3421

3421 ALLEGRO

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Technical content

The A3421xKA and A3422xKA Hall-effect, direction-detection sensors are a new generation of special-function integrated sensors that are capable of sensing the direction of rotation of a ring magnet. These transducers provide separate digital outputs that provide information on magnet rotation speed, direction, and magnet pole count. These devices eliminate the major manufacturing hurdles encountered in fine-pitch direction-detection applications, namely maintaining accurate mechani- cal location between the two active Hall elements. Here, the two Hall elements are photolithographically aligned to better than 1 µm, as contrasted with 100 µm or worse mechanical location tolerance when manufactured discretely. These highly sensitive, temperature-stable, magnetic transducers are ideal for use in digital-encoder systems in the harsh environments of automotive or industrial applications. The A3421xKA is a high-hysteresis device designed for low-resolution pulse counting while the A3422xKA is a high-sensitivity device optimized for use with high-density magnets. The A3421xKA and A3422xKA monolithic integrated circuits contain two independent Hall-effect latches whose digital outputs are internally coupled to CMOS logic circuitry that decodes signal speed and direction. Extremely low-drift BiCMOS circuitry is used for the amplifiers to ensure symmetry between the two latches so that signal quadrature can be maintained. An on-chip voltage regulator allows the use of these devices from a 4.5 V to 18 V supply. Both devices have standard open-collector outputs; the logic operation of both devices is the same. Two operating temperature ranges are provided; suffix ‘E–’ is for the automotive and industrial temperature range of -40°C to +85°C, suffix ‘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- petitive solution to linear magnetic sensing in harsh environments.

FEATURES

I Internal Direction-Decoding Circuitry I Two Matched Hall Latches On A Single Substrate I Superior Temperature Stability I 4.5 V to 18 V Operation Electrically Defined Power-On State Under-Voltage Lockout HALL-EFFECT, DIRECTION-DETECTION SENSORS Always order by complete part number, e.g., A3421EKA . X VCC 1 432 5 Dwg. PH-015 SUPPLY DIRECTION GROUND E1 OUTPUT SPEED LOGIC X E1 E2 Pinning is shown viewed from branded side. ABSOLUTE MAXIMUM RATINGS Magnetic Flux Density, B . . . . Unlimited Package Power Dissipation, Operating Temperature Range, T A Storage Temperature Range,

3421 AND

(subject to change without notice) September 6, 2000 Data Sheet 27650.1

3421 AND 3422

HALL-EFFECT, DIRECTION-DETECTION SENSORS

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 (508) 853-5000 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 Copyright © 1999 Allegro MicroSystems, Inc.

HALL-EFFECT, DIRECTION-DETECTION SENSORS www.allegromicro.com 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 Under-Voltage Lockout V CC(UV) IOUT = 20 mA, VCC = 0 → 5 V — 3.5 — V Under-Voltage 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. 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 RθJA = 164°C/W 0.6 150 NOTES:1. Maximum supply voltage must be adjusted for power dissipation and ambient temperature. 2. Typical Data is at V CC = 12 V and TA = +25°C and is for design information only.

HALL-EFFECT, DIRECTION-DETECTION SENSORS Worcester, Massachusetts 01615-0036 (508) 853-5000 A3421xKA A3422xKA Operate Point B OP TA = -40°C 140 185 300 — 29 85 G TA = +25°C 130 160 280 — 29 75 G TA = Maximum 120 — 260 — — 75 G Release Point3 BRP TA = -40°C -300 -190 -140 -85 -19 — G TA = +25°C -280 -175 -130 -75 -18 — G TA = Maximum -260 — -120 -75 -16 — G Hysteresis B hys TA = -40°C 280 375 — 10 48 — G TA = +25°C 260 335 — 10 46 — G TA = Maximum 240 — — 10 — — G Operate Differential B OP1 - BOP2 —— ±80 — — ±60 G Release Differential B RP1 - BRP2 —— ±80 — — ±60 G MAGNETIC CHARACTERISTICS over operating voltage range. NOTES:1. Magnetic flux density is measured at most sensitive area of device, nominally located 0.014” (0.37 mm) below the branded face of the package. 2. Typical Data is at V CC = 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).

HALL-EFFECT, DIRECTION-DETECTION SENSORS www.allegromicro.com TYPICAL A3421xKA CHARACTERISTICS TYPICAL A3422xKA 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 0 50 100 AMBIENT TEMPERATURE IN °C -50 Dwg. GH-026-2 SWITCH POINTS IN GAUSS OPERATE POINT RELEASE POINT 150-25 25 75 125 100 150 200 250 -250 -200 -150 -100 -50 V = 8 VCC 0 25 50 75 100 AMBIENT TEMPERATURE IN °C -50 Dwg. GH-051-2 125-25 HYSTERESIS IN GAUSS 100 150 400 500 300 200 V = 8 VCC

HALL-EFFECT, DIRECTION-DETECTION SENSORS Worcester, Massachusetts 01615-0036 (508) 853-5000 TYPICAL ELECTRICAL CHARACTERISTICS 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

HALL-EFFECT, DIRECTION-DETECTION SENSORS www.allegromicro.com 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, DIREC- TION will always be updated before SPEED and is updated at every transition of E1 OUTPUT and E2 OUT- PUT (internal) allowing the use of up-down counters without the loss of pulses. Power-On State. At power on, the logic circutry 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 BOP and BRP. If either sensor is subjected to a field greater than BOP, the internal logic will set accordingly. The integrated circuit contains an internal voltage regula- tor 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 quadra- ture 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 Τ) 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 nΤ/4 = 1.5 mm, where n is any odd integer. Therefore, ring magnets with pole-pair spacings equal to 6 mm (n = 1), 2 mm (n = 3), 1.2 mm (n = 5), etc. are permit- ted. 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 SENSORS Worcester, Massachusetts 01615-0036 (508) 853-5000 APPLICATIONS INFORMATION Operation with Fine-Pitch Ring Magnets. For targets with a circular pitch of less than 4 mm, a perfor- mance improvement can be observed by rotating 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 applica- tions information on magnets and Hall-effect sensors is also available in the “Hsall-Effect IC Applications Guide” which can be found in the latest issue of the Allegro MicroSystems Electronic Data Book, AMS-702 or Appli- cation Note 27701, or at www.allegromicro.com 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 4 5 3 A Rotated sensor for fine-pitch ring magnets

HALL-EFFECT, DIRECTION-DETECTION SENSORS www.allegromicro.com CRITERIA FOR DEVICE QUALIFICATION All Allegro sensors are subjected to stringent qualification requirements prior to being released to production. To become qualified, except for the destructive ESD tests, no failures are permitted. Test Method and Samples Qualification Test Test Conditions Test Length Per Lot Comments Temperature Humidity JESD22-A101, 1000 hrs 77 Device biased for Bias Life T A = 85°C, RH = 85% minimum power Bias Life JESD22-A108, 1000 hrs 77 TA = 150°C, TJ = 165°C (Surge Operating Life) JESD22-A108, 1000 hrs 77 TA = 175°C, TJ = 190°C Autoclave, Unbiased JESD22-A102, 96 hrs 77 TA = 121°C, 15 psig High-Temperature JESD22-A103, 1000 hrs 77 (Bake) Storage Life T A = 170°C Temperature Cycle JESD22-A104 1000 cycles 77 -55 °C to +150°C ESD, CDF-AEC-Q100-002 Pre/Post 3 per Test to failure Human Body Model Reading test All leads > 8 kV SENSOR LOCATIONS (±0.005” [0.13 mm] die placement) A E1 E2 Dwg. MH-007-1 0.014" 0.37 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

HALL-EFFECT, DIRECTION-DETECTION SENSORS Worcester, Massachusetts 01615-0036 (508) 853-5000 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 13 4 5 2 0.063 0.059 45° 0.600 0.560 0.083 MAX 0.252 0.247 0.181 0.176 SEE NOTE SURFACE-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 po int (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. Dwg. MH-010H mm 0.46 0.44 0.35 0.48 0.36 1.27 BSC 13 4 5 2 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 SENSORS www.allegromicro.com HALL-EFFECT SENSORS Partial Part Avail. Oper. Characteristics at T A = +25°C Number Temp. B OP max B RP min B hys typ Features Notes RATIOMETRIC, LINEAR HALL-EFFECT SENSORS 3503 S typ. 1.3 mV/G 3507 E/Ltyp. 2.5 mV/G 3508 S typ. 2.5 mV/G 3515 E/Ltyp. 5.0 mV/G chopper stabilized 3516 E/Ltyp. 2.5 mV/G chopper stabilized 3517 L/S typ. 5.0 mV/G chopper stabilized 3518 L/S typ. 2.5 mV/G chopper stabilized GEARTOOTH/RING MAGNET (DUAL ELEMENT) HALL-EFFECT SENSORS in order of BOP

3060 K/S +35 -35 30 ac coupled

3422 E/L+75 -75 46 direction detection

3059 K/S +100 -100 130 ac coupled

3056 E/L+150 -150 50 zero-speed

3058 E/L+250 -250 200 zero-speed

3421 E/L+280 -280 335 direction detection

SPECIAL-PURPOSE HALL-EFFECT SENSORS 3054 K/S +300 +5.0 50 unipolar switch, multiplexed 4 3209 E ±60 ±5.0 7.7 400 µW, chopper stabilized 3210 E ±60 ±5.0 7.7 25 µW, chopper stabilized

3422 E/L+85 -85 46 direction detection

3425 L+24 -24 19 dual, chopper stabilized 1

Operating Temperature Ranges: Notes 1. Protected. 4. Multiplexed two-wire sensor; after proper address, power/signal bus current indicates magnetic field condition.

HALL-EFFECT, DIRECTION-DETECTION SENSORS Worcester, Massachusetts 01615-0036 (508) 853-5000 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 responsibil- ity for its use; nor for any infringements of patents or other rights of third parties that may result from its use.