A3421EKA

3421 AND 3422 PRELIMINARY INFORMATION (subject to change without notice) September 6, 2000 HALL-EFFECT, DIRECTION-DETECTION SENSORS 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 mechanical 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-competitive solution to linear magnetic sensing in harsh environments. Data Sheet 27650.1 E1 E2 X X LOGIC VCC 1 2 3 4 5 DIRECTION GROUND E1 OUTPUT SUPPLY Dwg. PH-015 Pinning is shown viewed from branded side. ABSOLUTE MAXIMUM RATINGS Supply Voltage, VCC . . . . . . . . . . . . . 18 V Magnetic Flux Density, B . . . . Unlimited Output OFF Voltage, VOUT . . . . . . . . VCC Output Sink Current, IOUT . . . . . . . 30 mA Package Power Dissipation, PD . . . . . . . . . . . . . . . . . . . . . . 500 mW Operating Temperature Range, TA Suffix ‘EKA’ . . . . . . . -40˚C to +85˚C Suffix ‘LKA’ . . . . . . -40˚C to +150˚C Storage Temperature Range, TS . . . . . . . . . . . . . . . -65˚C to +170˚C SPEED FEATURES I I I I Internal Direction-Decoding Circuitry Two Matched Hall Latches On A Single Substrate Superior Temperature Stability 4.5 V to 18 V Operation Electrically Defined Power-On State Under-Voltage Lockout Always order by complete part number, e.g., A3421EKA . 3421 AND 3422 HALL-EFFECT, DIRECTION-DETECTION SENSORS FUNCTIONAL BLOCK DIAGRAM 1 SUPPLY 2 DIRECTION UVLO REG LOGIC POWER-ON LOGIC 3 GROUND 4 E1 OUTPUT E2 X E1 X 5 SPEED Dwg. FH-018 TIMING DIAGRAM CHANGE IN DIRECTION td DIRECTION Dwg. WH-012A +B 0 BOP1 BRP1 -B +B 0 BRP2 -B BOP2 OUT E1 OUT E2 (INTERNAL) SPEED (OUT E1 XOR OUT E2) 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 Copyright © 1999 Allegro MicroSystems, Inc. 3421 AND 3422 HALL-EFFECT, DIRECTION-DETECTION SENSORS ELECTRICAL CHARACTERISTICS over operating temperature range. Limits Characteristic Supply Voltage Range Output Leakage Current Output Saturation Voltage Power-On State Under-Voltage Lockout Under-Voltage Hysteresis Power-On Time Output Rise Time Output Fall Time Direction Change Delay Supply Current Symbol VCC IOFF VOUT(SAT) POS VCC(UV) VCC(hys) tpo tr tf td ICC Test Conditions Operating, TJ < 165°C1 VOUT = VCC = 18 V IOUT = 20 mA VCC = 0 → 5 V, BRP1 < B < BOP1, BRP2 < B < BOP2 IOUT = 20 mA, VCC = 0 → 5 V Lockout (VCC(UV)) - Shutdown VCC > 4.5 V CL = 20 pF, RL = 820 Ω CL = 20 pF, RL = 820 Ω CL = 20 pF, RL = 820 Ω VCC = 8 V, All outputs OFF Min. 4.5 — — OFF — — — — — 0.5 5.0 Typ. —