRECTION-DETECTION SENSOR Worcester, Massachusetts 01615-0036 (508) 853-50006 Outputs. The device provides three saturated outputs: DIRECTION, E1 OUTPUT, and SPEED. DIRECTION provides the direction output of the sensor and is defined as OFF (high) for the direction E1 to E2 and ON (low) for the direction E2 to E1. SPEED provides an XOR’d output of the two sensors. Because of internal delays, DIRECTION will always be updated before SPEED and is updated at every transition of E1 OUTPUT and E2 OUTPUT (internal) allowing the use of up-down counters without the loss of pulses. Power-On State. At power on, the logic circuitry is reset to provide an OFF (high) at DIRECTION and an OFF (high) for E1 and E2 (internal) for magnetic fields less than B OP . This eliminates ambiguity when the device is powered up and either sensor detects a field between B OP and BRP . If either sensor is sub- jected to a field greater than BOP , the internal logic will set accordingly. The integrated circuit contains an internal voltage regulator that powers the Hall sensors and both the analog and digital circuitry. This regulator allows operation over a wide supply voltage range and provides some immunity to supply noise. The device also contains CMOS logic circuitry that decodes the direction of rotation of the ring magnet. Quadrature/Direction Detection. Internal logic circuitry provides outputs representing speed and direction of the magnetic field across the face of the package. For the direction signal to be appropriately updated, a quadrature relationship must be maintained between the ring magnet pole width*, the sensor-to- sensor spacing, and, to a lesser extent, the magnetic switch points. For optimal design, the sensor should be actuated with a ring magnet pole width* two times the sensor-to-sensor spacing. This will produce a sinusoidal magnetic field whose period (denoted as is then four times the sensor-to-sensor spacing. A quadrature relationship can also be maintained for a ring magnet that has a period that satisfies the rela- tionship n Τ/4 = 1.5 mm, where n is any odd integer. Therefore, ring magnets with pole-pair spacing equal to 6 mm (n = 1), 2 mm (n = 3), 1.2 mm (n = 5), etc. are permitted. The response of the device to the magnetic field produced by a rotating ring magnet is shown on page 2. Note the phase shift between the two integrated sensors. * “Pole” refers to a single pole (North or South) unless stated as “pole pair” (North and South). Functional Description

HALL-EFFECT, DIRECTION-DETECTION SENSOR www.allegromicro.com 7 Applications Information Operation with Fine-Pitch Ring Magnets. For targets with a circular pitch of less than 4 mm, a performance improvement can be observed by rotat- ing the front face of the sensor subassembly (see below). This sensor rotation decreases the effective sensor-to-sensor spacing, provided that the Hall elements are not rotated beyond the width of the target. Applications. It is strongly recommended that an external 0.01 µF 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 internal logic. 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 the “Hall- Effect IC Applications Guide” which can be found in the latest issue of Application Note 27701, at www.allegromicro.com/techpub2/an/an27701 Dwg. MH-024 α TARGET FACE WIDTH, F >1.50 SIN α (mm) >0.059 SIN α (inch)

1.50 COS α (mm)

0.059 COS α (inch)

A 0.059" 1.50 mm 12 45 3 A Rotated Sensor for Fine-Pitch Ring Magnets

HALL-EFFECT, DIRECTION-DETECTION SENSOR Worcester, Massachusetts 01615-0036 (508) 853-50008 Sensor Locations A E1 E2 Dwg. MH-007-1A 0.0165" 0.42 mm NOM BRANDED SURFACE ACTIVE AREA DEPTH 0.059" 1.50 mm 12 4 5 3 0.096" 2.44 mm 0.072" 1.83 mm Allegro Criteria for Device Qualification Contact Allegro MicroSystems for qualification information.

HALL-EFFECT, DIRECTION-DETECTION SENSOR www.allegromicro.com 9 Package Designator 'KA' Dimensions in Inches (controlling dimensions) Dimensions in Millimeters (for reference only) Dwg. MH-010H in 0.018 0.0173 0.0138 0.0189 0.0142 0.050 BSC 1 3 4 52 0.063 0.059 45° 0.600 0.560 0.083 MAX 0.252 0.247 0.181 0.176 SEE NOTE Horizontal-Mount Lead Form (add ‘-TL’ to part number) 2.41 ±0.13 0.51 MIN FLAT Dwg. MH-015 mm 0.10 MAX 0.051 MAX 0°–8° 0.095 ±0.005 0.020 MIN FLAT Dwg. MH-015 in 0.004 MAX 0.002 MAX 0°–8° 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-010H mm 0.46 0.44 0.35 0.48 0.36 1.27 BSC 1 3 4 52 1.60 1.50 45° 15.24 14.23 2.11 MAX 6.40 6.27 4.60 4.47 SEE NOTE

HALL-EFFECT, DIRECTION-DETECTION SENSOR Worcester, Massachusetts 01615-0036 (508) 853-500010 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; 5,694,038; 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 responsibility for its use; nor for any infringements of patents or other rights of third parties that may result from its use.